"use strict";

const fs = require('fs');
const crypto = require('crypto');
const http = require('http');
const https = require('https');
const { WebSocketServer } = require('ws');
const express = require('express');
const url = require('url');
const compression = require('compression');
const sqlite3 = require('better-sqlite3');

require('dotenv').config();

let DEBUG = process.env.DEBUG || 0;

let HTTP_PORT = process.env.HTTP_PORT || 8080;
let HTTPS_PORT = process.env.HTTPS_PORT;

let SITE_HOST = process.env.SITE_HOST || "localhost";
let SITE_NAME = process.env.SITE_NAME || "Untitled";
let SITE_URL = process.env.SITE_URL;
if (!SITE_URL) {
	if (HTTPS_PORT)
		SITE_URL = "https://" + SITE_HOST + ":" + HTTPS_PORT;
	else
		SITE_URL = "http://" + SITE_HOST + ":" + HTTP_PORT;
}

/*
 * Main database.
 */

let db = new sqlite3(process.env.DATABASE || "./db");
db.pragma("journal_mode = WAL");
db.pragma("synchronous = NORMAL");
db.pragma("foreign_keys = ON");

function SQL(s) {
	return db.prepare(s);
}

/*
 * Notification mail setup.
 */

let mailer = null;
if (process.env.MAIL_HOST && process.env.MAIL_PORT && process.env.MAIL_FROM) {
	mailer = require("nodemailer").createTransport({
		host: process.env.MAIL_HOST,
		port: process.env.MAIL_PORT,
		ignoreTLS: true
	});
	console.log("Mail notifications enabled: ", mailer.options);
} else {
	console.log("Mail notifications disabled.");
}

/*
 * Login session management.
 */

const COOKIE = (process.env.COOKIE || "login") + "=";

db.exec("delete from logins where expires < julianday()");
const login_sql_select = SQL("select user_id from logins where sid = ? and expires > julianday()").pluck();
const login_sql_insert = SQL("insert into logins values (abs(random()) % (1<<48), ?, julianday() + 28) returning sid").pluck();
const login_sql_delete = SQL("delete from logins where sid = ?");
const login_sql_touch = SQL("update logins set expires = julianday() + 28 where sid = ? and expires < julianday() + 27");

function make_cookie(sid, age) {
	if (SITE_HOST !== "localhost")
		return `${COOKIE}${sid}; Path=/; Domain=${SITE_HOST}; Max-Age=${age}; HttpOnly`;
	return `${COOKIE}${sid}; Path=/; Max-Age=${age}; HttpOnly`;
}

function login_cookie(req) {
	let c = req.headers.cookie;
	if (c) {
		let i = c.indexOf(COOKIE);
		if (i >= 0)
			return parseInt(c.substring(i+COOKIE.length));
	}
	return 0;
}

function login_insert(res, user_id) {
	let sid = login_sql_insert.get(user_id);
	res.setHeader("Set-Cookie", make_cookie(sid, 2419200));
}

function login_touch(res, sid) {
	if (login_sql_touch.run(sid).changes === 1)
		res.setHeader("Set-Cookie", make_cookie(sid, 2419200));
}

function login_delete(res, sid) {
	login_sql_delete.run(sid);
	res.setHeader("Set-Cookie", make_cookie("", 0));
}

/*
 * Web server setup.
 */

express.static.mime.define({ "image/avif": ["avif"] });

function set_static_headers(res, path) {
	if (path.match(/\.(jpg|png|svg|avif|webp|ico|woff2)$/))
		res.setHeader("Cache-Control", "max-age=86400");
	else
		res.setHeader("Cache-Control", "max-age=60");
}

let app = express();
app.locals.SITE_NAME = SITE_NAME;
app.locals.SITE_URL = SITE_URL;
app.set('x-powered-by', false);
app.set('etag', false);
app.set('view engine', 'pug');

app.use(compression());
app.use(express.static('public', { redirect: false, etag: false, cacheControl: false, setHeaders: set_static_headers }));
app.use(express.urlencoded({extended:false}));

let wss;

if (HTTPS_PORT) {
	let https_server = https.createServer({
		key: fs.readFileSync(process.env.SSL_KEY || "key.pem"),
		cert: fs.readFileSync(process.env.SSL_CERT || "cert.pem")
	}, app);
	wss = new WebSocketServer({server: https_server});
	https_server.listen(HTTPS_PORT, "0.0.0.0", () => console.log("Listening to HTTPS on *:" + HTTPS_PORT));
	https_server.keepAliveTimeout = 0;

	// Force HTTPS by redirecting HTTP.
	let redirect_app = express();
	redirect_app.all("*", (req, res) => res.redirect(308, SITE_URL + req.url));
	let redirect_server = http.createServer(redirect_app);
	redirect_server.listen(HTTP_PORT, "0.0.0.0", () => console.log("Redirecting from HTTP on *:" + HTTP_PORT));
} else {
	let http_server = http.createServer(app);
	wss = new WebSocketServer({server: http_server});
	http_server.keepAliveTimeout = 0;
	http_server.listen(HTTP_PORT, "0.0.0.0", () => console.log("Listening to HTTP on *:" + HTTP_PORT));
}

/*
 * MISC FUNCTIONS
 */

function random_seed() {
	return crypto.randomInt(1, 0x7ffffffe);
}

function SLOG(socket, ...msg) {
	let time = new Date().toISOString().substring(11,19);
	let name = (socket.user ? socket.user.name : "guest").padEnd(20);
	let ip = String(socket.ip).padEnd(15);
	let ws = "----------";
	console.log(time, ip, ws, name, "WS",
		socket.title_id,
		socket.game_id,
		socket.role,
		...msg);
}

function human_date(time) {
	var date = time ? new Date(time + " UTC") : new Date(0);
	var seconds = (Date.now() - date.getTime()) / 1000;
	var days = Math.floor(seconds / 86400);
	if (days === 0) {
		if (seconds < 60) return "Now";
		if (seconds < 120) return "1 minute ago";
		if (seconds < 3600) return Math.floor(seconds / 60) + " minutes ago";
		if (seconds < 7200) return "1 hour ago";
		if (seconds < 86400) return Math.floor(seconds / 3600) + " hours ago";
	}
	if (days === 1) return "Yesterday";
	if (days < 14) return days + " days ago";
	if (days < 31) return Math.floor(days / 7) + " weeks ago";
	return date.toISOString().substring(0,10);
}

function is_email(email) {
	return email.match(/^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\.[a-zA-Z0-9-]+)*$/);
}

function clean_user_name(name) {
	name = name.replace(/^ */,'').replace(/ *$/,'').replace(/  */g,' ');
	if (name.length > 50)
		name = name.substring(0, 50);
	return name;
}

const USER_NAME_RE = /^[\p{Alpha}\p{Number}'_-]+( [\p{Alpha}\p{Number}'_-]+)*$/u;

function is_valid_user_name(name) {
	if (name.length < 2)
		return false;
	if (name.length > 50)
		return false;
	return USER_NAME_RE.test(name);
}

function hash_password(password, salt) {
	let hash = crypto.createHash('sha256');
	hash.update(password);
	hash.update(salt);
	return hash.digest('hex');
}

function get_avatar(mail) {
	if (!mail)
		mail = "foo@example.com";
	let digest = crypto.createHash('md5').update(mail.trim().toLowerCase()).digest('hex');
	return '//www.gravatar.com/avatar/' + digest + '?d=mp';
}

