discord_bot.js

var fs = require('fs');

process.on('unhandledRejection', (reason) => {
	console.error(reason);
	process.exit(1);
});

try {
	var Discord = require("discord.js");
} catch (e) {
	console.log(e.stack);
	console.log(process.version);
	console.log("Please run npm install and ensure it passes with no errors!");
	process.exit();
}
console.log("Starting DiscordBot\nNode version: " + process.version + "\nDiscord.js version: " + Discord.version);



// Get authentication data
try {
	var AuthDetails = require(__dirname + "/auth.json");
} catch (e) {
	console.log("Please create an auth.json like auth.json.example with a bot token or an email and password.\n" + e.stack);
	process.exit();
}

// Load custom permissions
var dangerousCommands = [ "eval", "update", "setUsername" ];
var Permissions = {};
try {
	Permissions = require(__dirname + "/permissions.json");
} catch (e) {
	Permissions.global = {};
	Permissions.users = {};
}

for (var i = 0; i < dangerousCommands.length; i++) {
	var cmd = dangerousCommands[ i ];
	if (!Permissions.global.hasOwnProperty(cmd)) {
		Permissions.global[ cmd ] = false;
	}
}
Permissions.checkPermission = function (user, permission) {
	try {
		var allowed = true;
		try {
			if (Permissions.global.hasOwnProperty(permission)) {
				allowed = Permissions.global[ permission ] === true;
			}
		} catch (e) { }
		try {
			if (Permissions.users[ user.id ].hasOwnProperty(permission)) {
				allowed = Permissions.users[ user.id ][ permission ] === true;
			}
		} catch (e) { }
		return allowed;
	} catch (e) { }
	return false;
}
fs.writeFile(__dirname + "/permissions.json", JSON.stringify(Permissions, null, 2));

//load config data
var Config = {};
try {
	Config = require(__dirname + "/config.json");
} catch (e) { //no config file, use defaults
	Config.debug = false;
	Config.commandPrefix = '!';
	try {
		if (fs.lstatSync(__dirname + "/config.json").isFile()) {
			console.log("WARNING: config.json found but we couldn't read it!\n" + e.stack);
		}
	} catch (e2) {
		fs.writeFile(__dirname + "/config.json", JSON.stringify(Config, null, 2));
	}
}
if (!Config.hasOwnProperty("commandPrefix")) {
	Config.commandPrefix = '!';
}

var messagebox;
var aliases;
try {
	aliases = require(__dirname + "/alias.json");
} catch (e) {
	//No aliases defined
	aliases = {};
}

