Musare/backend/logic/stations.js

import async from "async";
import mongoose from "mongoose";

import CoreClass from "../core";

let StationsModule;
let CacheModule;
let DBModule;
let UtilsModule;
let WSModule;
let SongsModule;
let PlaylistsModule;
let NotificationsModule;

class _StationsModule extends CoreClass {
	// eslint-disable-next-line require-jsdoc
	constructor() {
		super("stations");

		StationsModule = this;
	}

	/**
	 * Initialises the stations module
	 *
	 * @returns {Promise} - returns promise (reject, resolve)
	 */
	async initialize() {
		CacheModule = this.moduleManager.modules.cache;
		DBModule = this.moduleManager.modules.db;
		UtilsModule = this.moduleManager.modules.utils;
		WSModule = this.moduleManager.modules.ws;
		SongsModule = this.moduleManager.modules.songs;
		PlaylistsModule = this.moduleManager.modules.playlists;
		NotificationsModule = this.moduleManager.modules.notifications;

		this.defaultSong = {
			songId: "60ItHLz5WEA",
			title: "Faded - Alan Walker",
			duration: 212,
			skipDuration: 0,
			likes: -1,
			dislikes: -1,
			requestedAt: Date.now()
		};

		this.userList = {};
		this.usersPerStation = {};
		this.usersPerStationCount = {};

		// TEMP
		CacheModule.runJob("SUB", {
			channel: "station.pause",
			cb: async stationId => {
				NotificationsModule.runJob("REMOVE", {
					subscription: `stations.nextSong?id=${stationId}`
				}).then();
			}
		});

		CacheModule.runJob("SUB", {
			channel: "station.resume",
			cb: async stationId => {
				StationsModule.runJob("INITIALIZE_STATION", { stationId }).then();
			}
		});

		CacheModule.runJob("SUB", {
			channel: "station.queueUpdate",
			cb: async stationId => {
				StationsModule.runJob("GET_STATION", { stationId }).then(station => {
					if (!station.currentSong && station.queue.length > 0) {
						StationsModule.runJob("INITIALIZE_STATION", {
							stationId
						}).then();
					}
				});
			}
		});

		CacheModule.runJob("SUB", {
			channel: "station.newOfficialPlaylist",
			cb: async stationId => {
				CacheModule.runJob("HGET", {
					table: "officialPlaylists",
					key: stationId
				}).then(playlistObj => {
					if (playlistObj) {
						WSModule.runJob("EMIT_TO_ROOM", {
							room: `station.${stationId}`,
							args: ["event:newOfficialPlaylist", playlistObj.songs]
						});
					}
				});
			}
		});

		const stationModel = (this.stationModel = await DBModule.runJob("GET_MODEL", { modelName: "station" }));
		const stationSchema = (this.stationSchema = await CacheModule.runJob("GET_SCHEMA", { schemaName: "station" }));

		return new Promise((resolve, reject) =>
			async.waterfall(
				[
					next => {
						this.setStage(2);
						CacheModule.runJob("HGETALL", { table: "stations" })
							.then(stations => {
								next(null, stations);
							})
							.catch(next);
					},

					(stations, next) => {
						this.setStage(3);

						if (!stations) return next();

						const stationIds = Object.keys(stations);

						return async.each(
							stationIds,
							(stationId, next) => {
								stationModel.findOne({ _id: stationId }, (err, station) => {
									if (err) next(err);
									else if (!station) {
										CacheModule.runJob("HDEL", {
											table: "stations",
											key: stationId
										})
											.then(() => {
												next();
											})
											.catch(next);
									} else next();
								});
							},
							next
						);
					},

					next => {
						this.setStage(4);
						stationModel.find({}, next);
					},

					(stations, next) => {
						this.setStage(5);
						async.each(
							stations,
							(station, next2) => {
								async.waterfall(
									[
										next => {
											CacheModule.runJob("HSET", {
												table: "stations",
												key: station._id,
												value: stationSchema(station)
											})
												.then(station => next(null, station))
												.catch(next);
										},

										(station, next) => {
											StationsModule.runJob(
												"INITIALIZE_STATION",
												{
													stationId: station._id
												},
												null,
												-1
											)
												.then(() => {
													next();
												})
												.catch(next);
										}
									],
									err => {
										next2(err);
									}
								);
							},
							next
						);
					}
				],
				async err => {
					if (err) {
						err = await UtilsModule.runJob("GET_ERROR", {
							error: err
						});
						reject(new Error(err));
					} else {
						resolve();
					}
				}
			)
		);
	}

