/*
 *
 * NOTE: The client side of hack.chat is currently in development,
 * a new, more modern but still minimal version will be released
 * soon. As a result of this, the current code has been deprecated
 * and will not actively be updated.
 *
*/

const verifyNickname = (nick) => /^[a-zA-Z0-9_]{1,24}$/.test(nick);

var frontpage = [
	"                            _           _         _       _   ",
	"                           | |_ ___ ___| |_   ___| |_ ___| |_ ",
	"                           |   |_ ||  _| '_| |  _|   |_ ||  _|",
	"                           |_|_|__/|___|_,_|.|___|_|_|__/|_|  ",
	"",
	"",
	"Welcome to hack.chat, a minimal, distraction-free chat application.",
	"Channels are created, joined and shared with the url, create your own channel by changing the text after the question mark.",
	"If you wanted your channel name to be 'your-channel': https://hack.chat/?your-channel",
	"There are no channel lists, so a secret channel name can be used for private discussions.",
	"",
	"Here are some pre-made channels you can join:",
	"?lounge ?meta",
	"?math ?physics ?chemistry",
	"?technology ?programming",
	"?games ?banana",
	"And here's a random one generated just for you: ?" + Math.random().toString(36).substr(2, 8),
	"",
	"Formatting:",
	"Whitespace is preserved, so source code can be pasted verbatim.",
	"Surround LaTeX with a dollar sign for inline style $\\zeta(2) = \\pi^2/6$, and two dollars for display. $$\\int_0^1 \\int_0^1 \\frac{1}{1-xy} dx dy = \\frac{\\pi^2}{6}$$",
	"For syntax highlight, the first line of the code block must begin with #<format> where <format> can be html, js or any known format.",
	"",
	"Current Github: https://github.com/hack-chat",
	"Legacy GitHub: https://github.com/AndrewBelt/hack.chat",
	"",
	"Bots, Android clients, desktop clients, browser extensions, docker images, programming libraries, server modules and more:",
	"https://github.com/hack-chat/3rd-party-software-list",
	"",
	"Server and web client released under the WTFPL and MIT open source license.",
	"No message history is retained on the hack.chat server."
].join("\n");

function $(query) {
	return document.querySelector(query);
}

function localStorageGet(key) {
	try {
		return window.localStorage[key]
	} catch (e) { }
}

function localStorageSet(key, val) {
	try {
		window.localStorage[key] = val
	} catch (e) { }
}

var ws;
var myNick = localStorageGet('my-nick') || '';
var myChannel = window.location.search.replace(/^\?/, '');
var lastSent = [""];
var lastSentPos = 0;

function join(channel) {
	if (document.domain == 'hack.chat') {
		// For https://hack.chat/
		ws = new WebSocket('wss://hack.chat/chat-ws');
	} else {
		// for local installs
		ws = new WebSocket('ws://' + document.domain + ':6060');
	}

	var wasConnected = false;

	ws.onopen = function () {
		if (!wasConnected) {
			if (location.hash) {
				myNick = location.hash.substr(1);
			} else {
				myNick = prompt('Nickname:', myNick);
			}
		}

		if (myNick) {
			localStorageSet('my-nick', myNick);
			send({ cmd: 'join', channel: channel, nick: myNick });
		}

		wasConnected = true;
	}

	ws.onclose = function () {
		if (wasConnected) {
			pushMessage({ nick: '!', text: "Server disconnected. Attempting to reconnect. . ." });
		}

		window.setTimeout(function () {
			join(channel);
		}, 2000);
	}

	ws.onmessage = function (message) {
		var args = JSON.parse(message.data);
		var cmd = args.cmd;
		var command = COMMANDS[cmd];
		command.call(null, args);
	}
}

var COMMANDS = {
	chat: function (args) {
		if (ignoredUsers.indexOf(args.nick) >= 0) {
			return;
		}

		pushMessage(args);
	},

	info: function (args) {
		args.nick = '*';

		pushMessage(args);
	},

	warn: function (args) {
		args.nick = '!';

		pushMessage(args);
	},

	onlineSet: function (args) {
		var nicks = args.nicks;

