DCIT/DCIT.Core/Services/DocumentProcessingService.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using DCIT.Core.Models;
using DCIT.Core.Utilities;
using DocumentFormat.OpenXml;
using DocumentFormat.OpenXml.Packaging;
using A = DocumentFormat.OpenXml.Drawing;
using C = DocumentFormat.OpenXml.Drawing.Charts;
using DW = DocumentFormat.OpenXml.Drawing.Wordprocessing;
using M = DocumentFormat.OpenXml.Math;
using Svg;
using V = DocumentFormat.OpenXml.Vml;
using W = DocumentFormat.OpenXml.Wordprocessing;

namespace DCIT.Core.Services
{
    public class DocumentProcessingService : IDocumentProcessingService
    {
        private static readonly string[] SupportedRasterExtensions = { ".png", ".jpg", ".jpeg", ".bmp", ".gif", ".tif", ".tiff" };
        private static readonly string[] SupportedNonBitmapExtensions = { ".wmf", ".emf", ".svg" };
        private static readonly string[] SupportedVisioPackageExtensions = { ".vsd", ".vsdx", ".vsdm" };
        private static readonly string[] BrokenFieldResultMarkers =
        {
            "错误!未找到引用源",
            "错误！未找到引用源",
            "错误! 未找到引用源",
            "错误！ 未找到引用源",
            "错误!书签未定义",
            "错误！书签未定义",
            "Error! Reference source not found",
            "Error! Bookmark not defined",
        };

        private const string SupportedDiffVersion = "1.0";
        private const string SupportedBmpCodecVersion = "1.0";
        private const int WorkingDocumentOpenRetryCount = 5;
        private const int WorkingDocumentOpenRetryDelayMilliseconds = 150;
        private const double NoiseTargetPixelRatio = 0.55d;
        private const int NoiseCellSize = 16;
        private const int BrokenFieldResultScanLimit = 50;
        private readonly DiffSerializationService _diffSerializationService;
        private readonly IDocConversionService _docConversionService;
        private readonly IDocumentFieldUpdateService _documentFieldUpdateService;
        private readonly IFontValidationService _fontValidationService;

        public DocumentProcessingService(DiffSerializationService diffSerializationService)
            : this(diffSerializationService, new OfficeDocConversionService(), null, new FontValidationService())
        {
        }

        public DocumentProcessingService(DiffSerializationService diffSerializationService, IDocConversionService docConversionService)
            : this(diffSerializationService, docConversionService, docConversionService as IDocumentFieldUpdateService, new FontValidationService())
        {
        }

        public DocumentProcessingService(
            DiffSerializationService diffSerializationService,
            IDocConversionService docConversionService,
            IDocumentFieldUpdateService documentFieldUpdateService)
            : this(diffSerializationService, docConversionService, documentFieldUpdateService, new FontValidationService())
        {
        }

        public DocumentProcessingService(
            DiffSerializationService diffSerializationService,
            IDocConversionService docConversionService,
            IDocumentFieldUpdateService documentFieldUpdateService,
            IFontValidationService fontValidationService)
        {
            if (diffSerializationService == null)
            {
                throw new ArgumentNullException("diffSerializationService");
            }

            if (fontValidationService == null)
            {
                throw new ArgumentNullException("fontValidationService");
            }

            _diffSerializationService = diffSerializationService;
            _docConversionService = docConversionService;
            _documentFieldUpdateService = documentFieldUpdateService;
            _fontValidationService = fontValidationService;
        }

        public FileProcessResult Replace(ReplaceFileRequest request, IProgress<FileProcessProgress> progress, CancellationToken cancellationToken)
        {
            if (request == null)
            {
                throw new ArgumentNullException("request");
            }

            var sourceExtension = NormalizeWordExtension(request.SourcePath);
            var outputExtension = NormalizeWordExtension(request.OutputPath);
            EnsureDirectoryForFile(request.OutputPath);
            EnsureDirectoryForFile(request.DiffPath);

            var finalPaths = GetUniqueReplacementOutputPaths(request.OutputPath, request.DiffPath);
            var finalOutputPath = finalPaths.OutputPath;
            var finalDiffPath = finalPaths.DiffPath;
            var finalBmpPath = finalPaths.BmpPath;
            var tempOutputPath = CreateTempPath(finalOutputPath);
            var tempDiffPath = CreateTempPath(finalDiffPath);
            var tempBmpPath = _diffSerializationService.GetBmpPath(tempDiffPath);
            var workingDocxPath = CreateWorkingDocxPath("replace");

            SafeDelete(tempOutputPath);
            SafeDelete(tempDiffPath);
            SafeDelete(tempBmpPath);
            SafeDelete(workingDocxPath);

            try
            {
                PrepareWorkingDocx(request.SourcePath, workingDocxPath, sourceExtension);
                var fontValidation = _fontValidationService.EnsureFontsAvailable(workingDocxPath);
                ReportFontFallback(progress, request.SourcePath, fontValidation);

                var baselineFieldFindings = ScanBrokenFieldResults(workingDocxPath);

                var rules = (request.RuleFile == null ? new List<RuleDefinition>() : request.RuleFile.Rules)
                    .Where(rule => rule != null && rule.IsEnabled && !string.IsNullOrEmpty(rule.SearchText) && rule.Target == RuleTarget.DocumentContent)
                    .ToList();

                var diff = _diffSerializationService.CreateBaseDocument();
                diff.SourceDocument = BuildDocumentInfo(request.SourcePath, request.SourceRootDirectory);
                diff.RuleFile = BuildRuleFileInfo(request.RuleFilePath, request.RuleFile, rules);
                diff.Payload = new DiffPayload();

                var touchedRoots = new HashSet<OpenXmlPartRootElement>();
                using (var document = OpenEditableWorkingDocument(request.SourcePath, workingDocxPath, "replace"))
                {
                    cancellationToken.ThrowIfCancellationRequested();
                    ProcessTextReplacements(document, rules, diff.Payload, touchedRoots, progress, request.SourcePath, cancellationToken);
                    if (request.EnableImageReplacement)
                    {
                        ProcessImageReplacements(document, diff.Payload, request.FixedImageSeed, cancellationToken);
                    }
                    SaveTouchedRoots(touchedRoots, document);
                }

                ValidateNoBrokenFieldResults(workingDocxPath, request.SourcePath, baselineFieldFindings, "替换", progress);
                CommitWorkingDocument(workingDocxPath, tempOutputPath, outputExtension);

                diff.ReplacedDocument = BuildDocumentInfo(tempOutputPath, Path.GetDirectoryName(finalOutputPath) ?? string.Empty, finalOutputPath);
                RecordFileNameChangeOperation(diff);
                diff.Payload.Statistics.TextReplaceCount = diff.Payload.Operations.Count(item => string.Equals(item.Type, "text", StringComparison.Ordinal));
                diff.Payload.Statistics.ImageReplaceCount = diff.Payload.Operations.Count(item => string.Equals(item.Type, "image", StringComparison.Ordinal));

                _diffSerializationService.Write(diff, tempDiffPath, request.EncryptDiff);
                File.Move(tempOutputPath, finalOutputPath);
                File.Move(tempDiffPath, finalDiffPath);
                File.Move(tempBmpPath, finalBmpPath);

                return new FileProcessResult
                {
                    OutputPath = finalOutputPath,
                    DiffPath = finalDiffPath,
                    BmpPath = finalBmpPath,
                    TextOperationCount = diff.Payload.Statistics.TextReplaceCount,
                    ImageOperationCount = diff.Payload.Statistics.ImageReplaceCount,
                };
            }
            catch
            {
                SafeDelete(tempOutputPath);
                SafeDelete(tempDiffPath);
                SafeDelete(tempBmpPath);
                throw;
            }
            finally
            {
                SafeDelete(workingDocxPath);
            }
        }

        public FileProcessResult Restore(RestoreFileRequest request, IProgress<FileProcessProgress> progress, CancellationToken cancellationToken)
        {
            if (request == null)
            {
                throw new ArgumentNullException("request");
            }

            var replacedExtension = NormalizeWordExtension(request.ReplacedPath);
            var outputExtension = NormalizeWordExtension(request.OutputPath);
            var loaded = _diffSerializationService.Load(request.DiffPath);
            if (loaded.Document == null || loaded.Document.Payload == null)
            {
                throw new InvalidDataException("差异文件缺少有效载荷。");
            }

            var currentFingerprint = HashUtility.ComputeFileSha256Base64(request.ReplacedPath);
            if (!string.Equals(currentFingerprint, loaded.Document.ReplacedDocument.Fingerprint, StringComparison.Ordinal))
            {
                throw new InvalidDataException(BuildReplacedFingerprintMismatchMessage(request.ReplacedPath, loaded.Document, currentFingerprint));
            }

            ValidateRestoreCompatibility(request, loaded.Document);
            ValidateDiffAlgorithm(loaded.Document);

            EnsureDirectoryForFile(request.OutputPath);
            var finalOutputPath = GetUniquePath(request.OutputPath);
            var tempOutputPath = CreateTempPath(finalOutputPath);
            var workingDocxPath = CreateWorkingDocxPath("restore");
            SafeDelete(tempOutputPath);
            SafeDelete(workingDocxPath);

            try
            {
                PrepareWorkingDocx(request.ReplacedPath, workingDocxPath, replacedExtension);
                var fontValidation = _fontValidationService.EnsureFontsAvailable(workingDocxPath);
                ReportFontFallback(progress, request.ReplacedPath, fontValidation);

                var baselineFieldFindings = ScanBrokenFieldResults(workingDocxPath);

                var touchedRoots = new HashSet<OpenXmlPartRootElement>();
                using (var document = OpenEditableWorkingDocument(request.ReplacedPath, workingDocxPath, "restore"))
                {
                    cancellationToken.ThrowIfCancellationRequested();
                    RestoreText(document, loaded.Document.Payload, progress, request.ReplacedPath, cancellationToken, touchedRoots);
                    RestoreImages(document, loaded.Document.Payload, cancellationToken);
                    SaveTouchedRoots(touchedRoots, document);
                }

                ValidateNoBrokenFieldResults(workingDocxPath, request.ReplacedPath, baselineFieldFindings, "恢复", progress);
                CommitWorkingDocument(workingDocxPath, tempOutputPath, outputExtension);
                File.Move(tempOutputPath, finalOutputPath);

                return new FileProcessResult
                {
                    OutputPath = finalOutputPath,
                    DiffPath = request.DiffPath,
                    BmpPath = Path.GetExtension(request.DiffPath).Equals(".bmp", StringComparison.OrdinalIgnoreCase) ? request.DiffPath : _diffSerializationService.GetBmpPath(request.DiffPath),
                    TextOperationCount = loaded.Document.Payload.Statistics.TextReplaceCount,
                    ImageOperationCount = loaded.Document.Payload.Statistics.ImageReplaceCount,
                };
            }
            catch
            {
                SafeDelete(tempOutputPath);
                throw;
            }
            finally
            {
                SafeDelete(workingDocxPath);
            }
        }

        private void ValidateRestoreCompatibility(RestoreFileRequest request, DiffDocument diff)
        {
            if (diff == null)
            {
                throw new ArgumentNullException("diff");
            }

            if (diff.App == null
                || !string.Equals(diff.App.Name, "DCIT", StringComparison.Ordinal)
                || !string.Equals(diff.App.Version, _diffSerializationService.AppVersion, StringComparison.Ordinal))
            {
                throw new InvalidDataException("差异文件程序版本与当前程序不兼容。");
            }

            if (diff.RuleFile != null
                && !string.IsNullOrWhiteSpace(diff.RuleFile.Fingerprint)
                && DiffContainsTextOperations(diff))
            {
                if (string.IsNullOrWhiteSpace(request.CurrentRuleFilePath) || !File.Exists(request.CurrentRuleFilePath))
                {
                    throw new InvalidDataException("恢复时必须提供与差异文件匹配的规则文件。");
                }

                var currentRuleFingerprint = HashUtility.ComputeFileSha256Base64(request.CurrentRuleFilePath);
                if (!string.Equals(currentRuleFingerprint, diff.RuleFile.Fingerprint, StringComparison.Ordinal))
                {
                    throw new InvalidDataException("当前规则文件与差异文件记录的规则指纹不匹配。");
                }
            }
        }

        private static void RecordFileNameChangeOperation(DiffDocument diff)
        {
            if (diff == null || diff.Payload == null)
            {
                return;
            }

            if (diff.Payload.Operations == null)
            {
                diff.Payload.Operations = new List<DiffOperation>();
            }

            var originalFileName = diff.SourceDocument == null ? null : diff.SourceDocument.FileName;
            var replacedFileName = diff.ReplacedDocument == null ? null : diff.ReplacedDocument.FileName;
            if (string.IsNullOrWhiteSpace(originalFileName)
                || string.IsNullOrWhiteSpace(replacedFileName)
                || string.Equals(originalFileName, replacedFileName, StringComparison.Ordinal))
            {
                return;
            }

            diff.Payload.Operations.Insert(0, new DiffOperation
            {
                OperationId = "F000001",
                Type = "fileName",
                ObjectType = "documentFileName",
                Position = new DiffPosition
                {
                    StoryType = "file",
                    ContainerPath = "fileName",
                    ParagraphIndex = -1,
                },
                OriginalText = originalFileName,
                WrittenText = replacedFileName,
            });
        }

        private static bool DiffContainsTextOperations(DiffDocument diff)
        {
            return diff != null
                && diff.Payload != null
                && diff.Payload.Operations != null
                && diff.Payload.Operations.Any(item => item != null && string.Equals(item.Type, "text", StringComparison.Ordinal));
        }

        private static string BuildReplacedFingerprintMismatchMessage(string replacedPath, DiffDocument diff, string currentFingerprint)
        {
            var replaced = diff == null ? null : diff.ReplacedDocument;
            return string.Format(
                CultureInfo.InvariantCulture,
                "恢复输入文档与差异文件记录的替换后文档指纹不匹配。 当前文件={0}; 差异记录文件名={1}; 差异记录相对路径={2}; 指纹算法={3}; 当前指纹={4}; 期望指纹={5}",
                replacedPath ?? string.Empty,
                replaced == null ? string.Empty : replaced.FileName ?? string.Empty,
                replaced == null ? string.Empty : replaced.RelativePath ?? string.Empty,
                replaced == null ? "SHA-256" : replaced.FingerprintAlgorithm ?? "SHA-256",
                currentFingerprint ?? string.Empty,
                replaced == null ? string.Empty : replaced.Fingerprint ?? string.Empty);
        }

        private static void ValidateDiffAlgorithm(DiffDocument diff)
        {
            if (diff.Algorithm == null
                || !string.Equals(diff.Algorithm.DiffVersion, SupportedDiffVersion, StringComparison.Ordinal)
                || !string.Equals(diff.Algorithm.BmpCodecVersion, SupportedBmpCodecVersion, StringComparison.Ordinal))
            {
                throw new InvalidDataException("差异文件算法版本不受支持。");
            }
        }

        private void PrepareWorkingDocx(string sourcePath, string workingDocxPath, string sourceExtension)
        {
            EnsureDocConversionService(sourceExtension);
            EnsureDirectoryForFile(workingDocxPath);

            if (string.Equals(sourceExtension, ".docx", StringComparison.OrdinalIgnoreCase))
            {
                File.Copy(sourcePath, workingDocxPath, true);
            }
            else
            {
                _docConversionService.Convert(sourcePath, workingDocxPath);
            }

            EnsureWritableFile(workingDocxPath);
            VerifyWorkingDocxIntegrity(workingDocxPath, sourcePath, sourceExtension);
        }

        private static void VerifyWorkingDocxIntegrity(string workingDocxPath, string sourcePath, string sourceExtension)
        {
            try
            {
                using (var document = WordprocessingDocument.Open(workingDocxPath, false))
                {
                    if (document.MainDocumentPart == null)
                    {
                        throw new InvalidDataException("工作文档缺少 MainDocumentPart。");
                    }
                }
            }
            catch (Exception ex)
            {
                var fileInfo = new FileInfo(workingDocxPath);
                throw new InvalidDataException(
                    string.Format(
                        CultureInfo.InvariantCulture,
                        "准备工作文档失败：生成的 .docx 不是有效的 ZIP/OpenXML 文件。源文件={0}; 工作文档={1}; 源扩展名={2}; 工作文件大小={3} 字节; 内部异常={4}: {5}",
                        sourcePath ?? string.Empty,
                        workingDocxPath ?? string.Empty,
                        sourceExtension ?? string.Empty,
                        fileInfo.Exists ? fileInfo.Length : -1,
                        ex == null ? string.Empty : ex.GetType().Name,
                        ex == null ? string.Empty : ex.Message),
                    ex);
            }
        }

        private static WordprocessingDocument OpenEditableWorkingDocument(string sourcePath, string workingDocxPath, string stage)
        {
            Exception lastError = null;
            for (var attempt = 1; attempt <= WorkingDocumentOpenRetryCount; attempt++)
            {
                try
                {
                    EnsureWritableFile(workingDocxPath);
                    return WordprocessingDocument.Open(workingDocxPath, true);
                }
                catch (UnauthorizedAccessException ex)
                {
                    lastError = ex;
                }
                catch (IOException ex)
                {
                    lastError = ex;
                }

                if (attempt < WorkingDocumentOpenRetryCount)
                {
                    Thread.Sleep(WorkingDocumentOpenRetryDelayMilliseconds * attempt);
                }
            }

            throw new IOException(BuildWorkingDocumentOpenFailureMessage(sourcePath, workingDocxPath, stage, lastError), lastError);
        }

        private void CommitWorkingDocument(string workingDocxPath, string targetPath, string targetExtension)
        {
            EnsureDocConversionService(targetExtension);
            EnsureDirectoryForFile(targetPath);

            if (string.Equals(targetExtension, ".docx", StringComparison.OrdinalIgnoreCase))
            {
                File.Copy(workingDocxPath, targetPath, true);
                return;
            }

            _docConversionService.Convert(workingDocxPath, targetPath);
        }

        private void EnsureDocConversionService(string extension)
        {
            if (string.Equals(extension, ".doc", StringComparison.OrdinalIgnoreCase) && _docConversionService == null)
            {
                throw new NotSupportedException("当前配置未提供 .doc 转换能力。");
            }
        }

        private static void EnsureDirectoryForFile(string path)
        {
            var directory = Path.GetDirectoryName(path);
            if (!string.IsNullOrWhiteSpace(directory))
            {
                Directory.CreateDirectory(directory);
            }
        }

        private void UpdateDynamicContent(string workingDocxPath)
        {
            if (_documentFieldUpdateService == null || string.IsNullOrWhiteSpace(workingDocxPath))
            {
                return;
            }