	/**
	 * Initialises a station
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {string} payload.stationId - id of the station to initialise
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	INITIALIZE_STATION(payload) {
		return new Promise((resolve, reject) => {
			// if (typeof cb !== 'function') cb = ()=>{};

			async.waterfall(
				[
					next => {
						StationsModule.runJob(
							"GET_STATION",
							{
								stationId: payload.stationId
							},
							this
						)
							.then(station => {
								next(null, station);
							})
							.catch(next);
					},
					(station, next) => {
						if (!station) return next("Station not found.");

						return NotificationsModule.runJob(
							"UNSCHEDULE",
							{
								name: `stations.nextSong?id=${station._id}`
							},
							this
						)
							.then()
							.catch()
							.finally(() => {
								NotificationsModule.runJob("SUBSCRIBE", {
									name: `stations.nextSong?id=${station._id}`,
									cb: () =>
										StationsModule.runJob("SKIP_STATION", {
											stationId: station._id
										}),
									unique: true,
									station
								})
									.then()
									.catch();

								if (station.paused) return next(true, station);

								return next(null, station);
							});
					},
					(station, next) => {
						if (!station.currentSong) {
							return StationsModule.runJob(
								"SKIP_STATION",
								{
									stationId: station._id
								},
								this
							)
								.then(station => {
									next(true, station);
								})
								.catch(next)
								.finally(() => {});
						}

						let timeLeft =
							station.currentSong.duration * 1000 - (Date.now() - station.startedAt - station.timePaused);

						if (Number.isNaN(timeLeft)) timeLeft = -1;

						if (station.currentSong.duration * 1000 < timeLeft || timeLeft < 0) {
							return StationsModule.runJob(
								"SKIP_STATION",
								{
									stationId: station._id
								},
								this
							)
								.then(station => {
									next(null, station);
								})
								.catch(next);
						}
						// name, time, cb, station
						NotificationsModule.runJob("SCHEDULE", {
							name: `stations.nextSong?id=${station._id}`,
							time: timeLeft,
							station
						});

						return next(null, station);
					}
				],
				async (err, station) => {
					if (err && err !== true) {
						err = await UtilsModule.runJob(
							"GET_ERROR",
							{
								error: err
							},
							this
						);
						reject(new Error(err));
					} else resolve(station);
				}
			);
		});
	}

	/**
	 * Attempts to get the station from Redis. If it's not in Redis, get it from Mongo and add it to Redis.
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {string} payload.stationId - id of the station
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	GET_STATION(payload) {
		return new Promise((resolve, reject) => {
			async.waterfall(
				[
					next => {
						CacheModule.runJob("HGET", { table: "stations", key: payload.stationId }, this)
							.then(station => next(null, station))
							.catch(next);
					},

					(station, next) => {
						if (station) return next(true, station);
						return StationsModule.stationModel.findOne({ _id: payload.stationId }, next);
					},

					(station, next) => {
						if (station) {
							station = StationsModule.stationSchema(station);
							CacheModule.runJob("HSET", {
								table: "stations",
								key: payload.stationId,
								value: station
							})
								.then()
								.catch();
							next(true, station);
						} else next("Station not found");
					}
				],
				async (err, station) => {
					if (err && err !== true) {
						err = await UtilsModule.runJob(
							"GET_ERROR",
							{
								error: err
							},
							this
						);
						reject(new Error(err));
					} else resolve(station);
				}
			);
		});
	}

	/**
	 * Attempts to get a station by name, firstly from Redis. If it's not in Redis, get it from Mongo and add it to Redis.
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {string} payload.stationName - the unique name of the station
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	async GET_STATION_BY_NAME(payload) {
		return new Promise((resolve, reject) =>
			async.waterfall(
				[
					next => {
						StationsModule.stationModel.findOne({ name: payload.stationName }, next);
					},

					(station, next) => {
						if (station) {
							station = StationsModule.stationSchema(station);
							CacheModule.runJob("HSET", {
								table: "stations",
								key: station._id,
								value: station
							});
							next(true, station);
						} else next("Station not found");
					}
				],
				(err, station) => {
					if (err && err !== true) return reject(new Error(err));
					return resolve(station);
				}
			)
		);
	}

	/**
	 * Updates the station in cache from mongo or deletes station in cache if no longer in mongo.
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {string} payload.stationId - the id of the station to update
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	UPDATE_STATION(payload) {
		return new Promise((resolve, reject) => {
			async.waterfall(
				[
					next => {
						StationsModule.stationModel.findOne({ _id: payload.stationId }, next);
					},