/*
 * USER AUTHENTICATION
 */

const SQL_BLACKLIST_MAIL = SQL("SELECT EXISTS ( SELECT 1 FROM blacklist_mail WHERE ? LIKE mail )").pluck();

const SQL_EXISTS_USER_NAME = SQL("SELECT EXISTS ( SELECT 1 FROM users WHERE name=? )").pluck();
const SQL_EXISTS_USER_MAIL = SQL("SELECT EXISTS ( SELECT 1 FROM users WHERE mail=? )").pluck();

const SQL_INSERT_USER = SQL("INSERT INTO users (name,mail,password,salt) VALUES (?,?,?,?) RETURNING user_id,name,mail,notify");

const SQL_SELECT_USER_BY_NAME = SQL("SELECT * FROM user_view WHERE name=?");
const SQL_SELECT_LOGIN_BY_MAIL = SQL("SELECT * FROM user_login_view WHERE mail=?");
const SQL_SELECT_LOGIN_BY_NAME = SQL("SELECT * FROM user_login_view WHERE name=?");
const SQL_SELECT_USER_PROFILE = SQL("SELECT * FROM user_profile_view WHERE name=?");
const SQL_SELECT_USER_NAME = SQL("SELECT name FROM users WHERE user_id=?").pluck();
const SQL_SELECT_USER_INFO = SQL(`
	select
		user_id,
		name,
		mail,
		(
			select
				count(*)
			from
				messages
			where
				to_id = user_id
				and is_read = 0
				and is_deleted_from_inbox = 0
		) as unread,
		(
			select
				count(*)
			from
				players
				join games using(game_id)
				join game_state using(game_id)
			where
				status = 1
				and players.user_id = users.user_id
				and active in ( players.role, 'Both', 'All' )
		) as active
	from
		users
	where user_id = ?
	`);

const SQL_OFFLINE_USER = SQL("SELECT * FROM user_view NATURAL JOIN user_last_seen WHERE user_id=? AND datetime('now') > datetime(atime,?)");

const SQL_SELECT_USER_NOTIFY = SQL("SELECT notify FROM users WHERE user_id=?").pluck();
const SQL_UPDATE_USER_NOTIFY = SQL("UPDATE users SET notify=? WHERE user_id=?");
const SQL_UPDATE_USER_NAME = SQL("UPDATE users SET name=? WHERE user_id=?");
const SQL_UPDATE_USER_MAIL = SQL("UPDATE users SET mail=? WHERE user_id=?");
const SQL_UPDATE_USER_ABOUT = SQL("UPDATE users SET about=? WHERE user_id=?");
const SQL_UPDATE_USER_PASSWORD = SQL("UPDATE users SET password=?, salt=? WHERE user_id=?");
const SQL_UPDATE_USER_LAST_SEEN = SQL("INSERT OR REPLACE INTO user_last_seen (user_id,atime) VALUES (?,datetime('now'))");

const SQL_FIND_TOKEN = SQL("SELECT token FROM tokens WHERE user_id=? AND datetime('now') < datetime(time, '+5 minutes')").pluck();
const SQL_CREATE_TOKEN = SQL("INSERT OR REPLACE INTO tokens (user_id,token,time) VALUES (?, lower(hex(randomblob(16))), datetime('now')) RETURNING token").pluck();
const SQL_VERIFY_TOKEN = SQL("SELECT EXISTS ( SELECT 1 FROM tokens WHERE user_id=? AND datetime('now') < datetime(time, '+20 minutes') AND token=? )").pluck();

function is_blacklisted(mail) {
	if (SQL_BLACKLIST_MAIL.get(mail) === 1)
		return true;
	return false;
}

function parse_user_agent(req) {
	let user_agent = req.headers["user-agent"];
	if (!user_agent)
		return "Browser";
	let agent = user_agent;
	if (user_agent.indexOf("Firefox/") >= 0)
		agent = "Firefox";
	else if (user_agent.indexOf("Chrome/") >= 0)
		agent = "Chrome";
	else if (user_agent.indexOf("Safari/") >= 0)
		agent = "Safari";
	else if (user_agent.indexOf("Edg/") >= 0)
		agent = "Edge";
	else if (user_agent.indexOf("OPR/") >= 0)
		agent = "Opera";
	else if (user_agent.indexOf("Opera") >= 0)
		agent = "Opera";
	else if (user_agent.indexOf("Googlebot") >= 0)
		agent = "Googlebot";
	else if (user_agent.indexOf("bingbot") >= 0)
		agent = "Bingbot";
	else if (user_agent.indexOf("; MSIE") >= 0)
		agent = "MSIE";
	else if (user_agent.indexOf("Trident/") >= 0)
		agent = "MSIE";
	else if (user_agent.indexOf("AppleWebKit/") >= 0)
		agent = "AppleWebKit";
	if (user_agent.indexOf("Mobile") >= 0)
		return agent + "/M";
	return agent;
}

app.use(function (req, res, next) {
	req.user_agent = parse_user_agent(req);
	if (req.user_agent === "MSIE")
		return res.redirect("/msie.html");
	let ip = req.ip || req.connection.remoteAddress || "0.0.0.0";
	res.setHeader('Cache-Control', 'no-store');
	let sid = login_cookie(req);
	if (sid) {
		let user_id = login_sql_select.get(sid);
		if (user_id) {
			login_touch(res, sid);
			req.user = SQL_SELECT_USER_INFO.get(user_id);
			SQL_UPDATE_USER_LAST_SEEN.run(user_id);
		}
	}

