backend/analytics/views.py

from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework import status, permissions
from .services import forecast_income
from .anomaly import get_anomalies
from .forecast import get_forecast
from finance.utils_mongo import get_user_db_id

class IncomeForecastView(APIView):
    permission_classes = [permissions.IsAuthenticated]

    def get(self, request):
        try:
            days = int(request.query_params.get('days', 30))
            data = forecast_income(get_user_db_id(request.user), days)
            return Response(data)
        except Exception as e:
            return Response({"error": str(e)}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

class AnomalyListView(APIView):
    permission_classes = [permissions.IsAuthenticated]

    def get(self, request):
        try:
            return Response(get_anomalies(get_user_db_id(request.user)))
        except Exception as e:
            return Response({"error": str(e)}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)

class ForecastView(APIView):
    permission_classes = [permissions.IsAuthenticated]

    def get(self, request):
        try:
            # Accurate AI-based forecasting (Chronos Bolt + Statistical Fallback)
            data = get_forecast(get_user_db_id(request.user))
            
            if data is None:
                 return Response({"error": "Insufficient data for AI forecast (need >5 days history)"}, status=status.HTTP_400_BAD_REQUEST)
                 
            return Response(data)
        except Exception as e:
            return Response({"error": str(e)}, status=status.HTTP_500_INTERNAL_SERVER_ERROR)