"""
Accounts views and viewsets
"""
from django.contrib.auth import get_user_model
from rest_framework import status, viewsets
from rest_framework.decorators import action
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from rest_framework_simplejwt.views import TokenObtainPairView

from apps.core.services import AuditService

from .models import Role
from .models import AcknowledgementChecklistItem, AcknowledgementContent, UserAcknowledgement
from .permissions import (
    CanManageAcknowledgementContent,
    CanManageOnboarding,
    CanViewOnboarding,
    IsOnboardingOwnerOrAdmin,
    IsProvisionalUser,
    IsPXAdmin,
    IsPXAdminOrReadOnly,
    IsOwnerOrPXAdmin,
)
from .serializers import (
    AccountActivationSerializer,
    AcknowledgementChecklistItemSerializer,
    AcknowledgementContentSerializer,
    AcknowledgeItemSerializer,
    ChangePasswordSerializer,
    ProvisionalUserSerializer,
    ResendInvitationSerializer,
    RoleSerializer,
    UserAcknowledgementSerializer,
    UserCreateSerializer,
    UserSerializer,
    UserUpdateSerializer,
    WizardProgressSerializer,
)

User = get_user_model()


class CustomTokenObtainPairView(TokenObtainPairView):
    """
    Custom JWT token view that logs user login and provides redirect info.
    """

    def post(self, request, *args, **kwargs):
        response = super().post(request, *args, **kwargs)

        # Log successful login and add redirect info
        if response.status_code == 200:
            username = request.data.get('username')
            try:
                user = User.objects.get(username=username)
                AuditService.log_from_request(
                    event_type='user_login',
                    description=f"User {user.email} logged in",
                    request=request,
                    content_object=user
                )

                # Add redirect URL to response data
                response_data = response.data
                response_data['redirect_url'] = self.get_redirect_url(user)
                response.data = response_data

            except User.DoesNotExist:
                pass

        return response

    def get_redirect_url(self, user):
        """
        Determine the appropriate redirect URL based on user role and hospital context.
        """
        # PX Admins need to select a hospital first
        if user.is_px_admin():
            from apps.organizations.models import Hospital
            # Check if there's already a hospital in session
            # Since we don't have access to request here, frontend should handle this
            # Return the hospital selector URL
            return '/health/select-hospital/'

        # Users without hospital assignment get error page
        if not user.hospital:
            return '/health/no-hospital/'

        # All other users go to dashboard
        return '/'


class UserViewSet(viewsets.ModelViewSet):
    """
    ViewSet for User model.

    Permissions:
    - List/Retrieve: Authenticated users
    - Create/Update/Delete: PX Admins only
    - Users can update their own profile
    """
    queryset = User.objects.all()
    permission_classes = [IsAuthenticated]
    filterset_fields = ['is_active', 'hospital', 'department', 'groups']
    search_fields = ['username', 'email', 'first_name', 'last_name', 'employee_id']
    ordering_fields = ['date_joined', 'email', 'last_name']
    ordering = ['-date_joined']

    def get_serializer_class(self):
        """Return appropriate serializer based on action"""
        if self.action == 'create':
            return UserCreateSerializer
        elif self.action in ['update', 'partial_update']:
            return UserUpdateSerializer
        return UserSerializer

    def get_permissions(self):
        """Set permissions based on action"""
        if self.action in ['create', 'destroy']:
            return [IsPXAdmin()]
        elif self.action in ['update', 'partial_update']:
            return [IsOwnerOrPXAdmin()]
        return [IsAuthenticated()]

    def get_queryset(self):
        """Filter queryset based on user role"""
        queryset = super().get_queryset()
        user = self.request.user

        # PX Admins see all users
        if user.is_px_admin():
            return queryset.select_related('hospital', 'department')

        # Hospital Admins see users in their hospital
        if user.is_hospital_admin() and user.hospital:
            return queryset.filter(hospital=user.hospital).select_related('hospital', 'department')

        # Department Managers see users in their department
        if user.is_department_manager() and user.department:
            return queryset.filter(department=user.department).select_related('hospital', 'department')

