from rest_framework import serializers

from .models import Video


class AbsoluteImageField(serializers.ImageField):
    def to_representation(self, value):
        if not value:
            return None
        request = self.context.get("request")
        url = value.url if hasattr(value, "url") else str(value)
        if request:
            return request.build_absolute_uri(url)
        return url


class AbsoluteFileField(serializers.FileField):
    def to_representation(self, value):
        if not value:
            return None
        request = self.context.get("request")
        url = value.url if hasattr(value, "url") else str(value)
        if request:
            return request.build_absolute_uri(url)
        return url


class AdminVideoListSerializer(serializers.ModelSerializer):
    thumbnail = AbsoluteImageField(required=False, allow_null=True)
    video_file = AbsoluteFileField(required=False, allow_null=True)

    class Meta:
        model = Video
        fields = [
            "id",
            "title",
            "slug",
            "thumbnail",
            "description",
            "video_type",
            "video_file",
            "video_url",
            "video_time",
            "status",
            "view_count",
            "created_at",
            "updated_at",
        ]
        read_only_fields = ["id", "view_count", "created_at", "updated_at"]


class AdminVideoDetailSerializer(serializers.ModelSerializer):
    thumbnail = AbsoluteImageField(required=False, allow_null=True)
    video_file = AbsoluteFileField(required=False, allow_null=True)
    remove_thumbnail = serializers.BooleanField(write_only=True, required=False, default=False)
    remove_video_file = serializers.BooleanField(write_only=True, required=False, default=False)

    class Meta:
        model = Video
        fields = [
            "id",
            "title",
            "slug",
            "thumbnail",
            "description",
            "video_type",
            "video_file",
            "video_url",
            "video_time",
            "status",
            "view_count",
            "created_at",
            "updated_at",
            "remove_thumbnail",
            "remove_video_file",
        ]
        read_only_fields = ["id", "view_count", "created_at", "updated_at"]

    def validate(self, attrs):
        video_type = attrs.get("video_type", getattr(self.instance, "video_type", None))
        video_url = attrs.get("video_url", getattr(self.instance, "video_url", None))
        video_file = attrs.get("video_file", getattr(self.instance, "video_file", None))
        remove_video_file = attrs.get("remove_video_file", False)

        if video_type == Video.VedioTypeChoices.YOUTUBE_LINK and not video_url:
            raise serializers.ValidationError({
                "video_url": "This field is required when video type is link.",
            })

        if video_type == Video.VedioTypeChoices.VIDEO_FILE and not video_file and not getattr(self.instance, "video_file", None):
            raise serializers.ValidationError({
                "video_file": "This field is required when video type is file.",
            })

        if video_type == Video.VedioTypeChoices.VIDEO_FILE and remove_video_file and "video_file" not in attrs:
            raise serializers.ValidationError({
                "video_file": "Please upload a new file before removing the current one.",
            })

        return attrs

    def create(self, validated_data):
        validated_data.pop("remove_thumbnail", False)
        validated_data.pop("remove_video_file", False)
        return super().create(validated_data)

    def update(self, instance, validated_data):
        remove_thumbnail = validated_data.pop("remove_thumbnail", False)
        remove_video_file = validated_data.pop("remove_video_file", False)

        if remove_thumbnail and instance.thumbnail:
            instance.thumbnail.delete(save=False)
            instance.thumbnail = None

        if remove_video_file and instance.video_file:
            instance.video_file.delete(save=False)
            instance.video_file = None

        return super().update(instance, validated_data)