	// Log non-static accesses.
	let time = new Date().toISOString().substring(11,19);
	let name = (req.user ? req.user.name : "guest").padEnd(20);
	let ua = req.user_agent.padEnd(10);
	ip = String(ip).padEnd(15);
	console.log(time, ip, ua, name, req.method, req.url);

	return next();
});

function must_be_logged_in(req, res, next) {
	if (!req.user)
		return res.redirect('/login?redirect=' + encodeURIComponent(req.originalUrl));
	return next();
}

app.get('/', function (req, res) {
	res.render('index.pug', { user: req.user, titles: TITLES });
});

app.get('/about', function (req, res) {
	res.render('about.pug', { user: req.user });
});

app.get('/logout', function (req, res) {
	let sid = login_cookie(req);
	if (sid)
		login_delete(res, sid);
	res.redirect('/login');
});

app.get('/login', function (req, res) {
	if (req.user)
		return res.redirect('/');
	res.render('login.pug', { redirect: req.query.redirect || '/profile' });
});

app.post('/login', function (req, res) {
	let name_or_mail = req.body.username;
	let password = req.body.password;
	let redirect = req.body.redirect;
	if (!is_email(name_or_mail))
		name_or_mail = clean_user_name(name_or_mail);
	let user = SQL_SELECT_LOGIN_BY_NAME.get(name_or_mail);
	if (!user)
		user = SQL_SELECT_LOGIN_BY_MAIL.get(name_or_mail);
	if (!user || is_blacklisted(user.mail) || hash_password(password, user.salt) != user.password)
		return setTimeout(() => res.render('login.pug', { flash: "Invalid login." }), 1000);
	login_insert(res, user.user_id);
	res.redirect(redirect);
});

app.get('/signup', function (req, res) {
	if (req.user)
		return res.redirect('/');
	res.render('signup.pug');
});

app.post('/signup', function (req, res) {
	function err(msg) {
		res.render('signup.pug', { flash: msg });
	}
	let name = req.body.username;
	let mail = req.body.mail;
	let password = req.body.password;
	name = clean_user_name(name);
	if (!is_valid_user_name(name))
		return err("Invalid user name!");
	if (SQL_EXISTS_USER_NAME.get(name))
		return err("That name is already taken.");
	if (!is_email(mail) || is_blacklisted(mail))
		return err("Invalid mail address!");
	if (SQL_EXISTS_USER_MAIL.get(mail))
		return err("That mail is already taken.");
	if (password.length < 4)
		return err("Password is too short!");
	if (password.length > 100)
		return err("Password is too long!");
	let salt = crypto.randomBytes(32).toString('hex');
	let hash = hash_password(password, salt);
	let user = SQL_INSERT_USER.get(name, mail, hash, salt);
	login_insert(res, user.user_id);
	res.redirect('/profile');
});

app.get('/forgot-password', function (req, res) {
	if (req.user)
		return res.redirect('/');
	res.render('forgot_password.pug');
});

app.post('/forgot-password', function (req, res) {
	let mail = req.body.mail;
	let user = SQL_SELECT_LOGIN_BY_MAIL.get(mail);
	if (user) {
		let token = SQL_FIND_TOKEN.get(user.user_id);
		if (!token) {
			token = SQL_CREATE_TOKEN.get(user.user_id);
			mail_password_reset_token(user, token);
		}
		return res.redirect('/reset-password/' + mail);
	}
	res.render('forgot_password.pug', { flash: "User not found." });
});

app.get('/reset-password', function (req, res) {
	if (req.user)
		return res.redirect('/');
	res.render('reset_password.pug', { mail: "", token: "" });
});

app.get('/reset-password/:mail', function (req, res) {
	if (req.user)
		return res.redirect('/');
	let mail = req.params.mail;
	res.render('reset_password.pug', { mail: mail, token: "" });
});

app.get('/reset-password/:mail/:token', function (req, res) {
	if (req.user)
		return res.redirect('/');
	let mail = req.params.mail;
	let token = req.params.token;
	res.render('reset_password.pug', { mail: mail, token: token });
});

app.post('/reset-password', function (req, res) {
	let mail = req.body.mail;
	let token = req.body.token;
	let password = req.body.password;
	function err(msg) {
		res.render('reset_password.pug', { mail: mail, token: token });
	}
	let user = SQL_SELECT_LOGIN_BY_MAIL.get(mail);
	if (!user)
		return err("User not found.");
	if (password.length < 4)
		return err("Password is too short!");
	if (password.length > 100)
		return err("Password is too long!");
	if (!SQL_VERIFY_TOKEN.get(user.user_id, token))
		return err("Invalid or expired token!");
	let salt = crypto.randomBytes(32).toString('hex');
	let hash = hash_password(password, salt);
	SQL_UPDATE_USER_PASSWORD.run(hash, salt, user.user_id);
	login_insert(res, user.user_id);
	return res.redirect('/profile');
});

app.get('/change-password', must_be_logged_in, function (req, res) {
	res.render('change_password.pug', { user: req.user });
});

app.post('/change-password', must_be_logged_in, function (req, res) {
	let oldpass = req.body.password;
	let newpass = req.body.newpass;
	// Get full user record including password and salt
	let user = SQL_SELECT_LOGIN_BY_MAIL.get(req.user.mail);
	if (newpass.length < 4)
		return res.render('change_password.pug', { user: req.user, flash: "Password is too short!" });
	if (newpass.length > 100)
		return res.render('change_password.pug', { user: req.user, flash: "Password is too long!" });
	let oldhash = hash_password(oldpass, user.salt);
	if (oldhash !== user.password)
		return res.render('change_password.pug', { user: req.user, flash: "Wrong password!" });
	let salt = crypto.randomBytes(32).toString('hex');
	let hash = hash_password(newpass, salt);
	return res.redirect('/profile');
});

