Musare/backend/logic/io.js

/**
 * @file
 */

import config from "config";
import async from "async";
import socketio from "socket.io";

import actions from "./actions";
import CoreClass from "../core";

let IOModule;
let AppModule;
let CacheModule;
let UtilsModule;
let DBModule;
let PunishmentsModule;

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

		IOModule = this;
	}

	/**
	 * Initialises the io module
	 *
	 * @returns {Promise} - returns promise (reject, resolve)
	 */
	async initialize() {
		this.setStage(1);

		AppModule = this.moduleManager.modules.app;
		CacheModule = this.moduleManager.modules.cache;
		UtilsModule = this.moduleManager.modules.utils;
		DBModule = this.moduleManager.modules.db;
		PunishmentsModule = this.moduleManager.modules.punishments;

		this.userModel = await DBModule.runJob("GET_MODEL", { modelName: "user" });

		this.setStage(2);

		const SIDname = config.get("cookie.SIDname");

		// TODO: Check every 30s/, for all sockets, if they are still allowed to be in the rooms they are in, and on socket at all (permission changing/banning)
		const server = await AppModule.runJob("SERVER");
		this._io = socketio(server);

		return new Promise(resolve => {
			this.setStage(3);

			this._io.use(async (socket, cb) => {
				if (this.getStatus() !== "READY") {
					this.log(
						"INFO",
						"IO_REJECTED_CONNECTION",
						`A user tried to connect, but the IO module is currently not ready. IP: ${socket.ip}`
					);
					return socket.disconnect(true);
				}

				let SID;

				socket.ip = socket.request.headers["x-forwarded-for"] || "0.0.0.0";

				return async.waterfall(
					[
						next => {
							UtilsModule.runJob("PARSE_COOKIES", {
								cookieString: socket.request.headers.cookie
							}).then(res => {
								SID = res[SIDname];
								next(null);
							});
						},

						next => {
							if (!SID) return next("No SID.");
							return next();
						},

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

						(session, next) => {
							if (!session) return next("No session found.");

							session.refreshDate = Date.now();

							socket.session = session;

							return CacheModule.runJob("HSET", {
								table: "sessions",
								key: SID,
								value: session
							}).then(session => {
								next(null, session);
							});
						},

						(res, next) => {
							// check if a session's user / IP is banned
							PunishmentsModule.runJob("GET_PUNISHMENTS", {})
								.then(punishments => {
									const isLoggedIn = !!(socket.session && socket.session.refreshDate);
									const userId = isLoggedIn ? socket.session.userId : null;

									const banishment = {
										banned: false,
										ban: 0
									};

									punishments.forEach(punishment => {
										if (punishment.expiresAt > banishment.ban) banishment.ban = punishment;
										if (
											punishment.type === "banUserId" &&
											isLoggedIn &&
											punishment.value === userId
										)
											banishment.banned = true;
										if (punishment.type === "banUserIp" && punishment.value === socket.ip)
											banishment.banned = true;
									});

									socket.banishment = banishment;

									next();
								})
								.catch(() => {
									next();
								});
						}
					],
					() => {
						if (!socket.session) socket.session = { socketId: socket.id };
						else socket.session.socketId = socket.id;

						cb();
					}
				);
			});

			this.setStage(4);

			this._io.on("connection", async socket => {
				let sessionInfo = "";

				if (this.getStatus() !== "READY") {
					this.log(
						"INFO",
						"IO_REJECTED_CONNECTION",
						`A user tried to connect, but the IO module is currently not ready. IP: ${socket.ip}.${sessionInfo}`
					);
					return socket.disconnect(true);
				}

				if (socket.session.sessionId) sessionInfo = ` UserID: ${socket.session.userId}.`;

				// if session is banned
				if (socket.banishment && socket.banishment.banned) {
					this.log(
						"INFO",
						"IO_BANNED_CONNECTION",
						`A user tried to connect, but is currently banned. IP: ${socket.ip}.${sessionInfo}`
					);

					socket.emit("keep.event:banned", socket.banishment.ban);

					return socket.disconnect(true);
				}

				this.log("INFO", "IO_CONNECTION", `User connected. IP: ${socket.ip}.${sessionInfo}`);