            _documentFieldUpdateService.UpdateDynamicContent(workingDocxPath);
        }

        private static void ReportFontFallback(IProgress<FileProcessProgress> progress, string filePath, FontValidationResult result)
        {
            if (progress == null || result == null || result.MissingFonts == null || result.MissingFonts.Count == 0)
            {
                return;
            }

            progress.Report(new FileProcessProgress
            {
                FilePath = filePath,
                FilePercent = 0,
                Message = "检测到缺失字体: " + string.Join(", ", result.MissingFonts) + "。已使用默认字体继续处理：中文/东亚=宋体，英文和数字=Times New Roman。",
                IsWarning = true,
            });
        }

        private static List<BrokenFieldFinding> ScanBrokenFieldResults(string workingDocxPath)
        {
            var findings = new List<BrokenFieldFinding>();
            if (string.IsNullOrWhiteSpace(workingDocxPath) || !File.Exists(workingDocxPath))
            {
                return findings;
            }

            using (var document = WordprocessingDocument.Open(workingDocxPath, false))
            {
                foreach (var context in EnumerateTextParts(document))
                {
                    foreach (var target in EnumerateTextTargets(context))
                    {
                        var state = BuildParagraphState(target);
                        if (string.IsNullOrEmpty(state.Text))
                        {
                            continue;
                        }

                        foreach (var marker in BrokenFieldResultMarkers)
                        {
                            var searchStart = 0;
                            while (searchStart < state.Text.Length)
                            {
                                var index = state.Text.IndexOf(marker, searchStart, StringComparison.OrdinalIgnoreCase);
                                if (index < 0)
                                {
                                    break;
                                }

                                findings.Add(BuildBrokenFieldFinding(target, state.Text, marker, index));

                                searchStart = index + Math.Max(marker.Length, 1);
                                if (findings.Count >= BrokenFieldResultScanLimit)
                                {
                                    break;
                                }
                            }

                            if (findings.Count >= BrokenFieldResultScanLimit)
                            {
                                break;
                            }
                        }

                        if (findings.Count >= BrokenFieldResultScanLimit)
                        {
                            break;
                        }
                    }

                    if (findings.Count >= BrokenFieldResultScanLimit)
                    {
                        break;
                    }
                }
            }

            return findings;
        }

        private static BrokenFieldFinding BuildBrokenFieldFinding(ParagraphTarget target, string paragraphText, string marker, int index)
        {
            var paragraphElement = target == null ? null : target.ParagraphElement;
            var hitCell = FindHitTableCell(paragraphElement);

            TryParseTableLocation(target == null ? null : target.ContainerPath, out var tableIndex, out var rowIndex, out var columnIndex);

            var fullText = NormalizeWhitespaceForReport(paragraphText ?? string.Empty);
            var previousText = GetSiblingParagraphText(paragraphElement, true);
            var nextText = GetSiblingParagraphText(paragraphElement, false);
            var sameRowCells = GetSameRowCellsSnapshot(paragraphElement, hitCell);
            var sameColumnCells = GetSameColumnCellsSnapshot(paragraphElement, hitCell);

            return new BrokenFieldFinding
            {
                StoryType = target == null ? string.Empty : (target.StoryType ?? string.Empty),
                ContainerPath = target == null ? string.Empty : (target.ContainerPath ?? string.Empty),
                ParagraphIndex = target == null ? 0 : target.ParagraphIndex,
                Marker = marker,
                Excerpt = CreateValidationExcerpt(paragraphText, index, marker.Length),
                FullParagraphText = TruncateForReport(fullText, 500),
                TableIndex = tableIndex,
                RowIndex = rowIndex,
                ColumnIndex = columnIndex,
                PreviousParagraphText = previousText,
                NextParagraphText = nextText,
                SameRowCellsText = sameRowCells,
                SameColumnCellsText = sameColumnCells,
            };
        }

        private static void ValidateNoBrokenFieldResults(
            string workingDocxPath,
            string sourcePath,
            IReadOnlyCollection<BrokenFieldFinding> baselineFindings,
            string operationName,
            IProgress<FileProcessProgress> progress)
        {
            if (string.IsNullOrWhiteSpace(workingDocxPath) || !File.Exists(workingDocxPath))
            {
                return;
            }

            var currentFindings = ScanBrokenFieldResults(workingDocxPath);
            if (currentFindings.Count == 0)
            {
                return;
            }

            var baselineIdentities = new HashSet<string>(
                (baselineFindings ?? Enumerable.Empty<BrokenFieldFinding>()).Select(item => item.Identity),
                StringComparer.Ordinal);

            var newFindings = currentFindings
                .Where(item => !baselineIdentities.Contains(item.Identity))
                .ToList();

            var baselineCount = currentFindings.Count - newFindings.Count;

            if (baselineCount > 0)
            {
                progress?.Report(new FileProcessProgress
                {
                    FilePath = sourcePath ?? string.Empty,
                    FilePercent = 0,
                    Message = string.Format(
                        CultureInfo.InvariantCulture,
                        "检测到源文档已存在 {0} 处交叉引用/域结果错误标记（属基线已存在问题），将继续完成{1}。",
                        baselineCount,
                        operationName ?? string.Empty),
                    IsWarning = true,
                });
            }

            if (newFindings.Count == 0)
            {
                return;
            }

            var detailBuilder = new StringBuilder();
            for (var i = 0; i < newFindings.Count; i++)
            {
                detailBuilder.AppendLine();
                detailBuilder.AppendLine("=== 命中 [" + (i + 1).ToString(CultureInfo.InvariantCulture) + "] ===");
                AppendFindingDetail(detailBuilder, newFindings[i]);
            }

            throw new InvalidDataException(
                string.Format(
                    CultureInfo.InvariantCulture,
                    "文档验证失败：检测到{0}过程中新增的交叉引用/域结果错误，禁止输出当前{1}结果。源文件={2}; 工作文件={3}; 新增命中数={4}; 基线已命中数={5}; 明细如下:{6}",
                    operationName ?? string.Empty,
                    operationName ?? string.Empty,
                    sourcePath ?? string.Empty,
                    workingDocxPath,
                    newFindings.Count,
                    baselineCount,
                    detailBuilder));
        }

        private static void AppendFindingDetail(StringBuilder sb, BrokenFieldFinding finding)
        {
            if (finding == null)
            {
                return;
            }

            sb.AppendLine("  Story       = " + (finding.StoryType ?? string.Empty));
            sb.AppendLine("  Container   = " + (finding.ContainerPath ?? string.Empty));
            if (finding.TableIndex.HasValue && finding.RowIndex.HasValue && finding.ColumnIndex.HasValue)
            {
                sb.AppendLine(string.Format(
                    CultureInfo.InvariantCulture,
                    "  表格位置    = 第{0}个表 第{1}行 第{2}列 (基于0的索引)",
                    finding.TableIndex.Value,
                    finding.RowIndex.Value,
                    finding.ColumnIndex.Value));
            }
            sb.AppendLine("  Paragraph   = " + finding.ParagraphIndex.ToString(CultureInfo.InvariantCulture));
            sb.AppendLine("  Marker      = " + (finding.Marker ?? string.Empty));
            sb.AppendLine("  Excerpt     = " + (finding.Excerpt ?? string.Empty));
            sb.AppendLine("  段落完整文本= " + (finding.FullParagraphText ?? string.Empty));
            if (!string.IsNullOrEmpty(finding.PreviousParagraphText))
            {
                sb.AppendLine("  前一段落    = " + finding.PreviousParagraphText);
            }
            if (!string.IsNullOrEmpty(finding.NextParagraphText))
            {
                sb.AppendLine("  后一段落    = " + finding.NextParagraphText);
            }
            if (!string.IsNullOrEmpty(finding.SameRowCellsText))
            {
                sb.AppendLine("  同行所有单元格 = " + finding.SameRowCellsText);
            }
            if (!string.IsNullOrEmpty(finding.SameColumnCellsText))
            {
                sb.AppendLine("  同列所有单元格 = " + finding.SameColumnCellsText);
            }
        }

        private static string CreateValidationExcerpt(string text, int index, int length)
        {
            if (string.IsNullOrEmpty(text))
            {
                return string.Empty;
            }

            const int Radius = 80;
            var start = Math.Max(0, index - Radius);
            var end = Math.Min(text.Length, index + length + Radius);
            var excerpt = text.Substring(start, end - start)
                .Replace('\r', ' ')
                .Replace('\n', ' ')
                .Replace('\t', ' ');

            if (start > 0)
            {
                excerpt = "..." + excerpt;
            }

            if (end < text.Length)
            {
                excerpt += "...";
            }

            return excerpt;
        }

        private static string TruncateForReport(string text, int maxLength)
        {
            if (string.IsNullOrEmpty(text))
            {
                return string.Empty;
            }

            const string ellipsis = "...";
            if (text.Length <= maxLength)
            {
                return text;
            }

            if (maxLength <= ellipsis.Length)
            {
                return text.Substring(0, maxLength);
            }

            return text.Substring(0, maxLength - ellipsis.Length) + ellipsis;
        }

        private static string NormalizeWhitespaceForReport(string text)
        {
            if (string.IsNullOrEmpty(text))
            {
                return string.Empty;
            }

            var sb = new StringBuilder(text.Length);
            var lastWasWhitespace = false;
            foreach (var ch in text)
            {
                if (ch == '\r' || ch == '\n' || ch == '\t' || ch == ' ')
                {
                    if (!lastWasWhitespace)
                    {
                        sb.Append(' ');
                        lastWasWhitespace = true;
                    }
                    continue;
                }

                sb.Append(ch);
                lastWasWhitespace = false;
            }

            return sb.ToString().Trim();
        }

        private static string ExtractParagraphVisibleText(OpenXmlElement paragraph)
        {
            if (paragraph == null)
            {
                return string.Empty;
            }

            var sb = new StringBuilder();
            foreach (var text in paragraph.Descendants<W.Text>())
            {
                if (text != null)
                {
                    sb.Append(text.Text);
                }
            }

            return sb.ToString();
        }

        private static void TryParseTableLocation(string containerPath, out int? tableIndex, out int? rowIndex, out int? columnIndex)
        {
            tableIndex = null;
            rowIndex = null;
            columnIndex = null;
            if (string.IsNullOrWhiteSpace(containerPath))
            {
                return;
            }

            var match = Regex.Match(containerPath, @"tbl\[(\d+)\]/tr\[(\d+)\]/tc\[(\d+)\]", RegexOptions.CultureInvariant);
            if (!match.Success)
            {
                return;
            }

            if (int.TryParse(match.Groups[1].Value, NumberStyles.Integer, CultureInfo.InvariantCulture, out var t))
            {
                tableIndex = t;
            }

            if (int.TryParse(match.Groups[2].Value, NumberStyles.Integer, CultureInfo.InvariantCulture, out var r))
            {
                rowIndex = r;
            }

            if (int.TryParse(match.Groups[3].Value, NumberStyles.Integer, CultureInfo.InvariantCulture, out var c))
            {
                columnIndex = c;
            }
        }

        private static string GetSiblingParagraphText(OpenXmlElement paragraph, bool previous)
        {
            if (paragraph == null)
            {
                return null;
            }

            var sibling = previous ? paragraph.PreviousSibling() : paragraph.NextSibling();
            if (sibling is W.Paragraph wp)
            {
                var text = NormalizeWhitespaceForReport(ExtractParagraphVisibleText(wp));
                return TruncateForReport(text, 200);
            }

            return null;
        }

        private static string GetSameRowCellsSnapshot(OpenXmlElement paragraph, OpenXmlElement hitCell)
        {
            if (paragraph == null || hitCell == null)
            {
                return null;
            }

            var row = hitCell.Parent as W.TableRow;
            if (row == null)
            {
                return null;
            }

            var sb = new StringBuilder();
            var colIdx = 0;
            foreach (var cell in row.Elements<W.TableCell>())
            {
                if (sb.Length > 0)
                {
                    sb.Append(" | ");
                }

                var firstPara = cell.Descendants<W.Paragraph>().FirstOrDefault();
                var text = firstPara != null ? ExtractParagraphVisibleText(firstPara) : string.Empty;
                text = NormalizeWhitespaceForReport(text);
                var marker = ReferenceEquals(cell, hitCell) ? "  <==命中此单元格" : string.Empty;
                sb.AppendFormat(
                    CultureInfo.InvariantCulture,
                    "[列{0}] {1}{2}",
                    colIdx,
                    TruncateForReport(text, 100),
                    marker);
                colIdx++;
            }

            return sb.ToString();
        }

        private static string GetSameColumnCellsSnapshot(OpenXmlElement paragraph, OpenXmlElement hitCell)
        {
            if (paragraph == null || hitCell == null)
            {
                return null;
            }

            var row = hitCell.Parent as W.TableRow;
            if (row == null)
            {
                return null;
            }

            var table = row.Parent as W.Table;
            if (table == null)
            {
                return null;
            }

            int hitColumnIndex;
            int hitRowIndex;
            {
                var cells = row.Elements<W.TableCell>().ToList();
                hitColumnIndex = cells.TakeWhile(c => !ReferenceEquals(c, hitCell)).Count();
                var rows = table.Elements<W.TableRow>().ToList();
                hitRowIndex = rows.TakeWhile(r => !ReferenceEquals(r, row)).Count();
            }

            var sb = new StringBuilder();
            var rowIdx = 0;
            foreach (var currentRow in table.Elements<W.TableRow>())
            {
                var cells = currentRow.Elements<W.TableCell>().ToList();
                if (hitColumnIndex < cells.Count)
                {
                    if (sb.Length > 0)
                    {
                        sb.Append(" | ");
                    }

                    var firstPara = cells[hitColumnIndex].Descendants<W.Paragraph>().FirstOrDefault();
                    var text = firstPara != null ? ExtractParagraphVisibleText(firstPara) : string.Empty;
                    text = NormalizeWhitespaceForReport(text);
                    var marker = rowIdx == hitRowIndex ? "  <==命中此行" : string.Empty;
                    sb.AppendFormat(
                        CultureInfo.InvariantCulture,
                        "[行{0}] {1}{2}",
                        rowIdx,
                        TruncateForReport(text, 100),
                        marker);
                }

                rowIdx++;
            }

            return sb.ToString();
        }

        private static OpenXmlElement FindHitTableCell(OpenXmlElement paragraph)
        {
            if (paragraph == null)
            {
                return null;
            }

            foreach (var ancestor in paragraph.Ancestors())
            {
                if (ancestor is W.TableCell)
                {
                    return ancestor;
                }
            }

            return null;
        }

        private static string NormalizeWordExtension(string path)
        {
            var extension = Path.GetExtension(path) ?? string.Empty;
            if (!extension.Equals(".doc", StringComparison.OrdinalIgnoreCase)
                && !extension.Equals(".docx", StringComparison.OrdinalIgnoreCase))
            {
                throw new NotSupportedException("当前版本仅支持 .doc 与 .docx 文档。");
            }

            return extension;
        }

        private static DiffDocumentInfo BuildDocumentInfo(string filePath, string rootDirectory)
        {
            return BuildDocumentInfo(filePath, rootDirectory, filePath);
        }

        private static DiffDocumentInfo BuildDocumentInfo(string fingerprintSourcePath, string rootDirectory, string logicalPath)
        {
            var metadataPath = string.IsNullOrWhiteSpace(logicalPath) ? fingerprintSourcePath : logicalPath;
            var relativePath = metadataPath;
            if (!string.IsNullOrWhiteSpace(rootDirectory) && Directory.Exists(rootDirectory))
            {
                try
                {
                    relativePath = PathUtility.GetRelativePath(rootDirectory, metadataPath);
                }
                catch
                {
                    relativePath = Path.GetFileName(metadataPath);
                }
            }

            return new DiffDocumentInfo
            {
                FileName = Path.GetFileName(metadataPath),
                RelativePath = relativePath,
                Extension = Path.GetExtension(metadataPath),
                FingerprintAlgorithm = "SHA-256",
                Fingerprint = HashUtility.ComputeFileSha256Base64(fingerprintSourcePath),
            };
        }

        private static DiffRuleFileInfo BuildRuleFileInfo(string ruleFilePath, RuleFile ruleFile, IList<RuleDefinition> effectiveRules)
        {
            var fileName = string.IsNullOrWhiteSpace(ruleFilePath) ? "unsaved.rule" : Path.GetFileName(ruleFilePath);
            string fingerprint;
            if (!string.IsNullOrWhiteSpace(ruleFilePath) && File.Exists(ruleFilePath))
            {
                fingerprint = HashUtility.ComputeFileSha256Base64(ruleFilePath);
            }
            else if (effectiveRules == null || effectiveRules.Count == 0)
            {
                fileName = string.Empty;
                fingerprint = string.Empty;
            }
            else
            {
                var json = Newtonsoft.Json.JsonConvert.SerializeObject(ruleFile ?? new RuleFile(), Newtonsoft.Json.Formatting.None);
                fingerprint = HashUtility.ComputeSha256Base64(json);
            }

            return new DiffRuleFileInfo
            {
                FileName = fileName,
                Version = ruleFile == null ? "1.0" : ruleFile.Version ?? "1.0",
                FingerprintAlgorithm = "SHA-256",
                Fingerprint = fingerprint,
            };
        }

        private static string CreateTempPath(string finalPath)
        {
            var directory = Path.GetDirectoryName(finalPath) ?? string.Empty;
            if (!string.IsNullOrWhiteSpace(directory))
            {
                Directory.CreateDirectory(directory);
            }

            var name = Path.GetFileNameWithoutExtension(finalPath);
            var extension = Path.GetExtension(finalPath);
            return Path.Combine(directory, string.Format("{0}.tmp-{1}{2}", name, Guid.NewGuid().ToString("N"), extension));
        }

        private static string CreateWorkingDocxPath(string prefix)
        {
            var directory = Path.Combine(Path.GetTempPath(), "DCIT", "processing", prefix ?? "document");
            Directory.CreateDirectory(directory);
            return Path.Combine(directory, Guid.NewGuid().ToString("N") + ".docx");
        }

        private static void EnsureWritableFile(string path)
        {
            if (string.IsNullOrWhiteSpace(path) || !File.Exists(path))
            {
                return;
            }

            var attributes = File.GetAttributes(path);
            if ((attributes & FileAttributes.ReadOnly) != 0)
            {
                File.SetAttributes(path, attributes & ~FileAttributes.ReadOnly);
            }
        }