/*
 * USER PROFILE
 */

app.get('/subscribe', must_be_logged_in, function (req, res) {
	SQL_UPDATE_USER_NOTIFY.run(1, req.user.user_id);
	res.redirect('/profile');
});

app.get('/unsubscribe', must_be_logged_in, function (req, res) {
	SQL_UPDATE_USER_NOTIFY.run(0, req.user.user_id);
	res.redirect('/profile');
});

app.get('/change-name', must_be_logged_in, function (req, res) {
	res.render('change_name.pug', { user: req.user });
});

app.post('/change-name', must_be_logged_in, function (req, res) {
	let newname = clean_user_name(req.body.newname);
	if (!is_valid_user_name(newname))
		return res.render('change_name.pug', { user: req.user, flash: "Invalid user name!" });
	if (SQL_EXISTS_USER_NAME.get(newname))
		return res.render('change_name.pug', { user: req.user, flash: "That name is already taken!" });
	SQL_UPDATE_USER_NAME.run(newname, req.user.user_id);
	return res.redirect('/profile');
});

app.get('/change-mail', must_be_logged_in, function (req, res) {
	res.render('change_mail.pug', { user: req.user });
});

app.post('/change-mail', must_be_logged_in, function (req, res) {
	let newmail = req.body.newmail;
	if (!is_email(newmail))
		res.render('change_mail.pug', { user: req.user, flash: "Invalid mail address!" });
	if (SQL_EXISTS_USER_MAIL.get(newmail))
		res.render('change_mail.pug', { user: req.user, flash: "That mail address is already taken!" });
	SQL_UPDATE_USER_MAIL.run(newmail, req.user.user_id);
	return res.redirect('/profile');
});

app.get('/change-about', must_be_logged_in, function (req, res) {
	let about = SQL_SELECT_USER_PROFILE.get(req.user.name).about;
	res.render('change_about.pug', { user: req.user, about: about || "" });
});

app.post('/change-about', must_be_logged_in, function (req, res) {
	SQL_UPDATE_USER_ABOUT.run(req.body.about, req.user.user_id);
	return res.redirect('/profile');
});

app.get('/user/:who_name', function (req, res) {
	let who = SQL_SELECT_USER_PROFILE.get(req.params.who_name);
	if (who) {
		who.avatar = get_avatar(who.mail);
		who.ctime = human_date(who.ctime);
		who.atime = human_date(who.atime);
		res.render('user.pug', { user: req.user, who: who });
	} else {
		return res.status(404).send("Invalid user name.");
	}
});

app.get('/users', function (req, res) {
	let rows = SQL("SELECT * FROM user_profile_view ORDER BY atime DESC").all();
	rows.forEach(row => {
		row.avatar = get_avatar(row.mail);
		row.ctime = human_date(row.ctime);
		row.atime = human_date(row.atime);
	});
	res.render('user_list.pug', { user: req.user, user_list: rows });
});

app.get('/chat', must_be_logged_in, function (req, res) {
	let chat = SQL_SELECT_USER_CHAT_N.all(req.user.user_id, 12*20);
	res.render('chat.pug', { user: req.user, chat: chat, page_size: 12 });
});

app.get('/chat/all', must_be_logged_in, function (req, res) {
	let chat = SQL_SELECT_USER_CHAT.all(req.user.user_id);
	res.render('chat.pug', { user: req.user, chat: chat, page_size: 0 });
});

/*
 * MESSAGES
 */

const MESSAGE_LIST_INBOX = SQL(`
	SELECT message_id, from_name, subject, time, is_read
	FROM message_view
	WHERE to_id=? AND is_deleted_from_inbox=0
	ORDER BY message_id DESC`);

const MESSAGE_LIST_OUTBOX = SQL(`
	SELECT message_id, to_name, subject, time, 1 as is_read
	FROM message_view
	WHERE from_id=? AND is_deleted_from_outbox=0
	ORDER BY message_id DESC`);

const MESSAGE_FETCH = SQL("SELECT * FROM message_view WHERE message_id=? AND ( from_id=? OR to_id=? )");
const MESSAGE_SEND = SQL("INSERT INTO messages (from_id,to_id,subject,body) VALUES (?,?,?,?)");
const MESSAGE_MARK_READ = SQL("UPDATE messages SET is_read=1 WHERE message_id=? AND is_read = 0");
const MESSAGE_DELETE_INBOX = SQL("UPDATE messages SET is_deleted_from_inbox=1 WHERE message_id=? AND to_id=?");
const MESSAGE_DELETE_OUTBOX = SQL("UPDATE messages SET is_deleted_from_outbox=1 WHERE message_id=? AND from_id=?");
const MESSAGE_DELETE_ALL_OUTBOX = SQL("UPDATE messages SET is_deleted_from_outbox=1 WHERE from_id=?");

app.get('/inbox', must_be_logged_in, function (req, res) {
	let messages = MESSAGE_LIST_INBOX.all(req.user.user_id);
	for (let i = 0; i < messages.length; ++i)
		messages[i].time = human_date(messages[i].time);
	res.render('message_inbox.pug', {
		user: req.user,
		messages: messages,
	});
});

app.get('/outbox', must_be_logged_in, function (req, res) {
	let messages = MESSAGE_LIST_OUTBOX.all(req.user.user_id);
	for (let i = 0; i < messages.length; ++i)
		messages[i].time = human_date(messages[i].time);
	res.render('message_outbox.pug', {
		user: req.user,
		messages: messages,
	});
});

app.get('/message/read/:message_id', must_be_logged_in, function (req, res) {
	let message_id = req.params.message_id | 0;
	let message = MESSAGE_FETCH.get(message_id, req.user.user_id, req.user.user_id);
	if (!message)
		return res.status(404).send("Invalid message ID.");
	if (message.to_id === req.user.user_id && message.is_read === 0) {
		MESSAGE_MARK_READ.run(message_id);
		req.user.unread --;
	}
	message.time = human_date(message.time);
	message.body = linkify_post(message.body);
	res.render('message_read.pug', {
		user: req.user,
		message: message,
	});
});

app.get('/message/send', must_be_logged_in, function (req, res) {
	res.render('message_send.pug', {
		user: req.user,
		to_name: "",
		subject: "",
		body: "",
	});
});

app.get('/message/send/:to_name', must_be_logged_in, function (req, res) {
	let to_name = req.params.to_name;
	res.render('message_send.pug', {
		user: req.user,
		to_name: to_name,
		subject: "",
		body: "",
	});
});

app.post('/message/send', must_be_logged_in, function (req, res) {
	let to_name = req.body.to.trim();
	let subject = req.body.subject.trim();
	let body = req.body.body.trim();
	let to_user = SQL_SELECT_USER_BY_NAME.get(to_name);
	if (!to_user) {
		return res.render('message_send.pug', {
			user: req.user,
			to_id: 0,
			to_name: to_name,
			subject: subject,
			body: body,
			flash: "Cannot find that user."
		});
	}
	let info = MESSAGE_SEND.run(req.user.user_id, to_user.user_id, subject, body);
	if (to_user.notify)
		mail_new_message(to_user, info.lastInsertRowid, req.user.name);
	res.redirect('/inbox');
});

function quote_body(message) {
	let when = new Date(message.time).toDateString();
	let who = message.from_name;
	let what = message.body.split("\n").join("\n> ");
	return "\n\n" + "On " + when + " " + who + " wrote:\n> " + what + "\n";
}

