# PRD 上传与解析接口

import logging
from concurrent.futures import ThreadPoolExecutor

from fastapi import APIRouter, UploadFile, File, HTTPException

from server.services.prd_manager.service import prd_service

logger = logging.getLogger(__name__)
router = APIRouter()

ALLOWED_EXTENSIONS = {".md", ".txt", ".docx", ".pdf"}
_parse_executor = ThreadPoolExecutor(max_workers=2)


@router.post("/upload")
async def upload_prd(file: UploadFile = File(...)):
    """上传 PRD 文件，立即返回 PRD ID，后台异步解析"""
    ext = "." + file.filename.rsplit(".", 1)[-1].lower() if "." in file.filename else ""
    if ext not in ALLOWED_EXTENSIONS:
        raise HTTPException(400, f"不支持的文件格式: {ext}，支持: {', '.join(ALLOWED_EXTENSIONS)}")

    content = await file.read()
    if len(content) == 0:
        raise HTTPException(400, "文件为空")

    try:
        # Quick: save and return immediately
        prd_version = await prd_service.upload_quick(file.filename, content)

        # Background: parse async (image analysis may take 60s+)
        _parse_executor.submit(_parse_in_background, prd_version["prd_id"], file.filename, content)

        return {
            "prd_id": prd_version["prd_id"],
            "filename": prd_version["filename"],
            "status": "parsing",
            "uploaded_at": prd_version["uploaded_at"],
        }
    except Exception as e:
        logger.error("PRD upload failed: %s", e)
        raise HTTPException(500, f"上传失败: {e}")


def _parse_in_background(prd_id: str, filename: str, content: bytes):
    """Run full parsing (text + images + vision analysis) in background thread."""
    import asyncio
    try:
        loop = asyncio.new_event_loop()
        asyncio.set_event_loop(loop)
        loop.run_until_complete(prd_service.parse_async(prd_id, filename, content))
    except Exception as e:
        logger.error("Background parse failed for %s: %s", prd_id, e)
        prd_service.set_status(prd_id, "error", str(e))


@router.get("/{prd_id}/status")
async def get_prd_status(prd_id: str):
    """获取 PRD 解析状态"""
    status = await prd_service.get_status(prd_id)
    if not status:
        raise HTTPException(404, "PRD not found")
    return status


@router.get("/{prd_id}")
async def get_prd(prd_id: str):
    """获取 PRD 详情与版本"""
    prd = await prd_service.get_prd(prd_id)
    if not prd:
        raise HTTPException(404, "PRD not found")
    return {
        "prd_id": prd["prd_id"],
        "filename": prd["filename"],
        "status": prd.get("status", "ready"),
        "full_text": prd.get("full_text", ""),
        "sections": prd.get("sections", []),
        "images": prd.get("images", []),
        "uploaded_at": prd["uploaded_at"],
    }