"""试卷上传 + 处理管线"""

import asyncio
import threading
from fastapi import APIRouter, UploadFile, File, Form, HTTPException, Depends
from app.services.supabase_client import get_supabase
from app.services.text_extractor import extract_pdf, get_full_text
from app.services.paper_processor import process_paper
from app.dependencies.auth import get_current_user_id

router = APIRouter()


def _upload_and_process_sync(
    paper_id: str,
    storage_path: str,
    paper_bytes: bytes,
    answer_bytes: bytes | None,
):
    """在独立线程中运行：Storage 上传 + AI 处理"""
    sb = get_supabase()
    try:
        paper_storage_path = f"{storage_path}/paper.pdf"
        sb.storage.from_("papers").upload(
            paper_storage_path, paper_bytes,
            file_options={"content-type": "application/pdf", "upsert": "true"},
        )
        paper_url = sb.storage.from_("papers").get_public_url(paper_storage_path)

        update_data: dict = {"paper_file_url": paper_url}

        if answer_bytes:
            answer_storage_path = f"{storage_path}/answer.pdf"
            sb.storage.from_("papers").upload(
                answer_storage_path, answer_bytes,
                file_options={"content-type": "application/pdf", "upsert": "true"},
            )
            update_data["answer_file_url"] = sb.storage.from_("papers").get_public_url(answer_storage_path)

        sb.table("papers").update(update_data).eq("id", paper_id).execute()
    except Exception:
        pass

    # process_paper 是 async，在新事件循环里跑
    asyncio.run(process_paper(paper_id, paper_bytes, answer_bytes))


@router.get("/")
async def list_papers():
    """获取试卷列表（公共资产，所有用户共享）"""
    sb = get_supabase()
    return (
        sb.table("papers")
        .select("id, course_code, year, term, exam_type, status, question_count, total_score, difficulty_level, processing_step, processing_progress, processing_total, created_at")
        .order("created_at", desc=True)
        .execute()
        .data
    )


@router.get("/mine")
async def my_papers(user_id: str = Depends(get_current_user_id)):
    """当前用户上传的试卷（含 processing 状态）"""
    sb = get_supabase()
    return (
        sb.table("papers")
        .select("id, course_code, year, term, exam_type, part_label, status, question_count, processing_step, processing_progress, processing_total, created_at")
        .eq("user_id", user_id)
        .order("created_at", desc=True)
        .execute()
        .data
    )


@router.post("/upload")
async def upload_paper(
    paper_file: UploadFile = File(...),
    answer_file: UploadFile | None = File(None),
    course_code: str = Form(...),
    year: int = Form(...),
    term: str = Form(...),
    exam_type: str = Form(...),
    user_id: str = Depends(get_current_user_id),
):
    """上传试卷 PDF（可选答案 PDF），触发后台处理"""
    sb = get_supabase()

    # 1. 读取文件内容（已在内存中，快）
    paper_bytes = await paper_file.read()
    answer_bytes = await answer_file.read() if answer_file else None

    # 2. 立即创建记录（status=processing），马上返回
    storage_path = f"{course_code.upper()}/{year}_{term}_{exam_type}"
    paper_record = sb.table("papers").insert({
        "user_id": user_id,
        "course_code": course_code.upper(),
        "year": year,
        "term": term,
        "exam_type": exam_type,
        "paper_file_url": "",   # 后台上传后更新
        "answer_file_url": None,
        "status": "processing",
    }).execute()

    paper_id = paper_record.data[0]["id"]

    # 3. 在独立线程中运行，完全不阻塞事件循环
    threading.Thread(
        target=_upload_and_process_sync,
        args=(paper_id, storage_path, paper_bytes, answer_bytes),
        daemon=True,
    ).start()

    return {
        "paper_id": paper_id,
        "status": "processing",
        "message": "试卷已上传，正在处理中...",
    }


@router.get("/{paper_id}")
async def get_paper(paper_id: str):
    """获取试卷信息 + 处理状态"""
    sb = get_supabase()
    result = sb.table("papers").select("*").eq("id", paper_id).execute()
    if not result.data:
        raise HTTPException(status_code=404, detail="Paper not found")
    return result.data[0]


@router.get("/{paper_id}/questions")
async def get_questions(paper_id: str):
    """获取试卷的所有题目（含 AI 三件套）"""
    sb = get_supabase()
    result = (
        sb.table("paper_questions")
        .select("*")
        .eq("paper_id", paper_id)
        .order("display_order")
        .execute()
    )
    return result.data