from rest_framework import status, viewsets
from rest_framework.decorators import api_view, permission_classes, throttle_classes, action
from rest_framework.permissions import AllowAny, IsAuthenticated
from rest_framework.response import Response
from rest_framework.throttling import AnonRateThrottle
from rest_framework_simplejwt.tokens import RefreshToken
from django.contrib.auth import authenticate
from django.contrib.auth.models import User
from .models import UserPreferences
from .serializers import (
    LoginSerializer, RegisterSerializer, UserSerializer, UserPreferencesSerializer,
    UserListSerializer, UserCreateSerializer, UserUpdateSerializer, PasswordChangeSerializer
)
from .permissions import HasUserManagementAccess


class AuthRateThrottle(AnonRateThrottle):
    rate = '5/minute'


@api_view(['POST'])
@permission_classes([AllowAny])
@throttle_classes([AuthRateThrottle])
def login(request):
    serializer = LoginSerializer(data=request.data)
    if serializer.is_valid():
        user = authenticate(
            username=serializer.validated_data['username'],
            password=serializer.validated_data['password']
        )
        if user:
            refresh = RefreshToken.for_user(user)
            return Response({
                'access': str(refresh.access_token),
                'refresh': str(refresh),
                'user': UserSerializer(user).data
            })
        return Response(
            {'detail': 'Invalid credentials'},
            status=status.HTTP_401_UNAUTHORIZED
        )
    return Response({'detail': serializer.errors}, status=status.HTTP_400_BAD_REQUEST)


@api_view(['POST'])
@permission_classes([AllowAny])
@throttle_classes([AuthRateThrottle])
def register(request):
    serializer = RegisterSerializer(data=request.data)
    if serializer.is_valid():
        user = serializer.save()
        refresh = RefreshToken.for_user(user)
        return Response({
            'access': str(refresh.access_token),
            'refresh': str(refresh),
            'user': UserSerializer(user).data
        }, status=status.HTTP_201_CREATED)
    return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


@api_view(['POST'])
@permission_classes([AllowAny])
@throttle_classes([AuthRateThrottle])
def refresh_token(request):
    refresh_token = request.data.get('refresh')
    if not refresh_token:
        return Response(
            {'detail': 'Refresh token required'},
            status=status.HTTP_400_BAD_REQUEST
        )
    try:
        refresh = RefreshToken(refresh_token)
        return Response({
            'access': str(refresh.access_token),
        })
    except Exception:
        return Response(
            {'detail': 'Invalid refresh token'},
            status=status.HTTP_401_UNAUTHORIZED
        )


@api_view(['GET'])
@permission_classes([IsAuthenticated])
def me(request):
    return Response(UserSerializer(request.user).data)


@api_view(['GET', 'PATCH'])
@permission_classes([IsAuthenticated])
def user_preferences(request):
    if request.method == 'GET':
        prefs, _ = UserPreferences.objects.get_or_create(user=request.user)
        serializer = UserPreferencesSerializer(prefs)
        return Response(serializer.data)

    elif request.method == 'PATCH':
        prefs, _ = UserPreferences.objects.get_or_create(user=request.user)
        serializer = UserPreferencesSerializer(prefs, data=request.data, partial=True)
        if serializer.is_valid():
            serializer.save()
            return Response(serializer.data)
        return Response(serializer.errors, status=400)


class UserManagementViewSet(viewsets.ModelViewSet):
    queryset = User.objects.all().select_related('profile')
    permission_classes = [HasUserManagementAccess]
    
    def get_serializer_class(self):
        if self.action == 'create':
            return UserCreateSerializer
        elif self.action in ['update', 'partial_update']:
            return UserUpdateSerializer
        return UserListSerializer
    
    def get_queryset(self):
        return User.objects.all().select_related('profile').order_by('-date_joined')
    
    @action(detail=True, methods=['post'])
    def set_password(self, request, pk=None):
        user = self.get_object()
        serializer = PasswordChangeSerializer(data=request.data)
        if serializer.is_valid():
            user.set_password(serializer.validated_data['password'])
            user.save()
            return Response({'status': 'password set'})
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)