from __future__ import annotations

from typing import Any

from fastapi import APIRouter, Depends, HTTPException, status
from pydantic import BaseModel

from app.core.security import AuthUser, get_current_user, hash_user_id
from app.db import SessionLocal
from app.models import Quiz, QuizAttempt
from app.services import analytics

router = APIRouter(tags=["quiz"])


class AnswersReq(BaseModel):
    answers: dict[str, Any]


def _grade(q: dict[str, Any], given: Any) -> bool:
    t = q["type"]
    try:
        if t == "mcq":
            return int(given) == int(q["answer"])
        if t == "true_false":
            g = given if isinstance(given, bool) else str(given).lower() in {"true", "vrai", "1"}
            return g == bool(q["answer"])
        if t == "numeric":
            val = float(str(given).replace(" ", "").replace(",", ".").replace("$", "").replace("%", ""))
            ans = float(q["answer"])
            tol = float(q.get("tolerance", 0.02))
            return abs(val - ans) <= max(abs(ans) * tol, 1e-9)
    except (TypeError, ValueError):
        return False
    return False


@router.get("/quiz/{quiz_id}")
async def get_quiz(quiz_id: str, auth: AuthUser = Depends(get_current_user)) -> dict:
    async with SessionLocal() as session:
        quiz = await session.get(Quiz, quiz_id)
    if not quiz or quiz.user_id != auth.id:
        raise HTTPException(status.HTTP_404_NOT_FOUND, detail="Quiz introuvable.")
    payload = dict(quiz.payload)
    payload["questions"] = [{k: v for k, v in q.items() if k not in {"answer", "explanation"}}
                            for q in payload.get("questions", [])]
    return payload


@router.post("/quiz/{quiz_id}/answers")
async def submit(quiz_id: str, req: AnswersReq, auth: AuthUser = Depends(get_current_user)) -> dict:
    async with SessionLocal() as session:
        quiz = await session.get(Quiz, quiz_id)
        if not quiz or quiz.user_id != auth.id:
            raise HTTPException(status.HTTP_404_NOT_FOUND, detail="Quiz introuvable.")
        questions = quiz.payload.get("questions", [])
        results = []
        correct = 0
        for q in questions:
            given = req.answers.get(q["id"])
            ok = _grade(q, given) if given is not None else False
            correct += int(ok)
            results.append({"id": q["id"], "correct": ok, "given": given,
                            "answer": q["answer"], "explanation": q.get("explanation", ""),
                            "unit": q.get("unit", "")})
        score = correct / len(questions) if questions else 0.0
        session.add(QuizAttempt(quiz_id=quiz_id, answers=req.answers, score=score))
        await session.commit()
    await analytics.record_event(hash_user_id(auth.id), quiz.course_code, "quiz", quiz.topic)
    return {"score": score, "correct": correct, "total": len(questions), "results": results}