        # Others see only themselves
        return queryset.filter(id=user.id)

    def perform_create(self, serializer):
        """Log user creation"""
        user = serializer.save()
        AuditService.log_from_request(
            event_type='other',
            description=f"User {user.email} created",
            request=self.request,
            content_object=user
        )

    def perform_update(self, serializer):
        """Log user update"""
        user = serializer.save()
        AuditService.log_from_request(
            event_type='other',
            description=f"User {user.email} updated",
            request=self.request,
            content_object=user
        )

    @action(detail=False, methods=['get'], permission_classes=[IsAuthenticated])
    def me(self, request):
        """Get current user profile"""
        serializer = self.get_serializer(request.user)
        return Response(serializer.data)

    @action(detail=False, methods=['put'], permission_classes=[IsAuthenticated])
    def update_profile(self, request):
        """Update current user profile"""
        serializer = UserUpdateSerializer(request.user, data=request.data, partial=True)
        serializer.is_valid(raise_exception=True)
        serializer.save()

        AuditService.log_from_request(
            event_type='other',
            description=f"User {request.user.email} updated their profile",
            request=request,
            content_object=request.user
        )

        return Response(UserSerializer(request.user).data)

    @action(detail=False, methods=['post'], permission_classes=[IsAuthenticated])
    def change_password(self, request):
        """Change user password"""
        serializer = ChangePasswordSerializer(data=request.data, context={'request': request})
        serializer.is_valid(raise_exception=True)

        # Change password
        request.user.set_password(serializer.validated_data['new_password'])
        request.user.save()

        AuditService.log_from_request(
            event_type='other',
            description=f"User {request.user.email} changed their password",
            request=request,
            content_object=request.user
        )

        return Response({'message': 'Password changed successfully'}, status=status.HTTP_200_OK)

    @action(detail=True, methods=['post'], permission_classes=[IsPXAdmin])
    def assign_role(self, request, pk=None):
        """Assign role to user (PX Admin only)"""
        user = self.get_object()
        role_id = request.data.get('role_id')

        try:
            role = Role.objects.get(id=role_id)
            user.groups.add(role.group)

            AuditService.log_from_request(
                event_type='role_change',
                description=f"Role {role.display_name} assigned to user {user.email}",
                request=request,
                content_object=user,
                metadata={'role': role.name}
            )

            return Response({'message': f'Role {role.display_name} assigned successfully'})
        except Role.DoesNotExist:
            return Response({'error': 'Role not found'}, status=status.HTTP_404_NOT_FOUND)

    @action(detail=True, methods=['post'], permission_classes=[IsPXAdmin])
    def remove_role(self, request, pk=None):
        """Remove role from user (PX Admin only)"""
        user = self.get_object()
        role_id = request.data.get('role_id')

        try:
            role = Role.objects.get(id=role_id)
            user.groups.remove(role.group)

            AuditService.log_from_request(
                event_type='role_change',
                description=f"Role {role.display_name} removed from user {user.email}",
                request=request,
                content_object=user,
                metadata={'role': role.name}
            )

            return Response({'message': f'Role {role.display_name} removed successfully'})
        except Role.DoesNotExist:
            return Response({'error': 'Role not found'}, status=status.HTTP_404_NOT_FOUND)


class RoleViewSet(viewsets.ModelViewSet):
    """
    ViewSet for Role model.

    Permissions:
    - List/Retrieve: Authenticated users
    - Create/Update/Delete: PX Admins only
    """
    queryset = Role.objects.all()
    serializer_class = RoleSerializer
    permission_classes = [IsPXAdminOrReadOnly]
    filterset_fields = ['name', 'level']
    search_fields = ['name', 'display_name', 'description']
    ordering_fields = ['level', 'name']
    ordering = ['-level', 'name']

    def get_queryset(self):
        return super().get_queryset().select_related('group')


# ==================== Onboarding ViewSets ====================

class AcknowledgementContentViewSet(viewsets.ModelViewSet):
    """
    ViewSet for AcknowledgementContent model.
    
    Permissions:
    - List/Retrieve: Authenticated users
    - Create/Update/Delete: PX Admins only
    """
    queryset = AcknowledgementContent.objects.all()
    serializer_class = AcknowledgementContentSerializer
    permission_classes = [CanManageAcknowledgementContent]
    filterset_fields = ['role', 'is_active']
    search_fields = ['code', 'title_en', 'title_ar', 'description_en', 'description_ar']
    ordering_fields = ['role', 'order']
    ordering = ['role', 'order']


class AcknowledgementChecklistItemViewSet(viewsets.ModelViewSet):
    """
    ViewSet for AcknowledgementChecklistItem model.
    
