Add time parser for timer command

* Fix grammar
* Fix countdown off by 4 seconds

commands/misc/timer.js

@@ -1,3 +1,4 @@
+const parseTime = require('../../util/parseTime');
 module.exports = {
 	name: "timer",
 	description: "Set a timer for a time in minutes.",
@@ -5,14 +6,13 @@ module.exports = {
 	execute({message, args}) {
 		if(args.length < 2)
 			return message.channel.send("Please specify a time in minutes, and a message to send after the timer has finished");
-		let time = parseInt(args[0]);
+		let time = parseTime(args[0]);
 		if(isNaN(time))
 			return message.channel.send("Specify a time in number of minutes");
-		time = time * 60000;
 		let sendText = args.slice(1).join(" ");
 		setTimeout(function(){
 			message.channel.send(`<@${message.author.id}>, ${sendText}`);
 		}, time);
-		message.channel.send(`I will remind you in <t:${Math.floor(new Date() / 1000) + (time / 1000)}:R>`);
+		message.channel.send(`I will remind you <t:${Math.floor(new Date() / 1000) + (time / 1000) - 4}:R>`);
 	}
 };

util/parseTime.js

@@ -0,0 +1,19 @@
+module.exports = function(time){
+	let timeInMilliseconds = parseInt(time.slice(0, time.length - 1))
+	let letter = time.slice(time.length - 1)
+	if(!isNaN(letter)) return parseInt(time) * 60000
+	switch (letter.toUpperCase()) {
+		case "H":
+			timeInMilliseconds = timeInMilliseconds * 3600000;	// 3 600 000
+			break;
+		case "M":
+			timeInMilliseconds = timeInMilliseconds * 60000;	// 60 000
+			break;
+		case "S":
+			timeInMilliseconds = timeInMilliseconds * 1000;		// 1 000
+			break;
+		default:
+			timeInMilliseconds = -1;
+	}
+	return timeInMilliseconds;
+}