"""使用 pypdf 库解析 PDF 文件"""

from typing import Optional, Tuple


def parse(file_path: str) -> Tuple[Optional[str], Optional[str]]:
    """使用 pypdf 库解析 PDF 文件"""
    try:
        from pypdf import PdfReader
    except ImportError:
        return None, "pypdf 库未安装"

    try:
        reader = PdfReader(file_path)
        md_content = []

        for page in reader.pages:
            text = page.extract_text(extraction_mode="plain")
            if text and text.strip():
                md_content.append(text.strip())
                md_content.append("")

        content = "\n".join(md_content).strip()
        if not content:
            return None, "文档为空"
        return content, None
    except Exception as e:
        return None, f"pypdf 解析失败: {str(e)}"