    Permissions:
    - List/Retrieve: Authenticated users
    - Create/Update/Delete: PX Admins only
    """
    queryset = AcknowledgementChecklistItem.objects.all()
    serializer_class = AcknowledgementChecklistItemSerializer
    permission_classes = [CanManageAcknowledgementContent]
    filterset_fields = ['role', 'content', 'is_required', 'is_active']
    search_fields = ['code', 'text_en', 'text_ar', 'description_en', 'description_ar']
    ordering_fields = ['role', 'order']
    ordering = ['role', 'order']
    
    def get_queryset(self):
        return super().get_queryset().select_related('content')


class UserAcknowledgementViewSet(viewsets.ReadOnlyModelViewSet):
    """
    ViewSet for UserAcknowledgement model.
    
    Permissions:
    - Users can view their own acknowledgements
    - PX Admins can view all
    """
    queryset = UserAcknowledgement.objects.all()
    serializer_class = UserAcknowledgementSerializer
    permission_classes = [IsOnboardingOwnerOrAdmin]
    filterset_fields = ['user', 'checklist_item', 'is_acknowledged']
    ordering_fields = ['-acknowledged_at']
    ordering = ['-acknowledged_at']
    
    def get_queryset(self):
        queryset = super().get_queryset()
        user = self.request.user
        
        # PX Admins see all
        if user.is_px_admin():
            return queryset.select_related('user', 'checklist_item')
        
        # Others see only their own
        return queryset.filter(user=user).select_related('user', 'checklist_item')


# ==================== Onboarding Actions for UserViewSet ====================

def onboarding_create_provisional(self, request):
    """Create provisional user"""
    from .services import OnboardingService, EmailService
    
    serializer = ProvisionalUserSerializer(data=request.data)
    serializer.is_valid(raise_exception=True)
    
    # Create provisional user
    user_data = serializer.validated_data.copy()
    roles = user_data.pop('roles', [])
    
    user = OnboardingService.create_provisional_user(user_data)
    
    # Assign roles
    for role_name in roles:
        from .models import Role as RoleModel
        try:
            role = RoleModel.objects.get(name=role_name)
            user.groups.add(role.group)
        except RoleModel.DoesNotExist:
            pass
    
    # Send invitation email
    EmailService.send_invitation_email(user, request)
    
    return Response(
        UserSerializer(user).data,
        status=status.HTTP_201_CREATED
    )


def onboarding_resend_invitation(self, request, pk=None):
    """Resend invitation email"""
    from .services import EmailService
    
    user = self.get_object()
    
    if not user.is_provisional:
        return Response(
            {'error': 'User is not a provisional user'},
            status=status.HTTP_400_BAD_REQUEST
        )
    
    EmailService.send_reminder_email(user, request)
    
    return Response({'message': 'Invitation email resent successfully'})


def onboarding_progress(self, request):
    """Get current user's onboarding progress"""
    from .services import OnboardingService
    
    user = request.user
    
    # Get checklist items
    required_items = OnboardingService.get_checklist_items(user).filter(is_required=True)
    acknowledged_items = UserAcknowledgement.objects.filter(
        user=user,
        checklist_item__in=required_items,
        is_acknowledged=True
    )
    
    progress = {
        'current_step': user.current_wizard_step,
        'completed_steps': user.wizard_completed_steps,
        'progress_percentage': OnboardingService.get_user_progress_percentage(user),
        'total_required_items': required_items.count(),
        'acknowledged_items': acknowledged_items.count()
    }
    
    serializer = WizardProgressSerializer(progress)
    return Response(serializer.data)


def onboarding_content(self, request):
    """Get wizard content for current user"""
    from .services import OnboardingService
    
    content = OnboardingService.get_wizard_content(request.user)
    serializer = AcknowledgementContentSerializer(content, many=True)
    return Response(serializer.data)


def onboarding_checklist(self, request):
    """Get checklist items for current user"""
    from .services import OnboardingService
    
    items = OnboardingService.get_checklist_items(request.user)
    
