"""
Auth domain views for ThrillWiki API v1.

This module contains all authentication-related API endpoints including
login, signup, logout, password management, social authentication,
user profiles, and top lists.
"""

import time
from django.contrib.auth import authenticate, login, logout, get_user_model
from django.contrib.sites.shortcuts import get_current_site
from django.core.exceptions import ValidationError
from django.utils import timezone
from django.conf import settings
from django.db.models import Q
from rest_framework import status
from rest_framework.views import APIView
from rest_framework.viewsets import ModelViewSet
from rest_framework.request import Request
from rest_framework.response import Response
from rest_framework.permissions import AllowAny, IsAuthenticated
from rest_framework.decorators import action
from allauth.socialaccount import providers
from drf_spectacular.utils import extend_schema, extend_schema_view

from apps.accounts.models import UserProfile, TopList, TopListItem
from .serializers import (
    # Authentication serializers
    LoginInputSerializer,
    LoginOutputSerializer,
    SignupInputSerializer,
    SignupOutputSerializer,
    LogoutOutputSerializer,
    UserOutputSerializer,
    PasswordResetInputSerializer,
    PasswordResetOutputSerializer,
    PasswordChangeInputSerializer,
    PasswordChangeOutputSerializer,
    SocialProviderOutputSerializer,
    AuthStatusOutputSerializer,
    # User profile serializers
    UserProfileCreateInputSerializer,
    UserProfileUpdateInputSerializer,
    UserProfileOutputSerializer,
    # Top list serializers
    TopListCreateInputSerializer,
    TopListUpdateInputSerializer,
    TopListOutputSerializer,
    TopListItemCreateInputSerializer,
    TopListItemUpdateInputSerializer,
    TopListItemOutputSerializer,
)

# Handle optional dependencies with fallback classes


class FallbackTurnstileMixin:
    """Fallback mixin if TurnstileMixin is not available."""

    def validate_turnstile(self, request):
        pass


# Try to import the real class, use fallback if not available
try:
    from apps.accounts.mixins import TurnstileMixin
except ImportError:
    TurnstileMixin = FallbackTurnstileMixin

UserModel = get_user_model()


# === AUTHENTICATION API VIEWS ===

@extend_schema_view(
    post=extend_schema(
        summary="User login",
        description="Authenticate user with username/email and password.",
        request=LoginInputSerializer,
        responses={
            200: LoginOutputSerializer,
            400: "Bad Request",
        },
        tags=["Authentication"],
    ),
)
class LoginAPIView(TurnstileMixin, APIView):
    """API endpoint for user login."""

    permission_classes = [AllowAny]
    authentication_classes = []
    serializer_class = LoginInputSerializer

    def post(self, request: Request) -> Response:
        try:
            # Validate Turnstile if configured
            self.validate_turnstile(request)
        except ValidationError as e:
            return Response({"error": str(e)}, status=status.HTTP_400_BAD_REQUEST)

        serializer = LoginInputSerializer(data=request.data)
        if serializer.is_valid():
            # type: ignore[index]
            email_or_username = serializer.validated_data["username"]
            password = serializer.validated_data["password"]  # type: ignore[index]

            # Optimized user lookup: single query using Q objects
            user = None

            # Single query to find user by email OR username
            try:
                if "@" in email_or_username:
                    # Email-like input: try email first, then username as fallback
                    user_obj = (
                        UserModel.objects.select_related()
                        .filter(
                            Q(email=email_or_username) | Q(username=email_or_username)
                        )
                        .first()
                    )
                else:
                    # Username-like input: try username first, then email as fallback
                    user_obj = (
                        UserModel.objects.select_related()
                        .filter(
                            Q(username=email_or_username) | Q(email=email_or_username)
                        )
                        .first()
                    )

                if user_obj:
                    user = authenticate(
                        # type: ignore[attr-defined]
                        request._request,
                        username=user_obj.username,
                        password=password,
                    )
            except Exception:
                # Fallback to original behavior
                user = authenticate(
                    # type: ignore[attr-defined]
                    request._request,
                    username=email_or_username,
                    password=password,
                )

            if user:
                if user.is_active:
                    login(request._request, user)  # type: ignore[attr-defined]
                    # Optimized token creation - get_or_create is atomic
                    from rest_framework.authtoken.models import Token

                    token, created = Token.objects.get_or_create(user=user)

                    response_serializer = LoginOutputSerializer(
                        {
                            "token": token.key,
                            "user": user,
                            "message": "Login successful",
                        }
                    )
                    return Response(response_serializer.data)
                else:
                    return Response(
                        {"error": "Account is disabled"},
                        status=status.HTTP_400_BAD_REQUEST,
                    )
            else:
                return Response(
                    {"error": "Invalid credentials"},
                    status=status.HTTP_400_BAD_REQUEST,
                )