					(station, next) => {
						if (!station) {
							CacheModule.runJob("HDEL", {
								table: "stations",
								key: payload.stationId
							})
								.then()
								.catch();
							return next("Station not found");
						}

						return CacheModule.runJob(
							"HSET",
							{
								table: "stations",
								key: payload.stationId,
								value: station
							},
							this
						)
							.then(station => {
								next(null, station);
							})
							.catch(next);
					}
				],
				async (err, station) => {
					if (err && err !== true) {
						err = await UtilsModule.runJob(
							"GET_ERROR",
							{
								error: err
							},
							this
						);
						reject(new Error(err));
					} else resolve(station);
				}
			);
		});
	}

	/**
	 * Fills up the official station playlist queue using the songs from the official station playlist
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {string} payload.stationId - the id of the station
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	FILL_UP_STATION_QUEUE_FROM_STATION_PLAYLIST(payload) {
		return new Promise((resolve, reject) => {
			const { stationId } = payload;
			async.waterfall(
				[
					next => {
						PlaylistsModule.runJob("GET_STATION_PLAYLIST", { stationId, includeSongs: true }, this)
							.then(response => {
								next(null, response.playlist);
							})
							.catch(next);
					},

					(playlist, next) => {
						UtilsModule.runJob("SHUFFLE", { array: playlist.songs }, this)
							.then(response => {
								next(null, response.array);
							})
							.catch(next);
					},

					(playlistSongs, next) => {
						StationsModule.runJob("GET_STATION", { stationId }, this)
							.then(station => {
								next(null, playlistSongs, station);
							})
							.catch(next);
					},

					(playlistSongs, station, next) => {
						const songsStillNeeded = 50 - station.queue.length;
						const currentSongs = station.queue;
						const currentSongIds = station.queue.map(song => song.songId);
						const songsToAdd = [];

						playlistSongs
							.map(song => song._doc)
							.every(song => {
								if (
									songsToAdd.length < songsStillNeeded &&
									currentSongIds.indexOf(song.songId) === -1
								) {
									songsToAdd.push(song);
									return true;
								}
								if (songsToAdd.length >= songsStillNeeded) return false;
								return true;
							});
						const newPlaylist = [...currentSongs, ...songsToAdd].map(song => {
							if (!song._id) song._id = null;
							return song;
						});
						next(null, newPlaylist);
					},

					(newPlaylist, next) => {
						StationsModule.stationModel.updateOne(
							{ _id: stationId },
							{ $set: { queue: newPlaylist } },
							{ runValidators: true },
							err => {
								if (err) next(err);
								else
									StationsModule.runJob(
										"UPDATE_STATION",
										{
											stationId
										},
										this
									)
										.then(() => {
											next(null);
										})
										.catch(next);
							}
						);
					}
				],
				err => {
					if (err) reject(err);
					else resolve();
				}
			);
		});
	}

	/**
	 * Gets next station song
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {string} payload.stationId - the id of the station
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	GET_NEXT_STATION_SONG(payload) {
		return new Promise((resolve, reject) => {
			const { stationId } = payload;

			async.waterfall(
				[
					next => {
						StationsModule.runJob("GET_STATION", { stationId }, this)
							.then(station => {
								next(null, station);
							})
							.catch(next);
					},

					(station, next) => {
						if (station.queue.length === 0) next("No songs available.");
						else {
							next(null, station.queue[0]);
						}
					},

					(song, next) => {
						if (!song._id) next(null, song);
						else
							SongsModule.runJob("GET_SONG", { id: song._id }, this)
								.then(response => {
									const { song } = response;

									if (song) {
										const newSong = {
											_id: song._id,
											songId: song.songId,
											title: song.title,
											artists: song.artists,
											duration: song.duration,
											thumbnail: song.thumbnail,
											requestedAt: song.requestedAt,
											likes: song.likes,
											dislikes: song.dislikes
										};

										return next(null, newSong);
									}

									return next(null, song);
								})
								.catch(err => {
									if (err.message === "Song not found.") {
										this.log(
											"ERROR",
											`In GET_NEXT_STATION_SONG, attempted to get song "${song._id}", but got the error "Song not found.". Ignoring it for now, but this is not normal.`
										);
										next(null, song);
									} else next(err);
								});
					}
				],
				(err, song) => {
					if (err) console.log(33333, err, payload);
					if (err) reject(err);
					else resolve({ song });
				}
			);
		});
	}