    # Include acknowledgement status
    from django.db import models
    acknowledged_ids = UserAcknowledgement.objects.filter(
        user=request.user,
        is_acknowledged=True
    ).values_list('checklist_item_id', flat=True)
    
    data = []
    for item in items:
        item_data = AcknowledgementChecklistItemSerializer(item).data
        item_data['is_acknowledged'] = item.id in acknowledged_ids
        data.append(item_data)
    
    return Response(data)


def onboarding_acknowledge(self, request):
    """Acknowledge a checklist item"""
    from .services import OnboardingService
    
    serializer = AcknowledgeItemSerializer(data=request.data)
    serializer.is_valid(raise_exception=True)
    
    try:
        item = AcknowledgementChecklistItem.objects.get(
            id=serializer.validated_data['checklist_item_id']
        )
    except AcknowledgementChecklistItem.DoesNotExist:
        return Response(
            {'error': 'Checklist item not found'},
            status=status.HTTP_404_NOT_FOUND
        )
    
    # Acknowledge item
    OnboardingService.acknowledge_item(
        request.user,
        item,
        signature=serializer.validated_data.get('signature', ''),
        request=request
    )
    
    return Response({'message': 'Item acknowledged successfully'})


def onboarding_complete(self, request):
    """Complete wizard and activate account"""
    from .services import OnboardingService, EmailService
    
    serializer = AccountActivationSerializer(data=request.data)
    serializer.is_valid(raise_exception=True)
    
    # Complete wizard
    success = OnboardingService.complete_wizard(
        request.user,
        serializer.validated_data['username'],
        serializer.validated_data['password'],
        serializer.validated_data['signature'],
        request=request
    )
    
    if not success:
        return Response(
            {'error': 'Failed to complete wizard. Please ensure all required items are acknowledged.'},
            status=status.HTTP_400_BAD_REQUEST
        )
    
    # Notify admins
    from django.contrib.auth import get_user_model
    User = get_user_model()
    admin_users = User.objects.filter(groups__name='PX Admin')
    EmailService.send_completion_notification(request.user, admin_users, request)
    
    return Response({'message': 'Account activated successfully'})


def onboarding_status(self, request, pk=None):
    """Get onboarding status for a specific user"""
    user = self.get_object()
    
    status_data = {
        'user': UserSerializer(user).data,
        'is_provisional': user.is_provisional,
        'acknowledgement_completed': user.acknowledgement_completed,
        'acknowledgement_completed_at': user.acknowledgement_completed_at,
        'current_wizard_step': user.current_wizard_step,
        'invitation_expires_at': user.invitation_expires_at,
        'progress_percentage': user.get_onboarding_progress_percentage()
    }
    
    return Response(status_data)


# Add onboarding actions to UserViewSet with proper function names
UserViewSet.onboarding_create_provisional = action(
    detail=False,
    methods=['post'],
    permission_classes=[CanManageOnboarding],
    url_path='onboarding/create-provisional'
)(onboarding_create_provisional)

UserViewSet.onboarding_resend_invitation = action(
    detail=True,
    methods=['post'],
    permission_classes=[CanManageOnboarding],
    url_path='onboarding/resend-invitation'
)(onboarding_resend_invitation)

UserViewSet.onboarding_progress = action(
    detail=False,
    methods=['get'],
    permission_classes=[IsProvisionalUser],
    url_path='onboarding/progress'
)(onboarding_progress)

UserViewSet.onboarding_content = action(
    detail=False,
    methods=['get'],
    permission_classes=[IsProvisionalUser],
    url_path='onboarding/content'
)(onboarding_content)

UserViewSet.onboarding_checklist = action(
    detail=False,
    methods=['get'],
    permission_classes=[IsProvisionalUser],
    url_path='onboarding/checklist'
)(onboarding_checklist)

UserViewSet.onboarding_acknowledge = action(
    detail=False,
    methods=['post'],
    permission_classes=[IsProvisionalUser],
    url_path='onboarding/acknowledge'
)(onboarding_acknowledge)

UserViewSet.onboarding_complete = action(
    detail=False,
    methods=['post'],
    permission_classes=[IsProvisionalUser],
    url_path='onboarding/complete'
)(onboarding_complete)

UserViewSet.onboarding_status = action(
    detail=True,
    methods=['get'],
    permission_classes=[CanViewOnboarding],
    url_path='onboarding/status'
)(onboarding_status)


# ==================== Onboarding ViewSets ====================