@snwfdhmp/soundcloud-downloader/src/info.ts

Download Soundcloud audio with Node.js, this is a forked version, the original script was written by @zackradisic and forked by @nasheedstation

/* eslint-disable camelcase */
import { AxiosInstance } from "axios";
import {
  handleRequestErrs,
  appendURL,
  extractIDFromPersonalizedTrackURL,
} from "./util";

import STREAMING_PROTOCOLS from "./protocols";
import FORMATS from "./formats";

/**
 * A Soundcloud user
 */
export interface User {
  kind: string;
  avatar_url: string;
  city: string;
  comments_count: number;
  country_code: string;
  created_at: string;
  description: string;
  followers_count: number;
  followings_count: number;
  first_name: string;
  full_name: string;
  groups_count: number;
  id: number;
  last_name: string;
  permalink_url: string;
  uri: string;
  username: string;
}

/**
 * Details about the track
 */
export interface TrackInfo {
  kind: string;
  monetization_model: string;
  id: number;
  policy: string;
  comment_count?: number;
  full_duration?: number;
  downloadable?: false;
  created_at?: string;
  description?: string;
  media?: { transcodings: Transcoding[] };
  title?: string;
  publisher_metadata?: string;
  duration?: number;
  has_downloads_left?: boolean;
  artwork_url?: string;
  public?: boolean;
  streamable?: true;
  tag_list?: string;
  genre?: string;
  reposts_count?: number;
  label_name?: string;
  state?: string;
  last_modified?: string;
  commentable?: boolean;
  uri?: string;
  download_count?: number;
  likes_count?: number;
  display_date?: string;
  user_id?: number;
  waveform_url?: string;
  permalink?: string;
  permalink_url?: string;
  user?: User;
  playback_count?: number;
}

/**
 * Details about a Set
 */
export interface SetInfo {
  duration: number;
  permalink_url: string;
  reposts_count: number;
  genre: string;
  permalink: string;
  purchase_url?: string;
  description?: string;
  uri: string;
  label_name?: string;
  tag_list: string;
  set_type: string;
  public: boolean;
  track_count: number;
  user_id: number;
  last_modified: string;
  license: string;
  tracks: TrackInfo[];
  id: number;
  release_date?: string;
  display_date: string;
  sharing: string;
  secret_token?: string;
  created_at: string;
  likes_count: number;
  kind: string;
  purchase_title?: string;
  managed_by_feeds: boolean;
  artwork_url?: string;
  is_album: boolean;
  user: User;
  published_at: string;
  embeddable_by: string;
}

/**
 * Represents an audio link to a Soundcloud Track
 */
export interface Transcoding {
  url: string;
  preset: string;
  snipped: boolean;
  format: { protocol: STREAMING_PROTOCOLS; mime_type: FORMATS };
}

const getTrackInfoBase = async (
  clientID: string,
  axiosRef: AxiosInstance,
  ids: number[],
  playlistID?: number,
  playlistSecretToken?: string
): Promise<TrackInfo[]> => {
  let url = appendURL(
    "https://api-v2.soundcloud.com/tracks",
    "ids",
    ids.join(","),
    "client_id",
    clientID
  );
  if (playlistID && playlistSecretToken) {
    url = appendURL(
      url,
      "playlistId",
      "" + playlistID,
      "playlistSecretToken",
      playlistSecretToken
    );
  }
  try {
    const { data } = await axiosRef.get(url);

    return data as TrackInfo[];
  } catch (err) {
    throw handleRequestErrs(err);
  }
};

/** @internal */
export const getInfoBase = async <T extends TrackInfo | SetInfo>(
  url: string,
  clientID: string,
  axiosRef: AxiosInstance
): Promise<T> => {
  try {
    const res = await axiosRef.get(
      appendURL(
        "https://api-v2.soundcloud.com/resolve",
        "url",
        url,
        "client_id",
        clientID
      ),
      {
        withCredentials: true,
      }
    );

    return res.data as T;
  } catch (err) {
    throw handleRequestErrs(err);
  }
};