	/**
	 * Removes first station queue song
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {string} payload.stationId - the id of the station
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	REMOVE_FIRST_QUEUE_SONG(payload) {
		return new Promise((resolve, reject) => {
			const { stationId } = payload;

			async.waterfall(
				[
					next => {
						StationsModule.stationModel.updateOne(
							{ _id: stationId },
							{ $pop: { queue: -1 } },
							{ runValidators: true },
							err => {
								if (err) next(err);
								else
									StationsModule.runJob(
										"UPDATE_STATION",
										{
											stationId
										},
										this
									)
										.then(() => {
											next(null);
										})
										.catch(next);
							}
						);
					}
				],
				err => {
					if (err) reject(err);
					else resolve();
				}
			);
		});
	}

	/**
	 * Skips a station
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {string} payload.stationId - the id of the station to skip
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	SKIP_STATION(payload) {
		return new Promise((resolve, reject) => {
			StationsModule.log("INFO", `Skipping station ${payload.stationId}.`);

			StationsModule.log("STATION_ISSUE", `SKIP_STATION_CB - Station ID: ${payload.stationId}.`);

			async.waterfall(
				[
					// Clears up any existing timers that would skip the station if the song ends
					next => {
						NotificationsModule.runJob("UNSCHEDULE", {
							name: `stations.nextSong?id=${payload.stationId}`
						})
							.then(() => {
								next();
							})
							.catch(next);
					},

					// Gets the station object
					next => {
						StationsModule.runJob(
							"GET_STATION",
							{
								stationId: payload.stationId
							},
							this
						)
							.then(station => {
								next(null, station);
							})
							.catch(() => {});
					},

					// eslint-disable-next-line consistent-return
					(station, next) => {
						if (!station) return next("Station not found.");

						if (station.type === "community" && station.partyMode && station.queue.length === 0)
							return next(null, null, -11, station); // Community station with party mode enabled and no songs in the queue

						if (station.type === "community" && station.partyMode && station.queue.length > 0) {
							// Community station with party mode enabled and songs in the queue
							if (station.paused) return next(null, null, -19, station);

							StationsModule.runJob("GET_NEXT_STATION_SONG", { stationId: station._id }, this)
								.then(response => {
									StationsModule.runJob(
										"REMOVE_FIRST_QUEUE_SONG",
										{ stationId: station._id },
										this
									).then(() => {
										next(null, response.song, 0, station);
									});
								})
								.catch(err => {
									if (err === "No songs available.") next(null, null, 0, station);
									else next(err);
								});

							// return StationsModule.stationModel.updateOne(
							// 	{ _id: payload.stationId },
							// 	{
							// 		$pull: {
							// 			queue: {
							// 				_id: station.queue[0]._id
							// 			}
							// 		}
							// 	},
							// 	err => {
							// 		if (err) return next(err);
							// 		return next(null, station.queue[0], -12, station);
							// 	}
							// );
						}

						if (station.type === "community" && !station.partyMode) {
							StationsModule.runJob(
								"FILL_UP_STATION_QUEUE_FROM_STATION_PLAYLIST",
								{ stationId: station._id },
								this
							)
								.then(() => {
									StationsModule.runJob("GET_NEXT_STATION_SONG", { stationId: station._id }, this)
										.then(response => {
											StationsModule.runJob(
												"REMOVE_FIRST_QUEUE_SONG",
												{ stationId: station._id },
												this
											).then(() => {
												next(null, response.song, 0, station);
											});
										})
										.catch(err => {
											if (err === "No songs available.") next(null, null, 0, station);
											else next(err);
										});
								})
								.catch(next);
						}

						// if (station.type === "community" && !station.partyMode) {
						// 	return DBModule.runJob("GET_MODEL", { modelName: "playlist" }, this).then(playlistModel =>
						// 		playlistModel.findOne({ _id: station.privatePlaylist }, (err, playlist) => {
						// 			if (err) return next(err);

						// 			if (!playlist) return next(null, null, -13, station);

						// 			playlist = playlist.songs;

						// 			if (playlist.length > 0) {
						// 				let currentSongIndex;

						// 				if (station.currentSongIndex < playlist.length - 1)
						// 					currentSongIndex = station.currentSongIndex + 1;
						// 				else currentSongIndex = 0;

						// 				const callback = (err, song) => {
						// 					if (err) return next(err);
						// 					if (song) return next(null, song, currentSongIndex, station);

						// 					const currentSong = {
						// 						songId: playlist[currentSongIndex].songId,
						// 						title: playlist[currentSongIndex].title,
						// 						duration: playlist[currentSongIndex].duration,
						// 						likes: -1,
						// 						dislikes: -1,
						// 						requestedAt: playlist[currentSongIndex].requestedAt
						// 					};