        private static string GetUniquePath(string requestedPath)
        {
            if (!File.Exists(requestedPath))
            {
                return requestedPath;
            }

            var directory = Path.GetDirectoryName(requestedPath) ?? string.Empty;
            var fileNameWithoutExtension = Path.GetFileNameWithoutExtension(requestedPath);
            var extension = Path.GetExtension(requestedPath);
            var index = 1;
            string candidate;
            do
            {
                candidate = Path.Combine(directory, string.Format("{0}_{1}{2}", fileNameWithoutExtension, index, extension));
                index++;
            }
            while (File.Exists(candidate));

            return candidate;
        }

        private ReplacementOutputPaths GetUniqueReplacementOutputPaths(string requestedOutputPath, string requestedDiffPath)
        {
            var outputDirectory = Path.GetDirectoryName(requestedOutputPath) ?? string.Empty;
            var diffDirectory = Path.GetDirectoryName(requestedDiffPath) ?? string.Empty;
            var outputFileNameWithoutExtension = Path.GetFileNameWithoutExtension(requestedOutputPath);
            var diffFileNameWithoutExtension = Path.GetFileNameWithoutExtension(requestedDiffPath);
            var outputExtension = Path.GetExtension(requestedOutputPath);
            var diffExtension = Path.GetExtension(requestedDiffPath);

            var index = 0;
            while (true)
            {
                var suffix = index == 0
                    ? string.Empty
                    : "_" + index.ToString(CultureInfo.InvariantCulture);
                var outputPath = Path.Combine(outputDirectory, outputFileNameWithoutExtension + suffix + outputExtension);
                var diffPath = Path.Combine(diffDirectory, diffFileNameWithoutExtension + suffix + diffExtension);
                var bmpPath = _diffSerializationService.GetBmpPath(diffPath);

                if (!File.Exists(outputPath) && !File.Exists(diffPath) && !File.Exists(bmpPath))
                {
                    return new ReplacementOutputPaths
                    {
                        OutputPath = outputPath,
                        DiffPath = diffPath,
                        BmpPath = bmpPath,
                    };
                }

                index++;
            }
        }

        private static void SafeDelete(string path)
        {
            try
            {
                if (!string.IsNullOrWhiteSpace(path) && File.Exists(path))
                {
                    File.Delete(path);
                }
            }
            catch
            {
            }
        }

        private static string BuildWorkingDocumentOpenFailureMessage(string sourcePath, string workingDocxPath, string stage, Exception exception)
        {
            var builder = new StringBuilder();
            builder.Append("无法以可编辑方式打开临时工作副本。");
            builder.Append(" 阶段=").Append(stage ?? string.Empty);
            builder.Append("; 源文件=").Append(sourcePath ?? string.Empty);
            builder.Append("; 临时工作文件=").Append(workingDocxPath ?? string.Empty);
            builder.Append("; 尝试次数=").Append(WorkingDocumentOpenRetryCount.ToString(CultureInfo.InvariantCulture));

            AppendFileSnapshot(builder, "源文件", sourcePath);
            AppendFileSnapshot(builder, "临时工作文件", workingDocxPath);

            if (exception != null)
            {
                builder.Append("; 最近异常=").Append(exception.GetType().FullName).Append(": ").Append(exception.Message);
            }

            return builder.ToString();
        }

        private static void AppendFileSnapshot(StringBuilder builder, string label, string path)
        {
            if (builder == null || string.IsNullOrWhiteSpace(path))
            {
                return;
            }

            try
            {
                if (!File.Exists(path))
                {
                    builder.Append("; ").Append(label).Append("存在=否");
                    return;
                }

                var info = new FileInfo(path);
                builder.Append("; ").Append(label).Append("存在=是");
                builder.Append("; ").Append(label).Append("大小=").Append(info.Length.ToString(CultureInfo.InvariantCulture));
                builder.Append("; ").Append(label).Append("属性=").Append(info.Attributes.ToString());
                builder.Append("; ").Append(label).Append("只读=").Append(info.IsReadOnly ? "是" : "否");
                builder.Append("; ").Append(label).Append("最后写入时间=").Append(info.LastWriteTime.ToString("yyyy-MM-dd HH:mm:ss.fff", CultureInfo.InvariantCulture));
                builder.Append("; ").Append(label).Append("最后写入时间(UTC)=").Append(info.LastWriteTimeUtc.ToString("yyyy-MM-dd HH:mm:ss.fff", CultureInfo.InvariantCulture));
                builder.Append("; ").Append(label).Append("SHA256=").Append(HashUtility.ComputeFileSha256Base64(path));
            }
            catch (Exception ex)
            {
                builder.Append("; ").Append(label).Append("快照失败=").Append(ex.GetType().FullName).Append(": ").Append(ex.Message);
            }
        }

        private static IEnumerable<PartContext> EnumerateTextParts(WordprocessingDocument document)
        {
            var main = document.MainDocumentPart;
            if (main == null)
            {
                yield break;
            }

            if (main.Document != null)
            {
                yield return new PartContext
                {
                    Part = main,
                    Root = main.Document,
                    PartUri = main.Uri.ToString(),
                    StoryType = "main",
                };
            }

            var queue = new Queue<OpenXmlPartContainer>();
            var visited = new HashSet<OpenXmlPart>();
            queue.Enqueue(main);

            while (queue.Count > 0)
            {
                var container = queue.Dequeue();
                foreach (var pair in container.Parts)
                {
                    var part = pair.OpenXmlPart;
                    if (part == null || !visited.Add(part))
                    {
                        continue;
                    }

                    if (part.RootElement != null && IsTextRelevantPart(part))
                    {
                        yield return new PartContext
                        {
                            Part = part,
                            Root = part.RootElement,
                            PartUri = part.Uri.ToString(),
                            StoryType = GetStoryType(part),
                        };
                    }

                    queue.Enqueue(part);
                }
            }
        }

        private static IEnumerable<ImageContext> EnumerateImageParts(WordprocessingDocument document)
        {
            foreach (var partContext in EnumerateTextParts(document))
            {
                var drawings = partContext.Root.Descendants<W.Drawing>().ToList();
                for (var index = 0; index < drawings.Count; index++)
                {
                    var drawing = drawings[index];
                    var blip = drawing.Descendants<A.Blip>()
                        .FirstOrDefault(item => item.Embed != null && !string.IsNullOrWhiteSpace(item.Embed.Value));
                    if (blip == null)
                    {
                        continue;
                    }

                    ImagePart imagePart;
                    try
                    {
                        imagePart = partContext.Part.GetPartById(blip.Embed.Value) as ImagePart;
                    }
                    catch
                    {
                        imagePart = null;
                    }

                    if (imagePart == null)
                    {
                        continue;
                    }

                    yield return CreateImageContext(partContext, drawing, blip, imagePart, index);
                }

                var vmlContainers = partContext.Root
                    .Descendants()
                    .Where(item =>
                        (item is W.Picture picture && !picture.Ancestors<W.EmbeddedObject>().Any())
                        || item is W.EmbeddedObject)
                    .ToList();
                for (var index = 0; index < vmlContainers.Count; index++)
                {
                    var containerElement = vmlContainers[index];
                    var imageData = containerElement.Descendants<V.ImageData>()
                        .FirstOrDefault(item => !string.IsNullOrWhiteSpace(GetVmlRelationshipId(item)));
                    if (imageData == null)
                    {
                        continue;
                    }

                    var relationshipId = GetVmlRelationshipId(imageData);
                    ImagePart imagePart;
                    try
                    {
                        imagePart = partContext.Part.GetPartById(relationshipId) as ImagePart;
                    }
                    catch
                    {
                        imagePart = null;
                    }

                    if (imagePart == null)
                    {
                        continue;
                    }

                    yield return CreateVmlImageContext(partContext, containerElement, imageData, imagePart, relationshipId, index);
                }
            }
        }

        private static ImageContext CreateImageContext(PartContext partContext, W.Drawing drawing, A.Blip blip, ImagePart imagePart, int drawingIndex)
        {
            var inline = drawing.GetFirstChild<DW.Inline>();
            var anchor = drawing.GetFirstChild<DW.Anchor>();
            var storyType = drawing.Ancestors().Any(item => string.Equals(item.LocalName, "txbxContent", StringComparison.OrdinalIgnoreCase))
                ? "textbox"
                : partContext.StoryType;

            long width = 0;
            long height = 0;
            if (inline != null && inline.Extent != null)
            {
                width = inline.Extent.Cx == null ? 0L : inline.Extent.Cx.Value;
                height = inline.Extent.Cy == null ? 0L : inline.Extent.Cy.Value;
            }
            else if (anchor != null && anchor.Extent != null)
            {
                width = anchor.Extent.Cx == null ? 0L : anchor.Extent.Cx.Value;
                height = anchor.Extent.Cy == null ? 0L : anchor.Extent.Cy.Value;
            }

            var transform = drawing.Descendants<A.Transform2D>().FirstOrDefault();
            var rotation = transform != null && transform.Rotation != null
                ? transform.Rotation.Value / 60000d
                : 0d;

            return new ImageContext
            {
                ParentPart = partContext.Part,
                ImagePart = imagePart,
                RelationshipId = blip.Embed.Value,
                RelationKey = (partContext.PartUri ?? string.Empty) + "::" + blip.Embed.Value,
                PartUri = imagePart.Uri.ToString(),
                StoryType = storyType,
                ContainerPath = BuildContainerPath(partContext.PartUri, drawing, partContext.Root),
                ContainerKind = "drawing",
                ObjectType = inline != null ? "inlineImage" : "floatingImage",
                Layout = new DiffImageLayout
                {
                    DisplayWidthEmu = width,
                    DisplayHeightEmu = height,
                    WrapMode = DetermineWrapMode(inline, anchor),
                    RotationDegree = rotation,
                },
                ObjectIndex = drawingIndex,
            };
        }

        private static ImageContext CreateVmlImageContext(PartContext partContext, OpenXmlElement containerElement, V.ImageData imageData, ImagePart imagePart, string relationshipId, int pictureIndex)
        {
            var shape = imageData.Ancestors<V.Shape>().FirstOrDefault();
            var styleMap = ParseVmlStyle(shape == null ? null : shape.Style == null ? null : shape.Style.Value);
            var storyType = containerElement.Ancestors().Any(item => string.Equals(item.LocalName, "txbxContent", StringComparison.OrdinalIgnoreCase))
                ? "textbox"
                : partContext.StoryType;
            var embeddedProgramId = GetEmbeddedProgramId(containerElement);
            var embeddedPackageExtension = GetEmbeddedPackageExtension(partContext.Part, containerElement);

            return new ImageContext
            {
                ParentPart = partContext.Part,
                ImagePart = imagePart,
                RelationshipId = relationshipId,
                RelationKey = (partContext.PartUri ?? string.Empty) + "::" + relationshipId,
                PartUri = imagePart.Uri.ToString(),
                StoryType = storyType,
                ContainerPath = BuildContainerPath(partContext.PartUri, containerElement, partContext.Root),
                ContainerKind = GetContainerKind(containerElement),
                EmbeddedProgramId = embeddedProgramId,
                EmbeddedPackageExtension = embeddedPackageExtension,
                ObjectType = DetermineVmlObjectType(styleMap, containerElement),
                Layout = new DiffImageLayout
                {
                    DisplayWidthEmu = ParseVmlDimensionToEmu(styleMap, "width"),
                    DisplayHeightEmu = ParseVmlDimensionToEmu(styleMap, "height"),
                    WrapMode = DetermineVmlWrapMode(styleMap, containerElement),
                    RotationDegree = ParseVmlRotation(styleMap),
                },
                ObjectIndex = pictureIndex,
            };
        }

        private static string DetermineWrapMode(DW.Inline inline, DW.Anchor anchor)
        {
            if (inline != null)
            {
                return "inline";
            }

            if (anchor == null)
            {
                return "unknown";
            }

            if (anchor.Elements<DW.WrapSquare>().Any())
            {
                return "square";
            }

            if (anchor.Elements<DW.WrapTight>().Any())
            {
                return "tight";
            }

            if (anchor.Elements<DW.WrapThrough>().Any())
            {
                return "through";
            }

            if (anchor.Elements<DW.WrapTopBottom>().Any())
            {
                return "topBottom";
            }

            if (anchor.Elements<DW.WrapNone>().Any())
            {
                return "none";
            }

            return "anchor";
        }

        private static string GetVmlRelationshipId(V.ImageData imageData)
        {
            if (imageData == null)
            {
                return null;
            }

            return imageData.RelationshipId == null || string.IsNullOrWhiteSpace(imageData.RelationshipId.Value)
                ? imageData.RelId == null ? null : imageData.RelId.Value
                : imageData.RelationshipId.Value;
        }

        private static string GetContainerKind(OpenXmlElement containerElement)
        {
            if (containerElement is W.EmbeddedObject)
            {
                return "embeddedObject";
            }

            if (containerElement is W.Picture)
            {
                return "vmlPicture";
            }

            return "unknown";
        }

        private static string GetEmbeddedProgramId(OpenXmlElement containerElement)
        {
            var oleObject = GetEmbeddedOleObjectElement(containerElement);
            return GetOpenXmlAttributeValue(oleObject, "ProgID");
        }

        private static string GetEmbeddedPackageExtension(OpenXmlPartContainer partContainer, OpenXmlElement containerElement)
        {
            var oleObject = GetEmbeddedOleObjectElement(containerElement);
            var relationshipId = GetOpenXmlAttributeValue(oleObject, "id");
            if (string.IsNullOrWhiteSpace(relationshipId) || partContainer == null)
            {
                return null;
            }

            try
            {
                var part = partContainer.GetPartById(relationshipId);
                return NormalizePackageExtension(part == null ? null : Path.GetExtension(part.Uri.ToString()));
            }
            catch
            {
                return null;
            }
        }

        private static OpenXmlElement GetEmbeddedOleObjectElement(OpenXmlElement containerElement)
        {
            return containerElement == null
                ? null
                : containerElement
                    .Descendants()
                    .FirstOrDefault(item => string.Equals(item.LocalName, "OLEObject", StringComparison.OrdinalIgnoreCase));
        }

        private static string GetOpenXmlAttributeValue(OpenXmlElement element, string localName)
        {
            if (element == null || string.IsNullOrWhiteSpace(localName))
            {
                return null;
            }

            var attributes = element.GetAttributes();
            if (attributes == null)
            {
                return null;
            }

            foreach (var attribute in attributes)
            {
                if (string.Equals(attribute.LocalName, localName, StringComparison.OrdinalIgnoreCase)
                    && !string.IsNullOrWhiteSpace(attribute.Value))
                {
                    return attribute.Value;
                }
            }

            return null;
        }

        private static string NormalizePackageExtension(string extension)
        {
            if (string.IsNullOrWhiteSpace(extension))
            {
                return null;
            }

            var normalized = extension.Trim();
            if (!normalized.StartsWith(".", StringComparison.Ordinal))
            {
                normalized = "." + normalized;
            }

            return normalized.ToLowerInvariant();
        }

        private static IDictionary<string, string> ParseVmlStyle(string style)
        {
            var map = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
            if (string.IsNullOrWhiteSpace(style))
            {
                return map;
            }

            var segments = style.Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
            foreach (var segment in segments)
            {
                var pair = segment.Split(new[] { ':' }, 2);
                if (pair.Length != 2)
                {
                    continue;
                }

                var key = (pair[0] ?? string.Empty).Trim();
                var value = (pair[1] ?? string.Empty).Trim();
                if (key.Length == 0)
                {
                    continue;
                }

                map[key] = value;
            }

            return map;
        }

        private static long ParseVmlDimensionToEmu(IDictionary<string, string> styleMap, string key)
        {
            if (styleMap == null || !styleMap.TryGetValue(key, out var rawValue) || string.IsNullOrWhiteSpace(rawValue))
            {
                return 0L;
            }

            var match = Regex.Match(rawValue.Trim(), @"^(?<value>-?\d+(?:\.\d+)?)(?<unit>[a-z%]*)$", RegexOptions.IgnoreCase);
            if (!match.Success)
            {
                return 0L;
            }

            if (!double.TryParse(match.Groups["value"].Value, NumberStyles.Float, CultureInfo.InvariantCulture, out var numericValue))
            {
                return 0L;
            }

            var unit = (match.Groups["unit"].Value ?? string.Empty).Trim().ToLowerInvariant();
            double inches;
            switch (unit)
            {
                case "":
                case "px":
                    inches = numericValue / 96d;
                    break;
                case "pt":
                    inches = numericValue / 72d;
                    break;
                case "pc":
                    inches = numericValue / 6d;
                    break;
                case "in":
                    inches = numericValue;
                    break;
                case "cm":
                    inches = numericValue / 2.54d;
                    break;
                case "mm":
                    inches = numericValue / 25.4d;
                    break;
                case "twip":
                case "dxa":
                    inches = numericValue / 1440d;
                    break;
                default:
                    return 0L;
            }

            return (long)Math.Round(inches * 914400d);
        }

        private static double ParseVmlRotation(IDictionary<string, string> styleMap)
        {
            if (styleMap == null || !styleMap.TryGetValue("rotation", out var rawValue) || string.IsNullOrWhiteSpace(rawValue))
            {
                return 0d;
            }

            var match = Regex.Match(rawValue.Trim(), @"-?\d+(?:\.\d+)?", RegexOptions.IgnoreCase);
            if (!match.Success)
            {
                return 0d;
            }

            return double.TryParse(match.Value, NumberStyles.Float, CultureInfo.InvariantCulture, out var numericValue)
                ? numericValue
                : 0d;
        }

        private static string DetermineVmlWrapMode(IDictionary<string, string> styleMap, OpenXmlElement containerElement)
        {
            var wrapType = GetVmlWordWrapType(containerElement);
            if (!string.IsNullOrWhiteSpace(wrapType))
            {
                var mapped = NormalizeVmlWrapMode(wrapType);
                if (!string.IsNullOrWhiteSpace(mapped))
                {
                    return mapped;
                }
            }

            var styleWrapMode = NormalizeVmlWrapMode(styleMap != null && styleMap.TryGetValue("mso-wrap-style", out var wrapStyle)
                ? wrapStyle
                : null);
            if (!string.IsNullOrWhiteSpace(styleWrapMode))
            {
                return styleWrapMode;
            }

            if (styleMap != null && styleMap.TryGetValue("position", out var position) && !string.IsNullOrWhiteSpace(position))
            {
                if (string.Equals(position.Trim(), "absolute", StringComparison.OrdinalIgnoreCase))
                {
                    return "anchor";
                }
            }

