from django.shortcuts import get_object_or_404
from drf_spectacular.types import OpenApiTypes
from drf_spectacular.utils import OpenApiParameter, extend_schema
from rest_framework.exceptions import ValidationError
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from rest_framework.throttling import ScopedRateThrottle
from rest_framework.views import APIView

from .models import Character, LeaderboardEntry, StreakRecord, UserHearts, UserStats


class GuestAwareReadThrottle(ScopedRateThrottle):
    """همون الگوی GuestAwareContentThrottle: کاربرِ مهمان (هر deviceId یک pk
    تازه) با IP کلید می‌خوره تا چرخشِ حساب سقفِ read رو دور نزنه."""

    def get_cache_key(self, request, view):
        user = request.user
        if user and user.is_authenticated and getattr(user, 'is_guest', False):
            ident = f'guest-ip:{self.get_ident(request)}'
        elif user and user.is_authenticated:
            ident = user.pk
        else:
            ident = self.get_ident(request)
        return self.cache_format % {'scope': self.scope, 'ident': ident}
from .serializers import (
    CharacterListResponseSerializer,
    LeaderboardResponseSerializer,
    SelectCharacterRequestSerializer,
    SelectCharacterResponseSerializer,
    StreakCalendarResponseSerializer,
    UserHeartsResponseSerializer,
    UserSummaryResponseSerializer,
)


class UserSummaryView(APIView):
    """GET /api/user/summary — پروفایل + آمار + استریک (ادغام‌شده)"""

    permission_classes = [IsAuthenticated]
    throttle_scope = 'read'
    throttle_classes = [GuestAwareReadThrottle]

    @extend_schema(responses=UserSummaryResponseSerializer, tags=['Progress & Gamification (progress)'])
    def get(self, request):
        user = request.user  # accounts.User، از طریق TadrisinoTokenAuthentication
        stats = UserStats.objects.filter(user_id=user.id).first()
        streak = StreakRecord.objects.filter(user_id=user.id).first()

        data = {
            'userId': str(user.id),
            'name': user.name,
            'avatar': user.avatar,
            'gradeId': user.grade_id,
            'xp': stats.xp if stats else 0,
            'coins': stats.coins if stats else 0,
            'streak': {
                'current': streak.current_streak if streak else 0,
                'longest': streak.longest_streak if streak else 0,
            },
            # اپ subscription هنوز در این فاز پیاده‌سازی نشده؛ فعلاً null.
            'subscription': None,
        }
        return Response(UserSummaryResponseSerializer(data).data)


class StreakCalendarView(APIView):
    """GET /api/user/streak/calendar — تقویم کامل روزهای فعال"""

    permission_classes = [IsAuthenticated]
    throttle_scope = 'read'
    throttle_classes = [GuestAwareReadThrottle]

    @extend_schema(responses=StreakCalendarResponseSerializer, tags=['Progress & Gamification (progress)'])
    def get(self, request):
        user = request.user
        streak = StreakRecord.objects.filter(user_id=user.id).first()

        data = {
            'currentStreak': streak.current_streak if streak else 0,
            'longestStreak': streak.longest_streak if streak else 0,
            'activeDays': list(streak.active_days.values_list('date', flat=True)) if streak else [],
        }
        return Response(StreakCalendarResponseSerializer(data).data)


class LeaderboardView(APIView):
    """GET /api/leaderboard?period= — رتبه‌بندی هفتگی/ماهانه"""

    throttle_scope = 'read'
    throttle_classes = [GuestAwareReadThrottle]

    @extend_schema(
        parameters=[OpenApiParameter('period', OpenApiTypes.STR, required=False,
                                      enum=['weekly', 'all_time'])],
        responses=LeaderboardResponseSerializer,
        tags=['Progress & Gamification (progress)'],
    )
    def get(self, request):
        period = request.query_params.get('period', 'weekly')
        entries = LeaderboardEntry.objects.filter(period=period).order_by('rank')[:50]

