scalesApp/backend/api/views.py

from rest_framework import viewsets, status
from rest_framework.decorators import action
from rest_framework.response import Response
from rest_framework.permissions import IsAuthenticated, AllowAny
from .models import ComPortReading, User
from .serializers import ComPortReadingSerializer, UserSerializer, UserDetailSerializer, ChangePasswordSerializer, VehicleSerializer, NomenclatureSerializer
from vehicles.models import Vehicle
from nomenclatures.models import Nomenclature


class UserViewSet(viewsets.ModelViewSet):
    """
    API endpoint for user management.

    list: Get all users
    create: Create a new user
    retrieve: Get a specific user
    update: Update a user
    destroy: Delete a user
    me: Get current authenticated user
    change_password: Change password for current user
    """
    queryset = User.objects.all()
    serializer_class = UserSerializer
    filterset_fields = ['role', 'is_admin', 'is_active']
    ordering = ['username']

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

    @action(detail=False, methods=['post'], permission_classes=[IsAuthenticated],
            url_path='change-password', url_name='change_password')
    def change_password(self, request):
        """Change password for current user"""
        serializer = ChangePasswordSerializer(
            data=request.data,
            context={'request': request}
        )
        if serializer.is_valid():
            serializer.save()
            return Response({
                'detail': 'Password updated successfully'
            }, status=status.HTTP_200_OK)
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)


class ComPortReadingViewSet(viewsets.ModelViewSet):
    """
    API endpoint for COM port readings.

    list: Get all readings with optional filtering
    create: Create a new reading (allows unauthenticated for serial bridge)
    retrieve: Get a specific reading
    destroy: Delete a reading
    latest: Get the latest reading
    by_port: Get readings for a specific port
    """
    queryset = ComPortReading.objects.all()
    serializer_class = ComPortReadingSerializer
    filterset_fields = ['port']
    ordering = ['-timestamp']

    def get_permissions(self):
        """Allow unauthenticated POST for serial bridge"""
        if self.action == 'create':
            return [AllowAny()]
        return [IsAuthenticated()]

    @action(detail=False, methods=['get'])
    def latest(self, request):
        """Get the latest reading"""
        reading = ComPortReading.objects.first()
        if reading:
            serializer = self.get_serializer(reading)
            return Response(serializer.data)
        return Response({'detail': 'No readings yet'}, status=status.HTTP_404_NOT_FOUND)
    
    @action(detail=False, methods=['get'])
    def by_port(self, request):
        """Get readings for a specific port"""
        port = request.query_params.get('port', None)
        if not port:
            return Response(
                {'detail': 'port parameter is required'},
                status=status.HTTP_400_BAD_REQUEST
            )
        readings = ComPortReading.objects.filter(port=port)
        serializer = self.get_serializer(readings, many=True)
        return Response(serializer.data)
    
    def get_client_ip(self, request):
        """Get client IP address"""
        x_forwarded_for = request.META.get('HTTP_X_FORWARDED_FOR')
        if x_forwarded_for:
            ip = x_forwarded_for.split(',')[0]
        else:
            ip = request.META.get('REMOTE_ADDR')
        return ip
    
    def perform_create(self, serializer):
        """Save the reading with client IP"""
        serializer.save(source_ip=self.get_client_ip(self.request))


class VehicleViewSet(viewsets.ModelViewSet):
    """
    API endpoint for vehicle management.

    list: Get all vehicles with pagination
    create: Create a new vehicle with optional extra data
    retrieve: Get a specific vehicle by ID
    update: Full update of vehicle and extra data
    partial_update: Partial update of vehicle
    destroy: Delete a vehicle (cascades to VehicleExtra)
    by_number: Get vehicle by vehicle_number
    """
    queryset = Vehicle.objects.select_related('extra').all()
    serializer_class = VehicleSerializer
    permission_classes = [IsAuthenticated]
    filterset_fields = ['vehicle_number']
    search_fields = ['vehicle_number']
    ordering = ['vehicle_number']

    @action(detail=False, methods=['get'], url_path='by-number')
    def by_number(self, request):
        """Get vehicle by vehicle_number query parameter"""
        vehicle_number = request.query_params.get('vehicle_number', None)
        if not vehicle_number:
            return Response(
                {'detail': 'vehicle_number parameter is required'},
                status=status.HTTP_400_BAD_REQUEST
            )

        try:
            vehicle = Vehicle.objects.get(vehicle_number=vehicle_number)
            serializer = self.get_serializer(vehicle)
            return Response(serializer.data)
        except Vehicle.DoesNotExist:
            return Response(
                {'detail': 'Vehicle not found'},
                status=status.HTTP_404_NOT_FOUND
            )


class NomenclatureViewSet(viewsets.ModelViewSet):
    """
    API endpoint for nomenclature management.

    list: Get all nomenclatures with pagination
    create: Create a new nomenclature with fields
    retrieve: Get a specific nomenclature by ID
    update: Full update of nomenclature and fields
    partial_update: Partial update of nomenclature
    destroy: Delete a nomenclature (cascades to fields)
    by_code: Get nomenclature by code
    by_applies_to: Filter nomenclatures by applies_to type
    """
    queryset = Nomenclature.objects.prefetch_related('nomenclaturefield_set').all()
    serializer_class = NomenclatureSerializer
    permission_classes = [IsAuthenticated]
    filterset_fields = ['applies_to', 'code']
    search_fields = ['code', 'name']
    ordering = ['code']

    @action(detail=False, methods=['get'], url_path='by-code')
    def by_code(self, request):
        """Get nomenclature by code query parameter"""
        code = request.query_params.get('code', None)
        if not code:
            return Response(
                {'detail': 'code parameter is required'},
                status=status.HTTP_400_BAD_REQUEST
            )

        try:
            nomenclature = Nomenclature.objects.get(code=code)
            serializer = self.get_serializer(nomenclature)
            return Response(serializer.data)
        except Nomenclature.DoesNotExist:
            return Response(
                {'detail': 'Nomenclature not found'},
                status=status.HTTP_404_NOT_FOUND
            )

    @action(detail=False, methods=['get'], url_path='by-applies-to')
    def by_applies_to(self, request):
        """Get nomenclatures filtered by applies_to query parameter"""
        applies_to = request.query_params.get('applies_to', None)
        if not applies_to:
            return Response(
                {'detail': 'applies_to parameter is required'},
                status=status.HTTP_400_BAD_REQUEST
            )

        if applies_to not in ['vehicle', 'container']:
            return Response(
                {'detail': 'applies_to must be either vehicle or container'},
                status=status.HTTP_400_BAD_REQUEST
            )

        nomenclatures = Nomenclature.objects.filter(applies_to=applies_to)
        page = self.paginate_queryset(nomenclatures)
        if page is not None:
            serializer = self.get_serializer(page, many=True)
            return self.get_paginated_response(serializer.data)

        serializer = self.get_serializer(nomenclatures, many=True)
        return Response(serializer.data)