from rest_framework import serializers
from django.core.files.uploadedfile import SimpleUploadedFile
from utils.image_compression import maybe_compress_uploaded_file

from .models import PlaylistItem, Podcast, PodcastCategory, PodcastCollection, PodcastPlaylist


class AbsoluteImageField(serializers.ImageField):
    def to_internal_value(self, data):
        uploaded = super().to_internal_value(data)
        compressed_bytes = maybe_compress_uploaded_file(uploaded)
        if compressed_bytes is None:
            return uploaded

        return SimpleUploadedFile(
            name=getattr(uploaded, "name", "image"),
            content=compressed_bytes,
            content_type=getattr(uploaded, "content_type", None),
        )

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


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


class AdminPodcastListSerializer(serializers.ModelSerializer):
    thumbnail = AbsoluteImageField(required=False, allow_null=True)
    audio_file = AbsoluteFileField(required=False, allow_null=True)
    categories_detail = AdminPodcastCategorySerializer(source="categories", many=True, read_only=True)
    collections_detail = AdminPodcastCollectionSerializer(source="collections", many=True, read_only=True)

    class Meta:
        model = Podcast
        fields = [
            "id",
            "title",
            "slug",
            "thumbnail",
            "status",
            "view_count",
            "download_count",
            "created_at",
            "updated_at",
            "categories_detail",
            "collections_detail",
            "audio_file"
        ]
        read_only_fields = ["id", "view_count", "download_count", "created_at", "updated_at"]

class AdminPodcastDetailSerializer(serializers.ModelSerializer):
    thumbnail = AbsoluteImageField(required=False, allow_null=True)
    audio_file = AbsoluteFileField(required=False, allow_null=True)
    audio_time = serializers.TimeField(required=False)
    categories = serializers.PrimaryKeyRelatedField(queryset=PodcastCategory.objects.all(), many=True, required=False)
    collections = serializers.PrimaryKeyRelatedField(queryset=PodcastCollection.objects.all(), many=True, required=False)
    categories_detail = AdminPodcastCategorySerializer(source="categories", many=True, read_only=True)
    collections_detail = AdminPodcastCollectionSerializer(source="collections", many=True, read_only=True)
    remove_thumbnail = serializers.BooleanField(write_only=True, required=False, default=False)
    remove_audio_file = serializers.BooleanField(write_only=True, required=False, default=False)

    bookmark_count = serializers.SerializerMethodField()

    class Meta:
        model = Podcast
        fields = [
            "id",
            "title",
            "slug",
            "thumbnail",
            "description",
            "audio_file",
            "audio_time",
            "status",
            "view_count",
            "download_count",
            "bookmark_count",
            "created_at",
            "updated_at",
            "categories",
            "collections",
            "categories_detail",
            "collections_detail",
            "remove_thumbnail",
            "remove_audio_file",
        ]
        read_only_fields = ["id", "view_count", "download_count", "bookmark_count", "created_at", "updated_at"]

    def get_bookmark_count(self, obj):
        from apps.bookmark.models.bookmark import Bookmark
        return Bookmark.objects.filter(service=Bookmark.ServiceChoices.PODCAST, content_id=obj.id, status=True).count()

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

    def update(self, instance, validated_data):
        remove_thumbnail = validated_data.pop("remove_thumbnail", False)
        remove_audio_file = validated_data.pop("remove_audio_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_audio_file and instance.audio_file:
            instance.audio_file.delete(save=False)
            instance.audio_file = None