app.get('/message/reply/:message_id', must_be_logged_in, function (req, res) {
	let message_id = req.params.message_id | 0;
	let message = MESSAGE_FETCH.get(message_id, req.user.user_id, req.user.user_id);
	if (!message)
		return res.status(404).send("Invalid message ID.");
	return res.render('message_send.pug', {
		user: req.user,
		to_id: message.from_id,
		to_name: message.from_name,
		subject: message.subject.startsWith("Re: ") ? message.subject : "Re: " + message.subject,
		body: quote_body(message),
	});
});

app.get('/message/delete/:message_id', must_be_logged_in, function (req, res) {
	let message_id = req.params.message_id | 0;
	MESSAGE_DELETE_INBOX.run(message_id, req.user.user_id);
	MESSAGE_DELETE_OUTBOX.run(message_id, req.user.user_id);
	res.redirect('/inbox');
});

app.get('/outbox/delete', must_be_logged_in, function (req, res) {
	MESSAGE_DELETE_ALL_OUTBOX.run(req.user.user_id);
	res.redirect('/outbox');
});

/*
 * FORUM
 */

const FORUM_PAGE_SIZE = 15;

const FORUM_COUNT_THREADS = SQL("SELECT COUNT(*) FROM threads").pluck();
const FORUM_LIST_THREADS = SQL("SELECT * FROM thread_view ORDER BY mtime DESC LIMIT ? OFFSET ?");
const FORUM_GET_THREAD = SQL("SELECT * FROM thread_view WHERE thread_id=?");
const FORUM_LIST_POSTS = SQL("SELECT * FROM post_view WHERE thread_id=?");
const FORUM_GET_POST = SQL("SELECT * FROM post_view WHERE post_id=?");
const FORUM_NEW_THREAD = SQL("INSERT INTO threads (author_id,subject) VALUES (?,?)");
const FORUM_NEW_POST = SQL("INSERT INTO posts (thread_id,author_id,body) VALUES (?,?,?)");
const FORUM_EDIT_POST = SQL("UPDATE posts SET body=?, mtime=datetime('now') WHERE post_id=? AND author_id=? RETURNING thread_id").pluck();

function show_forum_page(req, res, page) {
	let thread_count = FORUM_COUNT_THREADS.get();
	let page_count = Math.ceil(thread_count / FORUM_PAGE_SIZE);
	let threads = FORUM_LIST_THREADS.all(FORUM_PAGE_SIZE, FORUM_PAGE_SIZE * (page - 1));
	for (let thread of threads) {
		thread.ctime = human_date(thread.ctime);
		thread.mtime = human_date(thread.mtime);
	}
	res.render('forum_view.pug', {
		user: req.user,
		threads: threads,
		current_page: page,
		page_count: page_count,
	});
}

function linkify_post(text) {
	text = text.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
	text = text.replace(/https?:\/\/\S+/g, (match) => {
		if (match.endsWith(".jpg") || match.endsWith(".png") || match.endsWith(".svg"))
			return `<a href="${match}"><img src="${match}"></a>`;
		return `<a href="${match}">${match}</a>`;
	});
	return text;
}

app.get('/forum', function (req, res) {
	show_forum_page(req, res, 1);
});

app.get('/forum/page/:page', function (req, res) {
	show_forum_page(req, res, req.params.page | 0);
});

app.get('/forum/thread/:thread_id', function (req, res) {
	let thread_id = req.params.thread_id | 0;
	let thread = FORUM_GET_THREAD.get(thread_id);
	let posts = FORUM_LIST_POSTS.all(thread_id);
	if (!thread)
		return res.status(404).send("Invalid thread ID.");
	for (let i = 0; i < posts.length; ++i) {
		posts[i].body = linkify_post(posts[i].body);
		posts[i].edited = posts[i].mtime !== posts[i].ctime;
		posts[i].ctime = human_date(posts[i].ctime);
		posts[i].mtime = human_date(posts[i].mtime);
	}
	res.render('forum_thread.pug', {
		user: req.user,
		thread: thread,
		posts: posts,
	});
});

app.get('/forum/post', must_be_logged_in, function (req, res) {
	res.render('forum_post.pug', {
		user: req.user,
	});
});

app.post('/forum/post', must_be_logged_in, function (req, res) {
	let user_id = req.user.user_id;
	let subject = req.body.subject.trim();
	let body = req.body.body;
	if (subject.length === 0)
		subject = "Untitled";
	let thread_id = FORUM_NEW_THREAD.run(user_id, subject).lastInsertRowid;
	FORUM_NEW_POST.run(thread_id, user_id, body);
	res.redirect('/forum/thread/'+thread_id);
});

app.get('/forum/edit/:post_id', must_be_logged_in, function (req, res) {
	// TODO: edit subject if editing first post
	let post_id = req.params.post_id | 0;
	let post = FORUM_GET_POST.get(post_id);
	if (!post || post.author_id != req.user.user_id)
		return res.status(404).send("Invalid post ID.");
	post.ctime = human_date(post.ctime);
	post.mtime = human_date(post.mtime);
	res.render('forum_edit.pug', {
		user: req.user,
		post: post,
	});
});

app.post('/forum/edit/:post_id', must_be_logged_in, function (req, res) {
	let user_id = req.user.user_id;
	let post_id = req.params.post_id | 0;
	let body = req.body.body;
	let thread_id = FORUM_EDIT_POST.get(body, post_id, user_id);
	res.redirect('/forum/thread/'+thread_id);
});

app.get('/forum/reply/:post_id', must_be_logged_in, function (req, res) {
	let post_id = req.params.post_id | 0;
	let post = FORUM_GET_POST.get(post_id);
	if (!post)
		return res.status(404).send("Invalid post ID.");
	let thread = FORUM_GET_THREAD.get(post.thread_id);
	post.body = linkify_post(post.body);
	post.edited = post.mtime !== post.ctime;
	post.ctime = human_date(post.ctime);
	post.mtime = human_date(post.mtime);
	res.render('forum_reply.pug', {
		user: req.user,
		thread: thread,
		post: post,
	});
});

app.post('/forum/reply/:thread_id', must_be_logged_in, function (req, res) {
	let thread_id = req.params.thread_id | 0;
	let user_id = req.user.user_id;
	let body = req.body.body;
	FORUM_NEW_POST.run(thread_id, user_id, body);
	res.redirect('/forum/thread/'+thread_id);
});

