from rest_framework import serializers
from django.contrib.auth import get_user_model

from .models import TimeEntry


User = get_user_model()


class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = User
        fields = ['id', 'username', 'first_name', 'last_name']


class TimeEntrySerializer(serializers.ModelSerializer):
    user = UserSerializer(read_only=True)

    class Meta:
        model = TimeEntry
        fields = [
            'id',
            'user',
            'date',
            'start_time',
            'end_time',
            'created_at',
            'updated_at',
            'duration',
            'day_of_week',
        ]
        read_only_fields = [
            'id',
            'user',
            'created_at',
            'updated_at',
            'duration',
            'day_of_week',
        ]

    def create(self, validated_data):
        validated_data['user'] = self.context['request'].user
        return super().create(validated_data)

    def update(self, instance, validated_data):
        validated_data.pop('user', None)
        return super().update(instance, validated_data)


class TimeEntryCreateSerializer(serializers.ModelSerializer):
    user_id = serializers.PrimaryKeyRelatedField(
        source='user',
        queryset=User.objects.all(),
        write_only=True,
        required=False,
    )

    class Meta:
        model = TimeEntry
        fields = ['user_id', '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’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.CharField()
    username = serializers.CharField()
    total_hours = serializers.FloatField()
    entries = serializers.ListField(child=serializers.DictField())