'use strict';

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_commands ?
      this.#page.on_response_received_commands_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 response = await this.#continuation[0].endpoint.call(this.#actions);

      return response;
    }

    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;