/*
 * GAME LOBBY
 */

let TITLES = {};
let RULES = {};
let HTML_ABOUT = {};
let HTML_CREATE = {};

function load_rules() {
	const SQL_SELECT_TITLES = SQL("SELECT * FROM titles");
	for (let title of SQL_SELECT_TITLES.all()) {
		let title_id = title.title_id;
		if (fs.existsSync(__dirname + "/public/" + title_id + "/rules.js")) {
			console.log("Loading rules for " + title_id);
			try {
				TITLES[title_id] = title;
				RULES[title_id] = require("./public/" + title_id + "/rules.js");
				HTML_ABOUT[title_id] = fs.readFileSync("./public/" + title_id + "/about.html");
				HTML_CREATE[title_id] = fs.readFileSync("./public/" + title_id + "/create.html");
			} catch (err) {
				console.log(err);
			}
		} else {
			console.log("Cannot find rules for " + title_id);
		}
	}
}

function get_game_roles(title_id, scenario, options) {
	let roles = RULES[title_id].roles;
	if (typeof roles === 'function')
		return roles(scenario, options);
	return roles;
}

load_rules();

const SQL_INSERT_GAME = SQL("INSERT INTO games (owner_id,title_id,scenario,options,is_private,is_random,description) VALUES (?,?,?,?,?,?,?)");
const SQL_DELETE_GAME = SQL("DELETE FROM games WHERE game_id=? AND owner_id=?");

const SQL_SELECT_USER_CHAT = SQL("SELECT game_id,time,name,message FROM game_chat_view WHERE game_id IN ( SELECT DISTINCT game_id FROM players WHERE user_id=? ) ORDER BY chat_id DESC").raw();
const SQL_SELECT_USER_CHAT_N = SQL("SELECT game_id,time,name,message FROM game_chat_view WHERE game_id IN ( SELECT DISTINCT game_id FROM players WHERE user_id=? ) ORDER BY chat_id DESC LIMIT ?").raw();

const SQL_SELECT_GAME_CHAT = SQL("SELECT chat_id,time,name,message FROM game_chat_view WHERE game_id=? AND chat_id>?").raw();
const SQL_INSERT_GAME_CHAT = SQL("INSERT INTO game_chat (game_id,user_id,message) VALUES (?,?,?) RETURNING chat_id,time,'',message").raw();

const SQL_SELECT_GAME_STATE = SQL("SELECT state FROM game_state WHERE game_id=?").pluck();
const SQL_UPDATE_GAME_STATE = SQL("INSERT OR REPLACE INTO game_state (game_id,state,active,mtime) VALUES (?,?,?,datetime('now'))");
const SQL_UPDATE_GAME_RESULT = SQL("UPDATE games SET status=?, result=? WHERE game_id=?");
const SQL_UPDATE_GAME_PRIVATE = SQL("UPDATE games SET is_private=1 WHERE game_id=?");
const SQL_INSERT_REPLAY = SQL("INSERT INTO game_replay (game_id,role,action,arguments) VALUES (?,?,?,?)");
const SQL_SELECT_REPLAY = SQL("SELECT role,action,arguments FROM game_replay WHERE game_id=?");

const SQL_SELECT_GAME = SQL("SELECT * FROM games WHERE game_id=?");
const SQL_SELECT_GAME_VIEW = SQL("SELECT * FROM game_view WHERE game_id=?");
const SQL_SELECT_GAME_FULL_VIEW = SQL("SELECT * FROM game_full_view WHERE game_id=?");
const SQL_SELECT_GAME_TITLE = SQL("SELECT title_id FROM games WHERE game_id=?").pluck();
const SQL_SELECT_GAME_RANDOM = SQL("SELECT is_random FROM games WHERE game_id=?").pluck();

const SQL_SELECT_GAME_HAS_TITLE_AND_STATUS = SQL("SELECT 1 FROM games WHERE game_id=? AND title_id=? AND status=?");

const SQL_SELECT_PLAYERS = SQL("SELECT * FROM players NATURAL JOIN user_view WHERE game_id=?");
const SQL_SELECT_PLAYERS_JOIN = SQL("SELECT role, user_id, name FROM players NATURAL JOIN users WHERE game_id=?");
const SQL_SELECT_PLAYER_ROLE = SQL("SELECT role FROM players WHERE game_id=? AND user_id=?").pluck();
const SQL_INSERT_PLAYER_ROLE = SQL("INSERT OR IGNORE INTO players (game_id,role,user_id) VALUES (?,?,?)");
const SQL_DELETE_PLAYER_ROLE = SQL("DELETE FROM players WHERE game_id=? AND role=?");
const SQL_UPDATE_PLAYER_ROLE = SQL("UPDATE players SET role=? WHERE game_id=? AND role=? AND user_id=?");

const SQL_AUTHORIZE_GAME_ROLE = SQL("SELECT 1 FROM players NATURAL JOIN games WHERE title_id=? AND game_id=? AND role=? AND user_id=?").pluck();

const SQL_SELECT_OPEN_GAMES = SQL("SELECT * FROM games WHERE status=0");
const SQL_COUNT_OPEN_GAMES = SQL("SELECT COUNT(*) FROM games WHERE owner_id=? AND status=0").pluck();

const SQL_SELECT_REMATCH = SQL("SELECT game_id FROM games WHERE status < 3 AND description=?").pluck();
const SQL_INSERT_REMATCH = SQL(`
	INSERT INTO games
		(owner_id, title_id, scenario, options, is_private, is_random, description)
	SELECT
		$user_id, title_id, scenario, options, is_private, is_random, $magic
	FROM games
	WHERE game_id = $game_id AND NOT EXISTS (
		SELECT * FROM games WHERE description=$magic
	)
`);

const QUERY_LIST_GAMES = SQL(`
	SELECT * FROM game_view
	WHERE is_private=0 AND status=?
	AND EXISTS ( SELECT 1 FROM players WHERE players.game_id = game_view.game_id )
	ORDER BY mtime DESC
	`);

const QUERY_LIST_GAMES_OF_TITLE = SQL(`
	SELECT * FROM game_view
	WHERE is_private=0 AND title_id=? AND status=?
	AND EXISTS ( SELECT 1 FROM players WHERE players.game_id = game_view.game_id )
	ORDER BY mtime DESC
	LIMIT ?
	`);

const QUERY_LIST_ACTIVE_GAMES_OF_USER = SQL(`
	select * from game_view
	where
		( owner_id=$user_id or game_id in ( select game_id from players where players.user_id=$user_id ) )
		and
		( status < 2 or mtime > datetime('now', '-7 days') )
	order by status asc, mtime desc
	`);