/** @internal */
const getSetInfoBase = async (
  url: string,
  clientID: string,
  axiosRef: AxiosInstance
): Promise<SetInfo> => {
  const setInfo = await getInfoBase<SetInfo>(url, clientID, axiosRef);
  const temp = [...setInfo.tracks].map((track) => track.id);
  const playlistID = setInfo.id;
  const playlistSecretToken = setInfo.secret_token;
  const incompleteTracks = setInfo.tracks.filter((track) => !track.title);
  if (incompleteTracks.length === 0) {
    return setInfo;
  }
  const completeTracks = setInfo.tracks.filter((track) => track.title);

  const ids = incompleteTracks.map((t) => t.id);
  if (ids.length > 50) {
    const splitIds: number[][] = [];
    for (let x = 0; x <= Math.floor(ids.length / 50); x++) {
      splitIds.push([]);
    }

    for (let x = 0; x < ids.length; x++) {
      const i = Math.floor(x / 50);
      splitIds[i].push(ids[x]);
    }

    const promises = splitIds.map(
      async (ids) =>
        await getTrackInfoByID(
          clientID,
          axiosRef,
          ids,
          playlistID,
          playlistSecretToken
        )
    );
    const info = await Promise.all(promises);
    setInfo.tracks = completeTracks.concat(...info);
    setInfo.tracks = sortTracks(setInfo.tracks, temp);
    return setInfo;
  }
  const info = await getTrackInfoByID(
    clientID,
    axiosRef,
    ids,
    playlistID,
    playlistSecretToken
  );

  setInfo.tracks = completeTracks.concat(info);
  setInfo.tracks = sortTracks(setInfo.tracks, temp);
  return setInfo;
};

/** @internal */
const sortTracks = (tracks: TrackInfo[], ids: number[]): TrackInfo[] => {
  for (let i = 0; i < ids.length; i++) {
    if (tracks[i].id !== ids[i]) {
      for (let j = 0; j < tracks.length; j++) {
        if (tracks[j].id === ids[i]) {
          const temp = tracks[i];
          tracks[i] = tracks[j];
          tracks[j] = temp;
        }
      }
    }
  }

  return tracks;
};

/** @internal */
const getInfo = async (
  url: string,
  clientID: string,
  axiosInstance: AxiosInstance
): Promise<TrackInfo> => {
  let data;
  if (
    url.includes("https://soundcloud.com/discover/sets/personalized-tracks::")
  ) {
    const idString = extractIDFromPersonalizedTrackURL(url);
    if (!idString)
      throw new Error("Could not parse track ID from given URL: " + url);
    let id: number;
    try {
      id = parseInt(idString);
    } catch (err) {
      throw new Error("Could not parse track ID from given URL: " + url);
    }

    data = (await getTrackInfoByID(clientID, axiosInstance, [id]))[0];
    if (!data) throw new Error("Could not find track with ID: " + id);
  } else {
    data = await getInfoBase<TrackInfo>(url, clientID, axiosInstance);
  }
  if (!data.media)
    throw new Error("The given URL does not link to a Soundcloud track");
  return data;
};

/** @internal */
export const getSetInfo = async (
  url: string,
  clientID: string,
  axiosInstance: AxiosInstance
): Promise<SetInfo> => {
  const data = await getSetInfoBase(url, clientID, axiosInstance);
  if (!data.tracks)
    throw new Error("The given URL does not link to a Soundcloud set");
  return data;
};

/** @intenral */
export const getTrackInfoByID = async (
  clientID: string,
  axiosInstance: AxiosInstance,
  ids: number[],
  playlistID?: number,
  playlistSecretToken?: string
): Promise<TrackInfo[]> => {
  return await getTrackInfoBase(
    clientID,
    axiosInstance,
    ids,
    playlistID,
    playlistSecretToken
  );
};
export default getInfo;