from django.shortcuts import get_object_or_404
from rest_framework import permissions, status
from rest_framework.response import Response
from rest_framework.views import APIView

from .game_services import game_payload, request_sudoku_hint, start_game, submit_game
from .models import Contest, ContestAttempt, MathGameAttempt, RealtimeMatch
from .services import (
    cancel_waiting_match,
    create_challenge,
    finalize_game_match,
    find_match,
    join_challenge,
    match_payload,
    notify_match_on_commit,
    refresh_match_state,
    start_attempt,
    submit_attempt,
)


class ContestListView(APIView):
    permission_classes = [permissions.AllowAny]

    def get(self, request):
        contests = Contest.objects.filter(status=Contest.Status.PUBLISHED).order_by(
            "kind", "title"
        )
        return Response(
            [
                {
                    "slug": contest.slug,
                    "title": contest.title,
                    "kind": contest.kind,
                    "track": contest.track,
                    "duration_seconds": contest.duration_seconds,
                    "starts_at": contest.starts_at,
                    "ends_at": contest.ends_at,
                }
                for contest in contests
            ]
        )


class AttemptStartView(APIView):
    def post(self, request, slug):
        contest = get_object_or_404(Contest, slug=slug)
        return Response(start_attempt(request.user, contest), status=status.HTTP_201_CREATED)


class AttemptSubmitView(APIView):
    def post(self, request, attempt_id):
        attempt = get_object_or_404(ContestAttempt, id=attempt_id, user=request.user)
        payload = submit_attempt(
            user=request.user,
            attempt_id=attempt_id,
            raw_answers=request.data.get("answers", []),
            submission_key=request.headers.get("Idempotency-Key"),
        )
        if attempt.match_id:
            match = refresh_match_state(attempt.match_id)
            return Response(match_payload(match, request.user))
        return Response(payload)


class MatchmakingView(APIView):
    def post(self, request, slug):
        contest = get_object_or_404(Contest, slug=slug)
        match = find_match(
            request.user,
            contest,
            request.data.get("game_kind", RealtimeMatch.GameKind.QUIZ),
        )
        return Response(match_payload(match, request.user), status=status.HTTP_202_ACCEPTED)


class MatchStateView(APIView):
    def get(self, request, match_id):
        existing = get_object_or_404(
            RealtimeMatch.objects.select_related("player_one", "player_two"),
            id=match_id,
        )
        if request.user.id not in (existing.player_one_id, existing.player_two_id):
            return Response(status=status.HTTP_403_FORBIDDEN)
        match = refresh_match_state(match_id)
        return Response(match_payload(match, request.user))


class ChallengeCreateView(APIView):
    def post(self, request, slug):
        contest = get_object_or_404(Contest, slug=slug)
        match = create_challenge(
            request.user,
            contest,
            request.data.get("game_kind", RealtimeMatch.GameKind.QUIZ),
        )
        return Response(match_payload(match, request.user), status=status.HTTP_201_CREATED)


class ChallengeJoinView(APIView):
    def post(self, request):
        match = join_challenge(request.user, request.data.get("challenge_code"))
        return Response(match_payload(match, request.user))


class MatchCancelView(APIView):
    def post(self, request, match_id):
        get_object_or_404(RealtimeMatch, id=match_id)
        match = cancel_waiting_match(request.user, match_id)
        return Response(match_payload(match, request.user))


class LeaderboardView(APIView):
    permission_classes = [permissions.AllowAny]

    def get(self, request, slug):
        contest = get_object_or_404(Contest, slug=slug)
        attempts = (
            ContestAttempt.objects.filter(
                contest=contest,
                status=ContestAttempt.Status.SUBMITTED,
                cheat_flags__isnull=True,
            )
            .select_related("user")
            .order_by("-score", "duration_ms", "submitted_at")[:100]
        )
        return Response(
            [
                {
                    "rank": index,
                    "nickname": attempt.user.nickname,
                    "track": attempt.user.track,
                    "score": attempt.score,
                    "correct_count": attempt.correct_count,
                    "duration_ms": attempt.duration_ms,
                }
                for index, attempt in enumerate(attempts, start=1)
            ]
        )


class MathGameCatalogView(APIView):
    permission_classes = [permissions.AllowAny]

    def get(self, request):
        return Response(
            [
                {
                    "kind": MathGameAttempt.Kind.TWENTY_FOUR,
                    "title": "24 点",
                    "summary": "四个数字各用一次，只用四则运算得到 24。",
                    "ability": "connection",
                    "estimated_minutes": 3,
                },
                {
                    "kind": MathGameAttempt.Kind.SUDOKU,
                    "title": "数独",
                    "summary": "在行、列和九宫格约束中完成 9×9 数字推理。",
                    "ability": "detection",
                    "estimated_minutes": 8,
                },
            ]
        )


class MathGameStartView(APIView):
    def post(self, request, kind):
        payload = start_game(
            request.user,
            kind,
            MathGameAttempt.Difficulty.STANDARD,
        )
        return Response(payload, status=status.HTTP_201_CREATED)


class MathGameSubmitView(APIView):
    def post(self, request, attempt_id):
        attempt = get_object_or_404(
            MathGameAttempt,
            id=attempt_id,
            user=request.user,
        )
        payload = submit_game(
            request.user,
            attempt_id,
            request.data,
            request.headers.get("Idempotency-Key"),
        )
        if attempt.match_id:
            match = finalize_game_match(attempt.match_id)
            if match.status != RealtimeMatch.Status.COMPLETED:
                notify_match_on_commit(match.id, "submitted")
            return Response(match_payload(match, request.user))
        return Response(payload)


class SudokuHintView(APIView):
    def post(self, request, attempt_id):
        return Response(request_sudoku_hint(request.user, attempt_id))


class MathGameHistoryView(APIView):
    def get(self, request):
        attempts = MathGameAttempt.objects.filter(user=request.user)[:20]
        return Response([game_payload(attempt) for attempt in attempts])