						// 					return next(null, currentSong, currentSongIndex, station);
						// 				};

						// 				if (mongoose.Types.ObjectId.isValid(playlist[currentSongIndex]._id))
						// 					return SongsModule.runJob(
						// 						"GET_SONG",
						// 						{
						// 							id: playlist[currentSongIndex]._id
						// 						},
						// 						this
						// 					)
						// 						.then(response => callback(null, response.song))
						// 						.catch(callback);
						// 				return SongsModule.runJob(
						// 					"GET_SONG_FROM_ID",
						// 					{
						// 						songId: playlist[currentSongIndex].songId
						// 					},
						// 					this
						// 				)
						// 					.then(response => callback(null, response.song))
						// 					.catch(callback);
						// 			}

						// 			return next(null, null, -14, station);
						// 		})
						// 	);
						// }

						if (station.type === "official") {
							StationsModule.runJob(
								"FILL_UP_STATION_QUEUE_FROM_STATION_PLAYLIST",
								{ stationId: station._id },
								this
							)
								.then(() => {
									StationsModule.runJob("GET_NEXT_STATION_SONG", { stationId: station._id }, this)
										.then(response => {
											StationsModule.runJob(
												"REMOVE_FIRST_QUEUE_SONG",
												{ stationId: station._id },
												this
											)
												.then(() => {
													next(null, response.song, 0, station);
												})
												.catch(next);
										})
										.catch(err => {
											if (err === "No songs available.") next(null, null, 0, station);
											else next(err);
										});
								})
								.catch(next);
						}
					},
					(song, currentSongIndex, station, next) => {
						const $set = {};

						if (song === null) $set.currentSong = null;
						else if (song.likes === -1 && song.dislikes === -1) {
							$set.currentSong = {
								songId: song.songId,
								title: song.title,
								duration: song.duration,
								skipDuration: 0,
								likes: -1,
								dislikes: -1,
								requestedAt: song.requestedAt
							};
						} else {
							$set.currentSong = {
								_id: song._id,
								songId: song.songId,
								title: song.title,
								artists: song.artists,
								duration: song.duration,
								likes: song.likes,
								dislikes: song.dislikes,
								skipDuration: song.skipDuration,
								thumbnail: song.thumbnail,
								requestedAt: song.requestedAt
							};
						}

						if (currentSongIndex >= 0) $set.currentSongIndex = currentSongIndex;
						$set.startedAt = Date.now();
						$set.timePaused = 0;
						if (station.paused) $set.pausedAt = Date.now();
						next(null, $set, station);
					},

					($set, station, next) => {
						StationsModule.stationModel.updateOne({ _id: station._id }, { $set }, err => {
							if (err) return next(err);

							return StationsModule.runJob("UPDATE_STATION", { stationId: station._id }, this)
								.then(station => {
									CacheModule.runJob("PUB", {
										channel: "station.queueUpdate",
										value: payload.stationId
									})
										.then()
										.catch();
									next(null, station);
								})
								.catch(next);
						});
					}
				],
				async (err, station) => {
					if (err) {
						err = await UtilsModule.runJob(
							"GET_ERROR",
							{
								error: err
							},
							this
						);
						StationsModule.log("ERROR", `Skipping station "${payload.stationId}" failed. "${err}"`);
						reject(new Error(err));
					} else {
						if (station.currentSong !== null && station.currentSong.songId !== undefined) {
							station.currentSong.skipVotes = 0;
						}
						// TODO Pub/Sub this

						WSModule.runJob("EMIT_TO_ROOM", {
							room: `station.${station._id}`,
							args: [
								"event:songs.next",
								{
									currentSong: station.currentSong,
									startedAt: station.startedAt,
									paused: station.paused,
									timePaused: 0
								}
							]
						})
							.then()
							.catch();

						if (station.privacy === "public") {
							WSModule.runJob("EMIT_TO_ROOM", {
								room: "home",
								args: ["event:station.nextSong", station._id, station.currentSong]
							})
								.then()
								.catch();
						} else {
							const sockets = await WSModule.runJob("GET_SOCKETS_FOR_ROOM", { room: "home" }, this);

							sockets.forEach(async socketId => {
								const socket = await WSModule.runJob("SOCKET_FROM_SOCKET_ID", { socketId }, this);
								const { session } = socket;

								if (session.sessionId) {
									CacheModule.runJob(
										"HGET",
										{ table: "sessions", key: session.sessionId },
										this
										// eslint-disable-next-line no-loop-func
									).then(session => {
										if (session) {
											DBModule.runJob("GET_MODEL", { modelName: "user" }, this).then(
												userModel => {
													userModel.findOne(
														{
															_id: session.userId
														},
														(err, user) => {
															if (!err && user) {
																if (user.role === "admin")
																	socket.dispatch(
																		"event:station.nextSong",
																		station._id,
																		station.currentSong
																	);
																else if (
																	station.type === "community" &&
																	station.owner === session.userId
																)
																	socket.dispatch(
																		"event:station.nextSong",
																		station._id,
																		station.currentSong
																	);
															}
														}
													);
												}
											);
										}
									});
								}
							});
						}

