from rest_framework import serializers
from .models import VideoCategory, Video, VideoCollection, VideoInCollection


class VideoCategoryListSerializer(serializers.ModelSerializer):
    video_count = serializers.SerializerMethodField()

    class Meta:
        model = VideoCategory
        fields = ['id', 'title', 'slug', 'video_count']

    def get_video_count(self, obj):
        return obj.videos.filter(status=True).count()


class VideoListSerializer(serializers.ModelSerializer):
    categories = VideoCategoryListSerializer(many=True, read_only=True)
    
    class Meta:
        model = Video
        fields = ['id', 'title', 'slug', 'thumbnail', 'description', 'video_time', 
                  'view_count', 'categories', 'created_at']

    



class VideoDetailSerializer(serializers.ModelSerializer):
    related_videos = serializers.SerializerMethodField()
    categories = VideoCategoryListSerializer(many=True, read_only=True)

    class Meta:
        model = Video
        fields = ['id', 'title', 'slug', 'thumbnail', 'description', 'video_type',
                  'video_file', 'video_url', 'video_time', 'view_count', 
                  'categories', 'created_at', 'related_videos']


    def get_related_videos(self, obj):
        # Get all collections that contain this video
        collections = obj.collections.all()

        if collections.exists():
            # Get all videos from all collections that contain this video
            related_videos = []
            video_ids = set()  # To track unique videos

            for collection in collections:
                # Get all videos in this collection ordered by priority
                videos_in_collection = VideoInCollection.objects.filter(
                    video_collection=collection
                ).exclude(video=obj).order_by('priority')

                # Add videos to our list if not already added
                for vic in videos_in_collection:
                    if vic.video.id not in video_ids:
                        related_videos.append(vic.video)
                        video_ids.add(vic.video.id)

            # Return the related videos using VideoListSerializer
            return VideoListSerializer(related_videos, many=True).data

        # # If not in a collection, return videos from the same category
        # elif obj.category:
        #     related = Video.objects.filter(
        #         category=obj.category,
        #         status=True
        #     ).exclude(id=obj.id)[:5]
        #     return VideoListSerializer(related, many=True).data
        return []