Dovodi_Backend/apps/library/serializers_admin.py

from rest_framework import serializers

from .models import Book, BookCollection, Category


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 AdminLibraryCategorySerializer(serializers.ModelSerializer):
    class Meta:
        model = Category
        fields = ["id", "title", "slug", "status", "created_at", "updated_at"]


class AdminLibraryCollectionSerializer(serializers.ModelSerializer):
    class Meta:
        model = BookCollection
        fields = ["id", "title", "slug", "summary", "display_position", "status", "order", "pin_top"]


class AdminBookListSerializer(serializers.ModelSerializer):
    thumbnail = AbsoluteImageField(required=False, allow_null=True)
    book_file = AbsoluteFileField(required=False, allow_null=True)
    categories_detail = AdminLibraryCategorySerializer(source="categories", many=True, read_only=True)

    class Meta:
        model = Book
        fields = [
            "id",
            "title",
            "slug",
            "slogan",
            "thumbnail",
            "author",
            "publisher",
            "file_type",
            "status",
            "pin",
            "view_count",
            "download_count",
            "created_at",
            "updated_at",
            "categories_detail",
            "book_file",
        ]
        read_only_fields = ["id", "view_count", "download_count", "created_at", "updated_at"]

from dj_language.models import Language
class AdminBookDetailSerializer(serializers.ModelSerializer):
    thumbnail = AbsoluteImageField(required=False, allow_null=True)
    book_file = AbsoluteFileField(required=False, allow_null=True)
    categories = serializers.PrimaryKeyRelatedField(queryset=Category.objects.all(), many=True, required=False)
    collections = serializers.PrimaryKeyRelatedField(queryset=BookCollection.objects.all(), many=True, required=False)
    categories_detail = AdminLibraryCategorySerializer(source="categories", many=True, read_only=True)
    collections_detail = AdminLibraryCollectionSerializer(source="collections", many=True, read_only=True)
    remove_thumbnail = serializers.BooleanField(write_only=True, required=False, default=False)
    remove_book_file = serializers.BooleanField(write_only=True, required=False, default=False)
    language = serializers.SlugRelatedField(
        slug_field='code', 
        queryset=Language.objects.all(),
        allow_null=True,
        required=False
    )

    class Meta:
        model = Book
        fields = [
            "id",
            "title",
            "slug",
            "slogan",
            "summary_title",
            "summary",
            "description",
            "thumbnail",
            "publisher",
            "year_of_publication",
            "author",
            "isbn",
            "numnber_of_volume",
            "language",
            "main_themes",
            "notable_works",
            "pages_count",
            "status",
            "pin",
            "view_count",
            "download_count",
            "file_type",
            "book_file",
            "created_at",
            "updated_at",
            "categories",
            "collections",
            "categories_detail",
            "collections_detail",
            "remove_thumbnail",
            "remove_book_file",
        ]
        read_only_fields = ["id", "view_count", "download_count", "created_at", "updated_at"]

    def create(self, validated_data):
        validated_data.pop("remove_thumbnail", False)
        validated_data.pop("remove_book_file", False)
        categories = validated_data.pop("categories", [])
        collections = validated_data.pop("collections", [])
        book = super().create(validated_data)
        if categories:
            book.categories.set(categories)
        if collections:
            book.collections.set(collections)
        return book

    def update(self, instance, validated_data):
        remove_thumbnail = validated_data.pop("remove_thumbnail", False)
        remove_book_file = validated_data.pop("remove_book_file", False)
        categories = validated_data.pop("categories", None)
        collections = validated_data.pop("collections", None)

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

        if remove_book_file and instance.book_file:
            instance.book_file.delete(save=False)
            instance.book_file = None

        book = super().update(instance, validated_data)
        if categories is not None:
            book.categories.set(categories)
        if collections is not None:
            book.collections.set(collections)
        return book