from django.contrib.auth import authenticate, login, logout
import logging
from django.contrib.auth.models import Group, Permission
from django.http import JsonResponse, HttpResponse
from django.views.decorators.csrf import csrf_exempt
from rest_framework.decorators import api_view, permission_classes, action
from rest_framework.response import Response
from rest_framework import viewsets, status, serializers
from rest_framework.throttling import AnonRateThrottle
from drf_spectacular.utils import extend_schema, OpenApiParameter, inline_serializer
from drf_spectacular.types import OpenApiTypes
import json
import secrets
from .permissions import IsAdmin, Authenticated
from dispatcharr.utils import network_access_allowed

from .models import User
from .serializers import UserSerializer, GroupSerializer, PermissionSerializer
from rest_framework_simplejwt.views import TokenObtainPairView, TokenRefreshView

logger = logging.getLogger(__name__)


class LoginRateThrottle(AnonRateThrottle):
    scope = "login"


class TokenObtainPairView(TokenObtainPairView):
    throttle_classes = [LoginRateThrottle]

    def post(self, request, *args, **kwargs):
        if not network_access_allowed(request, "UI"):
            # Log blocked login attempt due to network restrictions
            from core.utils import log_system_event
            username = request.data.get("username", 'unknown')
            client_ip = request.META.get('REMOTE_ADDR', 'unknown')
            user_agent = request.META.get('HTTP_USER_AGENT', 'unknown')
            logger.info(f"Login blocked by network policy: user={username} ip={client_ip} ua={user_agent}")
            log_system_event(
                event_type='login_failed',
                user=username,
                client_ip=client_ip,
                user_agent=user_agent,
                reason='Network access denied',
            )
            return Response({"error": "Forbidden"}, status=status.HTTP_403_FORBIDDEN)

        # Get the response from the parent class first
        username = request.data.get("username")

        # Log login attempt
        from core.utils import log_system_event
        client_ip = request.META.get('REMOTE_ADDR', 'unknown')
        user_agent = request.META.get('HTTP_USER_AGENT', 'unknown')

        try:
            logger.debug(f"Attempting JWT login for user={username}")
            response = super().post(request, *args, **kwargs)

            # If login was successful, update last_login and log success
            if response.status_code == 200:
                if username:
                    from django.utils import timezone
                    try:
                        user = User.objects.get(username=username)
                        user.last_login = timezone.now()
                        user.save(update_fields=['last_login'])

                        # Log successful login
                        log_system_event(
                            event_type='login_success',
                            user=username,
                            client_ip=client_ip,
                            user_agent=user_agent,
                        )
                        logger.info(f"Login success: user={username} ip={client_ip}")
                    except User.DoesNotExist:
                        pass  # User doesn't exist, but login somehow succeeded
            else:
                # Log failed login attempt
                log_system_event(
                    event_type='login_failed',
                    user=username or 'unknown',
                    client_ip=client_ip,
                    user_agent=user_agent,
                    reason='Invalid credentials',
                )
                logger.info(f"Login failed: user={username} ip={client_ip}")

            return response

        except Exception as e:
            # If parent class raises an exception (e.g., validation error), log failed attempt
            log_system_event(
                event_type='login_failed',
                user=username or 'unknown',
                client_ip=client_ip,
                user_agent=user_agent,
                reason=f'Authentication error: {str(e)[:100]}',
            )
            logger.error(f"Login error for user={username}: {e}")
            raise  # Re-raise the exception to maintain normal error flow


class TokenRefreshView(TokenRefreshView):
    def post(self, request, *args, **kwargs):
        # Custom logic here
        if not network_access_allowed(request, "UI"):
            # Log blocked token refresh attempt due to network restrictions
            from core.utils import log_system_event
            client_ip = request.META.get('REMOTE_ADDR', 'unknown')
            user_agent = request.META.get('HTTP_USER_AGENT', 'unknown')
            logger.info(f"Token refresh blocked by network policy: ip={client_ip} ua={user_agent}")
            log_system_event(
                event_type='login_failed',
                user='token_refresh',
                client_ip=client_ip,
                user_agent=user_agent,
                reason='Network access denied (token refresh)',
            )
            return Response({"error": "Unauthorized"}, status=status.HTTP_403_FORBIDDEN)

        return super().post(request, *args, **kwargs)