						WSModule.runJob("GET_SOCKETS_FOR_ROOM", { room: `station.${station._id}` }).then(sockets => {
							if (station.currentSong !== null && station.currentSong.songId !== undefined) {
								WSModule.runJob("SOCKETS_JOIN_SONG_ROOM", {
									sockets,
									room: `song.${station.currentSong.songId}`
								});
								if (!station.paused) {
									NotificationsModule.runJob("SCHEDULE", {
										name: `stations.nextSong?id=${station._id}`,
										time: station.currentSong.duration * 1000,
										station
									});
								}
							} else {
								WSModule.runJob("SOCKETS_LEAVE_SONG_ROOMS", {
									sockets
								});
							}
						});

						resolve({ station });
					}
				}
			);
		});
	}

	/**
	 * Checks if a user can view/access a station
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {object} payload.station - the station object of the station in question
	 * @param {string} payload.userId - the id of the user in question
	 * @param {boolean} payload.hideUnlisted - whether the user is allowed to see unlisted stations or not
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	CAN_USER_VIEW_STATION(payload) {
		return new Promise((resolve, reject) => {
			async.waterfall(
				[
					next => {
						if (payload.station.privacy === "public") return next(true);
						if (payload.station.privacy === "unlisted")
							if (payload.hideUnlisted === true) return next();
							else return next(true);
						if (!payload.userId) return next("Not allowed");

						return next();
					},

					next => {
						DBModule.runJob("GET_MODEL", { modelName: "user" }, this).then(userModel => {
							userModel.findOne({ _id: payload.userId }, next);
						});
					},

					(user, next) => {
						if (!user) return next("Not allowed");
						if (user.role === "admin") return next(true);
						if (payload.station.type === "official") return next("Not allowed");
						if (payload.station.owner === payload.userId) return next(true);

						return next("Not allowed");
					}
				],
				async errOrResult => {
					if (errOrResult !== true && errOrResult !== "Not allowed") {
						errOrResult = await UtilsModule.runJob(
							"GET_ERROR",
							{
								error: errOrResult
							},
							this
						);
						reject(new Error(errOrResult));
					} else {
						resolve(errOrResult === true);
					}
				}
			);
		});
	}

	/**
	 * Checks if a user has favorited a station or not
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {object} payload.stationId - the id of the station in question
	 * @param {string} payload.userId - the id of the user in question
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	HAS_USER_FAVORITED_STATION(payload) {
		return new Promise((resolve, reject) => {
			async.waterfall(
				[
					next => {
						DBModule.runJob("GET_MODEL", { modelName: "user" }, this).then(userModel => {
							userModel.findOne({ _id: payload.userId }, next);
						});
					},

					(user, next) => {
						if (!user) return next("User not found.");
						if (user.favoriteStations.indexOf(payload.stationId) !== -1) return next(null, true);
						return next(null, false);
					}
				],
				async (err, isStationFavorited) => {
					if (err && err !== true) {
						err = await UtilsModule.runJob("GET_ERROR", { error: err }, this);
						return reject(new Error(err));
					}

					return resolve(isStationFavorited);
				}
			);
		});
	}

	/**
	 * Returns a list of sockets in a room that can and can't know about a station
	 *
	 * @param {object} payload - the payload object
	 * @param {object} payload.station - the station object
	 * @param {string} payload.room - the websockets room to get the sockets from
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	GET_SOCKETS_THAT_CAN_KNOW_ABOUT_STATION(payload) {
		return new Promise((resolve, reject) => {
			WSModule.runJob("GET_SOCKETS_FOR_ROOM", { room: payload.room }, this)
				.then(socketsObject => {
					const sockets = Object.keys(socketsObject).map(socketKey => socketsObject[socketKey]);
					let socketsThatCan = [];
					const socketsThatCannot = [];

					if (payload.station.privacy === "public") {
						socketsThatCan = sockets;
						resolve({ socketsThatCan, socketsThatCannot });
					} else {
						async.eachLimit(
							sockets,
							1,
							(socket, next) => {
								const { session } = socket;

								async.waterfall(
									[
										next => {
											if (!session.sessionId) next("No session id");
											else next();
										},

										next => {
											CacheModule.runJob(
												"HGET",
												{
													table: "sessions",
													key: session.sessionId
												},
												this
											)
												.then(response => {
													next(null, response);
												})
												.catch(next);
										},