var commands = {
	"alias": {
		usage: "<name> <actual command>",
		description: "Creates command aliases. Useful for making simple commands on the fly",
		process: function (bot, msg, suffix) {
			var args = suffix.split(" ");
			var name = args.shift();
			if (!name) {
				msg.channel.send(Config.commandPrefix + "alias " + this.usage + "\n" + this.description);
			} else if (commands[ name ] || name === "help") {
				msg.channel.send("overwriting commands with aliases is not allowed!");
			} else {
				var command = args.shift();
				aliases[ name ] = [ command, args.join(" ") ];
				//now save the new alias
				require("fs").writeFile(__dirname + "/alias.json", JSON.stringify(aliases, null, 2), null);
				msg.channel.send("created alias " + name);
			}
		}
	},
	"aliases": {
		description: "lists all recorded aliases",
		process: function (bot, msg, suffix) {
			var text = "current aliases:\n";
			for (var a in aliases) {
				if (typeof a === 'string')
					text += a + " ";
			}
			msg.channel.send(text);
		}
	},
	"ping": {
		description: "responds pong, useful for checking if bot is alive",
		process: function (bot, msg, suffix) {
			msg.channel.send(msg.author + " pong!");
			if (suffix) {
				msg.channel.send("note that !ping takes no arguments!");
			}
		}
	},
	"idle": {
		usage: "[status]",
		description: "sets bot status to idle",
		process: function (bot, msg, suffix) {
			bot.user.setStatus("idle");
			bot.user.setGame(suffix);
		}
	},
	"online": {
		usage: "[status]",
		description: "sets bot status to online",
		process: function (bot, msg, suffix) {
			bot.user.setStatus("online");
			bot.user.setGame(suffix);
		}
	},
	"say": {
		usage: "<message>",
		description: "bot says message",
		process: function (bot, msg, suffix) { msg.channel.send(suffix); }
	},
	"announce": {
		usage: "<message>",
		description: "bot says message with text to speech",
		process: function (bot, msg, suffix) { msg.channel.send(suffix, { tts: true }); }
	},
	"msg": {
		usage: "<user> <message to leave user>",
		description: "leaves a message for a user the next time they come online",
		process: function (bot, msg, suffix) {
			var args = suffix.split(' ');
			var user = args.shift();
			var message = args.join(' ');
			if (user.startsWith('<@')) {
				user = user.substr(2, user.length - 3);
			}
			var target = msg.channel.guild.members.find("id", user);
			if (!target) {
				target = msg.channel.guild.members.find("username", user);
			}
			messagebox[ target.id ] = {
				channel: msg.channel.id,
				content: target + ", " + msg.author + " said: " + message
			};
			updateMessagebox();
			msg.channel.send("message saved.")
		}
	},
	"eval": {
		usage: "<command>",
		description: 'Executes arbitrary javascript in the bot process. User must have "eval" permission',
		process: function (bot, msg, suffix) {
			if (Permissions.checkPermission(msg.author, "eval")) {
				msg.channel.send(eval(suffix, bot));
			} else {
				msg.channel.send(msg.author + " doesn't have permission to execute eval!");
			}
		}
	}
};

if (AuthDetails.hasOwnProperty("client_id")) {
	commands[ "invite" ] = {
		description: "generates an invite link you can use to invite the bot to your server",
		process: function (bot, msg, suffix) {
			msg.channel.send("invite link: https://discordapp.com/oauth2/authorize?&client_id=" + AuthDetails.client_id + "&scope=bot&permissions=470019135");
		}
	}
}


try {
	messagebox = require(__dirname + "/messagebox.json");
} catch (e) {
	//no stored messages
	messagebox = {};
}
function updateMessagebox() {
	require("fs").writeFile(__dirname + "/messagebox.json", JSON.stringify(messagebox, null, 2), null);
}

var bot = new Discord.Client();

bot.on("ready", function () {
	console.log("Logged in! Serving in " + bot.guilds.array().length + " servers");
	require(__dirname + "/plugins.js").init();
	console.log("type " + Config.commandPrefix + "help in Discord for a commands list.");
	bot.user.setGame(Config.commandPrefix + "help | " + bot.guilds.array().length + " Servers");
});

bot.on("disconnected", function () {

	console.log("Disconnected!");
	process.exit(1); //exit node.js with an error

});