            return "inline";
        }

        private static string NormalizeVmlWrapMode(string wrapValue)
        {
            if (!string.IsNullOrWhiteSpace(wrapValue))
            {
                var normalized = wrapValue.Trim().ToLowerInvariant();
                switch (normalized)
                {
                    case "square":
                        return "square";
                    case "tight":
                        return "tight";
                    case "through":
                        return "through";
                    case "topandbottom":
                    case "top-bottom":
                    case "topbottom":
                        return "topBottom";
                    case "none":
                        return "none";
                    case "inline":
                        return "inline";
                    case "anchor":
                        return "anchor";
                }
            }

            return null;
        }

        private static string GetVmlWordWrapType(OpenXmlElement containerElement)
        {
            if (containerElement == null)
            {
                return null;
            }

            foreach (var descendant in containerElement.Descendants())
            {
                if (!string.Equals(descendant.LocalName, "wrap", StringComparison.OrdinalIgnoreCase))
                {
                    continue;
                }

                if (!string.Equals(descendant.NamespaceUri ?? string.Empty, "urn:schemas-microsoft-com:office:word", StringComparison.OrdinalIgnoreCase))
                {
                    continue;
                }

                var attributes = descendant.GetAttributes();
                if (attributes == null)
                {
                    continue;
                }

                var typeAttribute = attributes.FirstOrDefault(item => string.Equals(item.LocalName, "type", StringComparison.OrdinalIgnoreCase));
                if (!string.IsNullOrWhiteSpace(typeAttribute.Value))
                {
                    return typeAttribute.Value;
                }
            }

            return null;
        }

        private static string DetermineVmlObjectType(IDictionary<string, string> styleMap, OpenXmlElement containerElement)
        {
            var wrapMode = DetermineVmlWrapMode(styleMap, containerElement);
            return string.Equals(wrapMode, "inline", StringComparison.OrdinalIgnoreCase)
                ? "inlineImage"
                : "floatingImage";
        }

        private static bool IsTextRelevantPart(OpenXmlPart part)
        {
            return part is HeaderPart
                || part is FooterPart
                || part is WordprocessingCommentsPart
                || part is FootnotesPart
                || part is EndnotesPart
                || part.GetType().Name.IndexOf("ChartPart", StringComparison.OrdinalIgnoreCase) >= 0;
        }

        private static string GetStoryType(OpenXmlPart part)
        {
            if (part is HeaderPart)
            {
                return "header";
            }

            if (part is FooterPart)
            {
                return "footer";
            }

            if (part is WordprocessingCommentsPart)
            {
                return "comment";
            }

            if (part is FootnotesPart)
            {
                return "footnote";
            }

            if (part is EndnotesPart)
            {
                return "endnote";
            }

            if (part.GetType().Name.IndexOf("ChartPart", StringComparison.OrdinalIgnoreCase) >= 0)
            {
                return "chart";
            }

            return "main";
        }

        private static void ProcessTextReplacements(
            WordprocessingDocument document,
            IList<RuleDefinition> rules,
            DiffPayload payload,
            ISet<OpenXmlPartRootElement> touchedRoots,
            IProgress<FileProcessProgress> progress,
            string filePath,
            CancellationToken cancellationToken)
        {
            var operationIndex = 1;
            foreach (var partContext in EnumerateTextParts(document))
            {
                var textTargets = EnumerateTextTargets(partContext).ToList();
                for (var paragraphListIndex = 0; paragraphListIndex < textTargets.Count; paragraphListIndex++)
                {
                    cancellationToken.ThrowIfCancellationRequested();
                    var target = textTargets[paragraphListIndex];
                    var paragraphTouched = false;

                    for (var ruleIndex = 0; ruleIndex < rules.Count; ruleIndex++)
                    {
                        var rule = rules[ruleIndex];
                        progress?.Report(new FileProcessProgress
                        {
                            FilePath = filePath,
                            FilePercent = rules.Count == 0 ? 100 : Math.Min(99, (ruleIndex * 100) / rules.Count),
                            CurrentRuleId = rule.Id,
                            CurrentRuleName = rule.Name,
                            CurrentFileTextCount = payload.Operations.Count(item => string.Equals(item.Type, "text", StringComparison.Ordinal)),
                            TotalTextCount = payload.Operations.Count(item => string.Equals(item.Type, "text", StringComparison.Ordinal)),
                            Message = "正在替换规则 " + (rule.Name ?? rule.Id ?? "-"),
                        });

                        var state = BuildParagraphState(target);
                        if (string.IsNullOrEmpty(state.Text))
                        {
                            continue;
                        }

                        var matches = FindMatches(state, rule);
                        if (matches.Count == 0)
                        {
                            continue;
                        }

                        for (var matchIndex = matches.Count - 1; matchIndex >= 0; matchIndex--)
                        {
                            var match = matches[matchIndex];
                            var position = BuildTextPosition(state, match);
                            var originalWidth = DisplayWidthUtility.Measure(match.OriginalText);
                            var truncatedText = DisplayWidthUtility.TruncateToWidth(match.ReplacementTemplateResult, originalWidth, out var truncated);
                            var writtenText = DisplayWidthUtility.PadToWidth(truncatedText, originalWidth, out var padded);

                            RewriteRange(state, match.StartIndex, match.Length, writtenText, updateFont: true);
                            var currentState = BuildParagraphState(target);
                            position.ParagraphTextLength = currentState.Text == null ? 0 : currentState.Text.Length;
                            position.ParagraphTextHash = BuildParagraphContentHash(currentState.Text);
                            payload.Operations.Add(new DiffOperation
                            {
                                OperationId = "T" + operationIndex.ToString("000000"),
                                Type = "text",
                                ObjectType = DetermineTextObjectType(target, state, match, position),
                                Position = position,
                                Rule = new DiffRuleHitInfo
                                {
                                    Id = rule.Id,
                                    Name = rule.Name,
                                    MatchMode = rule.MatchMode == RuleMatchMode.RegularExpression ? "regex" : "plain",
                                    Pattern = rule.SearchText,
                                    HitIndex = matches.Count - matchIndex,
                                },
                                OriginalText = match.OriginalText,
                                ReplacementTemplateResult = match.ReplacementTemplateResult,
                                WrittenText = writtenText,
                                DisplayWidthOriginal = originalWidth,
                                DisplayWidthWritten = DisplayWidthUtility.Measure(writtenText),
                                Truncated = truncated,
                                PaddingApplied = padded,
                            });
                            operationIndex++;
                            paragraphTouched = true;
                        }
                    }

                    if (paragraphTouched)
                    {
                        touchedRoots.Add(partContext.Root);
                    }
                }
            }

            progress?.Report(new FileProcessProgress
            {
                FilePath = filePath,
                FilePercent = 100,
                TotalTextCount = payload.Operations.Count(item => string.Equals(item.Type, "text", StringComparison.Ordinal)),
                CurrentFileTextCount = payload.Operations.Count(item => string.Equals(item.Type, "text", StringComparison.Ordinal)),
                Message = "文本替换完成",
            });
        }

        private static void RestoreText(
            WordprocessingDocument document,
            DiffPayload payload,
            IProgress<FileProcessProgress> progress,
            string filePath,
            CancellationToken cancellationToken,
            ISet<OpenXmlPartRootElement> touchedRoots)
        {
            var textTargets = EnumerateTextParts(document)
                .SelectMany(EnumerateTextTargets)
                .ToList();
            var paragraphLookup = textTargets.ToDictionary(
                target => BuildParagraphLookupKey(target.StoryType, target.ContainerPath, target.ParagraphIndex),
                target => target,
                StringComparer.OrdinalIgnoreCase);
            var paragraphScopeLookup = textTargets
                .GroupBy(target => BuildParagraphScopeKey(target.StoryType, target.ContainerPath), StringComparer.OrdinalIgnoreCase)
                .ToDictionary(group => group.Key, group => group.ToList(), StringComparer.OrdinalIgnoreCase);

            var operations = payload.Operations
                .Where(item => string.Equals(item.Type, "text", StringComparison.Ordinal))
                .Reverse()
                .ToList();

            for (var index = 0; index < operations.Count; index++)
            {
                cancellationToken.ThrowIfCancellationRequested();
                var operation = operations[index];
                var key = BuildParagraphLookupKey(operation.Position.StoryType, operation.Position.ContainerPath, operation.Position.ParagraphIndex);
                var scopeKey = BuildParagraphScopeKey(operation.Position.StoryType, operation.Position.ContainerPath);
                ParagraphTarget target;
                ParagraphState state;
                TextRange range = null;
                string actualWritten = null;
                var fallbackState = default(ParagraphState);
                if (paragraphLookup.TryGetValue(key, out var exactTarget))
                {
                    fallbackState = BuildParagraphState(exactTarget);
                    if (TryResolveOperationInParagraph(fallbackState, operation, out range, out actualWritten)
                        && ShouldTrustExactRestoreCandidate(operation, fallbackState, range))
                    {
                        target = exactTarget;
                        state = fallbackState;
                    }
                    else
                    {
                        target = null;
                        state = null;
                    }
                }
                else
                {
                    target = null;
                    state = null;
                }

                if (target == null)
                {
                    if (!TryResolveRestoreTargetFallback(paragraphScopeLookup, scopeKey, operation, out target, out state, out range, out actualWritten, out var ambiguous))
                    {
                        if (ambiguous)
                        {
                            throw new InvalidDataException("恢复失败：同一容器内定位到多个候选段落。 " + BuildRestoreOperationContext(operation, key, fallbackState));
                        }

                        if (fallbackState == null)
                        {
                            throw new InvalidDataException("恢复失败：未找到匹配的文本位置。 " + BuildRestoreOperationContext(operation, key, null));
                        }

                        throw new InvalidDataException(
                            "恢复失败：当前位置文本与记录不匹配，且未找到可回退段落。 "
                            + BuildRestoreOperationContext(operation, key, fallbackState)
                            + "; 记录写入文本="
                            + (operation.WrittenText ?? string.Empty)
                            + "; 当前文本="
                            + ExtractTextRange(fallbackState, TryCreateDiagnosticRange(fallbackState, operation)));
                    }
                }

                RewriteRange(state, range.StartIndex, range.Length, operation.OriginalText ?? string.Empty);
                touchedRoots.Add(target.PartContext.Root);

                progress?.Report(new FileProcessProgress
                {
                    FilePath = filePath,
                    FilePercent = operations.Count == 0 ? 100 : Math.Min(100, ((index + 1) * 100) / operations.Count),
                    CurrentRuleId = operation.Rule == null ? null : operation.Rule.Id,
                    CurrentRuleName = operation.Rule == null ? null : operation.Rule.Name,
                    CurrentFileTextCount = index + 1,
                    TotalTextCount = operations.Count,
                    Message = "正在恢复文本操作 " + operation.OperationId,
                });
            }
        }

        private static void ProcessImageReplacements(WordprocessingDocument document, DiffPayload payload, int? fixedImageSeed, CancellationToken cancellationToken)
        {
            var operationIndex = payload.Operations.Count(item => string.Equals(item.Type, "image", StringComparison.Ordinal)) + 1;
            var processedByRelation = new Dictionary<string, ProcessedImageResult>(StringComparer.OrdinalIgnoreCase);

            foreach (var image in EnumerateImageParts(document))
            {
                cancellationToken.ThrowIfCancellationRequested();
                var extension = (Path.GetExtension(image.PartUri) ?? string.Empty).ToLowerInvariant();
                var isRaster = SupportedRasterExtensions.Contains(extension, StringComparer.OrdinalIgnoreCase);
                var isNonBitmap = SupportedNonBitmapExtensions.Contains(extension, StringComparer.OrdinalIgnoreCase);
                if (!isRaster && !isNonBitmap)
                {
                    continue;
                }

                if (!processedByRelation.TryGetValue(image.RelationKey, out var processed))
                {
                    processed = isRaster
                        ? ProcessBitmapImage(image, extension, fixedImageSeed)
                        : ProcessNonBitmapImage(image, extension, fixedImageSeed);
                    processedByRelation[image.RelationKey] = processed;
                }

                payload.Operations.Add(new DiffOperation
                {
                    OperationId = "I" + operationIndex.ToString("000000"),
                    Type = "image",
                    ObjectType = image.ObjectType,
                    ContainerKind = image.ContainerKind,
                    EmbeddedProgramId = image.EmbeddedProgramId,
                    EmbeddedPackageExtension = image.EmbeddedPackageExtension,
                    Position = new DiffPosition
                    {
                        StoryType = image.StoryType,
                        ContainerPath = image.ContainerPath,
                        ParagraphIndex = 0,
                        StartRunIndex = 0,
                        StartCharOffset = 0,
                        EndRunIndex = 0,
                        EndCharOffset = 0,
                        ObjectIndex = image.ObjectIndex,
                    },
                    SourceKind = processed.SourceKind,
                    OriginalImage = processed.OriginalImage,
                    ConvertedBitmapImage = processed.ConvertedBitmapImage,
                    NewImage = processed.NewImage,
                    Seed = processed.Seed,
                    NoiseSummary = new DiffNoiseSummary
                    {
                        ModifiedPixelRatio = processed.ModifiedPixelRatio,
                    },
                    Layout = image.Layout,
                });
                operationIndex++;
            }
        }

        private static ProcessedImageResult ProcessBitmapImage(ImageContext image, string extension, int? fixedImageSeed)
        {
            var originalBytes = ReadImageBytes(image.ImagePart);
            var stableKey = image.ContainerPath ?? image.PartUri ?? image.RelationKey;
            var seed = fixedImageSeed.HasValue ? DeriveFixedSeed(fixedImageSeed.Value, stableKey) : CreateRandomSeed();
            DiffImageData originalImage;
            DiffImageData newImage;
            double ratio;

            using (var originalStream = new MemoryStream(originalBytes))
            using (var loadedImage = Image.FromStream(originalStream, true, true))
            using (var bitmap = new Bitmap(loadedImage))
            {
                ratio = ApplyNoise(bitmap, seed);
                newImage = CreateBitmapImageData(bitmap, extension);
                originalImage = CreateDiffImageData(extension, bitmap.Width, bitmap.Height, originalBytes);
            }

            WriteImageData(image, Convert.FromBase64String(newImage.Data), newImage.Format);

            return new ProcessedImageResult
            {
                SourceKind = "bitmap",
                OriginalImage = originalImage,
                NewImage = newImage,
                ModifiedPixelRatio = ratio,
                Seed = seed,
            };
        }

        private static ProcessedImageResult ProcessNonBitmapImage(ImageContext image, string extension, int? fixedImageSeed)
        {
            var originalBytes = ReadImageBytes(image.ImagePart);
            var stableKey = image.ContainerPath ?? image.PartUri ?? image.RelationKey;
            var seed = fixedImageSeed.HasValue ? DeriveFixedSeed(fixedImageSeed.Value, stableKey) : CreateRandomSeed();
            var bitmapFormat = GetNonBitmapTargetFormat(image);
            var convertedBitmapImage = RasterizeNonBitmapImage(image, extension, originalBytes, bitmapFormat);
            DiffImageData newImage;
            double ratio;

            using (var convertedStream = new MemoryStream(Convert.FromBase64String(convertedBitmapImage.Data)))
            using (var loadedImage = Image.FromStream(convertedStream, true, true))
            using (var bitmap = new Bitmap(loadedImage))
            {
                ratio = ApplyNoise(bitmap, seed);
                newImage = CreateBitmapImageData(bitmap, bitmapFormat);
            }

            WriteImageData(image, Convert.FromBase64String(newImage.Data), newImage.Format);

            return new ProcessedImageResult
            {
                SourceKind = "nonBitmap",
                OriginalImage = CreateDiffImageData(extension, convertedBitmapImage.WidthPx, convertedBitmapImage.HeightPx, originalBytes),
                ConvertedBitmapImage = convertedBitmapImage,
                NewImage = newImage,
                ModifiedPixelRatio = ratio,
                Seed = seed,
            };
        }

        private static void RestoreImages(WordprocessingDocument document, DiffPayload payload, CancellationToken cancellationToken)
        {
            var images = EnumerateImageParts(document).ToList();
            var imageBytesCache = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);

            var processedRelations = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
            var operations = payload.Operations
                .Where(item => string.Equals(item.Type, "image", StringComparison.Ordinal))
                .Reverse()
                .ToList();

            foreach (var operation in operations)
            {
                cancellationToken.ThrowIfCancellationRequested();
                if (operation.Position == null || string.IsNullOrWhiteSpace(operation.Position.ContainerPath))
                {
                    throw new InvalidDataException("图像恢复缺少位置。");
                }

                var resolution = ResolveImageRestoreTarget(images, operation, imageBytesCache, processedRelations);
                if (resolution == null || resolution.Image == null)
                {
                    throw new InvalidDataException("未找到可恢复的图像容器。 " + BuildImageRestoreContext(operation, null, images.Count));
                }

                var image = resolution.Image;
                if (processedRelations.Contains(image.RelationKey))
                {
                    continue;
                }

                if (operation.Layout != null && !resolution.LayoutMatches)
                {
                    throw new InvalidDataException("图像恢复失败：当前图像布局与记录不匹配。 " + BuildImageRestoreContext(operation, resolution, images.Count));
                }

                if (operation.NewImage != null && !resolution.SkipContentVerification)
                {
                    var actual = GetImageDataBase64(image, imageBytesCache);
                    if (!string.Equals(actual, operation.NewImage.Data, StringComparison.Ordinal))
                    {
                        throw new InvalidDataException("图像恢复失败：当前图像内容与记录不匹配。 " + BuildImageRestoreContext(operation, resolution, images.Count));
                    }
                }

                var restoreImage = string.Equals(operation.SourceKind, "nonBitmap", StringComparison.OrdinalIgnoreCase)
                    ? operation.ConvertedBitmapImage
                    : operation.OriginalImage;
                if (restoreImage == null || string.IsNullOrWhiteSpace(restoreImage.Data))
                {
                    throw new InvalidDataException("图像恢复缺少原始图像数据。");
                }

