HashModifier: 一个文件hash修改工具

def modify_jpeg_iptc(file_path):
    """修改JPEG/JPG图片的IPTC元数据"""
    # 加载或创建 EXIF 数据
    exif_dict = {}
    try:
        exif_dict = piexif.load(file_path)
    except:
        exif_dict = {"0th": {}, "Exif": {}, "GPS": {}, "1st": {}, "thumbnail": None}

    # 写入唯一时间戳，保证每次 hash 不同
    timestamp = datetime.now().strftime("%Y%m%d%H%M%S%f")

    exif_dict["0th"][piexif.ImageIFD.ImageDescription] = (
        f"Modified: {timestamp}".encode("utf-8")
    )
    exif_dict["0th"][piexif.ImageIFD.Software] = b"HashModifier"
    exif_dict["0th"][piexif.ImageIFD.DateTime] = (
        datetime.now().strftime("%Y:%m:%d %H:%M:%S").encode("utf-8")
    )

    exif_bytes = piexif.dump(exif_dict)
    img = Image.open(file_path)
    img.save(file_path, "JPEG", exif=exif_bytes, quality="keep")

    return True

def modify_png_metadata(file_path):
    """修改PNG图片的元数据"""
    from PIL import PngImagePlugin

    img = Image.open(file_path)
    metadata = PngImagePlugin.PngInfo()

    # 保留现有的文本块
    for key, value in img.info.items():
        if isinstance(key, str) and isinstance(value, str):
            metadata.add_text(key, value)

    # 添加新的 tEXt 块
    timestamp = datetime.now().strftime("%Y%m%d%H%M%S%f")
    metadata.add_text("Software", "HashModifier")
    metadata.add_text("ModificationTime", timestamp)

    # save() 时 PNG 编码器会将这些文本块写入文件
    img.save(file_path, "PNG", pnginfo=metadata)
    return True

def modify_webp_metadata(file_path):
    img = Image.open(file_path)

    # 获取所有帧和时长
    frames = []
    durations = []
    for frame in ImageSequence.Iterator(img):
        frames.append(frame.copy())
        durations.append(frame.info.get('duration', 100))

    # 读取已有 EXIF 或创建新的
    exif_dict = {}
    if "exif" in img.info:
        exif_dict = piexif.load(img.info["exif"])
    else:
        exif_dict = {"0th": {}, ...}

    # 写入时间戳
    timestamp = datetime.now().strftime("%Y%m%d%H%M%S%f")
    exif_dict["0th"][piexif.ImageIFD.ImageDescription] = (
        f"WebP_Modified_{timestamp}".encode("utf-8")
    )
    exif_bytes = piexif.dump(exif_dict)

    # 保存时保留所有帧和时长
    frames[0].save(
        file_path,
        format="WEBP",
        save_all=True,
        append_images=frames[1:],
        exif=exif_bytes,
        duration=durations,   # 传入帧时长列表
        lossless=False,
        quality=95,
        method=6
    )

    return True

def process_folder(input_folder):
    # 1. 创建输出文件夹（输入文件夹名 + _hash_modified）
    output_folder_name = f"{input_folder.name}_hash_modified"

    # 2. 遍历所有子目录，保持层级结构
    for root, dirs, files in os.walk(input_folder):
        rel_path = Path(root).relative_to(input_folder)
        output_subfolder = output_folder / rel_path
        output_subfolder.mkdir(parents=True, exist_ok=True)

        for file in files:
            file_path = Path(root) / file
            if file_path.suffix.lower() in SUPPORTED_EXTENSIONS:
                # 复制 → 修改 → 验证 hash 已变化
                original_hash = calculate_file_hash(file_path)
                output_file = output_subfolder / file
                shutil.copy2(file_path, output_file)
                modify_image_metadata(output_file)
                new_hash = calculate_file_hash(output_file)

                if original_hash != new_hash:
                    print(f"✓ {file}")