#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
SRS 解析工具 - 主程序入口
"""

import argparse
import os
import sys
import logging
from pathlib import Path

# 添加当前目录到Python路径
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))

from src.utils import load_config, setup_logging, validate_file_path, ensure_directory_exists, get_env_or_config
from src.document_parser import create_parser
from src.document_parser import Section
from src.requirement_extractor import RequirementExtractor
from src.json_generator import JSONGenerator

logger = logging.getLogger(__name__)


def create_llm(config: dict):
    """
    创建LLM实例
    
    Args:
        config: 配置字典
        
    Returns:
        LLM实例或None
    """
    llm_config = config.get('llm', {})
    
    # 当前版本仅支持LLM模式
    if not llm_config.get('enabled', True):
        raise ValueError("当前版本仅支持LLM模式，请将配置 llm.enabled 设为 true")
    
    provider = llm_config.get('provider', 'qwen')
    
    # 获取API密钥（优先使用环境变量）
    api_key = get_env_or_config('DASHSCOPE_API_KEY', llm_config.get('api_key'))
    
    if not api_key:
        raise ValueError("未配置API密钥：请设置环境变量 DASHSCOPE_API_KEY 或在 config.yaml 中配置 llm.api_key")
    
    try:
        from src.llm_interface import QwenLLM
        
        model = llm_config.get('model', 'qwen-plus')
        temperature = llm_config.get('temperature', 0.3)
        max_tokens = llm_config.get('max_tokens', 1024)
        
        llm = QwenLLM(
            api_key=api_key,
            model=model,
            temperature=temperature,
            max_tokens=max_tokens
        )
        
        logger.info(f"成功创建LLM实例: {provider} ({model})")
        return llm
        
    except ImportError as e:
        raise RuntimeError(f"无法导入LLM模块: {e}。请安装依赖：pip install dashscope") from e
    except Exception as e:
        raise RuntimeError(f"创建LLM实例失败: {e}") from e


def parse_chapter_selector(selector: str) -> list:
    """解析章节筛选参数。"""
    if not selector:
        return []
    chapters = [x.strip() for x in selector.split(',') if x.strip()]
    valid = []
    for chapter in chapters:
        if not chapter or not all(p.isdigit() for p in chapter.split('.')):
            raise ValueError(f"无效章节编号: {chapter}，仅支持如 3 或 3.1 的格式")
        valid.append(chapter)
    return valid


def _clone_section_with_children(section: Section) -> Section:
    copied = Section(
        level=section.level,
        title=section.title,
        number=section.number,
        content=section.content,
        uid=section.uid,
    )
    copied.tables = list(section.tables)
    copied.blocks = list(section.blocks)
    for child in section.children:
        copied.add_child(_clone_section_with_children(child))
    return copied


def filter_sections_by_chapters(sections: list, chapters: list) -> list:
    """按章节前缀过滤章节树（如3匹配3及3.x）。"""
    if not chapters:
        return sections

    def matched(number: str) -> bool:
        number = (number or "").strip()
        if not number:
            return False
        for chapter in chapters:
            if number == chapter or number.startswith(f"{chapter}."):
                return True
        return False

    def recurse(section: Section) -> Section:
        if matched(section.number):
            return _clone_section_with_children(section)

        copied = Section(
            level=section.level,
            title=section.title,
            number=section.number,
            content=section.content,
            uid=section.uid,
        )
        copied.tables = list(section.tables)
        copied.blocks = list(section.blocks)

        for child in section.children:
            filtered_child = recurse(child)
            if filtered_child:
                copied.add_child(filtered_child)

        return copied if copied.children else None

    filtered = []
    for s in sections:
        fs = recurse(s)
        if fs:
            filtered.append(fs)
    return filtered


def main():
    """主程序入口"""
    
    # 解析命令行参数
    parser = argparse.ArgumentParser(
        description='SRS需求文档解析工具',
        formatter_class=argparse.RawDescriptionHelpFormatter,
        epilog="""
示例用法：
  python main.py --input sample.pdf --output output.json
  python main.py -i requirements.docx -o output.json --verbose
    python main.py -i DC-SRS.pdf -o output.json
        """
    )
    
    parser.add_argument(
        '--input', '-i',
        type=str,
        required=True,
        help='输入的SRS文档路径（支持.docx和.pdf）'
    )
    
    parser.add_argument(
        '--output', '-o',
        type=str,
        default='output.json',
        help='输出JSON文件路径（默认：output.json）'
    )
    
    parser.add_argument(
        '--config', '-c',
        type=str,
        default=None,
        help='配置文件路径（默认：./config.yaml）'
    )
    
    parser.add_argument(
        '--verbose', '-v',
        action='store_true',
        help='输出详细日志'
    )

    parser.add_argument(
        '--chapters',
        type=str,
        default=None,
        help='按章节提取（如: 3 或 3,4.1）；输入3表示提取第3章及其子章节'
    )
    