                WriteImageData(image, Convert.FromBase64String(restoreImage.Data), restoreImage.Format);
                processedRelations.Add(image.RelationKey);
            }
        }

        private static ImageRestoreCandidate ResolveImageRestoreTarget(
            IList<ImageContext> images,
            DiffOperation operation,
            IDictionary<string, string> imageBytesCache,
            ISet<string> processedRelations)
        {
            if (images == null || images.Count == 0 || operation == null || operation.Position == null)
            {
                return null;
            }

            var exactPathCandidate = images
                .Where(item => string.Equals(item.ContainerPath, operation.Position.ContainerPath, StringComparison.OrdinalIgnoreCase))
                .Select(item => BuildImageRestoreCandidate(item, operation, imageBytesCache, processedRelations))
                .OrderBy(item => item.IsProcessed ? 1 : 0)
                .ThenByDescending(item => item.ContentMatches)
                .ThenByDescending(item => item.ContainerKindMatches)
                .ThenByDescending(item => item.EmbeddedProgramMatches)
                .ThenByDescending(item => item.EmbeddedPackageMatches)
                .ThenByDescending(item => item.ObjectTypeMatches)
                .ThenByDescending(item => item.LayoutMatches)
                .FirstOrDefault();
            if (exactPathCandidate != null && exactPathCandidate.ContentMatches)
            {
                return exactPathCandidate;
            }

            if (CanUseStructuralImageRestoreFallback(exactPathCandidate, operation, exactPath: true))
            {
                exactPathCandidate.SkipContentVerification = true;
                return exactPathCandidate;
            }

            var candidates = images
                .Select(item => BuildImageRestoreCandidate(item, operation, imageBytesCache, processedRelations))
                .Where(item =>
                    item.StoryMatches
                    && item.ObjectTypeCompatible
                    && item.LayoutMatches
                    && item.ContentMatches
                    && item.ContainerKindMatches
                    && item.EmbeddedProgramMatches
                    && item.EmbeddedPackageMatches)
                .OrderBy(item => item.IsProcessed ? 1 : 0)
                .ThenByDescending(item => item.ContainerKindMatches)
                .ThenByDescending(item => item.EmbeddedProgramMatches)
                .ThenByDescending(item => item.EmbeddedPackageMatches)
                .ThenByDescending(item => item.ObjectTypeMatches)
                .ThenByDescending(item => item.PathSimilarity)
                .ThenBy(item => item.ObjectIndexDistance)
                .ThenBy(item => item.Image.ContainerPath ?? string.Empty, StringComparer.OrdinalIgnoreCase)
                .ToList();

            if (candidates.Count == 0)
            {
                return ResolveStructuralImageRestoreTarget(images, operation, imageBytesCache, processedRelations) ?? exactPathCandidate;
            }

            var top = candidates[0];
            var ambiguous = candidates
                .Where(item =>
                    item.IsProcessed == top.IsProcessed
                    && item.PathSimilarity == top.PathSimilarity
                    && item.ObjectIndexDistance == top.ObjectIndexDistance
                    && !string.Equals(item.Image.RelationKey, top.Image.RelationKey, StringComparison.OrdinalIgnoreCase))
                .FirstOrDefault();
            if (ambiguous != null)
            {
                throw new InvalidDataException("图像恢复失败：存在多个等价候选图像，无法唯一定位。 " + BuildImageRestoreContext(operation, top, images.Count));
            }

            return top;
        }

        private static ImageRestoreCandidate ResolveStructuralImageRestoreTarget(
            IList<ImageContext> images,
            DiffOperation operation,
            IDictionary<string, string> imageBytesCache,
            ISet<string> processedRelations)
        {
            var candidates = images
                .Select(item => BuildImageRestoreCandidate(item, operation, imageBytesCache, processedRelations))
                .Where(item => CanUseStructuralImageRestoreFallback(item, operation, exactPath: false))
                .OrderBy(item => item.IsProcessed ? 1 : 0)
                .ThenByDescending(item => item.ObjectTypeMatches)
                .ThenByDescending(item => item.PathSimilarity)
                .ThenBy(item => item.ObjectIndexDistance)
                .ThenBy(item => item.Image.ContainerPath ?? string.Empty, StringComparer.OrdinalIgnoreCase)
                .ToList();

            if (candidates.Count == 0)
            {
                return null;
            }

            var top = candidates[0];
            var ambiguous = candidates
                .Where(item =>
                    item.IsProcessed == top.IsProcessed
                    && item.ObjectTypeMatches == top.ObjectTypeMatches
                    && item.PathSimilarity == top.PathSimilarity
                    && item.ObjectIndexDistance == top.ObjectIndexDistance
                    && !string.Equals(item.Image.RelationKey, top.Image.RelationKey, StringComparison.OrdinalIgnoreCase))
                .FirstOrDefault();
            if (ambiguous != null)
            {
                throw new InvalidDataException("图像恢复失败：存在多个结构等价候选图像，无法唯一定位。 " + BuildImageRestoreContext(operation, top, images.Count));
            }

            top.SkipContentVerification = true;
            return top;
        }

        private static bool CanUseStructuralImageRestoreFallback(ImageRestoreCandidate candidate, DiffOperation operation, bool exactPath)
        {
            if (candidate == null || candidate.Image == null || operation == null)
            {
                return false;
            }

            if (!IsVmlRestoreCandidate(candidate, operation))
            {
                return false;
            }

            if (!candidate.StoryMatches
                || !candidate.ContainerKindMatches
                || !candidate.EmbeddedProgramMatches
                || !candidate.EmbeddedPackageMatches
                || !candidate.ObjectTypeCompatible
                || !candidate.LayoutMatches)
            {
                return false;
            }

            return exactPath
                || candidate.ObjectIndexDistance <= 2
                || candidate.PathSimilarity >= 400;
        }

        private static bool IsVmlRestoreCandidate(ImageRestoreCandidate candidate, DiffOperation operation)
        {
            var expectedPath = operation == null || operation.Position == null ? null : operation.Position.ContainerPath;
            return IsVmlImageContainerKind(candidate.Image.ContainerKind)
                || IsVmlImageContainerKind(operation == null ? null : operation.ContainerKind)
                || IsVmlLikeContainerPath(candidate.Image.ContainerPath)
                || IsVmlLikeContainerPath(expectedPath);
        }

        private static bool IsVmlImageContainerKind(string containerKind)
        {
            return string.Equals(containerKind, "vmlPicture", StringComparison.OrdinalIgnoreCase)
                || string.Equals(containerKind, "embeddedObject", StringComparison.OrdinalIgnoreCase);
        }

        private static ImageRestoreCandidate BuildImageRestoreCandidate(
            ImageContext image,
            DiffOperation operation,
            IDictionary<string, string> imageBytesCache,
            ISet<string> processedRelations)
        {
            var expectedStoryType = operation.Position == null ? null : operation.Position.StoryType;
            var expectedObjectType = operation.ObjectType;
            var expectedLayout = operation.Layout;
            var expectedImageData = operation.NewImage == null ? null : operation.NewImage.Data;
            var expectedPath = operation.Position == null ? null : operation.Position.ContainerPath;
            var expectedObjectIndex = operation.Position == null ? null : operation.Position.ObjectIndex;
            var expectedContainerKind = operation.ContainerKind;
            var expectedEmbeddedProgramId = operation.EmbeddedProgramId;
            var expectedEmbeddedPackageExtension = NormalizePackageExtension(operation.EmbeddedPackageExtension);
            var objectTypeMatches = string.IsNullOrWhiteSpace(expectedObjectType)
                || string.Equals(image.ObjectType ?? string.Empty, expectedObjectType ?? string.Empty, StringComparison.OrdinalIgnoreCase);
            var objectTypeCompatible = objectTypeMatches
                || IsCompatibleImageObjectType(expectedObjectType, image.ObjectType, expectedPath, image.ContainerPath);
            var allowCompatibleLayout = (objectTypeCompatible && !objectTypeMatches)
                || IsVmlImageContainerKind(expectedContainerKind)
                || IsVmlImageContainerKind(image.ContainerKind)
                || IsVmlLikeContainerPath(expectedPath)
                || IsVmlLikeContainerPath(image.ContainerPath);
            var containerKindMatches = string.IsNullOrWhiteSpace(expectedContainerKind)
                || string.Equals(image.ContainerKind ?? string.Empty, expectedContainerKind ?? string.Empty, StringComparison.OrdinalIgnoreCase);
            var embeddedProgramMatches = string.IsNullOrWhiteSpace(expectedEmbeddedProgramId)
                || string.Equals(image.EmbeddedProgramId ?? string.Empty, expectedEmbeddedProgramId ?? string.Empty, StringComparison.OrdinalIgnoreCase);
            var embeddedPackageMatches = string.IsNullOrWhiteSpace(expectedEmbeddedPackageExtension)
                || string.Equals(
                    NormalizePackageExtension(image.EmbeddedPackageExtension) ?? string.Empty,
                    expectedEmbeddedPackageExtension ?? string.Empty,
                    StringComparison.OrdinalIgnoreCase);

            return new ImageRestoreCandidate
            {
                Image = image,
                IsProcessed = processedRelations != null && processedRelations.Contains(image.RelationKey),
                StoryMatches = string.IsNullOrWhiteSpace(expectedStoryType)
                    || string.Equals(image.StoryType ?? string.Empty, expectedStoryType ?? string.Empty, StringComparison.OrdinalIgnoreCase),
                ContainerKindMatches = containerKindMatches,
                EmbeddedProgramMatches = embeddedProgramMatches,
                EmbeddedPackageMatches = embeddedPackageMatches,
                ObjectTypeMatches = objectTypeMatches,
                ObjectTypeCompatible = objectTypeCompatible,
                LayoutMatches = expectedLayout == null || IsLayoutEquivalent(image.Layout, expectedLayout, allowCompatibleLayout),
                ContentMatches = string.IsNullOrWhiteSpace(expectedImageData)
                    || string.Equals(GetImageDataBase64(image, imageBytesCache), expectedImageData, StringComparison.Ordinal),
                PathSimilarity = ComputeContainerPathSimilarity(image.ContainerPath, expectedPath),
                ObjectIndexDistance = ComputeObjectIndexDistance(image.ObjectIndex, expectedObjectIndex),
            };
        }

        private static string GetImageDataBase64(ImageContext image, IDictionary<string, string> imageBytesCache)
        {
            if (image == null)
            {
                return string.Empty;
            }

            var cacheKey = image.RelationKey ?? image.ContainerPath ?? image.PartUri ?? Guid.NewGuid().ToString("N");
            if (!imageBytesCache.TryGetValue(cacheKey, out var data))
            {
                data = Convert.ToBase64String(ReadImageBytes(image.ImagePart));
                imageBytesCache[cacheKey] = data;
            }

            return data;
        }

        private static int ComputeContainerPathSimilarity(string actualPath, string expectedPath)
        {
            if (string.IsNullOrWhiteSpace(actualPath) || string.IsNullOrWhiteSpace(expectedPath))
            {
                return 0;
            }

            if (string.Equals(actualPath, expectedPath, StringComparison.OrdinalIgnoreCase))
            {
                return int.MaxValue;
            }

            var actualSegments = actualPath.Split(new[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
            var expectedSegments = expectedPath.Split(new[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
            var length = Math.Min(actualSegments.Length, expectedSegments.Length);
            var score = 0;
            for (var index = 0; index < length; index++)
            {
                if (!string.Equals(actualSegments[index], expectedSegments[index], StringComparison.OrdinalIgnoreCase))
                {
                    break;
                }

                score += 100;
            }

            return score;
        }

        private static int ComputeObjectIndexDistance(int actualIndex, int? expectedIndex)
        {
            if (!expectedIndex.HasValue)
            {
                return 0;
            }

            return Math.Abs(actualIndex - expectedIndex.Value);
        }

        private static string BuildImageRestoreContext(DiffOperation operation, ImageRestoreCandidate candidate, int imageCount)
        {
            var builder = new StringBuilder();
            builder.Append("OperationId=").Append(operation == null ? string.Empty : operation.OperationId ?? string.Empty);
            builder.Append("; ObjectType=").Append(operation == null ? string.Empty : operation.ObjectType ?? string.Empty);
            builder.Append("; ContainerKind=").Append(operation == null ? string.Empty : operation.ContainerKind ?? string.Empty);
            builder.Append("; EmbeddedProgramId=").Append(operation == null ? string.Empty : operation.EmbeddedProgramId ?? string.Empty);
            builder.Append("; EmbeddedPackageExtension=").Append(operation == null ? string.Empty : operation.EmbeddedPackageExtension ?? string.Empty);
            builder.Append("; StoryType=").Append(operation == null || operation.Position == null ? string.Empty : operation.Position.StoryType ?? string.Empty);
            builder.Append("; Position=").Append(BuildDiffPositionSummary(operation == null ? null : operation.Position));
            builder.Append("; TotalImages=").Append(imageCount.ToString(CultureInfo.InvariantCulture));
            if (candidate != null && candidate.Image != null)
            {
                builder.Append("; CandidatePath=").Append(candidate.Image.ContainerPath ?? string.Empty);
                builder.Append("; CandidateRelation=").Append(candidate.Image.RelationKey ?? string.Empty);
                builder.Append("; CandidateContainerKind=").Append(candidate.Image.ContainerKind ?? string.Empty);
                builder.Append("; CandidateEmbeddedProgramId=").Append(candidate.Image.EmbeddedProgramId ?? string.Empty);
                builder.Append("; CandidateEmbeddedPackageExtension=").Append(candidate.Image.EmbeddedPackageExtension ?? string.Empty);
                builder.Append("; CandidateObjectType=").Append(candidate.Image.ObjectType ?? string.Empty);
                builder.Append("; CandidateWrapMode=").Append(candidate.Image.Layout == null ? string.Empty : candidate.Image.Layout.WrapMode ?? string.Empty);
                builder.Append("; CandidateObjectIndex=").Append(candidate.Image.ObjectIndex.ToString(CultureInfo.InvariantCulture));
                builder.Append("; CandidateStoryMatch=").Append(candidate.StoryMatches ? "Y" : "N");
                builder.Append("; CandidateContainerKindMatch=").Append(candidate.ContainerKindMatches ? "Y" : "N");
                builder.Append("; CandidateEmbeddedProgramMatch=").Append(candidate.EmbeddedProgramMatches ? "Y" : "N");
                builder.Append("; CandidateEmbeddedPackageMatch=").Append(candidate.EmbeddedPackageMatches ? "Y" : "N");
                builder.Append("; CandidateObjectTypeMatch=").Append(candidate.ObjectTypeMatches ? "Y" : "N");
                builder.Append("; CandidateObjectTypeCompatible=").Append(candidate.ObjectTypeCompatible ? "Y" : "N");
                builder.Append("; CandidateLayoutMatch=").Append(candidate.LayoutMatches ? "Y" : "N");
                builder.Append("; CandidateContentMatch=").Append(candidate.ContentMatches ? "Y" : "N");
                builder.Append("; CandidatePathSimilarity=").Append(candidate.PathSimilarity == int.MaxValue ? "Exact" : candidate.PathSimilarity.ToString(CultureInfo.InvariantCulture));
                builder.Append("; CandidateObjectIndexDistance=").Append(candidate.ObjectIndexDistance.ToString(CultureInfo.InvariantCulture));
            }

            return builder.ToString();
        }

        private static string BuildDiffPositionSummary(DiffPosition position)
        {
            if (position == null)
            {
                return "<null>";
            }

            return string.Format(
                CultureInfo.InvariantCulture,
                "story={0},container={1},paragraph={2},objectIndex={3},textStart={4},textEnd={5},runStart={6}:{7},runEnd={8}:{9}",
                position.StoryType ?? string.Empty,
                position.ContainerPath ?? string.Empty,
                position.ParagraphIndex,
                position.ObjectIndex.HasValue ? position.ObjectIndex.Value.ToString(CultureInfo.InvariantCulture) : "<null>",
                position.StartTextOffset,
                position.EndTextOffset,
                position.StartRunIndex,
                position.StartCharOffset,
                position.EndRunIndex,
                position.EndCharOffset);
        }

        private static byte[] ReadImageBytes(ImagePart imagePart)
        {
            using (var stream = imagePart.GetStream(FileMode.Open, FileAccess.Read))
            using (var memory = new MemoryStream())
            {
                stream.CopyTo(memory);
                return memory.ToArray();
            }
        }

        private static string GetNonBitmapTargetFormat(ImageContext image)
        {
            return IsVisioEmbeddedObject(image) ? ".bmp" : ".png";
        }

        private static bool IsVisioEmbeddedObject(ImageContext image)
        {
            if (image == null || !string.Equals(image.ContainerKind, "embeddedObject", StringComparison.OrdinalIgnoreCase))
            {
                return false;
            }

            if (IsVisioProgramId(image.EmbeddedProgramId))
            {
                return true;
            }

            var packageExtension = NormalizePackageExtension(image.EmbeddedPackageExtension);
            return !string.IsNullOrWhiteSpace(packageExtension)
                && SupportedVisioPackageExtensions.Contains(packageExtension, StringComparer.OrdinalIgnoreCase);
        }

        private static bool IsVisioProgramId(string programId)
        {
            return !string.IsNullOrWhiteSpace(programId)
                && programId.Trim().StartsWith("Visio.", StringComparison.OrdinalIgnoreCase);
        }

        private static DiffImageData RasterizeNonBitmapImage(ImageContext image, string extension, byte[] originalBytes, string targetBitmapFormat)
        {
            var backgroundColor = GetNonBitmapPreviewBackground(image, extension, targetBitmapFormat);
            using (var bitmap = CreateNonBitmapPreview(image, extension, originalBytes, backgroundColor))
            {
                return CreateBitmapImageData(bitmap, targetBitmapFormat);
            }
        }

        private static Color GetNonBitmapPreviewBackground(ImageContext image, string extension, string targetBitmapFormat)
        {
            if (IsVisioEmbeddedObject(image)
                || IsMetafileExtension(extension)
                || string.Equals(NormalizeImageFormat(targetBitmapFormat), "bmp", StringComparison.OrdinalIgnoreCase))
            {
                return Color.White;
            }

            return Color.Transparent;
        }

        private static bool IsMetafileExtension(string extension)
        {
            return string.Equals(extension, ".wmf", StringComparison.OrdinalIgnoreCase)
                || string.Equals(extension, ".emf", StringComparison.OrdinalIgnoreCase);
        }

        private static Bitmap CreateNonBitmapPreview(ImageContext image, string extension, byte[] originalBytes, Color backgroundColor)
        {
            if (string.Equals(extension, ".svg", StringComparison.OrdinalIgnoreCase))
            {
                using (var stream = new MemoryStream(originalBytes))
                {
                    var svgDocument = SvgDocument.Open<SvgDocument>(stream);
                    if (svgDocument == null)
                    {
                        throw new InvalidDataException("SVG 图像无法解析。");
                    }

                    using (var rendered = svgDocument.Draw())
                    {
                        if (rendered == null)
                        {
                            throw new InvalidDataException("SVG 图像无法渲染。");
                        }