        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


@extend_schema_view(
    post=extend_schema(
        summary="User registration",
        description="Register a new user account.",
        request=SignupInputSerializer,
        responses={
            201: SignupOutputSerializer,
            400: "Bad Request",
        },
        tags=["Authentication"],
    ),
)
class SignupAPIView(TurnstileMixin, APIView):
    """API endpoint for user registration."""

    permission_classes = [AllowAny]
    authentication_classes = []
    serializer_class = SignupInputSerializer

    def post(self, request: Request) -> Response:
        try:
            # Validate Turnstile if configured
            self.validate_turnstile(request)
        except ValidationError as e:
            return Response({"error": str(e)}, status=status.HTTP_400_BAD_REQUEST)

        serializer = SignupInputSerializer(data=request.data)
        if serializer.is_valid():
            user = serializer.save()
            login(request._request, user)  # type: ignore[attr-defined]
            from rest_framework.authtoken.models import Token

            token, created = Token.objects.get_or_create(user=user)

            response_serializer = SignupOutputSerializer(
                {
                    "token": token.key,
                    "user": user,
                    "message": "Registration successful",
                }
            )
            return Response(response_serializer.data, status=status.HTTP_201_CREATED)

        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


@extend_schema_view(
    post=extend_schema(
        summary="User logout",
        description="Logout the current user and invalidate their token.",
        responses={
            200: LogoutOutputSerializer,
            401: "Unauthorized",
        },
        tags=["Authentication"],
    ),
)
class LogoutAPIView(APIView):
    """API endpoint for user logout."""

    permission_classes = [IsAuthenticated]
    serializer_class = LogoutOutputSerializer

    def post(self, request: Request) -> Response:
        try:
            # Delete the token for token-based auth
            if hasattr(request.user, "auth_token"):
                request.user.auth_token.delete()

            # Logout from session
            logout(request._request)  # type: ignore[attr-defined]

            response_serializer = LogoutOutputSerializer(
                {"message": "Logout successful"}
            )
            return Response(response_serializer.data)
        except Exception as e:
            return Response(
                {"error": "Logout failed"}, status=status.HTTP_500_INTERNAL_SERVER_ERROR
            )


@extend_schema_view(
    get=extend_schema(
        summary="Get current user",
        description="Retrieve information about the currently authenticated user.",
        responses={
            200: UserOutputSerializer,
            401: "Unauthorized",
        },
        tags=["Authentication"],
    ),
)
class CurrentUserAPIView(APIView):
    """API endpoint to get current user information."""

    permission_classes = [IsAuthenticated]
    serializer_class = UserOutputSerializer

    def get(self, request: Request) -> Response:
        serializer = UserOutputSerializer(request.user)
        return Response(serializer.data)


@extend_schema_view(
    post=extend_schema(
        summary="Request password reset",
        description="Send a password reset email to the user.",
        request=PasswordResetInputSerializer,
        responses={
            200: PasswordResetOutputSerializer,
            400: "Bad Request",
        },
        tags=["Authentication"],
    ),
)
class PasswordResetAPIView(APIView):
    """API endpoint to request password reset."""

    permission_classes = [AllowAny]
    serializer_class = PasswordResetInputSerializer

    def post(self, request: Request) -> Response:
        serializer = PasswordResetInputSerializer(
            data=request.data, context={"request": request}
        )
        if serializer.is_valid():
            serializer.save()

            response_serializer = PasswordResetOutputSerializer(
                {"detail": "Password reset email sent"}
            )
            return Response(response_serializer.data)

        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


@extend_schema_view(
    post=extend_schema(
        summary="Change password",
        description="Change the current user's password.",
        request=PasswordChangeInputSerializer,
        responses={
            200: PasswordChangeOutputSerializer,
            400: "Bad Request",
            401: "Unauthorized",
        },
        tags=["Authentication"],
    ),
)
class PasswordChangeAPIView(APIView):
    """API endpoint to change password."""

