interface MediaItem {
  ...
}

interface PlaylistMeta {
  ...
}

// Maybe a generic parameter for the options object?
// Maybe a generic parameter for the SourceData?
abstract class MediaSource {
  static api: number = 3;
  static name: string;

  // This schema would automatically be merged with an `{ enabled: { type: boolean } }` schema using `allOf`
  static schema: JSONSchema;
  
  constructor(options: object /* or maybe a generic type */);

  get(context: SourceContext, sourceIDs: string[]): Promise<MediaItem[]>;
  search(context: SourceContext, query: string, pagination?: any): Promise<MediaItem[]>;

  // Get media items in a playlist. sourceID may be ID or a playlist URL or etc
  // optional
  getPlaylistItems(context: SourceContext, sourceID: string): Promise<MediaItem[]>;
  // Get playlists owned by the user [throw error if user has no connected account]
  // optional
  getSelfPlaylists(context: SourceContext): Promise<PlaylistMeta[]>;
  // Get (public) playlists owned by some other user or similar concept.
  // optional
  getUserPlaylists(context: SourceContext, userID: string): Promise<PlaylistMeta[]>;
  // maybe?
  // optional
  searchPlaylists(context: SourceContext, query: string): Promise<PlaylistMeta[]>;  

  // optional
  close(): Promise<void> | void {}
}

import { createMediaSource, MediaSource } = require('@u-wave/media-source');

class YouTubeSource implements MediaSource {
  // ...
}

export = createMediaSource(YouTubeSource, {
  name: 'youtube',
  schema: {
    // ...
  },
})