#flask_app/general/截取pdf通用函数.py
import concurrent.futures
import os

import regex
from PyPDF2 import PdfReader

from flask_app.general.clean_pdf import extract_common_header, clean_page_content

def get_start_and_common_header(input_path,end_page):
    common_header = extract_common_header(input_path)
    last_begin_index = 0
    begin_pattern = regex.compile(
        r'.*(?<!见\s*)(?<!与\s*)(?<!"\s*)(?<!“\s*)(?<!”\s*)(?:招标公告|磋商公告|谈判公告|邀请书|邀请函|投标邀请|磋商邀请|谈判邀请)[\)）]?\s*$',
        regex.MULTILINE
    )
    # 新增目录匹配模式
    catalog_pattern = regex.compile(r'\s*目\s*录\s*$', regex.MULTILINE)

    pdf_document = PdfReader(input_path)
    for i, page in enumerate(pdf_document.pages):
        if i > end_page:
            return common_header, 0  # 如果页码大于end_page，直接返回last_begin_index=0
        text = page.extract_text()
        if text:
            cleaned_text = clean_page_content(text, common_header)
            # 检查是否存在"目录"
            if catalog_pattern.search(cleaned_text):
                continue  # 如果存在目录，跳过当前页面
            if begin_pattern.search(cleaned_text):
                last_begin_index = i  # 更新第一个匹配的索引，页码从0开始
                return common_header, last_begin_index
    return common_header, last_begin_index

def check_pdf_pages(pdf_path, mode,logger):
    try:
        reader = PdfReader(pdf_path)
        num_pages = len(reader.pages)
        logger.info(f"PDF '{pdf_path}' 的总页数为: {num_pages}")
        if num_pages <= 50:
            logger.info("PDF页数小于或等于50页，跳过切分逻辑。")
            if mode==1:
                return ['', '', '', '', '', '', '']
            else:
                return ['','','','']
        # 若页数大于50页，返回None表示继续处理
        return None
    except Exception as e:
        logger.error(f"无法读取 PDF 页数: {e}")
        # 返回空列表意味着无法执行后续处理逻辑
        if mode == 1:
            return ['', '', '', '', '', '', '']
        else:
            return ['', '', '', '']