        # نام کاربر از accounts.User خونده می‌شه (فقط برای نمایش، بدون FK واقعی).
        from accounts.models import User as AccountUser
        user_ids = [e.user_id for e in entries]
        names = {u.id: u.name for u in AccountUser.objects.filter(id__in=user_ids)}

        data = {
            'period': period,
            'entries': [
                {
                    'rank': e.rank,
                    'userId': str(e.user_id),
                    'name': names.get(e.user_id, ''),
                    'xpInPeriod': e.xp_in_period,
                }
                for e in entries
            ],
        }
        return Response(LeaderboardResponseSerializer(data).data)


class UserHeartsView(APIView):
    """GET /api/user/hearts — وضعیت فعلی جان‌ها (هارت)"""

    permission_classes = [IsAuthenticated]

    @extend_schema(responses=UserHeartsResponseSerializer, tags=['Progress & Gamification (progress)'])
    def get(self, request):
        from subscription.services import has_unlimited_hearts

        user = request.user
        hearts, _ = UserHearts.objects.get_or_create(user_id=user.id)
        if hearts.apply_regen():
            hearts.save(update_fields=['current_hearts', 'next_refill_at'])

        unlimited = has_unlimited_hearts(user.id)
        data = {
            'currentHearts': hearts.max_hearts if unlimited else hearts.current_hearts,
            'maxHearts': hearts.max_hearts,
            'nextRefillAt': None if unlimited else hearts.next_refill_at,
            'isUnlimited': unlimited,
        }
        return Response(UserHeartsResponseSerializer(data).data)


class CharacterListView(APIView):
    """
    GET /api/characters — کاتالوگِ کاراکترهای گیمیفیکیشن (مثلِ ماسکات‌های
    Duolingo)، به‌همراه این‌که کدوم برای کاربرِ فعلی باز شده (unlock_xp <= XP
    کاربر) و کدوم انتخاب‌شده‌ست.
    """

    permission_classes = [IsAuthenticated]
    throttle_scope = 'read'
    throttle_classes = [GuestAwareReadThrottle]

    @extend_schema(responses=CharacterListResponseSerializer, tags=['Progress & Gamification (progress)'])
    def get(self, request):
        stats = UserStats.objects.filter(user_id=request.user.id).first()
        xp = stats.xp if stats else 0
        selected_id = stats.selected_character_id if stats else None

        data = {
            'characters': [
                {
                    'characterId': str(c.id),
                    'slug': c.slug,
                    'name': c.name,
                    'icon': c.icon,
                    'unlockXp': c.unlock_xp,
                    'unlocked': xp >= c.unlock_xp,
                    'selected': c.id == selected_id,
                }
                for c in Character.objects.all()
            ],
        }
        return Response(CharacterListResponseSerializer(data).data)


class SelectCharacterView(APIView):
    """POST /api/characters/select — انتخابِ کاراکترِ فعال؛ فقط کاراکترِ باز‌شده قابلِ انتخابه."""

    permission_classes = [IsAuthenticated]
    throttle_scope = 'user_profile_write'
    throttle_classes = [ScopedRateThrottle]

    @extend_schema(
        request=SelectCharacterRequestSerializer,
        responses=SelectCharacterResponseSerializer,
        tags=['Progress & Gamification (progress)'],
    )
    def post(self, request):
        serializer = SelectCharacterRequestSerializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        character = get_object_or_404(Character, pk=serializer.validated_data['characterId'])

        stats, _ = UserStats.objects.get_or_create(user_id=request.user.id)
        if stats.xp < character.unlock_xp:
            raise ValidationError('این کاراکتر هنوز باز نشده است.')

        stats.selected_character_id = character.id
        stats.save(update_fields=['selected_character_id'])

        data = {'characterId': str(character.id), 'selected': True}
        return Response(SelectCharacterResponseSerializer(data).data)