YouTube.js/lib/core/Feed.js

const ResultsParser = require('../parser/contents');
const { InnertubeError } = require('../utils/Utils');

// TODO: add a way subdivide into sections and return subfeeds?

class Feed {
    #page;
    /**
     * @type {import('../parser/contents/classes/ContinuationItem')[]}
     */
    #continuation;
    /**
     * @type {import('../core/Actions')}
     */
    #actions;

    memo;
    constructor(actions, data, already_parsed = false) {
        if (data.on_response_received_actions || data.on_response_received_endpoints || already_parsed)
            this.#page = data;
        else
            this.#page = ResultsParser.parseResponse(data);
        this.memo = 
            this.#page.on_response_received_actions ? 
                this.#page.on_response_received_actions_memo : 
            this.#page.on_response_received_endpoints ? 
                this.#page.on_response_received_endpoints_memo : 
                this.#page.contents_memo;
        
        this.#actions = actions;
    }


    /**
     * Get the original page data
     */
    get page() {
        return this.#page;
    }

    get actions() {
        return this.#actions;
    }

    /**
     * Get all videos on a given page via memo
     *
     * @param {Map<string, any[]>} memo
     * @returns {Array<import('../parser/contents/classes/Video') | import('../parser/contents/classes/GridVideo') | import('../parser/contents/classes/CompactVideo') | import('../parser/contents/classes/PlaylistVideo') | import('../parser/contents/classes/PlaylistPanelVideo') | import('../parser/contents/classes/WatchCardCompactVideo')>}
     */
    static getVideosFromMemo(memo) {
        const videos = memo.get('Video') || [];
        const grid_videos = memo.get('GridVideo') || [];
        const compact_videos = memo.get('CompactVideo') || [];
        const playlist_videos = memo.get('PlaylistVideo') || [];
        const playlist_panel_videos = memo.get('PlaylistPanelVideo') || [];
        const watch_card_compact_videos = memo.get('WatchCardCompactVideo') || [];
        return [...videos, ...grid_videos, ...compact_videos, ...playlist_videos, ...playlist_panel_videos, ...watch_card_compact_videos];
    }

    /**
     * Get all playlists on a given page via memo
     *
     * @param {Map<string, any[]>} memo
     * @returns {Array<import('../parser/contents/classes/Playlist') | import('../parser/contents/classes/GridPlaylist')>}
     */
    static getPlaylistsFromMemo(memo) {
        const playlists = memo.get('Playlist') || [];
        const grid_playlists = memo.get('GridPlaylist') || [];
        return [...playlists, ...grid_playlists];
    }

    /**
     * Get all the videos in the feed
     */
    get videos() {
        return Feed.getVideosFromMemo(this.memo);
    }

    /**
     * Get all playlists in the feed
     *
     * @returns {Array<import('../parser/contents/classes/Playlist') | import('../parser/contents/classes/GridPlaylist')>}
     */
    get playlists() {
        return Feed.getPlaylistsFromPage(this.memo);
    }

    /**
     * Get all the community posts in the feed
     *
     * @returns {import('../parser/contents/classes/BackstagePost')[]}
     */
    get backstage_posts() {
        return this.memo.get('BackstagePost');
    }

    /**
     * Get all the channels in the feed
     *
     * @returns {Array<import('../parser/contents/Channel') | import('../parser/contents/GridChannel')>}
     */
    get channels() {
        const channels = this.memo.get('Channel') || [];
        const grid_channels = this.memo.get('GridChannel') || [];
        return [...channels, ...grid_channels];
    }

    get has_continuation() {
        return (this.memo.get('ContinuationItem') || []).length > 0;
    }

    async getContinuationData() {
        if (this.#continuation) {
            if (this.#continuation.length > 1) 
                throw new InnertubeError('There are too many continuations, you\'ll need to find the correct one yourself in this.page');
            if (this.#continuation.length === 0)
                throw new InnertubeError('There are no continuations');
            const continuation = this.#continuation[0];
            return await continuation.endpoint.call(this.#actions);
        }

        this.#continuation = this.memo.get('ContinuationItem');

        if (this.#continuation) 
            return this.getContinuationData();
        
        return null;
    }

    get shelves() {
      return this.#page.contents_memo.get('Shelf');
    }
  
    getShelf(title) {
      return this.shelves.find(shelf => shelf.title.toString() === title);
    }
  
    get shelf_content() {
      return this.shelves.map(shelf => ({
        title: shelf.title.toString(),
        content: shelf.content.contents,
      }));
    }

    async getContinuation() {
        const continuation_data = await this.getContinuationData();

        return new Feed(this.actions, continuation_data, true);
    }
}

module.exports = Feed;