from rest_framework import serializers
from django.contrib.auth.models import User
from .models import TimeEntry

class TimeEntrySerializer(serializers.ModelSerializer):
    user = serializers.StringRelatedField(read_only=True)
    username = serializers.CharField(source='user.username', read_only=True)
    
    class Meta:
        model = TimeEntry
        fields = ['id', 'user', 'username', 'date', 'start_time', 'end_time', 'duration', 'created_at']
        read_only_fields = ['user', 'duration', 'created_at']

class TimeEntryCreateSerializer(serializers.ModelSerializer):
    class Meta:
        model = TimeEntry
        fields = ['date', 'start_time', 'end_time']

    def validate(self, attrs):
        if not attrs.get('start_time') and not attrs.get('end_time'):
            raise serializers.ValidationError('Une heure d’entrée ou de sortie est requise.')
        if attrs.get('start_time') and attrs.get('end_time') and attrs['end_time'] <= attrs['start_time']:
            raise serializers.ValidationError('L’heure de sortie doit être après l’heure d’entrée.')
        return attrs

class TimeEntryUpdateSerializer(serializers.ModelSerializer):
    class Meta:
        model = TimeEntry
        fields = ['start_time', 'end_time']

    def validate(self, attrs):
        if not attrs.get('start_time') and not attrs.get('end_time'):
            raise serializers.ValidationError('Une heure d’entrée ou de sortie est requise.')
        if attrs.get('start_time') and attrs.get('end_time') and attrs['end_time'] <= attrs['start_time']:
            raise serializers.ValidationError('L’heure de sortie doit être après l’heure d’entrée.')
        return attrs

class WeeklySummarySerializer(serializers.Serializer):
    user = serializers.StringRelatedField()
    username = serializers.CharField()
    total_hours = serializers.FloatField()
    days = serializers.ListField()
    
    def to_representation(self, instance):
        data = super().to_representation(instance)
        # Format the days data for frontend consumption
        formatted_days = []
        for day in data['days']:
            formatted_days.append({
                'date': day['date'],
                'day': day['day'],
                'start_time': day['start_time'],
                'end_time': day['end_time'],
                'duration': day['duration']
            })
        data['days'] = formatted_days
        return data