"""端到端验证：process_image 输出 vs 实际写入 docx 的图片字节。

目的:
    用户反馈"从文档复制出来的图底部有 1/4 空白"，但独立测试 process_image
    输出已是紧致裁剪。本脚本走完整 sign_word 链路，把生成的 docx 解开来看
    word/media/ 下真实的图片字节，对比 process_image 的输出，定位空白来源:

    - 若字节完全一致 → 空白来自 Word 段落渲染（行高/对齐），不是图片本身
    - 若字节不一致   → 我们的链路在某个环节给图片加了 padding，需进一步定位

使用:
    python image_test/e2e_test.py
"""
import io
import sys
import zipfile
from pathlib import Path

BASE_DIR = Path(__file__).resolve().parent
PROJECT_ROOT = BASE_DIR.parent
INPUT_IMAGE = BASE_DIR / "input" / "test1.jpg"
OUT_DIR = BASE_DIR / "output" / "e2e"
DOCX_OUT = OUT_DIR / "signed.docx"


def _ensure_project_on_path():
    if str(PROJECT_ROOT) not in sys.path:
        sys.path.insert(0, str(PROJECT_ROOT))


def _make_test_docx(path):
    """构造一份带 SET USER_test 域代码的 docx，正文段落使用偏大行高。

    段落行高 2cm（lineRule=exact），模拟用户文档里的固定行高场景。
    """
    from docx import Document
    from docx.shared import Cm, Pt
    from docx.enum.text import WD_LINE_SPACING
    from lib import field_codes

    doc = Document()
    p = doc.add_paragraph()
    p.paragraph_format.line_spacing_rule = WD_LINE_SPACING.EXACTLY
    p.paragraph_format.line_spacing = Cm(2.0)
    p.add_run("正文前 ")

    runs = field_codes.build_set_field_runs("test")
    for r in runs:
        p._element.append(r)

    p.add_run(" 正文中 ")
    p.add_run("正文后")
    doc.save(str(path))


def _image_stats(data):
    from PIL import Image, ImageChops
    img = Image.open(io.BytesIO(data))
    if img.mode != 'RGBA':
        img = img.convert('RGBA')
    r, g, b, a = img.split()
    luma = Image.merge('RGB', (r, g, b)).convert('L')
    alpha_mask = a.point(lambda p: 255 if p > 30 else 0)
    luma_mask = luma.point(lambda p: 255 if p < 210 else 0)
    combined = ImageChops.darker(alpha_mask, luma_mask)
    total = img.size[0] * img.size[1] or 1
    return {
        'size': img.size,
        'mode': img.mode,
        'content_pct': 100.0 * sum(combined.histogram()[1:]) / total,
        'alpha_pct': 100.0 * sum(alpha_mask.histogram()[1:]) / total,
        'bbox': combined.getbbox(),
        'sha256': __import__('hashlib').sha256(data).hexdigest()[:16],
    }


def main():
    _ensure_project_on_path()

    if not INPUT_IMAGE.exists():
        print(f"测试图片不存在: {INPUT_IMAGE}")
        sys.exit(1)

    OUT_DIR.mkdir(parents=True, exist_ok=True)
    src_docx = OUT_DIR / "input.docx"
    _make_test_docx(src_docx)

    with open(src_docx, 'rb') as f:
        docx_data = f.read()
    with open(INPUT_IMAGE, 'rb') as f:
        image_bytes = f.read()

    from lib.image_processor import process_image
    from lib.word_signer import sign_word

    processed = process_image(
        image_bytes, is_signature=True,
        noise_level=0, rotate_min=0, rotate_max=0,
        log_source='e2e测试',
    )

    params = {
        'docx_name': 'input.docx',
        'match_mode': 'upload',
        'stamps': [{
            'marker': 'USER_test',
            'image_base64': __import__('base64').b64encode(image_bytes).decode(),
            'image_filename': 'test1.jpg',
            'is_signature': True,
        }],
        'use_global_height': True,
        'height': 2.5,
    }

    result, err = sign_word(docx_data, params, log_source='e2e测试', trace_id='e2e')
    if err:
        print(f"sign_word 失败: {err}")
        sys.exit(1)

    with open(DOCX_OUT, 'wb') as f:
        f.write(result['data'])

    print(f"已生成: {DOCX_OUT}")
    print(f"warnings: {result.get('warnings', [])}")
    print(f"success_count: {result.get('success_count', 0)}")
    print()

    print("=== process_image 直出 ===")
    s1 = _image_stats(processed)
    print(f"  尺寸={s1['size']} 内容={s1['content_pct']:.1f}% "
          f"alpha={s1['alpha_pct']:.1f}% bbox={s1['bbox']} sha={s1['sha256']}")
    print()

    print("=== docx 内 word/media/ 实际图片 ===")
    with zipfile.ZipFile(DOCX_OUT, 'r') as z:
        medias = sorted(n for n in z.namelist() if n.startswith('word/media/'))
        if not medias:
            print("  未找到任何图片！")
            return
        for name in medias:
            data = z.read(name)
            s2 = _image_stats(data)
            same = "一致" if data == processed else "不一致"
            print(f"  [{name}] 尺寸={s2['size']} 内容={s2['content_pct']:.1f}% "
                  f"alpha={s2['alpha_pct']:.1f}% bbox={s2['bbox']} sha={s2['sha256']} 字节={same}")
            print(f"    原始 {len(processed)} bytes vs docx {len(data)} bytes")


if __name__ == '__main__':
    main()