    permission_classes = [IsAuthenticated]
    serializer_class = PasswordChangeInputSerializer

    def post(self, request: Request) -> Response:
        serializer = PasswordChangeInputSerializer(
            data=request.data, context={"request": request}
        )
        if serializer.is_valid():
            serializer.save()

            response_serializer = PasswordChangeOutputSerializer(
                {"detail": "Password changed successfully"}
            )
            return Response(response_serializer.data)

        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


@extend_schema_view(
    get=extend_schema(
        summary="Get social providers",
        description="Retrieve available social authentication providers.",
        responses={200: "List of social providers"},
        tags=["Authentication"],
    ),
)
class SocialProvidersAPIView(APIView):
    """API endpoint to get available social authentication providers."""

    permission_classes = [AllowAny]
    serializer_class = SocialProviderOutputSerializer

    def get(self, request: Request) -> Response:
        from django.core.cache import cache
        from django.contrib.sites.shortcuts import get_current_site

        site = get_current_site(request._request)  # type: ignore[attr-defined]

        # Cache key based on site and request host
        cache_key = (
            f"social_providers:{getattr(site, 'id', site.pk)}:{request.get_host()}"
        )

        # Try to get from cache first (cache for 15 minutes)
        cached_providers = cache.get(cache_key)
        if cached_providers is not None:
            return Response(cached_providers)

        providers_list = []

        # Optimized query: filter by site and order by provider name
        from allauth.socialaccount.models import SocialApp

        social_apps = SocialApp.objects.filter(sites=site).order_by("provider")

        for social_app in social_apps:
            try:
                # Simplified provider name resolution - avoid expensive provider class loading
                provider_name = social_app.name or social_app.provider.title()

                # Build auth URL efficiently
                auth_url = request.build_absolute_uri(
                    f"/accounts/{social_app.provider}/login/"
                )

                providers_list.append(
                    {
                        "id": social_app.provider,
                        "name": provider_name,
                        "authUrl": auth_url,
                    }
                )

            except Exception:
                # Skip if provider can't be loaded
                continue

        # Serialize and cache the result
        serializer = SocialProviderOutputSerializer(providers_list, many=True)
        response_data = serializer.data

        # Cache for 15 minutes (900 seconds)
        cache.set(cache_key, response_data, 900)

        return Response(response_data)


@extend_schema_view(
    post=extend_schema(
        summary="Check authentication status",
        description="Check if user is authenticated and return user data.",
        responses={200: AuthStatusOutputSerializer},
        tags=["Authentication"],
    ),
)
class AuthStatusAPIView(APIView):
    """API endpoint to check authentication status."""

    permission_classes = [AllowAny]
    serializer_class = AuthStatusOutputSerializer

    def post(self, request: Request) -> Response:
        if request.user.is_authenticated:
            response_data = {
                "authenticated": True,
                "user": request.user,
            }
        else:
            response_data = {
                "authenticated": False,
                "user": None,
            }

        serializer = AuthStatusOutputSerializer(response_data)
        return Response(serializer.data)


# === USER PROFILE API VIEWS ===

class UserProfileViewSet(ModelViewSet):
    """ViewSet for managing user profiles."""

    queryset = UserProfile.objects.select_related("user").all()
    permission_classes = [IsAuthenticated]

    def get_serializer_class(self):
        """Return appropriate serializer based on action."""
        if self.action == "create":
            return UserProfileCreateInputSerializer
        elif self.action in ["update", "partial_update"]:
            return UserProfileUpdateInputSerializer
        return UserProfileOutputSerializer

    def get_queryset(self):
        """Filter profiles based on user permissions."""
        if self.request.user.is_staff:
            return self.queryset
        return self.queryset.filter(user=self.request.user)

    @action(detail=False, methods=["get"])
    def me(self, request):
        """Get current user's profile."""
        try:
            profile = UserProfile.objects.get(user=request.user)
            serializer = self.get_serializer(profile)
            return Response(serializer.data)
        except UserProfile.DoesNotExist:
            return Response(
                {"error": "Profile not found"}, status=status.HTTP_404_NOT_FOUND
            )


# === TOP LIST API VIEWS ===

class TopListViewSet(ModelViewSet):
    """ViewSet for managing user top lists."""

