Find playlist by name

import { Client, Playlist } from '[email protected]';

import { Paging } from "spotify-types";

type Spotify = {

  token: string;

}

const MAX_PLAYLISTS_PER_PAGE = 50; // this is the max limit allowed by the API

export async function main(

  spotifyCredentials: Spotify,

  playlistName: string,

  fetchIntervalMs: number = 1000,

  failOnNotFound: boolean = false

): Promise<Playlist | null> {

  const client = await Client.create({

    token: spotifyCredentials.token,

    userAuthorizedToken: true

  });

  console.log(`Finding playlist with name '${playlistName}'`);

  let offset = 0;

  while (true) {

      const result: Paging<Playlist | null> = await client.fetch('/me/playlists', {

        params: {

          limit: MAX_PLAYLISTS_PER_PAGE,

          offset: offset

        }

      });

      const playlists = result.items.filter((item): item is Playlist => item !== null);

      offset += playlists.length;

      console.log(`Fetched ${playlists.length} valid (non-null) playlists (${offset} total)`);

      for (const playlist of playlists) {

        if (playlist.name === playlistName) {

          console.log(`Found playlist '${playlist.name}' (id: ${playlist.id})`)

          return playlist;

        }

      }

      if (result.items.length < MAX_PLAYLISTS_PER_PAGE) {

        break;

      }

      // wait for a specified interval between calls to avoid being rate limited

      await new Promise(res => setTimeout(res, fetchIntervalMs));

  }

  const errorMessage = `Failed to find playlist with name '${playlistName}'`;

  console.error(errorMessage);

  if (failOnNotFound) {

    throw new Error(errorMessage);

  }

  return null;

}