		usersClear();

		nicks.forEach(function (nick) {
			userAdd(nick);
		});

		pushMessage({ nick: '*', text: "Users online: " + nicks.join(", ") })
	},

	onlineAdd: function (args) {
		var nick = args.nick;

		userAdd(nick);

		if ($('#joined-left').checked) {
			pushMessage({ nick: '*', text: nick + " joined" });
		}
	},

	onlineRemove: function (args) {
		var nick = args.nick;

		userRemove(nick);

		if ($('#joined-left').checked) {
			pushMessage({ nick: '*', text: nick + " left" });
		}
	}
}

function pushMessage(args) {
	// Message container
	var messageEl = document.createElement('div');

	if (args.text.includes('@' + myNick.split('#')[0] + ' ')) {
		messageEl.classList.add('refmessage');
	} else {
		messageEl.classList.add('message');
	}

	if (verifyNickname(myNick) && args.nick == myNick) {
		messageEl.classList.add('me');
	} else if (args.nick == '!') {
		messageEl.classList.add('warn');
	} else if (args.nick == '*') {
		messageEl.classList.add('info');
	} else if (args.admin) {
		messageEl.classList.add('admin');
	} else if (args.mod) {
		messageEl.classList.add('mod');
	}

	// Nickname
	var nickSpanEl = document.createElement('span');
	nickSpanEl.classList.add('nick');
	messageEl.appendChild(nickSpanEl);

	if (args.trip) {
		var tripEl = document.createElement('span');
		tripEl.textContent = args.trip + " ";
		tripEl.classList.add('trip');
		nickSpanEl.appendChild(tripEl);
	}

	if (args.nick) {
		var nickLinkEl = document.createElement('a');
		nickLinkEl.textContent = args.nick;

		nickLinkEl.onclick = function () {
			insertAtCursor("@" + args.nick + " ");
			$('#chatinput').focus();
		}

		var date = new Date(args.time || Date.now());
		nickLinkEl.title = date.toLocaleString();
		nickSpanEl.appendChild(nickLinkEl);
	}

	// Text
	var textEl = document.createElement('pre');
	textEl.classList.add('text');

	textEl.textContent = args.text || '';
	textEl.innerHTML = textEl.innerHTML.replace(/(\?|https?:\/\/)\S+?(?=[,.!?:)]?\s|$)/g, parseLinks);

	if ($('#syntax-highlight').checked && textEl.textContent.indexOf('#') == 0) {
		var lang = textEl.textContent.split(/\s+/g)[0].replace('#', '');
		var codeEl = document.createElement('code');
		codeEl.classList.add(lang);
		var content = textEl.textContent.replace('#' + lang, '');
		codeEl.textContent = content.trim();
		hljs.highlightBlock(codeEl);
		textEl.innerHTML = '';
		textEl.appendChild(codeEl);
	} else if ($('#parse-latex').checked) {
		// Temporary hotfix for \rule spamming, see https://github.com/Khan/KaTeX/issues/109
		textEl.innerHTML = textEl.innerHTML.replace(/\\rule|\\\\\s*\[.*?\]/g, '');
		try {
			renderMathInElement(textEl, {
				delimiters: [
					{ left: "$$", right: "$$", display: true },
					{ left: "$", right: "$", display: false },
				]
			})
		} catch (e) {
			console.warn(e);
		}
	}

	messageEl.appendChild(textEl);

	// Scroll to bottom
	var atBottom = isAtBottom();
	$('#messages').appendChild(messageEl);
	if (atBottom) {
		window.scrollTo(0, document.body.scrollHeight);
	}

	unread += 1;
	updateTitle();
}

function insertAtCursor(text) {
	var input = $('#chatinput');
	var start = input.selectionStart || 0;
	var before = input.value.substr(0, start);
	var after = input.value.substr(start);

	before += text;
	input.value = before + after;
	input.selectionStart = input.selectionEnd = before.length;

	updateInputSize();
}

function send(data) {
	if (ws && ws.readyState == ws.OPEN) {
		ws.send(JSON.stringify(data));
	}
}

function parseLinks(g0) {
	var a = document.createElement('a');