function checkMessageForCommand(msg, isEdit) {
	//check if message is a command
	if (msg.author.id != bot.user.id && (msg.content.startsWith(Config.commandPrefix))) {
		console.log("treating " + msg.content + " from " + msg.author + " as command");
		var cmdTxt = msg.content.split(" ")[ 0 ].substring(Config.commandPrefix.length);
		var suffix = msg.content.substring(cmdTxt.length + Config.commandPrefix.length + 1);//add one for the ! and one for the space
		if (msg.isMentioned(bot.user)) {
			try {
				cmdTxt = msg.content.split(" ")[ 1 ];
				suffix = msg.content.substring(bot.user.mention().length + cmdTxt.length + Config.commandPrefix.length + 1);
			} catch (e) { //no command
				msg.channel.send("Yes?");
				return;
			}
		}
		alias = aliases[ cmdTxt ];
		if (alias) {
			console.log(cmdTxt + " is an alias, constructed command is " + alias.join(" ") + " " + suffix);
			cmdTxt = alias[ 0 ];
			suffix = alias[ 1 ] + " " + suffix;
		}
		var cmd = commands[ cmdTxt ];
		if (cmdTxt === "help") {
			//help is special since it iterates over the other commands
			if (suffix) {
				var cmds = suffix.split(" ").filter(function (cmd) { return commands[ cmd ] });
				var info = "";
				for (var i = 0; i < cmds.length; i++) {
					var cmd = cmds[ i ];
					info += "**" + Config.commandPrefix + cmd + "**";
					var usage = commands[ cmd ].usage;
					if (usage) {
						info += " " + usage;
					}
					var description = commands[ cmd ].description;
					if (description instanceof Function) {
						description = description();
					}
					if (description) {
						info += "\n\t" + description;
					}
					info += "\n"
				}
				msg.channel.send(info);
			} else {
				msg.author.send("**Available Commands:**").then(function () {
					var batch = "";
					var sortedCommands = Object.keys(commands).sort();
					for (var i in sortedCommands) {
						var cmd = sortedCommands[ i ];
						var info = "**" + Config.commandPrefix + cmd + "**";
						var usage = commands[ cmd ].usage;
						if (usage) {
							info += " " + usage;
						}
						var description = commands[ cmd ].description;
						if (description instanceof Function) {
							description = description();
						}
						if (description) {
							info += "\n\t" + description;
						}
						var newBatch = batch + "\n" + info;
						if (newBatch.length > (1024 - 8)) { //limit message length
							msg.author.send(batch);
							batch = info;
						} else {
							batch = newBatch
						}
					}
					if (batch.length > 0) {
						msg.author.send(batch);
					}
				});
			}
		}
		else if (cmd) {
			if (Permissions.checkPermission(msg.author, cmdTxt)) {
				try {
					cmd.process(bot, msg, suffix, isEdit);
				} catch (e) {
					var msgTxt = "command " + cmdTxt + " failed :(";
					if (Config.debug) {
						msgTxt += "\n" + e.stack;
					}
					msg.channel.send(msgTxt);
				}
			} else {
				msg.channel.send("You are not allowed to run " + cmdTxt + "!");
			}
		} else {
			msg.channel.send(cmdTxt + " not recognized as a command!").then((message => message.delete(5000)))
		}
	} else {
		//message isn't a command or is from us
		//drop our own messages to prevent feedback loops
		if (msg.author == bot.user) {
			return;
		}

		if (msg.author != bot.user && msg.isMentioned(bot.user)) {
			msg.channel.send("yes?"); //using a mention here can lead to looping
		} else {

		}
	}
}

bot.on("message", (msg) => checkMessageForCommand(msg, false));
bot.on("messageUpdate", (oldMessage, newMessage) => {
	checkMessageForCommand(newMessage, true);
});

//Log user status changes
bot.on("presence", function (user, status, gameId) {
	//if(status === "online"){
	//console.log("presence update");
	console.log(user + " went " + status);
	//}
	try {
		if (status != 'offline') {
			if (messagebox.hasOwnProperty(user.id)) {
				console.log("found message for " + user.id);
				var message = messagebox[ user.id ];
				var channel = bot.channels.get("id", message.channel);
				delete messagebox[ user.id ];
				updateMessagebox();
				bot.send(channel, message.content);
			}
		}
	} catch (e) { }
});


exports.addCommand = function (commandName, commandObject) {
	try {
		commands[ commandName ] = commandObject;
	} catch (err) {
		console.log(err);
	}
}
exports.commandCount = function () {
	return Object.keys(commands).length;
}
if (AuthDetails.bot_token) {
	console.log("logging in with token");
	bot.login(AuthDetails.bot_token);
} else {
	console.log("Logging in with user credentials is no longer supported!\nYou can use token based log in with a user account, see\nhttps://discord.js.org/#/docs/main/master/general/updating");
}