from rest_framework import generics, status
from rest_framework.response import Response
from rest_framework.permissions import IsAuthenticated
from rest_framework.views import APIView
from django.contrib.auth.models import User
from django.utils import timezone
from datetime import datetime, date, timedelta
from .models import TimeEntry
from .serializers import (
    TimeEntrySerializer, 
    TimeEntryCreateSerializer, 
    TimeEntryUpdateSerializer,
    WeeklySummarySerializer
)

class TimeEntryListView(generics.ListAPIView):
    serializer_class = TimeEntrySerializer
    permission_classes = [IsAuthenticated]

    def get_queryset(self):
        user = self.request.user
        # Staff members can view all entries, regular users only their own
        if user.is_staff or user.is_superuser:
            return TimeEntry.objects.all()
        return TimeEntry.objects.filter(user=user)

class TimeEntryCreateView(generics.CreateAPIView):
    serializer_class = TimeEntryCreateSerializer
    permission_classes = [IsAuthenticated]

    def perform_create(self, serializer):
        serializer.save(user=self.request.user)

class TimeEntryDetailView(generics.RetrieveUpdateDestroyAPIView):
    serializer_class = TimeEntrySerializer
    permission_classes = [IsAuthenticated]

    def get_queryset(self):
        user = self.request.user
        # Staff members can view all entries, regular users only their own
        if user.is_staff or user.is_superuser:
            return TimeEntry.objects.all()
        return TimeEntry.objects.filter(user=user)

class TimeEntryUpdateView(APIView):
    permission_classes = [IsAuthenticated]

    def put(self, request, entry_id):
        try:
            entry = TimeEntry.objects.get(id=entry_id)
            # Check if user is authorized to update this entry
            if not (request.user.is_staff or request.user.is_superuser or entry.user == request.user):
                return Response(
                    {'error': 'Accès refusé'}, 
                    status=status.HTTP_403_FORBIDDEN
                )
            
            serializer = TimeEntryUpdateSerializer(entry, data=request.data)
            if serializer.is_valid():
                serializer.save()
                return Response(serializer.data)
            return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
        except TimeEntry.DoesNotExist:
            return Response(
                {'error': 'Pointage non trouvé'}, 
                status=status.HTTP_404_NOT_FOUND
            )

class WeeklySummaryView(APIView):
    permission_classes = [IsAuthenticated]

    def get(self, request, user_id=None):
        # If user_id is provided and user is staff, get that user's summary
        # Otherwise, get current user's summary
        if user_id and (request.user.is_staff or request.user.is_superuser):
            try:
                user = User.objects.get(id=user_id)
            except User.DoesNotExist:
                return Response(
                    {'error': 'Utilisateur non trouvé'}, 
                    status=status.HTTP_404_NOT_FOUND
                )
        else:
            user = request.user

        # Get current week (Monday to Sunday)
        today = timezone.now().date()
        start_of_week = today - timedelta(days=today.weekday())
        end_of_week = start_of_week + timedelta(days=6)
        
        # Get all time entries for the current week for this user
        entries = TimeEntry.objects.filter(
            user=user,
            date__gte=start_of_week,
            date__lte=end_of_week
        ).order_by('date')
        
        # Group entries by day
        days_data = []
        for i in range(7):
            current_day = start_of_week + timedelta(days=i)
            day_entries = entries.filter(date=current_day)
            
            if day_entries.exists():
                # Get the first entry for this day (assuming one entry per day)
                entry = day_entries.first()
                days_data.append({
                    'date': entry.date.isoformat(),
                    'day': entry.date.strftime('%A'),
                    'start_time': str(entry.start_time),
                    'end_time': str(entry.end_time),
                    'duration': entry.duration
                })
            else:
                days_data.append({
                    'date': current_day.isoformat(),
                    'day': current_day.strftime('%A'),
                    'start_time': None,
                    'end_time': None,
                    'duration': 0
                })
        
        total_hours = sum(entry.duration for entry in entries)
        
        summary = {
            'user': user.username,
            'username': user.username,
            'total_hours': round(total_hours, 2),
            'days': days_data
        }
        
        serializer = WeeklySummarySerializer(summary)
        return Response(serializer.data)

class UserWeeklySummaryView(APIView):
    permission_classes = [IsAuthenticated]

    def get(self, request):
        # Get current user's weekly summary
        user = request.user
        
        # Get current week (Monday to Sunday)
        today = timezone.now().date()
        start_of_week = today - timedelta(days=today.weekday())
        end_of_week = start_of_week + timedelta(days=6)
        
        # Get all time entries for the current week for this user
        entries = TimeEntry.objects.filter(
            user=user,
            date__gte=start_of_week,
            date__lte=end_of_week
        ).order_by('date')
        
        # Group entries by day
        days_data = []
        for i in range(7):
            current_day = start_of_week + timedelta(days=i)
            day_entries = entries.filter(date=current_day)
            
            if day_entries.exists():
                # Get the first entry for this day (assuming one entry per day)
                entry = day_entries.first()
                days_data.append({
                    'date': entry.date.isoformat(),
                    'day': entry.date.strftime('%A'),
                    'start_time': str(entry.start_time),
                    'end_time': str(entry.end_time),
                    'duration': entry.duration
                })
            else:
                days_data.append({
                    'date': current_day.isoformat(),
                    'day': current_day.strftime('%A'),
                    'start_time': None,
                    'end_time': None,
                    'duration': 0
                })
        
        total_hours = sum(entry.duration for entry in entries)
        
        summary = {
            'user': user.username,
            'username': user.username,
            'total_hours': round(total_hours, 2),
            'days': days_data
        }
        
        serializer = WeeklySummarySerializer(summary)
        return Response(serializer.data)