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


class AdminPodcastPlaylistItemPodcastSerializer(serializers.ModelSerializer):
    thumbnail = AbsoluteImageField(required=False, allow_null=True)

    class Meta:
        model = Podcast
        fields = ["id", "title", "slug", "thumbnail", "audio_time", "status"]


class AdminPodcastPlaylistItemSerializer(serializers.ModelSerializer):
    podcast_detail = AdminPodcastPlaylistItemPodcastSerializer(source="podcast", read_only=True)

    class Meta:
        model = PlaylistItem
        fields = ["id", "playlist", "podcast", "priority", "created_at", "updated_at", "podcast_detail"]
        read_only_fields = ["id", "created_at", "updated_at", "podcast_detail"]

    def validate(self, attrs):
        playlist = attrs.get("playlist", getattr(self.instance, "playlist", None))
        podcast = attrs.get("podcast", getattr(self.instance, "podcast", None))
        if playlist and podcast:
            query = PlaylistItem.objects.filter(podcast=podcast).exclude(playlist=playlist)
            if self.instance:
                query = query.exclude(pk=self.instance.pk)
            existing = query.select_related("playlist").first()
            if existing:
                raise serializers.ValidationError({
                    "podcast": f'This podcast is already used in playlist "{existing.playlist.title}".',
                })
        return attrs


class AdminPodcastPlaylistListSerializer(serializers.ModelSerializer):
    thumbnail = AbsoluteImageField(required=False, allow_null=True)
    categories_detail = AdminPodcastCategorySerializer(source="categories", many=True, read_only=True)
    collections_detail = AdminPodcastCollectionSerializer(source="collections", many=True, read_only=True)
    items_count = serializers.SerializerMethodField()

    class Meta:
        model = PodcastPlaylist
        fields = [
            "id",
            "title",
            "slug",
            "thumbnail",
            "slogan",
            "status",
            "order",
            "view_count",
            "total_time",
            "created_at",
            "updated_at",
            "categories_detail",
            "collections_detail",
            "items_count",
        ]
        read_only_fields = ["id", "view_count", "total_time", "created_at", "updated_at", "items_count"]

    def get_items_count(self, obj):
        return obj.playlist_items.count()


class AdminPodcastPlaylistDetailSerializer(serializers.ModelSerializer):
    thumbnail = AbsoluteImageField(required=False, allow_null=True)
    categories = serializers.PrimaryKeyRelatedField(queryset=PodcastCategory.objects.all(), many=True, required=False)
    collections = serializers.PrimaryKeyRelatedField(queryset=PodcastCollection.objects.all(), many=True, required=False)
    categories_detail = AdminPodcastCategorySerializer(source="categories", many=True, read_only=True)
    collections_detail = AdminPodcastCollectionSerializer(source="collections", many=True, read_only=True)
    playlist_items_detail = AdminPodcastPlaylistItemSerializer(source="playlist_items", many=True, read_only=True)
    remove_thumbnail = serializers.BooleanField(write_only=True, required=False, default=False)

    bookmark_count = serializers.SerializerMethodField()

    class Meta:
        model = PodcastPlaylist
        fields = [
            "id",
            "title",
            "slug",
            "slogan",
            "description",
            "thumbnail",
            "order",
            "status",
            "view_count",
            "bookmark_count",
            "total_time",
            "created_at",
            "updated_at",
            "categories",
            "collections",
            "categories_detail",
            "collections_detail",
            "playlist_items_detail",
            "remove_thumbnail",
        ]
        read_only_fields = ["id", "view_count", "bookmark_count", "total_time", "created_at", "updated_at", "playlist_items_detail"]

    def get_bookmark_count(self, obj):
        from apps.bookmark.models.bookmark import Bookmark
        return Bookmark.objects.filter(service=Bookmark.ServiceChoices.PODCAST_PLAYLIST, content_id=obj.id, status=True).count()

    def create(self, validated_data):
        validated_data.pop("remove_thumbnail", False)
        categories = validated_data.pop("categories", [])
        collections = validated_data.pop("collections", [])
        playlist = super().create(validated_data)
        if categories:
            playlist.categories.set(categories)
        if collections:
            playlist.collections.set(collections)
        playlist.total_time = playlist.calculate_total_time()
        playlist.save(update_fields=["total_time"])
        return playlist

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

        playlist = super().update(instance, validated_data)
        if categories is not None:
            playlist.categories.set(categories)
        if collections is not None:
            playlist.collections.set(collections)
        playlist.total_time = playlist.calculate_total_time()
        playlist.save(update_fields=["total_time"])
        return playlist