const QUERY_LIST_FINISHED_GAMES_OF_USER = SQL(`
	select * from game_view
	where
		( owner_id=$user_id or game_id in ( select game_id from players where players.user_id=$user_id ) )
		and
		status = 2
	order by status asc, mtime desc
	`);

function is_active(game, players, user_id) {
	if (game.status !== 1 || user_id === 0)
		return false;
	let active = game.active;
	for (let i = 0; i < players.length; ++i) {
		let p = players[i];
		if ((p.user_id === user_id) && (active === 'All' || active === 'Both' || active === p.role))
			return true;
	}
	return false;
}

function is_shared(game, players, user_id) {
	let n = 0;
	for (let i = 0; i < players.length; ++i)
		if (players[i].user_id === user_id)
			++n;
	return n > 1;
}

function is_solo(players) {
	return players.every(p => p.user_id === players[0].user_id)
}

function format_options(options) {
	function to_english(k) {
		if (k === true || k === 1) return 'yes';
		if (k === false) return 'no';
		return k.replace(/_/g, " ").replace(/^\w/, c => c.toUpperCase());
	}
	if (!options || options === '{}')
		return "None";
	options = JSON.parse(options);
	return Object.entries(options||{}).map(([k,v]) => (v === true || v === 1) ? to_english(k) : `${to_english(k)}=${to_english(v)}`).join(", ");
}

function annotate_game(game, user_id) {
	let players = SQL_SELECT_PLAYERS_JOIN.all(game.game_id);
	game.player_names = players.map(p => {
		let name = p.name.replace(/ /g, '\xa0');
		return p.user_id > 0 ? `<a href="/user/${p.name}">${name}</a>` : name;
	}).join(", ");
	game.options = format_options(game.options);
	game.is_active = is_active(game, players, user_id);
	game.is_shared = is_shared(game, players, user_id);
	game.is_yours = false;
	game.your_role = null;
	if (user_id > 0) {
		for (let i = 0; i < players.length; ++i) {
			if (players[i].user_id === user_id) {
				game.is_yours = 1;
				game.your_role = players[i].role;
			}
		}
	}
	game.ctime = human_date(game.ctime);
	game.mtime = human_date(game.mtime);
}

function annotate_games(games, user_id) {
	for (let i = 0; i < games.length; ++i) {
		let game = games[i];
		if (game.status === 0) {
			let players = SQL_SELECT_PLAYERS_JOIN.all(game.game_id);
			game.is_ready = RULES[game.title_id].ready(game.scenario, JSON.parse(game.options), players);
		} else {
			game.is_ready = false;
		}
		annotate_game(game, user_id);
	}
}

app.get('/profile', must_be_logged_in, function (req, res) {
	req.user.notify = SQL_SELECT_USER_NOTIFY.get(req.user.user_id);
	let avatar = get_avatar(req.user.mail);
	res.render('profile.pug', {
		user: req.user,
		avatar: avatar,
	});
});

app.get('/games', function (req, res) {
	res.redirect('/games/public');
});

app.get('/games/active', must_be_logged_in, function (req, res) {
	req.user.notify = SQL_SELECT_USER_NOTIFY.get(req.user.user_id);
	let games = QUERY_LIST_ACTIVE_GAMES_OF_USER.all({user_id: req.user.user_id});
	annotate_games(games, req.user.user_id);
	let open_games = games.filter(game => game.status === 0);
	let active_games = games.filter(game => game.status === 1);
	let finished_games = games.filter(game => game.status === 2);
	res.render('games_active.pug', {
		user: req.user,
		open_games: open_games.filter(g => !g.is_ready),
		ready_games: open_games.filter(g => g.is_ready),
		active_games: active_games,
		finished_games: finished_games,
	});
});

app.get('/games/finished', must_be_logged_in, function (req, res) {
	req.user.notify = SQL_SELECT_USER_NOTIFY.get(req.user.user_id);
	let games = QUERY_LIST_FINISHED_GAMES_OF_USER.all({user_id: req.user.user_id});
	annotate_games(games, req.user.user_id);
	res.render('games_finished.pug', {
		user: req.user,
		finished_games: games,
	});
});

app.get('/games/public', function (req, res) {
	let open_games = QUERY_LIST_GAMES.all(0);
	let active_games = QUERY_LIST_GAMES.all(1);
	if (req.user) {
		annotate_games(open_games, req.user.user_id);
		annotate_games(active_games, req.user.user_id);
	} else {
		annotate_games(open_games, 0);
		annotate_games(active_games, 0);
	}
	res.render('games_public.pug', {
		user: req.user,
		open_games: open_games.filter(g => !g.is_ready),
		ready_games: open_games.filter(g => g.is_ready),
		active_games: active_games,
	});
});

app.get('/info/:title_id', function (req, res) {
	return res.redirect('/' + req.params.title_id);
});

function get_title_page(req, res, title_id) {
	let title = TITLES[title_id];
	if (!title)
		return res.status(404).send("Invalid title.");
	let open_games = QUERY_LIST_GAMES_OF_TITLE.all(title_id, 0, 1000);
	let active_games = QUERY_LIST_GAMES_OF_TITLE.all(title_id, 1, 1000);
	let finished_games = QUERY_LIST_GAMES_OF_TITLE.all(title_id, 2, 50);
	annotate_games(open_games, req.user ? req.user.user_id : 0);
	annotate_games(active_games, req.user ? req.user.user_id : 0);
	annotate_games(finished_games, req.user ? req.user.user_id : 0);
	res.render('info.pug', {
		user: req.user,
		title: title,
		about_html: HTML_ABOUT[title_id],
		open_games: open_games.filter(g => !g.is_ready),
		ready_games: open_games.filter(g => g.is_ready),
		active_games: active_games,
		finished_games: finished_games,
	});
}

for (let title_id in TITLES)
	app.get('/' + title_id, (req, res) => get_title_page(req, res, title_id));

app.get('/create/:title_id', must_be_logged_in, function (req, res) {
	let title_id = req.params.title_id;
	let title = TITLES[title_id];
	if (!title)
		return res.status(404).send("Invalid title.");
	res.render('create.pug', {
		user: req.user,
		title: title,
		scenarios: RULES[title_id].scenarios,
		create_html: HTML_CREATE[title_id],
	});
});

function options_json_replacer(key, value) {
	if (key === 'scenario') return undefined;
	if (key === 'description') return undefined;
	if (key === 'is_random') return undefined;
	if (key === 'is_private') return undefined;
	if (value === 'true') return true;
	if (value === 'false') return false;
	if (value === '') return undefined;
	return value;
}