	a.innerHTML = g0;

	var url = a.textContent;

	a.href = url;
	a.target = '_blank';

	return a.outerHTML;
}

var windowActive = true;
var unread = 0;

window.onfocus = function () {
	windowActive = true;

	updateTitle();
}

window.onblur = function () {
	windowActive = false;
}

window.onscroll = function () {
	if (isAtBottom()) {
		updateTitle();
	}
}

function isAtBottom() {
	return (window.innerHeight + window.scrollY) >= (document.body.scrollHeight - 1);
}

function updateTitle() {
	if (windowActive && isAtBottom()) {
		unread = 0;
	}

	var title;
	if (myChannel) {
		title = "?" + myChannel;
	} else {
		title = "hack.chat";
	}

	if (unread > 0) {
		title = '(' + unread + ') ' + title;
	}

	document.title = title;
}

$('#footer').onclick = function () {
	$('#chatinput').focus();
}

$('#chatinput').onkeydown = function (e) {
	if (e.keyCode == 13 /* ENTER */ && !e.shiftKey) {
		e.preventDefault();

		// Submit message
		if (e.target.value != '') {
			var text = e.target.value;
			e.target.value = '';

			send({ cmd: 'chat', text: text });

			lastSent[0] = text;
			lastSent.unshift("");
			lastSentPos = 0;

			updateInputSize();
		}
	} else if (e.keyCode == 38 /* UP */) {
		// Restore previous sent messages
		if (e.target.selectionStart === 0 && lastSentPos < lastSent.length - 1) {
			e.preventDefault();

			if (lastSentPos == 0) {
				lastSent[0] = e.target.value;
			}

			lastSentPos += 1;
			e.target.value = lastSent[lastSentPos];
			e.target.selectionStart = e.target.selectionEnd = e.target.value.length;

			updateInputSize();
		}
	} else if (e.keyCode == 40 /* DOWN */) {
		if (e.target.selectionStart === e.target.value.length && lastSentPos > 0) {
			e.preventDefault();

			lastSentPos -= 1;
			e.target.value = lastSent[lastSentPos];
			e.target.selectionStart = e.target.selectionEnd = 0;

			updateInputSize();
		}
	} else if (e.keyCode == 27 /* ESC */) {
		e.preventDefault();

		// Clear input field
		e.target.value = "";
		lastSentPos = 0;
		lastSent[lastSentPos] = "";

		updateInputSize();
	} else if (e.keyCode == 9 /* TAB */) {
		// Tab complete nicknames starting with @
		e.preventDefault();

		var pos = e.target.selectionStart || 0;
		var text = e.target.value;
		var index = text.lastIndexOf('@', pos);

		if (index >= 0) {
			var stub = text.substring(index + 1, pos).toLowerCase();
			// Search for nick beginning with stub
			var nicks = onlineUsers.filter(function (nick) {
				return nick.toLowerCase().indexOf(stub) == 0
			});

			if (nicks.length == 1) {
				insertAtCursor(nicks[0].substr(stub.length) + " ");
			}
		}
	}
}

function updateInputSize() {
	var atBottom = isAtBottom();

	var input = $('#chatinput');
	input.style.height = 0;
	input.style.height = input.scrollHeight + 'px';
	document.body.style.marginBottom = $('#footer').offsetHeight + 'px';

	if (atBottom) {
		window.scrollTo(0, document.body.scrollHeight);
	}
}

$('#chatinput').oninput = function () {
	updateInputSize();
}

updateInputSize();


/* sidebar */

$('#sidebar').onmouseenter = $('#sidebar').ontouchstart = function (e) {
	$('#sidebar-content').classList.remove('hidden');
        $('#sidebar').classList.add('expand');
	e.stopPropagation();
}

$('#sidebar').onmouseleave = document.ontouchstart = function () {
	if (!$('#pin-sidebar').checked) {
		$('#sidebar-content').classList.add('hidden');
                $('#sidebar').classList.remove('expand');
	}
}

$('#clear-messages').onclick = function () {
	// Delete children elements
	var messages = $('#messages');
	while (messages.firstChild) {
		messages.removeChild(messages.firstChild);
	}
}