    queryset = (
        TopList.objects.select_related("user").prefetch_related("items__ride").all()
    )
    permission_classes = [IsAuthenticated]

    def get_serializer_class(self):
        """Return appropriate serializer based on action."""
        if self.action == "create":
            return TopListCreateInputSerializer
        elif self.action in ["update", "partial_update"]:
            return TopListUpdateInputSerializer
        return TopListOutputSerializer

    def get_queryset(self):
        """Filter lists based on user permissions and visibility."""
        queryset = self.queryset

        if not self.request.user.is_staff:
            # Non-staff users can only see their own lists and public lists
            queryset = queryset.filter(Q(user=self.request.user) | Q(is_public=True))

        return queryset.order_by("-created_at")

    def perform_create(self, serializer):
        """Set the user when creating a top list."""
        serializer.save(user=self.request.user)

    @action(detail=False, methods=["get"])
    def my_lists(self, request):
        """Get current user's top lists."""
        lists = self.get_queryset().filter(user=request.user)
        serializer = self.get_serializer(lists, many=True)
        return Response(serializer.data)

    @action(detail=True, methods=["post"])
    def duplicate(self, request, pk=None):
        """Duplicate a top list for the current user."""
        original_list = self.get_object()

        # Create new list
        new_list = TopList.objects.create(
            user=request.user,
            name=f"Copy of {original_list.name}",
            description=original_list.description,
            is_public=False,  # Duplicated lists are private by default
        )

        # Copy all items
        for item in original_list.items.all():
            TopListItem.objects.create(
                top_list=new_list,
                ride=item.ride,
                position=item.position,
                notes=item.notes,
            )

        serializer = self.get_serializer(new_list)
        return Response(serializer.data, status=status.HTTP_201_CREATED)


class TopListItemViewSet(ModelViewSet):
    """ViewSet for managing top list items."""

    queryset = TopListItem.objects.select_related("top_list__user", "ride").all()
    permission_classes = [IsAuthenticated]

    def get_serializer_class(self):
        """Return appropriate serializer based on action."""
        if self.action == "create":
            return TopListItemCreateInputSerializer
        elif self.action in ["update", "partial_update"]:
            return TopListItemUpdateInputSerializer
        return TopListItemOutputSerializer

    def get_queryset(self):
        """Filter items based on user permissions."""
        queryset = self.queryset

        if not self.request.user.is_staff:
            # Non-staff users can only see items from their own lists or public lists
            queryset = queryset.filter(
                Q(top_list__user=self.request.user) | Q(top_list__is_public=True)
            )

        return queryset.order_by("top_list_id", "position")

    def perform_create(self, serializer):
        """Validate user can add items to the list."""
        top_list = serializer.validated_data["top_list"]
        if top_list.user != self.request.user and not self.request.user.is_staff:
            raise PermissionError("You can only add items to your own lists")
        serializer.save()

    def perform_update(self, serializer):
        """Validate user can update items in the list."""
        top_list = serializer.instance.top_list
        if top_list.user != self.request.user and not self.request.user.is_staff:
            raise PermissionError("You can only update items in your own lists")
        serializer.save()

    def perform_destroy(self, instance):
        """Validate user can delete items from the list."""
        if (
            instance.top_list.user != self.request.user
            and not self.request.user.is_staff
        ):
            raise PermissionError("You can only delete items from your own lists")
        instance.delete()

    @action(detail=False, methods=["post"])
    def reorder(self, request):
        """Reorder items in a top list."""
        top_list_id = request.data.get("top_list_id")
        item_ids = request.data.get("item_ids", [])

        if not top_list_id or not item_ids:
            return Response(
                {"error": "top_list_id and item_ids are required"},
                status=status.HTTP_400_BAD_REQUEST,
            )

        try:
            top_list = TopList.objects.get(id=top_list_id)
            if top_list.user != request.user and not request.user.is_staff:
                return Response(
                    {"error": "Permission denied"}, status=status.HTTP_403_FORBIDDEN
                )

            # Update positions
            for position, item_id in enumerate(item_ids, 1):
                TopListItem.objects.filter(id=item_id, top_list=top_list).update(
                    position=position
                )

            return Response({"success": True})

        except TopList.DoesNotExist:
            return Response(
                {"error": "Top list not found"}, status=status.HTTP_404_NOT_FOUND
            )