										(session, next) => {
											if (!session) next("No session");
											else {
												DBModule.runJob("GET_MODEL", { modelName: "user" }, this)
													.then(userModel => {
														next(null, userModel);
													})
													.catch(next);
											}
										},

										(userModel, next) => {
											if (!userModel) next("No user model");
											else
												userModel.findOne(
													{
														_id: session.userId
													},
													next
												);
										},

										(user, next) => {
											if (!user) next("No user found");
											else if (user.role === "admin") {
												socketsThatCan.push(socket);
												next();
											} else if (
												payload.station.type === "community" &&
												payload.station.owner === session.userId
											) {
												socketsThatCan.push(socket);
												next();
											}
										}
									],
									err => {
										if (err) socketsThatCannot.push(socket);
										next();
									}
								);
							},
							err => {
								if (err) reject(err);
								else resolve({ socketsThatCan, socketsThatCannot });
							}
						);
					}
				})
				.catch(reject);
		});
	}

	/**
	 * Adds a playlist to be included in a station
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {object} payload.stationId - the id of the station to include the playlist in
	 * @param {object} payload.playlistId - the id of the playlist to be included
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	INCLUDE_PLAYLIST(payload) {
		return new Promise((resolve, reject) => {
			async.waterfall(
				[
					next => {
						if (!payload.stationId) next("Please specify a station id");
						else if (!payload.playlistId) next("Please specify a playlist id");
						else next();
					},

					next => {
						StationsModule.runJob("GET_STATION", { stationId: payload.stationId }, this)
							.then(station => {
								next(null, station);
							})
							.catch(next);
					},

					(station, next) => {
						if (station.playlist === payload.playlistId) next("You cannot include the station playlist");
						else if (station.includedPlaylists.indexOf(payload.playlistId) !== -1)
							next("This playlist is already included");
						else if (station.excludedPlaylists.indexOf(payload.playlistId) !== -1)
							next(
								"This playlist is currently excluded, please remove it from there before including it"
							);
						else
							PlaylistsModule.runJob("GET_PLAYLIST", { playlistId: payload.playlistId }, this)
								.then(() => {
									next(null);
								})
								.catch(next);
					},

					next => {
						DBModule.runJob(
							"GET_MODEL",
							{
								modelName: "station"
							},
							this
						).then(stationModel => {
							stationModel.updateOne(
								{ _id: payload.stationId },
								{ $push: { includedPlaylists: payload.playlistId } },
								next
							);
						});
					},

					(res, next) => {
						StationsModule.runJob(
							"UPDATE_STATION",
							{
								stationId: payload.stationId
							},
							this
						)
							.then(() => {
								next();
							})
							.catch(next);
					}
				],
				async err => {
					if (err && err !== true) {
						err = await UtilsModule.runJob("GET_ERROR", { error: err }, this);
						return reject(new Error(err));
					}

					return resolve();
				}
			);
		});
	}

	/**
	 * Removes a playlist that is included in a station
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {object} payload.stationId - the id of the station
	 * @param {object} payload.playlistId - the id of the playlist
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	REMOVE_INCLUDED_PLAYLIST(payload) {
		return new Promise((resolve, reject) => {
			async.waterfall(
				[
					next => {
						if (!payload.stationId) next("Please specify a station id");
						else if (!payload.playlistId) next("Please specify a playlist id");
						else next();
					},

					next => {
						StationsModule.runJob("GET_STATION", { stationId: payload.stationId }, this)
							.then(station => {
								next(null, station);
							})
							.catch(next);
					},

					(station, next) => {
						if (station.includedPlaylists.indexOf(payload.playlistId) === -1)
							next("This playlist isn't included");
						else next();
					},

					next => {
						DBModule.runJob(
							"GET_MODEL",
							{
								modelName: "station"
							},
							this
						).then(stationModel => {
							stationModel.updateOne(
								{ _id: payload.stationId },
								{ $pull: { includedPlaylists: payload.playlistId } },
								next
							);
						});
					},

