"""用户答题记录 + 拍照批改 + 错题本"""

import asyncio
from fastapi import APIRouter, UploadFile, File, Form, HTTPException, Depends
from pydantic import BaseModel
from app.services.supabase_client import get_supabase
from app.services.grader import ocr_photo, grade_answer
from app.dependencies.auth import get_current_user_id

router = APIRouter()


class AttemptCreate(BaseModel):
    question_id: str
    attempt_type: str  # "select" | "input" | "photo"
    user_answer: str | None = None
    is_correct: bool | None = None


class AttemptUpdate(BaseModel):
    in_error_book: bool | None = None
    mastered: bool | None = None


@router.post("/")
async def create_attempt(data: AttemptCreate, user_id: str = Depends(get_current_user_id)):
    """记录一次答题"""
    sb = get_supabase()
    record = {
        "user_id": user_id,
        "question_id": data.question_id,
        "attempt_type": data.attempt_type,
        "user_answer": data.user_answer,
        "is_correct": data.is_correct,
    }
    # Auto add to error book if wrong
    if data.is_correct is False:
        record["in_error_book"] = True

    result = sb.table("user_attempts").insert(record).execute()
    return result.data[0]


@router.post("/photo")
async def photo_attempt(
    question_id: str = Form(...),
    photo: UploadFile = File(...),
    user_id: str = Depends(get_current_user_id),
):
    """拍照上传 → OCR → AI批改"""
    sb = get_supabase()

    # 1. Read photo
    photo_bytes = await photo.read()

    # 2. Upload to storage
    storage_path = f"attempts/{user_id}/{question_id}/{photo.filename}"
    sb.storage.from_("attempt-photos").upload(
        storage_path, photo_bytes,
        file_options={"content-type": photo.content_type or "image/jpeg", "upsert": "true"},
    )
    photo_url = sb.storage.from_("attempt-photos").get_public_url(storage_path)

    # 3. OCR (run in thread pool to avoid blocking event loop)
    ocr_text = await asyncio.to_thread(ocr_photo, photo_bytes)

    # 4. Fetch question for grading context
    q_result = sb.table("paper_questions").select("*").eq("id", question_id).execute()
    if not q_result.data:
        raise HTTPException(status_code=404, detail="Question not found")
    question = q_result.data[0]

    # 5. AI grading (run in thread pool)
    grade_result = await asyncio.to_thread(grade_answer, question, ocr_text)

    # 6. Save attempt
    record = {
        "user_id": user_id,
        "question_id": question_id,
        "attempt_type": "photo",
        "photo_url": photo_url,
        "photo_ocr_text": ocr_text,
        "is_correct": grade_result.get("is_correct", False),
        "feedback": grade_result.get("feedback", ""),
        "error_at_step": grade_result.get("error_at_step"),
        "in_error_book": not grade_result.get("is_correct", False),
    }
    result = sb.table("user_attempts").insert(record).execute()

    return {
        "attempt": result.data[0],
        "ocr_text": ocr_text,
        "grade": grade_result,
    }


@router.get("/error-book")
async def get_error_book(
    course_code: str | None = None,
    user_id: str = Depends(get_current_user_id),
):
    """获取错题本"""
    sb = get_supabase()
    attempts = (
        sb.table("user_attempts")
        .select("*")
        .eq("user_id", user_id)
        .eq("in_error_book", True)
        .eq("mastered", False)
        .order("created_at", desc=True)
        .execute()
        .data
    )
    if not attempts:
        return []

    question_ids = list({attempt["question_id"] for attempt in attempts})
    questions = (
        sb.table("paper_questions")
        .select("*")
        .in_("id", question_ids)
        .execute()
        .data
    )
    questions_by_id = {question["id"]: question for question in questions}

    paper_ids = list({question["paper_id"] for question in questions})
    papers = (
        sb.table("papers")
        .select("id, course_code, year, term, exam_type, part_label")
        .in_("id", paper_ids)
        .execute()
        .data
    )
    papers_by_id = {paper["id"]: paper for paper in papers}

    enriched = []
    for attempt in attempts:
        question = questions_by_id.get(attempt["question_id"])
        if not question:
            continue
        paper = papers_by_id.get(question["paper_id"])
        if course_code and paper and paper.get("course_code") != course_code.upper():
            continue

        enriched.append(
            {
                **attempt,
                "paper_questions": {
                    **question,
                    "paper": paper,
                },
            }
        )
    return enriched


@router.get("/by-paper/{paper_id}")
async def get_paper_attempts(paper_id: str, user_id: str = Depends(get_current_user_id)):
    """获取某张试卷所有题目的最新判卷记录"""
    sb = get_supabase()
    attempts = (
        sb.table("user_attempts")
        .select("question_id, is_correct, feedback, photo_ocr_text, attempt_type, created_at")
        .eq("user_id", user_id)
        .order("created_at", desc=True)
        .execute()
        .data
    )
    # 只保留 photo 类型的，且只保留每题最新一条
    question_ids = (
        sb.table("paper_questions")
        .select("id")
        .eq("paper_id", paper_id)
        .execute()
        .data
    )
    qid_set = {q["id"] for q in question_ids}
    seen: set[str] = set()
    result = []
    for a in attempts:
        if a["question_id"] not in qid_set:
            continue
        if a["question_id"] in seen:
            continue
        if a["attempt_type"] != "photo":
            continue
        seen.add(a["question_id"])
        result.append(a)
    return result


@router.patch("/{attempt_id}")
async def update_attempt(attempt_id: str, data: AttemptUpdate):
    """更新错题状态（标记掌握等）"""
    sb = get_supabase()
    update = {}
    if data.in_error_book is not None:
        update["in_error_book"] = data.in_error_book
    if data.mastered is not None:
        update["mastered"] = data.mastered
    if not update:
        raise HTTPException(status_code=400, detail="Nothing to update")

    result = sb.table("user_attempts").update(update).eq("id", attempt_id).execute()
    if not result.data:
        raise HTTPException(status_code=404, detail="Attempt not found")
    return result.data[0]