steeldonutcollection/frontend/templatetags/playlists.py

from random import choices

from django import template

from backend.models import Playlist


register = template.Library()


@register.simple_tag
def other_videos(playlist, video, count=4):
    videos = playlist.videos.all().order_by("-published")

    older = sorted(
        list(videos.filter(published__lt=video.published)), key=lambda x: x.published)
    newer = sorted(
        list(videos.filter(published__gt=video.published)), key=lambda x: x.published)

    newer_out = newer[:count-1]
    older_out = older[-count+len(newer_out):]

    return sorted(older_out + newer_out, key=lambda x: x.published)

@register.simple_tag
def next_video(playlist, video):
    try:
        return playlist.videos.filter(published__gt=video.published).order_by('published').first()
    except:
        return None