// Restore settings from localStorage

if (localStorageGet('pin-sidebar') == 'true') {
	$('#pin-sidebar').checked = true;
	$('#sidebar-content').classList.remove('hidden');
}

if (localStorageGet('joined-left') == 'false') {
	$('#joined-left').checked = false;
}

if (localStorageGet('parse-latex') == 'false') {
	$('#parse-latex').checked = false;
}

$('#pin-sidebar').onchange = function (e) {
	localStorageSet('pin-sidebar', !!e.target.checked);
}

$('#joined-left').onchange = function (e) {
	localStorageSet('joined-left', !!e.target.checked);
}

$('#parse-latex').onchange = function (e) {
	localStorageSet('parse-latex', !!e.target.checked);
}

// User list
var onlineUsers = [];
var ignoredUsers = [];

function userAdd(nick) {
	var user = document.createElement('a');
	user.textContent = nick;

	user.onclick = function (e) {
		userInvite(nick)
	}

	var userLi = document.createElement('li');
	userLi.appendChild(user);
	$('#users').appendChild(userLi);
	onlineUsers.push(nick);
}

function userRemove(nick) {
	var users = $('#users');
	var children = users.children;

	for (var i = 0; i < children.length; i++) {
		var user = children[i];
		if (user.textContent == nick) {
			users.removeChild(user);
		}
	}

	var index = onlineUsers.indexOf(nick);
	if (index >= 0) {
		onlineUsers.splice(index, 1);
	}
}

function usersClear() {
	var users = $('#users');

	while (users.firstChild) {
		users.removeChild(users.firstChild);
	}

	onlineUsers.length = 0;
}

function userInvite(nick) {
	send({ cmd: 'invite', nick: nick });
}

function userIgnore(nick) {
	ignoredUsers.push(nick);
}

/* color scheme switcher */

var schemes = [
	'android',
	'atelier-dune',
	'atelier-forest',
	'atelier-heath',
	'atelier-lakeside',
	'atelier-seaside',
	'bright',
	'chalk',
	'default',
	'eighties',
	'greenscreen'
	'mariana',
	'mocha',
	'monokai',
	'nese',
	'ocean',
	'pop',
	'railscasts',
	'solarized',
	'tomorrow'
];

var highlights = [
	'agate',
	'androidstudio',
	'darcula',
	'github',
	'rainbow',
	'tomorrow',
	'xcode',
	'zenburn'
]

var currentScheme = 'atelier-dune';
var currentHighlight = 'darcula';

function setScheme(scheme) {
	currentScheme = scheme;
	$('#scheme-link').href = "schemes/" + scheme + ".css";
	localStorageSet('scheme', scheme);
}

function setHighlight(scheme) {
	currentHighlight = scheme;
	$('#highlight-link').href = "//cdnjs.cloudflare.com/ajax/libs/highlight.js/9.12.0/styles/" + scheme + ".min.css";
	localStorageSet('highlight', scheme);
}

// Add scheme options to dropdown selector
schemes.forEach(function (scheme) {
	var option = document.createElement('option');
	option.textContent = scheme;
	option.value = scheme;
	$('#scheme-selector').appendChild(option);
});

highlights.forEach(function (scheme) {
	var option = document.createElement('option');
	option.textContent = scheme;
	option.value = scheme;
	$('#highlight-selector').appendChild(option);
});

$('#scheme-selector').onchange = function (e) {
	setScheme(e.target.value);
}

$('#highlight-selector').onchange = function (e) {
	setHighlight(e.target.value);
}

// Load sidebar configaration values from local storage if available
if (localStorageGet('scheme')) {
	setScheme(localStorageGet('scheme'));
}

if (localStorageGet('highlight')) {
	setHighlight(localStorageGet('highlight'));
}

$('#scheme-selector').value = currentScheme;
$('#highlight-selector').value = currentHighlight;

/* main */

if (myChannel == '') {
	pushMessage({ text: frontpage });
	$('#footer').classList.add('hidden');
	$('#sidebar').classList.add('hidden');
} else {
	join(myChannel);
}