    # 解析命令行参数
    args = parser.parse_args()
    
    # 加载配置
    config = load_config(args.config)
    
    # 设置日志
    if args.verbose:
        config.setdefault('logging', {})['level'] = 'DEBUG'
    setup_logging(config)
    
    logger.info("=" * 60)
    logger.info("SRS需求文档解析工具启动（LLM增强版）")
    logger.info("=" * 60)
    
    try:
        # 验证输入文件
        if not validate_file_path(args.input, ['.pdf', '.docx']):
            logger.error(f"输入文件验证失败: {args.input}")
            return False
        
        logger.info(f"输入文件: {args.input}")
        
        # 创建输出目录
        output_dir = os.path.dirname(args.output) or '.'
        if output_dir != '.' and not ensure_directory_exists(output_dir):
            logger.error(f"无法创建输出目录: {output_dir}")
            return False
        
        logger.info(f"输出文件: {args.output}")
        
        # 创建LLM实例（必需）
        llm = create_llm(config)
        logger.info("LLM增强模式已启用")
        
        # 步骤1：解析文档
        logger.info("\n" + "=" * 60)
        logger.info("步骤1：解析文档")
        logger.info("=" * 60)
        
        doc_parser = create_parser(args.input)
        if llm:
            doc_parser.set_llm(llm)
        
        sections = doc_parser.parse()
        document_title = doc_parser.get_document_title()

        selected_chapters = parse_chapter_selector(args.chapters) if args.chapters else []
        if selected_chapters:
            sections = filter_sections_by_chapters(sections, selected_chapters)
            if not sections:
                raise ValueError(f"未匹配到指定章节: {', '.join(selected_chapters)}")
            logger.info(f"章节筛选已启用: {', '.join(selected_chapters)}")
        
        logger.info(f"成功解析文档，提取{len(sections)}个顶级章节")
        
        # 打印章节结构
        def print_sections(sections, indent=0):
            for section in sections:
                logger.info("  " * indent + f"- {section.number} {section.title}")
                if section.children:
                    print_sections(section.children, indent + 1)
        
        if args.verbose:
            logger.info("章节结构：")
            print_sections(sections)
        
        # 步骤2：提取需求
        logger.info("\n" + "=" * 60)
        logger.info("步骤2：提取需求（LLM增强模式）")
        logger.info("=" * 60)
        
        extractor = RequirementExtractor(config, llm=llm)
        requirements = extractor.extract_from_sections(sections)
        
        # 统计需求信息
        stats = extractor.get_statistics()
        logger.info(f"\n需求统计：")
        for req_type, count in stats['by_type'].items():
            logger.info(f"  {req_type}: {count}项")
        logger.info(f"  总计: {stats['total']}项")
        
        # 步骤3：生成JSON
        logger.info("\n" + "=" * 60)
        logger.info("步骤3：生成JSON")
        logger.info("=" * 60)
        
        generator = JSONGenerator(config)
        json_output = generator.generate(
            sections,
            requirements,
            document_title
        )
        
        logger.info(f"JSON结构生成完成")
        
        # 步骤4：保存文件
        logger.info("\n" + "=" * 60)
        logger.info("步骤4：保存结果")
        logger.info("=" * 60)
        
        generator.save_to_file(json_output, args.output)
        logger.info(f"成功保存JSON文件到: {args.output}")
        
        # 打印输出文件大小
        if os.path.exists(args.output):
            file_size = os.path.getsize(args.output)
            logger.info(f"文件大小: {file_size} 字节")
        
        logger.info("\n" + "=" * 60)
        logger.info("SRS需求文档解析完成！")
        logger.info("=" * 60)
        
        return True
        
    except Exception as e:
        logger.error(f"处理过程中出现错误: {e}", exc_info=True)
        return False


if __name__ == '__main__':
    success = main()
    sys.exit(0 if success else 1)