				// catch when the socket has been disconnected
				socket.on("disconnect", () => {
					if (socket.session.sessionId) sessionInfo = ` UserID: ${socket.session.userId}.`;
					this.log("INFO", "IO_DISCONNECTION", `User disconnected. IP: ${socket.ip}.${sessionInfo}`);
				});

				socket.use((data, next) => {
					if (data.length === 0) return next(new Error("Not enough arguments specified."));
					if (typeof data[0] !== "string") return next(new Error("First argument must be a string."));

					const namespaceAction = data[0];
					if (
						!namespaceAction ||
						namespaceAction.indexOf(".") === -1 ||
						namespaceAction.indexOf(".") !== namespaceAction.lastIndexOf(".")
					)
						return next(new Error("Invalid first argument"));
					const namespace = data[0].split(".")[0];
					const action = data[0].split(".")[1];

					if (!namespace) return next(new Error("Invalid namespace."));
					if (!action) return next(new Error("Invalid action."));
					if (!actions[namespace]) return next(new Error("Namespace not found."));
					if (!actions[namespace][action]) return next(new Error("Action not found."));

					return next();
				});

				// catch errors on the socket (internal to socket.io)
				socket.on("error", console.error);

				if (socket.session.sessionId) {
					CacheModule.runJob("HGET", {
						table: "sessions",
						key: socket.session.sessionId
					})
						.then(session => {
							if (session && session.userId) {
								IOModule.userModel.findOne({ _id: session.userId }, (err, user) => {
									if (err || !user) return socket.emit("ready", false);

									let role = "";
									let username = "";
									let userId = "";
									if (user) {
										role = user.role;
										username = user.username;
										userId = session.userId;
									}

									return socket.emit("ready", true, role, username, userId);
								});
							} else socket.emit("ready", false);
						})
						.catch(() => {
							socket.emit("ready", false);
						});
				} else socket.emit("ready", false);

				// have the socket listen for each action
				return Object.keys(actions).forEach(namespace => {
					Object.keys(actions[namespace]).forEach(action => {
						// the full name of the action
						const name = `${namespace}.${action}`;

						// listen for this action to be called
						socket.on(name, async (...args) => {
							let cb = args[args.length - 1];

							if (typeof cb !== "function")
								cb = () => {
									this.this.log("INFO", "IO_MODULE", `There was no callback provided for ${name}.`);
								};
							else args.pop();

							if (this.getStatus() !== "READY") {
								this.log(
									"INFO",
									"IO_REJECTED_ACTION",
									`A user tried to execute an action, but the IO module is currently not ready. Action: ${namespace}.${action}.`
								);
								return;
							}
							this.log("INFO", "IO_ACTION", `A user executed an action. Action: ${namespace}.${action}.`);

							let failedGettingSession = false;
							// load the session from the cache
							if (socket.session.sessionId)
								await CacheModule.runJob("HGET", {
									table: "sessions",
									key: socket.session.sessionId
								})
									.then(session => {
										// make sure the sockets sessionId isn't set if there is no session
										if (socket.session.sessionId && session === null)
											delete socket.session.sessionId;
									})
									.catch(() => {
										failedGettingSession = true;
										if (typeof cb === "function")
											cb({
												status: "error",
												message: "An error occurred while obtaining your session"
											});
									});
							if (!failedGettingSession)
								try {
									// call the action, passing it the session, and the arguments socket.io passed us
									actions[namespace][action].apply(
										null,
										[socket.session].concat(args).concat([
											result => {
												this.log(
													"INFO",
													"IO_ACTION",
													`Response to action. Action: ${namespace}.${action}. Response status: ${result.status}`
												);
												// respond to the socket with our message
												if (typeof cb === "function") cb(result);
											}
										])
									);
								} catch (err) {
									if (typeof cb === "function")
										cb({
											status: "error",
											message: "An error occurred while executing the specified action."
										});

									this.log(
										"ERROR",
										"IO_ACTION_ERROR",
										`Some type of exception occurred in the action ${namespace}.${action}. Error message: ${err.message}`
									);
								}
						});
					});
				});
			});

			this.setStage(5);

			return resolve();
		});
	}

	/**
	 * Returns the socket io variable
	 *
	 * @returns {Promise} - returns a promise (resolve, reject)
	 */
	IO() {
		return new Promise(resolve => {
			resolve(IOModule._io);
		});
	}
}

export default new _IOModule();