                        return CreateLayoutBitmap(rendered, image.Layout, backgroundColor);
                    }
                }
            }

            using (var stream = new MemoryStream(originalBytes))
            using (var loadedImage = Image.FromStream(stream, true, true))
            {
                return CreateLayoutBitmap(loadedImage, image.Layout, backgroundColor);
            }
        }

        private static Bitmap CreateLayoutBitmap(Image image, DiffImageLayout layout, Color backgroundColor)
        {
            var width = ResolvePixelLength(layout == null ? 0L : layout.DisplayWidthEmu, image == null ? 0 : image.Width);
            var height = ResolvePixelLength(layout == null ? 0L : layout.DisplayHeightEmu, image == null ? 0 : image.Height);
            var bitmap = new Bitmap(width, height, PixelFormat.Format32bppArgb);
            using (var graphics = Graphics.FromImage(bitmap))
            {
                graphics.Clear(backgroundColor);
                graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
                graphics.SmoothingMode = SmoothingMode.HighQuality;
                graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
                graphics.DrawImage(image, new Rectangle(0, 0, width, height));
            }

            return bitmap;
        }

        private static int ResolvePixelLength(long emuLength, int fallback)
        {
            if (emuLength > 0)
            {
                return Math.Max(1, (int)Math.Round(emuLength / 9525d));
            }

            return Math.Max(1, fallback <= 0 ? 1 : fallback);
        }

        private static DiffImageData CreateBitmapImageData(Bitmap bitmap, string extension)
        {
            using (var output = new MemoryStream())
            {
                var normalizedExtension = NormalizeImageFormat(extension);
                bitmap.Save(output, GetImageFormat("." + normalizedExtension));
                return CreateDiffImageData(normalizedExtension, bitmap.Width, bitmap.Height, output.ToArray());
            }
        }

        private static DiffImageData CreateDiffImageData(string formatOrExtension, int width, int height, byte[] data)
        {
            return new DiffImageData
            {
                Format = NormalizeImageFormat(formatOrExtension),
                WidthPx = width,
                HeightPx = height,
                Data = Convert.ToBase64String(data ?? Array.Empty<byte>()),
            };
        }

        private static string NormalizeImageFormat(string formatOrExtension)
        {
            var normalized = (formatOrExtension ?? string.Empty).Trim().TrimStart('.').ToLowerInvariant();
            switch (normalized)
            {
                case "jpeg":
                    return "jpg";
                case "tiff":
                    return "tif";
                default:
                    return normalized;
            }
        }

        private static void WriteImageData(ImageContext image, byte[] bytes, string targetFormat)
        {
            if (image == null)
            {
                throw new ArgumentNullException("image");
            }

            var normalizedFormat = NormalizeImageFormat(targetFormat);
            if (!IsImagePartFormatMatch(image.PartUri, normalizedFormat))
            {
                var originalPart = image.ImagePart;
                image.ParentPart.DeletePart(originalPart);
                image.ImagePart = CreateImagePart(image.ParentPart, GetImagePartType(normalizedFormat), image.RelationshipId);
                image.PartUri = image.ImagePart.Uri.ToString();
            }

            using (var writeStream = image.ImagePart.GetStream(FileMode.Create, FileAccess.Write))
            {
                writeStream.Write(bytes, 0, bytes.Length);
            }
        }

        private static ImagePart CreateImagePart(OpenXmlPart parentPart, PartTypeInfo partType, string relationshipId)
        {
            if (parentPart is MainDocumentPart mainDocumentPart)
            {
                return mainDocumentPart.AddImagePart(partType, relationshipId);
            }

            if (parentPart is HeaderPart headerPart)
            {
                return headerPart.AddImagePart(partType, relationshipId);
            }

            if (parentPart is FooterPart footerPart)
            {
                return footerPart.AddImagePart(partType, relationshipId);
            }

            if (parentPart is WordprocessingCommentsPart commentsPart)
            {
                return commentsPart.AddImagePart(partType, relationshipId);
            }

            if (parentPart is FootnotesPart footnotesPart)
            {
                return footnotesPart.AddImagePart(partType, relationshipId);
            }

            if (parentPart is EndnotesPart endnotesPart)
            {
                return endnotesPart.AddImagePart(partType, relationshipId);
            }

            if (parentPart is ChartPart chartPart)
            {
                return chartPart.AddImagePart(partType, relationshipId);
            }

            throw new NotSupportedException("Unsupported image parent part: " + parentPart.GetType().FullName);
        }

        private static bool IsImagePartFormatMatch(string partUri, string normalizedFormat)
        {
            var extension = (Path.GetExtension(partUri) ?? string.Empty).ToLowerInvariant();
            switch (normalizedFormat)
            {
                case "jpg":
                    return string.Equals(extension, ".jpg", StringComparison.OrdinalIgnoreCase)
                        || string.Equals(extension, ".jpeg", StringComparison.OrdinalIgnoreCase);
                case "tif":
                    return string.Equals(extension, ".tif", StringComparison.OrdinalIgnoreCase)
                        || string.Equals(extension, ".tiff", StringComparison.OrdinalIgnoreCase);
                default:
                    return string.Equals(extension, "." + normalizedFormat, StringComparison.OrdinalIgnoreCase);
            }
        }

        private static PartTypeInfo GetImagePartType(string normalizedFormat)
        {
            switch (NormalizeImageFormat(normalizedFormat))
            {
                case "jpg":
                    return ImagePartType.Jpeg;
                case "bmp":
                    return ImagePartType.Bmp;
                case "gif":
                    return ImagePartType.Gif;
                case "tif":
                    return ImagePartType.Tiff;
                case "wmf":
                    return ImagePartType.Wmf;
                case "emf":
                    return ImagePartType.Emf;
                case "svg":
                    return ImagePartType.Svg;
                default:
                    return ImagePartType.Png;
            }
        }

        private static bool IsLayoutEquivalent(DiffImageLayout current, DiffImageLayout expected, bool allowCompatibleWrapModes = false)
        {
            if (current == null && expected == null)
            {
                return true;
            }

            if (current == null || expected == null)
            {
                return false;
            }

            var wrapModesMatch = string.Equals(current.WrapMode ?? string.Empty, expected.WrapMode ?? string.Empty, StringComparison.OrdinalIgnoreCase)
                || (allowCompatibleWrapModes && AreCompatibleVmlWrapModes(current.WrapMode, expected.WrapMode));

            return AreEmuLengthsEquivalent(current.DisplayWidthEmu, expected.DisplayWidthEmu)
                && AreEmuLengthsEquivalent(current.DisplayHeightEmu, expected.DisplayHeightEmu)
                && wrapModesMatch
                && Math.Abs(current.RotationDegree - expected.RotationDegree) <= 0.1d;
        }

        private static bool IsCompatibleImageObjectType(string expectedObjectType, string actualObjectType, string expectedPath, string actualPath)
        {
            if (string.IsNullOrWhiteSpace(expectedObjectType) || string.IsNullOrWhiteSpace(actualObjectType))
            {
                return false;
            }

            if (string.Equals(expectedObjectType, actualObjectType, StringComparison.OrdinalIgnoreCase))
            {
                return true;
            }

            var inlineOrFloating = (string.Equals(expectedObjectType, "inlineImage", StringComparison.OrdinalIgnoreCase)
                    && string.Equals(actualObjectType, "floatingImage", StringComparison.OrdinalIgnoreCase))
                || (string.Equals(expectedObjectType, "floatingImage", StringComparison.OrdinalIgnoreCase)
                    && string.Equals(actualObjectType, "inlineImage", StringComparison.OrdinalIgnoreCase));
            if (!inlineOrFloating)
            {
                return false;
            }

            return IsVmlLikeContainerPath(expectedPath) || IsVmlLikeContainerPath(actualPath);
        }

        private static bool AreCompatibleVmlWrapModes(string currentWrapMode, string expectedWrapMode)
        {
            var left = NormalizeWrapModeForCompatibility(currentWrapMode);
            var right = NormalizeWrapModeForCompatibility(expectedWrapMode);
            if (string.IsNullOrWhiteSpace(left) || string.IsNullOrWhiteSpace(right))
            {
                return false;
            }

            if (string.Equals(left, right, StringComparison.OrdinalIgnoreCase))
            {
                return true;
            }

            var floatingModes = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
            {
                "inline",
                "anchor",
                "square",
                "tight",
                "through",
                "topBottom",
                "none",
            };
            return floatingModes.Contains(left) && floatingModes.Contains(right);
        }

        private static string NormalizeWrapModeForCompatibility(string wrapMode)
        {
            if (string.IsNullOrWhiteSpace(wrapMode))
            {
                return null;
            }

            var normalized = wrapMode.Trim();
            if (string.Equals(normalized, "topandbottom", StringComparison.OrdinalIgnoreCase)
                || string.Equals(normalized, "top-bottom", StringComparison.OrdinalIgnoreCase))
            {
                return "topBottom";
            }

            return normalized;
        }

        private static bool IsVmlLikeContainerPath(string path)
        {
            if (string.IsNullOrWhiteSpace(path))
            {
                return false;
            }

            return path.IndexOf("/pict[", StringComparison.OrdinalIgnoreCase) >= 0
                || path.IndexOf("/object[", StringComparison.OrdinalIgnoreCase) >= 0;
        }

        private static bool AreEmuLengthsEquivalent(long current, long expected)
        {
            if (current == expected)
            {
                return true;
            }

            if (current <= 0 || expected <= 0)
            {
                return false;
            }

            var delta = Math.Abs(current - expected);
            var baseline = Math.Max(current, expected);
            const long absoluteToleranceEmu = 19050L;
            var relativeToleranceEmu = (long)Math.Ceiling(baseline * 0.02d);
            var tolerance = Math.Max(absoluteToleranceEmu, relativeToleranceEmu);
            return delta <= tolerance;
        }

        private static void SaveTouchedRoots(ISet<OpenXmlPartRootElement> touchedRoots, WordprocessingDocument document)
        {
            foreach (var root in touchedRoots)
            {
                root.Save();
            }

            if (document.MainDocumentPart != null && document.MainDocumentPart.Document != null)
            {
                document.MainDocumentPart.Document.Save();
            }
        }

        private static int CreateRandomSeed()
        {
            using (var rng = RandomNumberGenerator.Create())
            {
                var buffer = new byte[4];
                do
                {
                    rng.GetBytes(buffer);
                    var candidate = BitConverter.ToInt32(buffer, 0) & int.MaxValue;
                    if (candidate != 0)
                    {
                        return candidate;
                    }
                }
                while (true);
            }
        }

        private static int DeriveFixedSeed(int fixedSeed, string stableKey)
        {
            var input = Encoding.UTF8.GetBytes(fixedSeed.ToString() + "::" + (stableKey ?? string.Empty));
            using (var sha = SHA256.Create())
            {
                var hash = sha.ComputeHash(input);
                var seed = BitConverter.ToInt32(hash, 0) & int.MaxValue;
                return seed == 0 ? 1 : seed;
            }
        }

        private static double ApplyNoise(Bitmap bitmap, int seed)
        {
            if (bitmap == null || bitmap.Width <= 0 || bitmap.Height <= 0)
            {
                return 0;
            }

            var random = new Random(seed);
            var total = bitmap.Width * bitmap.Height;
            var target = Math.Min(total, (int)Math.Ceiling(total * NoiseTargetPixelRatio));
            var modified = 0;

            var cells = CreateNoiseCells(bitmap.Width, bitmap.Height, target, random);
            foreach (var cell in cells)
            {
                modified += ApplyNoiseToCell(bitmap, cell, random);
            }

            return (double)modified / total;
        }

        private static IList<NoiseCell> CreateNoiseCells(int width, int height, int target, Random random)
        {
            var total = width * height;
            var assigned = 0;
            var cells = new List<NoiseCell>();

            for (var y = 0; y < height; y += NoiseCellSize)
            {
                for (var x = 0; x < width; x += NoiseCellSize)
                {
                    var cellWidth = Math.Min(NoiseCellSize, width - x);
                    var cellHeight = Math.Min(NoiseCellSize, height - y);
                    var area = cellWidth * cellHeight;
                    var exactQuota = ((double)area * target) / total;
                    var quota = (int)Math.Floor(exactQuota);

                    assigned += quota;
                    cells.Add(new NoiseCell
                    {
                        X = x,
                        Y = y,
                        Width = cellWidth,
                        Height = cellHeight,
                        Area = area,
                        Quota = quota,
                        Fraction = exactQuota - quota,
                        TieBreaker = random.NextDouble(),
                    });
                }
            }

            var remaining = target - assigned;
            foreach (var cell in cells.OrderByDescending(item => item.Fraction).ThenBy(item => item.TieBreaker).Take(remaining))
            {
                cell.Quota++;
            }

            return cells;
        }

        private static int ApplyNoiseToCell(Bitmap bitmap, NoiseCell cell, Random random)
        {
            if (cell.Quota <= 0)
            {
                return 0;
            }

            var indexes = Enumerable.Range(0, cell.Area).ToArray();
            for (var i = 0; i < cell.Quota; i++)
            {
                var swapIndex = i + random.Next(cell.Area - i);
                var selected = indexes[swapIndex];
                indexes[swapIndex] = indexes[i];
                indexes[i] = selected;

                var x = cell.X + (selected % cell.Width);
                var y = cell.Y + (selected / cell.Width);
                var source = bitmap.GetPixel(x, y);
                bitmap.SetPixel(x, y, CreateNoiseColor(source, random));
            }

            return cell.Quota;
        }

        private static Color CreateNoiseColor(Color source, Random random)
        {
            int r;
            int g;
            int b;

            switch (random.Next(5))
            {
                case 0:
                    r = 0;
                    g = 0;
                    b = 0;
                    break;
                case 1:
                    r = 255;
                    g = 255;
                    b = 255;
                    break;
                case 2:
                    r = 255 - source.R;
                    g = 255 - source.G;
                    b = 255 - source.B;
                    break;
                case 3:
                    r = random.Next(256);
                    g = random.Next(256);
                    b = random.Next(256);
                    break;
                default:
                    r = source.R < 128 ? random.Next(192, 256) : random.Next(0, 64);
                    g = source.G < 128 ? random.Next(192, 256) : random.Next(0, 64);
                    b = source.B < 128 ? random.Next(192, 256) : random.Next(0, 64);
                    break;
            }

            if (r == source.R && g == source.G && b == source.B)
            {
                r = 255 - source.R;
                g = 255 - source.G;
                b = 255 - source.B;
                if (r == source.R && g == source.G && b == source.B)
                {
                    r = (r + 127) % 256;
                }
            }

            return Color.FromArgb(source.A, r, g, b);
        }

        private static ImageFormat GetImageFormat(string extension)
        {
            switch ((extension ?? string.Empty).ToLowerInvariant())
            {
                case ".jpg":
                case ".jpeg":
                    return ImageFormat.Jpeg;
                case ".bmp":
                    return ImageFormat.Bmp;
                case ".gif":
                    return ImageFormat.Gif;
                case ".tif":
                case ".tiff":
                    return ImageFormat.Tiff;
                default:
                    return ImageFormat.Png;
            }
        }

        private static ParagraphTarget BuildParagraphTarget(PartContext context, W.Paragraph paragraph)
        {
            var container = paragraph.Parent;
            var paragraphIndex = 0;
            if (container != null)
            {
                paragraphIndex = container.ChildElements.OfType<W.Paragraph>().TakeWhile(item => !ReferenceEquals(item, paragraph)).Count();
            }

            var storyType = paragraph.Ancestors().Any(item => string.Equals(item.LocalName, "txbxContent", StringComparison.OrdinalIgnoreCase))
                ? "textbox"
                : context.StoryType;

            return new ParagraphTarget
            {
                PartContext = context,
                ParagraphElement = paragraph,
                StoryType = storyType,
                ContainerPath = BuildContainerPath(context.PartUri, container, context.Root),
                ParagraphIndex = paragraphIndex,
            };
        }

        private static ParagraphTarget BuildParagraphTarget(PartContext context, A.Paragraph paragraph)
        {
            var container = paragraph.Parent;
            var paragraphIndex = 0;
            if (container != null)
            {
                paragraphIndex = container.ChildElements.OfType<A.Paragraph>().TakeWhile(item => !ReferenceEquals(item, paragraph)).Count();
            }

            return new ParagraphTarget
            {
                PartContext = context,
                ParagraphElement = paragraph,
                StoryType = context.StoryType,
                ContainerPath = BuildContainerPath(context.PartUri, container, context.Root),
                ParagraphIndex = paragraphIndex,
            };
        }

        private static IEnumerable<ParagraphTarget> EnumerateTextTargets(PartContext context)
        {
            if (context == null || context.Root == null)
            {
                yield break;
            }

            if (string.Equals(context.StoryType, "chart", StringComparison.OrdinalIgnoreCase))
            {
                foreach (var paragraph in context.Root.Descendants<A.Paragraph>())
                {
                    yield return BuildParagraphTarget(context, paragraph);
                }

                yield break;
            }

            foreach (var paragraph in context.Root.Descendants<W.Paragraph>())
            {
                yield return BuildParagraphTarget(context, paragraph);
            }
        }

        private static string BuildContainerPath(string partUri, OpenXmlElement container, OpenXmlElement root)
        {
            var builder = new StringBuilder(partUri ?? string.Empty);
            var elements = new Stack<OpenXmlElement>();
            var current = container ?? root;
            while (current != null)
            {
                elements.Push(current);
                if (ReferenceEquals(current, root))
                {
                    break;
                }

                current = current.Parent;
            }

            while (elements.Count > 0)
            {
                var element = elements.Pop();
                var parent = element.Parent;
                var index = 0;
                if (parent != null)
                {
                    index = parent.ChildElements
                        .OfType<OpenXmlElement>()
                        .Where(item => string.Equals(item.LocalName, element.LocalName, StringComparison.OrdinalIgnoreCase))
                        .TakeWhile(item => !ReferenceEquals(item, element))
                        .Count();
                }

                builder.Append('/');
                builder.Append(element.LocalName);
                builder.Append('[');
                builder.Append(index);
                builder.Append(']');
            }

            return builder.ToString();
        }

        private static ParagraphState BuildParagraphState(ParagraphTarget target)
        {
            var textBuilder = new StringBuilder();
            var leaves = new List<TextLeaf>();
            var runList = new List<OpenXmlElement>();
            var runOffsets = new Dictionary<OpenXmlElement, int>();
            var logicalWordBoundaries = new HashSet<int>();
            TextLeaf previousLeaf = null;

