"""从 docx 提取所有内嵌图片，方便定位实际插入到文档里的图片字节。

用法:
    python image_test/extract_docx_images.py <signed.docx>

输出:
    image_test/output/docx_images/<图片名>.png  (按 docx 内顺序编号)
    每张图打印尺寸 + 紧致度诊断
"""
import io
import sys
import zipfile
from pathlib import Path
from PIL import Image, ImageChops

BASE_DIR = Path(__file__).resolve().parent
OUT_DIR = BASE_DIR / "output" / "docx_images"


def analyze_image(data):
    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,
        'bbox': combined.getbbox(),
        'alpha_pct': 100.0 * sum(alpha_mask.histogram()[1:]) / total,
    }


def main():
    if len(sys.argv) < 2:
        print("用法: python image_test/extract_docx_images.py <signed.docx>")
        sys.exit(1)

    docx_path = Path(sys.argv[1])
    if not docx_path.exists():
        print(f"文件不存在: {docx_path}")
        sys.exit(1)

    OUT_DIR.mkdir(parents=True, exist_ok=True)

    with zipfile.ZipFile(docx_path, 'r') as z:
        media_files = sorted([n for n in z.namelist()
                              if n.startswith('word/media/')])

        if not media_files:
            print("docx 内未找到 word/media/ 下的图片")
            return

        print(f"找到 {len(media_files)} 张图片\n")

        for i, name in enumerate(media_files, 1):
            data = z.read(name)
            ext = Path(name).suffix or '.png'
            out_path = OUT_DIR / f"image_{i:02d}{ext}"
            with open(out_path, 'wb') as f:
                f.write(data)

            try:
                stats = analyze_image(data)
                print(f"[{i:02d}] {name}")
                print(f"     尺寸={stats['size']} 模式={stats['mode']} "
                      f"alpha像素={stats['alpha_pct']:.1f}% "
                      f"内容={stats['content_pct']:.1f}% bbox={stats['bbox']}")
                print(f"     已保存: {out_path}")
            except Exception as e:
                print(f"[{i:02d}] {name}: 解析失败 {e}")
            print()


if __name__ == '__main__':
    main()