					(res, next) => {
						StationsModule.runJob(
							"UPDATE_STATION",
							{
								stationId: payload.stationId
							},
							this
						)
							.then(() => {
								next();
							})
							.catch(next);
					}
				],
				async err => {
					if (err && err !== true) {
						err = await UtilsModule.runJob("GET_ERROR", { error: err }, this);
						return reject(new Error(err));
					}

					return resolve();
				}
			);
		});
	}

	/**
	 * Adds a playlist to be excluded in a station
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {object} payload.stationId - the id of the station
	 * @param {object} payload.playlistId - the id of the playlist
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	EXCLUDE_PLAYLIST(payload) {
		return new Promise((resolve, reject) => {
			async.waterfall(
				[
					next => {
						if (!payload.stationId) next("Please specify a station id");
						else if (!payload.playlistId) next("Please specify a playlist id");
						else next();
					},

					next => {
						StationsModule.runJob("GET_STATION", { stationId: payload.stationId }, this)
							.then(station => {
								next(null, station);
							})
							.catch(next);
					},

					(station, next) => {
						if (station.playlist === payload.playlistId) next("You cannot exclude the station playlist");
						else if (station.excludedPlaylists.indexOf(payload.playlistId) !== -1)
							next("This playlist is already excluded");
						else if (station.includedPlaylists.indexOf(payload.playlistId) !== -1)
							next(
								"This playlist is currently included, please remove it from there before excluding it"
							);
						else
							PlaylistsModule.runJob("GET_PLAYLIST", { playlistId: payload.playlistId }, this)
								.then(() => {
									next(null);
								})
								.catch(next);
					},

					next => {
						DBModule.runJob(
							"GET_MODEL",
							{
								modelName: "station"
							},
							this
						).then(stationModel => {
							stationModel.updateOne(
								{ _id: payload.stationId },
								{ $push: { excludedPlaylists: payload.playlistId } },
								next
							);
						});
					},

					(res, next) => {
						StationsModule.runJob(
							"UPDATE_STATION",
							{
								stationId: payload.stationId
							},
							this
						)
							.then(() => {
								next();
							})
							.catch(next);
					}
				],
				async err => {
					if (err && err !== true) {
						err = await UtilsModule.runJob("GET_ERROR", { error: err }, this);
						return reject(new Error(err));
					}

					return resolve();
				}
			);
		});
	}

	/**
	 * Removes a playlist that is excluded in a station
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {object} payload.stationId - the id of the station
	 * @param {object} payload.playlistId - the id of the playlist
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	REMOVE_EXCLUDED_PLAYLIST(payload) {
		return new Promise((resolve, reject) => {
			console.log(112, payload);
			async.waterfall(
				[
					next => {
						if (!payload.stationId) next("Please specify a station id");
						else if (!payload.playlistId) next("Please specify a playlist id");
						else next();
					},

					next => {
						StationsModule.runJob("GET_STATION", { stationId: payload.stationId }, this)
							.then(station => {
								next(null, station);
							})
							.catch(next);
					},

					(station, next) => {
						if (station.excludedPlaylists.indexOf(payload.playlistId) === -1)
							next("This playlist isn't excluded");
						else next();
					},

					next => {
						DBModule.runJob(
							"GET_MODEL",
							{
								modelName: "station"
							},
							this
						).then(stationModel => {
							stationModel.updateOne(
								{ _id: payload.stationId },
								{ $pull: { excludedPlaylists: payload.playlistId } },
								next
							);
						});
					},

					(res, next) => {
						StationsModule.runJob(
							"UPDATE_STATION",
							{
								stationId: payload.stationId
							},
							this
						)
							.then(() => {
								next();
							})
							.catch(next);
					}
				],
				async err => {
					if (err && err !== true) {
						err = await UtilsModule.runJob("GET_ERROR", { error: err }, this);
						return reject(new Error(err));
					}

					return resolve();
				}
			);
		});
	}

	/**
	 * Gets stations that include or exclude a specific playlist
	 *
	 * @param {object} payload - object that contains the payload
	 * @param {string} payload.playlistId - the playlist id
	 * @returns {Promise} - returns promise (reject, resolve)
	 */
	GET_STATIONS_THAT_INCLUDE_OR_EXCLUDE_PLAYLIST(payload) {
		return new Promise((resolve, reject) => {
			DBModule.runJob(
				"GET_MODEL",
				{
					modelName: "station"
				},
				this
			).then(stationModel => {
				stationModel.find(
					{ $or: [{ includedPlaylists: payload.playlistId }, { excludedPlaylists: payload.playlistId }] },
					(err, stations) => {
						if (err) reject(err);
						else resolve({ stationIds: stations.map(station => station._id) });
					}
				);
			});
		});
	}
}

export default new _StationsModule();