            foreach (var element in target.ParagraphElement.Descendants())
            {
                var leaf = element as OpenXmlLeafTextElement;
                if (leaf != null)
                {
                    if (!IsSupportedTextLeaf(leaf) || !IsVisibleText(leaf))
                    {
                        continue;
                    }

                    previousLeaf = AppendLeaf(leaves, textBuilder, runList, runOffsets, logicalWordBoundaries, previousLeaf, target.ParagraphElement, element, new TextLeaf
                    {
                        TextElement = leaf,
                        Text = leaf.Text ?? string.Empty,
                        IsEquationText = IsEquationLeaf(leaf),
                    }) ?? previousLeaf;
                    continue;
                }

                if (!VmlTextMetadataUtility.IsVmlShapeElement(element))
                {
                    continue;
                }

                foreach (var binding in VmlTextMetadataUtility.CreateBindings(element))
                {
                    previousLeaf = AppendLeaf(leaves, textBuilder, runList, runOffsets, logicalWordBoundaries, previousLeaf, target.ParagraphElement, element, new TextLeaf
                    {
                        Text = binding.Text ?? string.Empty,
                        IsEquationText = binding.IsEquationText,
                        IsChartText = binding.IsChartText,
                        ApplyText = binding.Apply,
                    }) ?? previousLeaf;
                }
            }

            return new ParagraphState
            {
                Target = target,
                Text = textBuilder.ToString(),
                Leaves = leaves,
                LogicalWordBoundaries = logicalWordBoundaries,
            };
        }

        private static TextLeaf AppendLeaf(
            ICollection<TextLeaf> leaves,
            StringBuilder textBuilder,
            IList<OpenXmlElement> runList,
            IDictionary<OpenXmlElement, int> runOffsets,
            ISet<int> logicalWordBoundaries,
            TextLeaf previousLeaf,
            OpenXmlElement paragraphElement,
            OpenXmlElement sourceElement,
            TextLeaf leaf)
        {
            if (leaf == null || string.IsNullOrEmpty(leaf.Text))
            {
                return null;
            }

            var run = FindOwningRun(paragraphElement, sourceElement);
            if (run == null)
            {
                return null;
            }

            if (!runOffsets.ContainsKey(run))
            {
                runOffsets[run] = 0;
                runList.Add(run);
            }

            var runIndex = runList.IndexOf(run);
            var runCharStart = runOffsets[run];
            runOffsets[run] += leaf.Text.Length;

            if (ShouldCreateLogicalWordBoundary(previousLeaf, leaf))
            {
                logicalWordBoundaries.Add(textBuilder.Length);
            }

            var globalStart = textBuilder.Length;
            textBuilder.Append(leaf.Text);
            leaf.Run = run;
            leaf.RunIndex = runIndex;
            leaf.RunCharStart = runCharStart;
            leaf.GlobalStart = globalStart;
            leaves.Add(leaf);
            return leaf;
        }

        private static bool ShouldCreateLogicalWordBoundary(TextLeaf previousLeaf, TextLeaf currentLeaf)
        {
            return previousLeaf != null
                && currentLeaf != null
                && (previousLeaf.IsChartText || currentLeaf.IsChartText);
        }

        private static bool IsSupportedTextLeaf(OpenXmlLeafTextElement text)
        {
            return text is W.Text
                || text is M.Text
                || text is A.Text;
        }

        private static OpenXmlElement FindOwningRun(OpenXmlElement paragraphElement, OpenXmlElement element)
        {
            var current = element == null ? null : element.Parent;
            while (current != null && !ReferenceEquals(current, paragraphElement))
            {
                if (current is W.Run || current is M.Run || current is A.Run)
                {
                    return current;
                }

                current = current.Parent;
            }

            return null;
        }

        private static bool IsEquationLeaf(OpenXmlLeafTextElement text)
        {
            return text != null && text.Ancestors().Any(item =>
                string.Equals(item.LocalName, "oMath", StringComparison.OrdinalIgnoreCase)
                || string.Equals(item.LocalName, "oMathPara", StringComparison.OrdinalIgnoreCase));
        }

        private static bool IsVisibleText(OpenXmlLeafTextElement text)
        {
            if (text is W.FieldCode || text is W.DeletedText)
            {
                return false;
            }

            if (text.Ancestors<W.DeletedRun>().Any())
            {
                return false;
            }

            var run = text.Ancestors<W.Run>().FirstOrDefault();
            if (run != null && run.RunProperties != null && run.RunProperties.Vanish != null)
            {
                return false;
            }

            return true;
        }

        private static List<TextMatch> FindMatches(ParagraphState state, RuleDefinition rule)
        {
            var matches = new List<TextMatch>();
            var text = state == null ? null : state.Text;
            if (string.IsNullOrEmpty(text) || string.IsNullOrEmpty(rule.SearchText))
            {
                return matches;
            }

            if (rule.MatchMode == RuleMatchMode.RegularExpression)
            {
                var pattern = rule.SearchText;
                var options = RegexOptions.CultureInvariant;
                if (!rule.IsCaseSensitive)
                {
                    options |= RegexOptions.IgnoreCase;
                }

                foreach (Match match in Regex.Matches(text, pattern, options))
                {
                    if (!match.Success || match.Length <= 0)
                    {
                        continue;
                    }

                    if (rule.IsWholeWord && !IsWholeWord(text, state.LogicalWordBoundaries, match.Index, match.Length))
                    {
                        continue;
                    }

                    matches.Add(new TextMatch
                    {
                        StartIndex = match.Index,
                        Length = match.Length,
                        OriginalText = match.Value,
                        ReplacementTemplateResult = match.Result(rule.ReplacementText ?? string.Empty),
                    });
                }

                return matches;
            }

            var comparison = rule.IsCaseSensitive ? StringComparison.Ordinal : StringComparison.OrdinalIgnoreCase;
            var start = 0;
            while (start < text.Length)
            {
                var index = text.IndexOf(rule.SearchText, start, comparison);
                if (index < 0)
                {
                    break;
                }

                if (!rule.IsWholeWord || IsWholeWord(text, state.LogicalWordBoundaries, index, rule.SearchText.Length))
                {
                    matches.Add(new TextMatch
                    {
                        StartIndex = index,
                        Length = rule.SearchText.Length,
                        OriginalText = text.Substring(index, rule.SearchText.Length),
                        ReplacementTemplateResult = rule.ReplacementText ?? string.Empty,
                    });
                }

                start = index + Math.Max(rule.SearchText.Length, 1);
            }

            return matches;
        }

        private static bool IsWholeWord(string text, ISet<int> logicalWordBoundaries, int start, int length)
        {
            var leftOk = start <= 0
                || (logicalWordBoundaries != null && logicalWordBoundaries.Contains(start))
                || GetWordCharClass(text[start - 1]) != GetWordCharClass(text[start]);
            var rightIndex = start + length;
            var rightOk = rightIndex >= text.Length
                || (logicalWordBoundaries != null && logicalWordBoundaries.Contains(rightIndex))
                || GetWordCharClass(text[rightIndex - 1]) != GetWordCharClass(text[rightIndex]);
            return leftOk && rightOk;
        }

        private static int GetWordCharClass(char character)
        {
            if ((character >= 'a' && character <= 'z')
                || (character >= 'A' && character <= 'Z')
                || (character >= '0' && character <= '9')
                || character == '_')
            {
                return 1;
            }

            if (character >= 0x4E00 && character <= 0x9FFF)
            {
                return 2;
            }

            return 0;
        }

        private static DiffPosition BuildTextPosition(ParagraphState state, TextMatch match)
        {
            var startLeaf = state.Leaves.First(item => item.GlobalStart <= match.StartIndex && match.StartIndex < item.GlobalEnd);
            var endIndexExclusive = match.StartIndex + match.Length;
            var endLeaf = state.Leaves.First(item => item.GlobalStart < endIndexExclusive && endIndexExclusive <= item.GlobalEnd);
            return new DiffPosition
            {
                StoryType = state.Target.StoryType,
                ContainerPath = state.Target.ContainerPath,
                ParagraphIndex = state.Target.ParagraphIndex,
                ParagraphTextLength = -1,
                ParagraphTextHash = null,
                StartTextOffset = match.StartIndex,
                EndTextOffset = endIndexExclusive,
                StartRunIndex = startLeaf.RunIndex,
                StartCharOffset = startLeaf.RunCharStart + (match.StartIndex - startLeaf.GlobalStart),
                EndRunIndex = endLeaf.RunIndex,
                EndCharOffset = endLeaf.RunCharStart + (endIndexExclusive - endLeaf.GlobalStart),
                ObjectIndex = null,
            };
        }

        private static string DetermineTextObjectType(ParagraphTarget target, ParagraphState state, TextMatch match, DiffPosition position)
        {
            if (string.Equals(position.StoryType, "chart", StringComparison.OrdinalIgnoreCase))
            {
                return "chartText";
            }

            var matchLeaves = state.Leaves
                .Where(item => item.GlobalStart < match.StartIndex + match.Length && match.StartIndex < item.GlobalEnd)
                .ToList();
            if (matchLeaves.Any(item => item.IsChartText))
            {
                return "chartText";
            }

            if (string.Equals(target.StoryType, "textbox", StringComparison.OrdinalIgnoreCase))
            {
                return "textbox";
            }

            if (target.ParagraphElement.Ancestors<W.TableCell>().Any())
            {
                return "tableCell";
            }

            if (target.ParagraphElement.Descendants<W.Hyperlink>().Any())
            {
                return "hyperlinkDisplay";
            }

            if (matchLeaves.Any(IsFieldResultLeaf))
            {
                return "fieldResult";
            }

            if (matchLeaves.Any(item => item.IsEquationText))
            {
                return "equationText";
            }

            if (string.Equals(position.StoryType, "comment", StringComparison.OrdinalIgnoreCase))
            {
                return "comment";
            }

            if (string.Equals(position.StoryType, "footnote", StringComparison.OrdinalIgnoreCase))
            {
                return "footnote";
            }

            if (string.Equals(position.StoryType, "endnote", StringComparison.OrdinalIgnoreCase))
            {
                return "endnote";
            }

            return "paragraph";
        }

        private static bool IsFieldResultLeaf(TextLeaf leaf)
        {
            if (leaf == null || leaf.TextElement == null)
            {
                return false;
            }

            if (leaf.TextElement.Ancestors<W.SimpleField>().Any())
            {
                return true;
            }

            var run = leaf.Run as W.Run;
            if (run == null)
            {
                return false;
            }

            return run.Descendants<W.FieldChar>().Any()
                || run.ElementsBefore().OfType<W.Run>().Any(item => item.Descendants<W.FieldChar>().Any(field =>
                    field.FieldCharType != null
                    && field.FieldCharType.Value == W.FieldCharValues.Separate));
        }

        private static void RewriteRange(ParagraphState state, int globalStart, int length, string replacement, bool updateFont = false)
        {
            var globalEnd = globalStart + length;
            var overlappingLeaves = state.Leaves
                .Where(item => item.GlobalStart < globalEnd && globalStart < item.GlobalEnd)
                .OrderBy(item => item.GlobalStart)
                .ToList();

            var remaining = replacement ?? string.Empty;
            for (var index = 0; index < overlappingLeaves.Count; index++)
            {
                var leaf = overlappingLeaves[index];
                var overlapStart = Math.Max(globalStart, leaf.GlobalStart);
                var overlapEnd = Math.Min(globalEnd, leaf.GlobalEnd);
                var localStart = overlapStart - leaf.GlobalStart;
                var localEnd = overlapEnd - leaf.GlobalStart;
                var originalSpanLength = localEnd - localStart;

                string assigned;
                if (index == overlappingLeaves.Count - 1)
                {
                    assigned = remaining;
                    remaining = string.Empty;
                }
                else
                {
                    var take = Math.Min(originalSpanLength, remaining.Length);
                    assigned = remaining.Substring(0, take);
                    remaining = remaining.Substring(take);
                }

                var updatedText = leaf.Text.Substring(0, localStart) + assigned + leaf.Text.Substring(localEnd);
                leaf.Text = updatedText;
                if (leaf.ApplyText != null)
                {
                    leaf.ApplyText(updatedText);
                }
                else if (leaf.TextElement != null)
                {
                    leaf.TextElement.Text = updatedText;
                    TrySetPreserveSpace(leaf.TextElement, updatedText);
                }

                if (updateFont && !string.IsNullOrEmpty(assigned))
                {
                    EnsureRunFont(leaf.Run, assigned);
                }
            }
        }

        private static void EnsureRunFont(OpenXmlElement run, string text)
        {
            var wordRun = run as W.Run;
            if (wordRun == null)
            {
                return;
            }

            var runProps = wordRun.RunProperties;
            if (runProps == null)
            {
                runProps = new W.RunProperties();
                wordRun.PrependChild(runProps);
            }

            var runFonts = runProps.RunFonts;
            if (runFonts == null)
            {
                runFonts = new W.RunFonts();
                runProps.PrependChild(runFonts);
            }

            var hasChinese = ContainsCjkCharacter(text);
            var hasEnglish = ContainsLatinLetter(text);

            if (hasChinese)
            {
                runFonts.EastAsia = "宋体";
                runFonts.Ascii = "宋体";
                runFonts.HighAnsi = "宋体";
            }
            else if (hasEnglish)
            {
                runFonts.Ascii = "Times New Roman";
                runFonts.HighAnsi = "Times New Roman";
            }
        }

        private static bool ContainsCjkCharacter(string text)
        {
            foreach (var c in text)
            {
                if ((c >= 0x4E00 && c <= 0x9FFF)
                    || (c >= 0x3400 && c <= 0x4DBF)
                    || (c >= 0xF900 && c <= 0xFAFF))
                {
                    return true;
                }
            }

            return false;
        }

        private static bool ContainsLatinLetter(string text)
        {
            foreach (var c in text)
            {
                if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
                {
                    return true;
                }
            }

            return false;
        }

        private static void TrySetPreserveSpace(OpenXmlLeafTextElement textElement, string updatedText)
        {
            var property = textElement.GetType().GetProperty("Space");
            if (property == null || !property.CanWrite)
            {
                return;
            }

            if (NeedsPreserve(updatedText))
            {
                property.SetValue(textElement, new EnumValue<SpaceProcessingModeValues>(SpaceProcessingModeValues.Preserve), null);
            }
            else
            {
                property.SetValue(textElement, null, null);
            }
        }

        private static TextRange ResolveRange(ParagraphState state, DiffOperation operation, string paragraphKey)
        {
            var position = operation == null ? null : operation.Position;
            var writtenText = operation == null ? string.Empty : (operation.WrittenText ?? string.Empty);
            if (position == null)
            {
                throw new InvalidDataException("恢复失败：差异操作缺少位置信息。");
            }

            if (position.StartTextOffset >= 0)
            {
                var startIndexFromParagraph = position.StartTextOffset;
                var writtenLengthFromParagraph = writtenText.Length;
                if (startIndexFromParagraph <= state.Text.Length && startIndexFromParagraph + writtenLengthFromParagraph <= state.Text.Length)
                {
                    return new TextRange
                    {
                        StartIndex = startIndexFromParagraph,
                        Length = writtenLengthFromParagraph,
                    };
                }

                if (position.EndTextOffset >= startIndexFromParagraph && position.EndTextOffset <= state.Text.Length)
                {
                    return new TextRange
                    {
                        StartIndex = startIndexFromParagraph,
                        Length = position.EndTextOffset - startIndexFromParagraph,
                    };
                }
            }

            var startLeaf = state.Leaves.FirstOrDefault(item =>
                item.RunIndex == position.StartRunIndex
                && item.RunCharStart <= position.StartCharOffset
                && position.StartCharOffset <= item.RunCharEnd);
            if (startLeaf == null)
            {
                throw new InvalidDataException("无法定位恢复起始位置。 " + BuildRestoreOperationContext(operation, paragraphKey, state));
            }

            var startIndex = startLeaf.GlobalStart + (position.StartCharOffset - startLeaf.RunCharStart);
            var writtenLength = writtenText.Length;
            if (startIndex + writtenLength <= state.Text.Length)
            {
                return new TextRange
                {
                    StartIndex = startIndex,
                    Length = writtenLength,
                };
            }

            var endLeaf = state.Leaves.FirstOrDefault(item =>
                item.RunIndex == position.EndRunIndex
                && item.RunCharStart <= position.EndCharOffset
                && position.EndCharOffset <= item.RunCharEnd);
            if (endLeaf == null)
            {
                throw new InvalidDataException("无法定位恢复结束位置。 " + BuildRestoreOperationContext(operation, paragraphKey, state));
            }

            var endIndex = endLeaf.GlobalStart + (position.EndCharOffset - endLeaf.RunCharStart);
            if (endIndex < startIndex)
            {
                throw new InvalidDataException("恢复位置非法。 " + BuildRestoreOperationContext(operation, paragraphKey, state));
            }

            return new TextRange
            {
                StartIndex = startIndex,
                Length = endIndex - startIndex,
            };
        }

        private static string BuildParagraphLookupKey(string storyType, string containerPath, int paragraphIndex)
        {
            return (storyType ?? string.Empty) + "|" + (containerPath ?? string.Empty) + "|" + paragraphIndex;
        }

        private static string BuildRestoreOperationContext(DiffOperation operation, string paragraphKey, ParagraphState state)
        {
            var builder = new StringBuilder();
            if (operation != null)
            {
                builder.Append("OperationId=").Append(operation.OperationId ?? string.Empty);
                builder.Append("; Type=").Append(operation.Type ?? string.Empty);
                builder.Append("; ObjectType=").Append(operation.ObjectType ?? string.Empty);
                if (operation.Rule != null)
                {
                    builder.Append("; RuleId=").Append(operation.Rule.Id ?? string.Empty);
                    builder.Append("; RuleName=").Append(operation.Rule.Name ?? string.Empty);
                    builder.Append("; Pattern=").Append(operation.Rule.Pattern ?? string.Empty);
                }

                builder.Append("; Position=").Append(FormatPosition(operation.Position));
                builder.Append("; OriginalText=").Append(operation.OriginalText ?? string.Empty);
                builder.Append("; WrittenText=").Append(operation.WrittenText ?? string.Empty);
            }

            builder.Append("; ParagraphKey=").Append(paragraphKey ?? string.Empty);
            if (state != null)
            {
                builder.Append("; ParagraphLength=").Append(state.Text == null ? "0" : state.Text.Length.ToString(CultureInfo.InvariantCulture));
                builder.Append("; ParagraphText=").Append(state.Text ?? string.Empty);
                builder.Append("; ParagraphHash=").Append(BuildParagraphContentHash(state.Text));
                builder.Append("; Leaves=").Append(FormatLeaves(state.Leaves));
            }