@csrf_exempt  # In production, consider CSRF protection strategies or ensure this endpoint is only accessible when no superuser exists.
def initialize_superuser(request):
    # If an admin-level user already exists, the system is configured
    if User.objects.filter(user_level__gte=10).exists():
        return JsonResponse({"superuser_exists": True})

    if request.method == "POST":
        try:
            data = json.loads(request.body)
            username = data.get("username")
            password = data.get("password")
            email = data.get("email", "")
            if not username or not password:
                return JsonResponse(
                    {"error": "Username and password are required."}, status=400
                )
            # Create the superuser
            User.objects.create_superuser(
                username=username, password=password, email=email, user_level=10
            )
            return JsonResponse({"superuser_exists": True})
        except Exception as e:
            return JsonResponse({"error": str(e)}, status=500)
    # For GET requests, indicate no superuser exists
    return JsonResponse({"superuser_exists": False})


# 🔹 1) Authentication APIs
class AuthViewSet(viewsets.ViewSet):
    """Handles user login and logout"""

    def get_permissions(self):
        """
        Login doesn't require auth, but logout does
        """
        if self.action == 'logout':
            return [Authenticated()]
        return []

    @extend_schema(
        description="Alias for POST /api/accounts/token/ — returns JWT access and refresh tokens.",
        request=inline_serializer(
            name="LoginRequest",
            fields={
                "username": serializers.CharField(),
                "password": serializers.CharField(),
            },
        ),
    )
    def login(self, request):
        """Delegates to TokenObtainPairView (JWT login). Throttling, logging, and
        network access checks are handled there."""
        view = TokenObtainPairView.as_view()
        return view(request._request)

    @extend_schema(
        description="Log out the current user",
    )
    def logout(self, request):
        """Logs out the authenticated user"""
        # Log logout event before actually logging out
        from core.utils import log_system_event
        username = request.user.username if request.user and request.user.is_authenticated else 'unknown'
        client_ip = request.META.get('REMOTE_ADDR', 'unknown')
        user_agent = request.META.get('HTTP_USER_AGENT', 'unknown')

        log_system_event(
            event_type='logout',
            user=username,
            client_ip=client_ip,
            user_agent=user_agent,
        )
        logger.info(f"Logout: user={username} ip={client_ip}")

        logout(request)
        return Response({"message": "Logout successful"})


# 🔹 2) User Management APIs
class UserViewSet(viewsets.ModelViewSet):
    """Handles CRUD operations for Users"""

    queryset = User.objects.all().prefetch_related('channel_profiles')
    serializer_class = UserSerializer

    def get_permissions(self):
        if self.action == "me":
            return [Authenticated()]

        return [IsAdmin()]

    @extend_schema(
        description="Retrieve a list of users",
        responses={200: UserSerializer(many=True)},
    )
    def list(self, request, *args, **kwargs):
        return super().list(request, *args, **kwargs)

    @extend_schema(description="Retrieve a specific user by ID")
    def retrieve(self, request, *args, **kwargs):
        return super().retrieve(request, *args, **kwargs)

    @extend_schema(description="Create a new user")
    def create(self, request, *args, **kwargs):
        return super().create(request, *args, **kwargs)

    @extend_schema(description="Update a user")
    def update(self, request, *args, **kwargs):
        return super().update(request, *args, **kwargs)

    @extend_schema(description="Delete a user")
    def destroy(self, request, *args, **kwargs):
        return super().destroy(request, *args, **kwargs)

