import os
from docx import Document
from PyPDF2 import PdfReader
from app.services.file_storage import get_file_content


async def parse_reference_file(file_path: str) -> str:
    ext = os.path.splitext(file_path)[1].lower()

    content = await get_file_content(file_path)

    if ext == ".txt":
        return content.decode("utf-8", errors="ignore")

    if ext == ".docx":
        from io import BytesIO
        doc = Document(BytesIO(content))
        return "\n".join(p.text for p in doc.paragraphs if p.text.strip())

    if ext == ".pdf":
        from io import BytesIO
        reader = PdfReader(BytesIO(content))
        return "\n".join(page.extract_text() or "" for page in reader.pages)

    raise ValueError(f"不支持的文件格式: {ext}")