            return builder.ToString();
        }

        private static string FormatPosition(DiffPosition position)
        {
            if (position == null)
            {
                return "<null>";
            }

            return string.Format(
                CultureInfo.InvariantCulture,
                "story={0},container={1},paragraph={2},paragraphTextLength={3},paragraphTextHash={4},textStart={5},textEnd={6},runStart={7}:{8},runEnd={9}:{10},objectIndex={11}",
                position.StoryType ?? string.Empty,
                position.ContainerPath ?? string.Empty,
                position.ParagraphIndex,
                position.ParagraphTextLength,
                position.ParagraphTextHash ?? "<null>",
                position.StartTextOffset,
                position.EndTextOffset,
                position.StartRunIndex,
                position.StartCharOffset,
                position.EndRunIndex,
                position.EndCharOffset,
                position.ObjectIndex.HasValue ? position.ObjectIndex.Value.ToString(CultureInfo.InvariantCulture) : "<null>");
        }

        private static string BuildParagraphScopeKey(string storyType, string containerPath)
        {
            return (storyType ?? string.Empty) + "|" + (containerPath ?? string.Empty);
        }

        private static string BuildParagraphContentHash(string text)
        {
            return HashUtility.ComputeSha256Base64(text ?? string.Empty);
        }

        private static bool TryResolveRestoreTargetFallback(
            IDictionary<string, List<ParagraphTarget>> paragraphScopeLookup,
            string scopeKey,
            DiffOperation operation,
            out ParagraphTarget target,
            out ParagraphState state,
            out TextRange range,
            out string actualWritten,
            out bool ambiguous)
        {
            target = null;
            state = null;
            range = null;
            actualWritten = null;
            ambiguous = false;

            if (paragraphScopeLookup == null || string.IsNullOrEmpty(scopeKey) || !paragraphScopeLookup.TryGetValue(scopeKey, out var candidates))
            {
                return false;
            }

            var resolvedCandidates = new List<ResolvedParagraphCandidate>();
            foreach (var candidate in candidates)
            {
                var candidateState = BuildParagraphState(candidate);
                var strictMatch = TryResolveOperationInParagraph(candidateState, operation, out var candidateRange, out var candidateWritten);
                var startOffsetDistance = 0;
                if (!strictMatch
                    && !TryResolveOperationByWrittenText(candidateState, operation, out candidateRange, out candidateWritten, out startOffsetDistance))
                {
                    continue;
                }

                resolvedCandidates.Add(new ResolvedParagraphCandidate
                {
                    Target = candidate,
                    State = candidateState,
                    Range = candidateRange,
                    ActualWritten = candidateWritten,
                    IsStrictMatch = strictMatch,
                    BoundaryPenalty = ComputeRangeBoundaryPenalty(candidateState, candidateRange),
                    StartOffsetDistance = strictMatch
                        ? ComputeStartOffsetDistance(operation == null ? null : operation.Position, candidateRange)
                        : startOffsetDistance,
                });
            }

            if (resolvedCandidates.Count == 0)
            {
                return false;
            }

            var filteredCandidates = resolvedCandidates;
            if (filteredCandidates.Any(item => item.IsStrictMatch))
            {
                filteredCandidates = filteredCandidates
                    .Where(item => item.IsStrictMatch)
                    .ToList();
            }

            if (filteredCandidates.Count > 1)
            {
                var bestBoundaryPenalty = filteredCandidates.Min(item => item.BoundaryPenalty);
                filteredCandidates = filteredCandidates
                    .Where(item => item.BoundaryPenalty == bestBoundaryPenalty)
                    .ToList();
            }

            var position = operation == null ? null : operation.Position;
            if (position != null && position.ParagraphIndex >= 0 && filteredCandidates.Count > 1)
            {
                var bestDistance = filteredCandidates
                    .Min(item => Math.Abs(item.Target.ParagraphIndex - position.ParagraphIndex));
                filteredCandidates = filteredCandidates
                    .Where(item => Math.Abs(item.Target.ParagraphIndex - position.ParagraphIndex) == bestDistance)
                    .ToList();
            }

            if (position != null && position.StartTextOffset >= 0 && filteredCandidates.Count > 1)
            {
                var bestOffsetDistance = filteredCandidates.Min(item => item.StartOffsetDistance);
                filteredCandidates = filteredCandidates
                    .Where(item => item.StartOffsetDistance == bestOffsetDistance)
                    .ToList();
            }

            if (filteredCandidates.Count != 1)
            {
                ambiguous = true;
                return false;
            }

            var resolved = filteredCandidates[0];
            target = resolved.Target;
            state = resolved.State;
            range = resolved.Range;
            actualWritten = resolved.ActualWritten;
            return true;
        }

        private static bool TryResolveOperationInParagraph(ParagraphState state, DiffOperation operation, out TextRange range, out string actualWritten)
        {
            range = null;
            actualWritten = null;
            if (state == null || !TryResolveRange(state, operation, out range))
            {
                return false;
            }

            actualWritten = ExtractTextRange(state, range);
            if (!string.Equals(actualWritten, operation == null ? string.Empty : (operation.WrittenText ?? string.Empty), StringComparison.Ordinal))
            {
                return false;
            }

            return MatchesParagraphLength(operation == null ? null : operation.Position, state);
        }

        private static bool MatchesParagraphLength(DiffPosition position, ParagraphState state)
        {
            if (position == null || state == null)
            {
                return true;
            }

            if (position.ParagraphTextLength < 0)
            {
                return true;
            }

            var currentLength = (state.Text ?? string.Empty).Length;
            return position.ParagraphTextLength == currentLength;
        }

        private static bool TryResolveOperationByWrittenText(
            ParagraphState state,
            DiffOperation operation,
            out TextRange range,
            out string actualWritten,
            out int startOffsetDistance)
        {
            range = null;
            actualWritten = null;
            startOffsetDistance = int.MaxValue;
            if (state == null || operation == null)
            {
                return false;
            }

            var writtenText = operation.WrittenText ?? string.Empty;
            if (string.IsNullOrEmpty(writtenText) || !MatchesParagraphIdentity(operation.Position, state))
            {
                return false;
            }

            var bestIndex = -1;
            var bestBoundaryPenalty = int.MaxValue;
            var searchStart = 0;
            while (searchStart <= state.Text.Length - writtenText.Length)
            {
                var matchIndex = state.Text.IndexOf(writtenText, searchStart, StringComparison.Ordinal);
                if (matchIndex < 0)
                {
                    break;
                }

                var candidateRange = new TextRange
                {
                    StartIndex = matchIndex,
                    Length = writtenText.Length,
                };
                var currentBoundaryPenalty = ComputeRangeBoundaryPenalty(state, candidateRange);
                var currentDistance = ComputeStartOffsetDistance(operation.Position, candidateRange);
                if (bestIndex < 0
                    || currentBoundaryPenalty < bestBoundaryPenalty
                    || (currentBoundaryPenalty == bestBoundaryPenalty && currentDistance < startOffsetDistance))
                {
                    bestIndex = matchIndex;
                    bestBoundaryPenalty = currentBoundaryPenalty;
                    startOffsetDistance = currentDistance;
                }

                searchStart = matchIndex + Math.Max(writtenText.Length, 1);
            }

            if (bestIndex < 0)
            {
                return false;
            }

            range = new TextRange
            {
                StartIndex = bestIndex,
                Length = writtenText.Length,
            };
            actualWritten = writtenText;
            return true;
        }

        private static bool MatchesParagraphIdentity(DiffPosition position, ParagraphState state)
        {
            if (position == null || state == null)
            {
                return true;
            }

            var text = state.Text ?? string.Empty;
            if (position.ParagraphTextLength >= 0 && position.ParagraphTextLength != text.Length)
            {
                return false;
            }

            if (!string.IsNullOrEmpty(position.ParagraphTextHash)
                && !string.Equals(position.ParagraphTextHash, BuildParagraphContentHash(text), StringComparison.Ordinal))
            {
                return false;
            }

            return true;
        }

        private static bool TryResolveRange(ParagraphState state, DiffOperation operation, out TextRange range)
        {
            range = null;
            var position = operation == null ? null : operation.Position;
            var writtenText = operation == null ? string.Empty : (operation.WrittenText ?? string.Empty);
            if (state == null || position == null)
            {
                return false;
            }

            if (position.StartTextOffset >= 0)
            {
                var startIndexFromParagraph = position.StartTextOffset;
                var writtenLengthFromParagraph = writtenText.Length;
                if (startIndexFromParagraph <= state.Text.Length && startIndexFromParagraph + writtenLengthFromParagraph <= state.Text.Length)
                {
                    range = new TextRange
                    {
                        StartIndex = startIndexFromParagraph,
                        Length = writtenLengthFromParagraph,
                    };
                    return true;
                }

                if (position.EndTextOffset >= startIndexFromParagraph && position.EndTextOffset <= state.Text.Length)
                {
                    range = new TextRange
                    {
                        StartIndex = startIndexFromParagraph,
                        Length = position.EndTextOffset - startIndexFromParagraph,
                    };
                    return true;
                }
            }

            var startLeaf = state.Leaves.FirstOrDefault(item =>
                item.RunIndex == position.StartRunIndex
                && item.RunCharStart <= position.StartCharOffset
                && position.StartCharOffset <= item.RunCharEnd);
            if (startLeaf == null)
            {
                return false;
            }

            var startIndex = startLeaf.GlobalStart + (position.StartCharOffset - startLeaf.RunCharStart);
            var writtenLength = writtenText.Length;
            if (startIndex + writtenLength <= state.Text.Length)
            {
                range = new TextRange
                {
                    StartIndex = startIndex,
                    Length = writtenLength,
                };
                return true;
            }

            var endLeaf = state.Leaves.FirstOrDefault(item =>
                item.RunIndex == position.EndRunIndex
                && item.RunCharStart <= position.EndCharOffset
                && position.EndCharOffset <= item.RunCharEnd);
            if (endLeaf == null)
            {
                return false;
            }

            var endIndex = endLeaf.GlobalStart + (position.EndCharOffset - endLeaf.RunCharStart);
            if (endIndex < startIndex)
            {
                return false;
            }

            range = new TextRange
            {
                StartIndex = startIndex,
                Length = endIndex - startIndex,
            };
            return true;
        }

        private static TextRange TryCreateDiagnosticRange(ParagraphState state, DiffOperation operation)
        {
            return TryResolveRange(state, operation, out var range) ? range : null;
        }

        private static int ComputeStartOffsetDistance(DiffPosition position, TextRange range)
        {
            if (position == null || range == null || position.StartTextOffset < 0)
            {
                return 0;
            }

            return Math.Abs(range.StartIndex - position.StartTextOffset);
        }

        private static bool ShouldTrustExactRestoreCandidate(DiffOperation operation, ParagraphState state, TextRange range)
        {
            if (operation == null)
            {
                return true;
            }

            if (HasStrongParagraphIdentity(operation.Position))
            {
                return true;
            }

            return ComputeRangeBoundaryPenalty(state, range) == 0;
        }

        private static bool HasStrongParagraphIdentity(DiffPosition position)
        {
            return position != null
                && (position.ParagraphTextLength >= 0 || !string.IsNullOrEmpty(position.ParagraphTextHash));
        }

        private static int ComputeRangeBoundaryPenalty(ParagraphState state, TextRange range)
        {
            if (state == null || string.IsNullOrEmpty(state.Text) || range == null || range.Length <= 0)
            {
                return 0;
            }

            if (range.StartIndex < 0 || range.StartIndex + range.Length > state.Text.Length)
            {
                return int.MaxValue;
            }

            var penalty = 0;
            var matchedText = ExtractTextRange(state, range);
            if (string.IsNullOrEmpty(matchedText))
            {
                return 0;
            }

            if (range.StartIndex > 0 && state.Text[range.StartIndex - 1] == matchedText[0])
            {
                penalty++;
            }

            var endIndex = range.StartIndex + range.Length;
            if (endIndex < state.Text.Length && state.Text[endIndex] == matchedText[matchedText.Length - 1])
            {
                penalty++;
            }

            return penalty;
        }

        private static string ExtractTextRange(ParagraphState state, TextRange range)
        {
            if (state == null || string.IsNullOrEmpty(state.Text) || range == null)
            {
                return string.Empty;
            }

            if (range.StartIndex < 0 || range.Length < 0 || range.StartIndex + range.Length > state.Text.Length)
            {
                return string.Empty;
            }

            return range.Length == 0 ? string.Empty : state.Text.Substring(range.StartIndex, range.Length);
        }

        private static string FormatLeaves(IEnumerable<TextLeaf> leaves)
        {
            if (leaves == null)
            {
                return "<null>";
            }

            return string.Join(
                " | ",
                leaves.Select(item => string.Format(
                    CultureInfo.InvariantCulture,
                    "run={0},runRange=[{1},{2}],globalRange=[{3},{4}],text={5}",
                    item == null ? -1 : item.RunIndex,
                    item == null ? -1 : item.RunCharStart,
                    item == null ? -1 : item.RunCharEnd,
                    item == null ? -1 : item.GlobalStart,
                    item == null ? -1 : item.GlobalEnd,
                    item == null ? string.Empty : item.Text ?? string.Empty)));
        }

        private static bool NeedsPreserve(string value)
        {
            return !string.IsNullOrEmpty(value)
                && (char.IsWhiteSpace(value[0]) || char.IsWhiteSpace(value[value.Length - 1]) || value.Contains("  "));
        }

        private sealed class ProcessedImageResult
        {
            public string SourceKind { get; set; }

            public DiffImageData OriginalImage { get; set; }

            public DiffImageData ConvertedBitmapImage { get; set; }

            public DiffImageData NewImage { get; set; }

            public double ModifiedPixelRatio { get; set; }

            public int Seed { get; set; }
        }

        private sealed class NoiseCell
        {
            public int X { get; set; }

            public int Y { get; set; }

            public int Width { get; set; }

            public int Height { get; set; }

            public int Area { get; set; }

            public int Quota { get; set; }

            public double Fraction { get; set; }

            public double TieBreaker { get; set; }
        }

        private class PartContext
        {
            public OpenXmlPart Part { get; set; }

            public OpenXmlPartRootElement Root { get; set; }

            public string PartUri { get; set; }

            public string StoryType { get; set; }
        }

        private class ParagraphTarget
        {
            public PartContext PartContext { get; set; }

            public OpenXmlElement ParagraphElement { get; set; }

            public string StoryType { get; set; }

            public string ContainerPath { get; set; }

            public int ParagraphIndex { get; set; }
        }

        private class ParagraphState
        {
            public ParagraphTarget Target { get; set; }

            public string Text { get; set; }

            public List<TextLeaf> Leaves { get; set; }

            public ISet<int> LogicalWordBoundaries { get; set; }
        }

        private class TextLeaf
        {
            public OpenXmlLeafTextElement TextElement { get; set; }

            public OpenXmlElement Run { get; set; }

            public int RunIndex { get; set; }

            public int RunCharStart { get; set; }

            public int RunCharEnd
            {
                get { return RunCharStart + (Text == null ? 0 : Text.Length); }
            }

            public int GlobalStart { get; set; }

            public int GlobalEnd
            {
                get { return GlobalStart + (Text == null ? 0 : Text.Length); }
            }

            public string Text { get; set; }

            public bool IsEquationText { get; set; }

            public bool IsChartText { get; set; }

            public Action<string> ApplyText { get; set; }
        }

        private class TextMatch
        {
            public int StartIndex { get; set; }

            public int Length { get; set; }

            public string OriginalText { get; set; }

            public string ReplacementTemplateResult { get; set; }
        }

        private class TextRange
        {
            public int StartIndex { get; set; }

            public int Length { get; set; }
        }

        private class ResolvedParagraphCandidate
        {
            public ParagraphTarget Target { get; set; }

            public ParagraphState State { get; set; }

            public TextRange Range { get; set; }

            public string ActualWritten { get; set; }

            public bool IsStrictMatch { get; set; }

            public int BoundaryPenalty { get; set; }

            public int StartOffsetDistance { get; set; }
        }

        private class ImageContext
        {
            public OpenXmlPart ParentPart { get; set; }

            public ImagePart ImagePart { get; set; }

            public string RelationshipId { get; set; }

            public string RelationKey { get; set; }

            public string PartUri { get; set; }

            public string StoryType { get; set; }

            public string ContainerPath { get; set; }

            public string ContainerKind { get; set; }

            public string EmbeddedProgramId { get; set; }

            public string EmbeddedPackageExtension { get; set; }

            public string ObjectType { get; set; }

            public DiffImageLayout Layout { get; set; }

            public int ObjectIndex { get; set; }
        }

        private class ImageRestoreCandidate
        {
            public ImageContext Image { get; set; }

            public bool IsProcessed { get; set; }

            public bool StoryMatches { get; set; }

            public bool ContainerKindMatches { get; set; }

            public bool EmbeddedProgramMatches { get; set; }

            public bool EmbeddedPackageMatches { get; set; }

            public bool ObjectTypeMatches { get; set; }

            public bool ObjectTypeCompatible { get; set; }

            public bool LayoutMatches { get; set; }

            public bool ContentMatches { get; set; }

            public bool SkipContentVerification { get; set; }

            public int PathSimilarity { get; set; }

            public int ObjectIndexDistance { get; set; }
        }

        private sealed class ReplacementOutputPaths
        {
            public string OutputPath { get; set; }

            public string DiffPath { get; set; }

            public string BmpPath { get; set; }
        }

        private sealed class BrokenFieldFinding
        {
            public string StoryType { get; set; }

            public string ContainerPath { get; set; }

            public int ParagraphIndex { get; set; }

            public string Marker { get; set; }

            public string Excerpt { get; set; }

            public string FullParagraphText { get; set; }

            public int? TableIndex { get; set; }

            public int? RowIndex { get; set; }

            public int? ColumnIndex { get; set; }

            public string PreviousParagraphText { get; set; }

            public string NextParagraphText { get; set; }

            public string SameRowCellsText { get; set; }

            public string SameColumnCellsText { get; set; }

            public string Identity =>
                string.Format(
                    CultureInfo.InvariantCulture,
                    "{0}|{1}|{2}|{3}",
                    StoryType ?? string.Empty,
                    ContainerPath ?? string.Empty,
                    ParagraphIndex,
                    Marker ?? string.Empty);
        }
    }
}