class DropReason:
    TEXT_BLCOK_HOR_OVERLAP = 'text_block_horizontal_overlap'  # 文字块有水平互相覆盖，导致无法准确定位文字顺序
    USEFUL_BLOCK_HOR_OVERLAP = (
        'useful_block_horizontal_overlap'  # 需保留的block水平覆盖
    )
    COMPLICATED_LAYOUT = 'complicated_layout'  # 复杂的布局，暂时不支持
    TOO_MANY_LAYOUT_COLUMNS = 'too_many_layout_columns'  # 目前不支持分栏超过2列的
    COLOR_BACKGROUND_TEXT_BOX = 'color_background_text_box'  # 含有带色块的PDF，色块会改变阅读顺序，目前不支持带底色文字块的PDF。
    HIGH_COMPUTATIONAL_lOAD_BY_IMGS = (
        'high_computational_load_by_imgs'  # 含特殊图片，计算量太大，从而丢弃
    )
    HIGH_COMPUTATIONAL_lOAD_BY_SVGS = (
        'high_computational_load_by_svgs'  # 特殊的SVG图，计算量太大，从而丢弃
    )
    HIGH_COMPUTATIONAL_lOAD_BY_TOTAL_PAGES = 'high_computational_load_by_total_pages'  # 计算量超过负荷，当前方法下计算量消耗过大
    MISS_DOC_LAYOUT_RESULT = 'missing doc_layout_result'  # 版面分析失败
    Exception = '_exception'  # 解析中发生异常
    ENCRYPTED = 'encrypted'  # PDF是加密的
    EMPTY_PDF = 'total_page=0'  # PDF页面总数为0
    NOT_IS_TEXT_PDF = 'not_is_text_pdf'  # 不是文字版PDF，无法直接解析
    DENSE_SINGLE_LINE_BLOCK = 'dense_single_line_block'  # 无法清晰的分段
    TITLE_DETECTION_FAILED = 'title_detection_failed'  # 探测标题失败
    TITLE_LEVEL_FAILED = (
        'title_level_failed'  # 分析标题级别失败（例如一级、二级、三级标题）
    )
    PARA_SPLIT_FAILED = 'para_split_failed'  # 识别段落失败
    PARA_MERGE_FAILED = 'para_merge_failed'  # 段落合并失败
    NOT_ALLOW_LANGUAGE = 'not_allow_language'  # 不支持的语种
    SPECIAL_PDF = 'special_pdf'
    PSEUDO_SINGLE_COLUMN = 'pseudo_single_column'  # 无法精确判断文字分栏
    CAN_NOT_DETECT_PAGE_LAYOUT = 'can_not_detect_page_layout'  # 无法分析页面的版面
    NEGATIVE_BBOX_AREA = 'negative_bbox_area'  # 缩放导致 bbox 面积为负
    OVERLAP_BLOCKS_CAN_NOT_SEPARATION = (
        'overlap_blocks_can_t_separation'  # 无法分离重叠的block
    )