from rest_framework import serializers
from .models import Comment, Rating, Like, Favorite


class CommentSerializer(serializers.ModelSerializer):
    """Serializer for Comment model."""

    target_type_display = serializers.CharField(source='get_target_type_display', read_only=True)
    ai_status_display = serializers.CharField(source='get_ai_status_display', read_only=True)
    author_username = serializers.CharField(source='author.username', read_only=True)

    class Meta:
        model = Comment
        fields = ('id', 'content', 'target_type', 'target_type_display', 'target_id',
                  'author', 'author_username', 'ai_status', 'ai_status_display',
                  'ai_rejection_reason', 'created_at')
        read_only_fields = ('id', 'author', 'ai_status', 'ai_rejection_reason', 'created_at')

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


class CommentCreateSerializer(serializers.ModelSerializer):
    """Serializer for creating comments."""

    class Meta:
        model = Comment
        fields = ('content', 'target_type', 'target_id')

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


class RatingSerializer(serializers.ModelSerializer):
    """Serializer for Rating model."""

    target_type_display = serializers.CharField(source='get_target_type_display', read_only=True)
    user_username = serializers.CharField(source='user.username', read_only=True)

    class Meta:
        model = Rating
        fields = ('id', 'user', 'user_username', 'target_type', 'target_type_display',
                  'target_id', 'score', 'created_at')
        read_only_fields = ('id', 'user', 'created_at')

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


class RatingCreateSerializer(serializers.ModelSerializer):
    """Serializer for creating/updating ratings."""

    class Meta:
        model = Rating
        fields = ('target_type', 'target_id', 'score')

    def create(self, validated_data):
        validated_data['user'] = self.context['request'].user
        # Check if rating already exists
        Rating.objects.filter(
            user=validated_data['user'],
            target_type=validated_data['target_type'],
            target_id=validated_data['target_id']
        ).delete()
        return super().create(validated_data)


class LikeSerializer(serializers.ModelSerializer):
    """Serializer for Like model."""

    target_type_display = serializers.CharField(source='get_target_type_display', read_only=True)
    user_username = serializers.CharField(source='user.username', read_only=True)

    class Meta:
        model = Like
        fields = ('id', 'user', 'user_username', 'target_type', 'target_type_display',
                  'target_id', 'created_at')
        read_only_fields = ('id', 'user', 'created_at')


class FavoriteSerializer(serializers.ModelSerializer):
    """Serializer for Favorite model."""

    target_type_display = serializers.CharField(source='get_target_type_display', read_only=True)
    user_username = serializers.CharField(source='user.username', read_only=True)

    class Meta:
        model = Favorite
        fields = ('id', 'user', 'user_username', 'target_type', 'target_type_display',
                  'target_id', 'created_at')
        read_only_fields = ('id', 'user', 'created_at')


class FavoriteCreateSerializer(serializers.ModelSerializer):
    """Serializer for creating/removing favorites."""

    class Meta:
        model = Favorite
        fields = ('target_type', 'target_id')

    def create(self, validated_data):
        validated_data['user'] = self.context['request'].user
        # Check if favorite already exists
        existing = Favorite.objects.filter(
            user=validated_data['user'],
            target_type=validated_data['target_type'],
            target_id=validated_data['target_id']
        ).first()

        if existing:
            existing.delete()
            return None  # Return None to indicate removal

        return super().create(validated_data)