"""
Accounts views and viewsets
"""

from django.contrib import messages
from django.contrib.auth import get_user_model
from django.contrib.auth.decorators import login_required
from django.shortcuts import render, redirect
from django.utils.translation import gettext as _
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.
        """
        # Check if user is a Source User first
        from apps.px_sources.models import SourceUser

        if SourceUser.objects.filter(user=user).exists():
            return "/px_sources/dashboard/"

        # 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 to 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")

        # Source Users see only themselves
        if user.is_source_user():
            return queryset.filter(id=user.id)

        # 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")


# ==================== Settings Views ====================


@login_required
def user_settings(request):
    """
    User settings page for managing notification preferences, profile, and security.
    """
    user = request.user

    if request.method == "POST":
        # Get form type
        form_type = request.POST.get("form_type", "preferences")

        if form_type == "preferences":
            # Update notification preferences
            user.notification_email_enabled = request.POST.get("notification_email_enabled", "off") == "on"
            user.notification_sms_enabled = request.POST.get("notification_sms_enabled", "off") == "on"
            user.preferred_notification_channel = request.POST.get("preferred_notification_channel", "email")
            user.explanation_notification_channel = request.POST.get("explanation_notification_channel", "email")
            user.phone = request.POST.get("phone", "")
            user.language = request.POST.get("language", "en")
            messages.success(request, _("Notification preferences updated successfully."))

        elif form_type == "profile":
            # Update profile information
            user.first_name = request.POST.get("first_name", "")
            user.last_name = request.POST.get("last_name", "")
            user.phone = request.POST.get("phone", "")
            user.bio = request.POST.get("bio", "")

            # Handle avatar upload
            if request.FILES.get("avatar"):
                user.avatar = request.FILES.get("avatar")

            messages.success(request, _("Profile updated successfully."))

        elif form_type == "password":
            # Change password
            current_password = request.POST.get("current_password")
            new_password = request.POST.get("new_password")
            confirm_password = request.POST.get("confirm_password")

            if not user.check_password(current_password):
                messages.error(request, _("Current password is incorrect."))
            elif new_password != confirm_password:
                messages.error(request, _("New passwords do not match."))
            elif len(new_password) < 8:
                messages.error(request, _("Password must be at least 8 characters long."))
            else:
                user.set_password(new_password)
                messages.success(request, _("Password changed successfully. Please login again."))

                # Re-authenticate user with new password
                from django.contrib.auth import update_session_auth_hash

                update_session_auth_hash(request, user)

        user.save()

        # Log the update
        AuditService.log_from_request(
            event_type="other", description=f"User {user.email} updated settings", request=request, content_object=user
        )

        return redirect("accounts:settings")

    context = {
        "user": user,
        "notification_channels": [("email", _("Email")), ("sms", _("SMS")), ("both", _("Both"))],
        "languages": [("en", _("English")), ("ar", _("Arabic"))],
    }

    # Add user statistics for PX Admin
    if user.is_px_admin():
        User = get_user_model()
        context["total_users_count"] = User.objects.count()
        context["active_users_count"] = User.objects.filter(is_active=True, is_provisional=False).count()
        context["provisional_users_count"] = User.objects.filter(is_provisional=True).count()
        context["inactive_users_count"] = User.objects.filter(is_active=False).count()

    return render(request, "accounts/settings.html", context)


# ==================== 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")

    @action(detail=True, methods=["get"], permission_classes=[IsAuthenticated])
    def download_pdf(self, request, pk=None):
        """
        Download PDF for a specific acknowledgement
        """
        from django.http import FileResponse, Http404
        import os

        acknowledgement = self.get_object()

        # Check if PDF exists
        if not acknowledgement.pdf_file:
            return Response({"error": "PDF not available for this acknowledgement"}, status=status.HTTP_404_NOT_FOUND)

        # Check file exists
        if not os.path.exists(acknowledgement.pdf_file.path):
            return Response({"error": "PDF file not found"}, status=status.HTTP_404_NOT_FOUND)

        # Return file
        try:
            response = FileResponse(open(acknowledgement.pdf_file.path, "rb"), content_type="application/pdf")

            # Generate filename
            filename = f"acknowledgement_{acknowledgement.id}_{acknowledgement.user.employee_id or acknowledgement.user.username}.pdf"
            response["Content-Disposition"] = f'attachment; filename="{filename}"'

            return response
        except Exception as e:
            return Response({"error": f"Error downloading PDF: {str(e)}"}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)


# ==================== 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 ====================