    @extend_schema(
        description="Get or update active user information. PATCH updates custom_properties with merge semantics.",
        methods=["GET", "PATCH"],
    )
    @action(detail=False, methods=["get", "patch"], url_path="me")
    def me(self, request):
        user = request.user
        if request.method == "PATCH":
            ALLOWED_FIELDS = {"custom_properties", "first_name", "last_name", "email", "password"}
            disallowed = set(request.data.keys()) - ALLOWED_FIELDS

            for key in disallowed:
                request.data.pop(key, None)

            # Strip admin-managed keys from custom_properties so users cannot
            # set their own XC credentials or network rules via this endpoint.
            ADMIN_ONLY_PROPS = {"xc_password", "allowed_networks"}
            cp = request.data.get("custom_properties")
            if isinstance(cp, dict):
                for key in ADMIN_ONLY_PROPS:
                    cp.pop(key, None)

            serializer = UserSerializer(user, data=request.data, partial=True)
            serializer.is_valid(raise_exception=True)
            serializer.save()
            return Response(serializer.data)
        serializer = UserSerializer(user)
        return Response(serializer.data)


# 🔹 3) Group Management APIs
class GroupViewSet(viewsets.ModelViewSet):
    """Handles CRUD operations for Groups"""

    queryset = Group.objects.all()
    serializer_class = GroupSerializer
    permission_classes = [Authenticated]

    @extend_schema(
        description="Retrieve a list of groups",
        responses={200: GroupSerializer(many=True)},
    )
    def list(self, request, *args, **kwargs):
        return super().list(request, *args, **kwargs)

    @extend_schema(description="Retrieve a specific group by ID")
    def retrieve(self, request, *args, **kwargs):
        return super().retrieve(request, *args, **kwargs)

    @extend_schema(description="Create a new group")
    def create(self, request, *args, **kwargs):
        return super().create(request, *args, **kwargs)

    @extend_schema(description="Update a group")
    def update(self, request, *args, **kwargs):
        return super().update(request, *args, **kwargs)

    @extend_schema(description="Delete a group")
    def destroy(self, request, *args, **kwargs):
        return super().destroy(request, *args, **kwargs)


# API Key management
class APIKeyViewSet(viewsets.ViewSet):
    permission_classes = [Authenticated]

    def list(self, request):
        user = request.user
        return Response({"key": user.api_key})

    @action(detail=False, methods=["post"], url_path="generate")
    def generate(self, request):
        target_user = request.user
        user_id = request.data.get("user_id")

        if user_id:
            from .permissions import IsAdmin

            if not IsAdmin().has_permission(request, self):
                return Response({"detail": "Not allowed to create keys for other users."}, status=status.HTTP_403_FORBIDDEN)

            try:
                target_user = User.objects.get(id=int(user_id))
            except Exception:
                return Response({"detail": "User not found."}, status=status.HTTP_404_NOT_FOUND)

        raw = secrets.token_urlsafe(40)
        target_user.api_key = raw
        target_user.save(update_fields=["api_key"])

        user_data = UserSerializer(target_user).data
        return Response({"key": raw, "user": user_data}, status=status.HTTP_201_CREATED)

    @action(detail=False, methods=["post"], url_path="revoke")
    def revoke(self, request):
        target_user = request.user
        user_id = request.data.get("user_id")

        if user_id:
            from .permissions import IsAdmin

            if not IsAdmin().has_permission(request, self):
                return Response({"detail": "Not allowed to revoke keys for other users."}, status=status.HTTP_403_FORBIDDEN)

            try:
                target_user = User.objects.get(id=int(user_id))
            except Exception:
                return Response({"detail": "User not found."}, status=status.HTTP_404_NOT_FOUND)

        target_user.api_key = None
        target_user.save(update_fields=["api_key"])

        return Response({"success": True})


# 🔹 4) Permissions List API
@extend_schema(
    description="Retrieve a list of all permissions",
    responses={200: PermissionSerializer(many=True)},
)
@api_view(["GET"])
@permission_classes([Authenticated])
def list_permissions(request):
    """Returns a list of all available permissions"""
    permissions = Permission.objects.all()
    serializer = PermissionSerializer(permissions, many=True)
    return Response(serializer.data)