app.post('/create/:title_id', must_be_logged_in, function (req, res) {
	let title_id = req.params.title_id;
	let descr = req.body.description;
	let priv = req.body.is_private === 'true';
	let rand = req.body.is_random === 'true';
	let user_id = req.user.user_id;
	let scenario = req.body.scenario;
	let options = JSON.stringify(req.body, options_json_replacer);
	let count = SQL_COUNT_OPEN_GAMES.get(user_id);
	if (count >= 5)
		return res.send("You have too many open games!");
	if (!(title_id in RULES))
		return res.send("Invalid title.");
	if (!RULES[title_id].scenarios.includes(scenario))
		return res.send("Invalid scenario.");
	let info = SQL_INSERT_GAME.run(user_id, title_id, scenario, options, priv ? 1 : 0, rand ? 1 : 0, descr);
	res.redirect('/join/'+info.lastInsertRowid);
});

app.get('/delete/:game_id', must_be_logged_in, function (req, res) {
	let game_id = req.params.game_id;
	let title_id = SQL_SELECT_GAME_TITLE.get(game_id);
	let info = SQL_DELETE_GAME.run(game_id, req.user.user_id);
	if (info.changes === 0)
		return res.send("Not authorized to delete that game ID.");
	if (info.changes === 1)
		update_join_clients_deleted(game_id);
	res.redirect('/'+title_id);
});

function join_rematch(req, res, game_id, role) {
	try {
		let is_random = SQL_SELECT_GAME_RANDOM.get(game_id);
		if (is_random) {
			let role = SQL_SELECT_PLAYER_ROLE.get(game_id, req.user.user_id);
			if (!role) {
				for (let i = 1; i <= 6; ++i) {
					let info = SQL_INSERT_PLAYER_ROLE.run(game_id, 'Random ' + i, req.user.user_id);
					if (info.changes === 1) {
						update_join_clients_players(game_id);
						break;
					}
				}
			}
		} else {
			let info = SQL_INSERT_PLAYER_ROLE.run(game_id, role, req.user.user_id);
			if (info.changes === 1)
				update_join_clients_players(game_id);
		}
	} catch (err) {
		console.log(err);
	}
	return res.redirect('/join/'+game_id);
}

app.get('/rematch/:old_game_id/:role', must_be_logged_in, function (req, res) {
	let old_game_id = req.params.old_game_id | 0;
	let role = req.params.role;
	let magic = "\u{1F503} " + old_game_id;
	let new_game_id = 0;
	let info = SQL_INSERT_REMATCH.run({user_id: req.user.user_id, game_id: old_game_id, magic: magic});
	if (info.changes === 1)
		new_game_id = info.lastInsertRowid;
	else
		new_game_id = SQL_SELECT_REMATCH.get(magic);
	if (new_game_id)
		return join_rematch(req, res, new_game_id, role);
	return res.status(404).send("Can't create or find rematch game!");
});

let join_clients = {};

function update_join_clients_deleted(game_id) {
	let list = join_clients[game_id];
	if (list && list.length > 0) {
		for (let res of list) {
			res.write("retry: 15000\n");
			res.write("event: deleted\n");
			res.write("data: The game doesn't exist.\n\n");
			res.flush();
		}
	}
}

function update_join_clients_game(game_id) {
	let list = join_clients[game_id];
	if (list && list.length > 0) {
		let game = SQL_SELECT_GAME_VIEW.get(game_id);
		for (let res of list) {
			res.write("retry: 15000\n");
			res.write("event: game\n");
			res.write("data: " + JSON.stringify(game) + "\n\n");
			res.flush();
		}
	}
}

function update_join_clients_players(game_id) {
	let list = join_clients[game_id];
	if (list && list.length > 0) {
		let players = SQL_SELECT_PLAYERS_JOIN.all(game_id);
		let ready = RULES[list.title_id].ready(list.scenario, list.options, players);
		for (let res of list) {
			res.write("retry: 15000\n");
			res.write("event: players\n");
			res.write("data: " + JSON.stringify(players) + "\n\n");
			res.write("event: ready\n");
			res.write("data: " + ready + "\n\n");
			res.flush();
		}
	}
}

app.get('/join/:game_id', must_be_logged_in, function (req, res) {
	let game_id = req.params.game_id | 0;
	let game = SQL_SELECT_GAME_VIEW.get(game_id);
	if (!game)
		return res.status(404).send("Invalid game ID.");
	annotate_game(game, req.user.user_id);
	let roles = get_game_roles(game.title_id, game.scenario, game.options);
	let players = SQL_SELECT_PLAYERS_JOIN.all(game_id);
	let ready = (game.status === 0) && RULES[game.title_id].ready(game.scenario, game.options, players);
	res.render('join.pug', {
		user: req.user,
		game: game,
		roles: roles,
		players: players,
		ready: ready,
	});
});

app.get('/join-events/:game_id', must_be_logged_in, function (req, res) {
	let game_id = req.params.game_id | 0;
	let game = SQL_SELECT_GAME_VIEW.get(game_id);
	let players = SQL_SELECT_PLAYERS_JOIN.all(game_id);

	res.setHeader("Content-Type", "text/event-stream");
	res.setHeader("Connection", "keep-alive");

	if (!game) {
		return res.send("event: deleted\ndata: The game doesn't exist.\n\n");
	}
	if (!(game_id in join_clients)) {
		join_clients[game_id] = [];
		join_clients[game_id].title_id = game.title_id;
		join_clients[game_id].scenario = game.scenario;
		join_clients[game_id].options = JSON.parse(game.options);
	}
	join_clients[game_id].push(res);

	res.on('close', () => {
		let list = join_clients[game_id];
		let i = list.indexOf(res);
		if (i >= 0)
			list.splice(i, 1);
	});

	res.write("retry: 15000\n\n");
	res.write("event: game\n");
	res.write("data: " + JSON.stringify(game) + "\n\n");
	res.write("event: players\n");
	res.write("data: " + JSON.stringify(players) + "\n\n");
	res.flush();
});

app.get('/join/:game_id/:role', must_be_logged_in, function (req, res) {
	let game_id = req.params.game_id | 0;
	let role = req.params.role;
	let game = SQL_SELECT_GAME.get(game_id);
	let roles = get_game_roles(game.title_id, game.scenario, game.options);
	if (game.is_random) {
		let m = role.match(/^Random (\d+)$/);
		if (!m || Number(m[1]) < 1 || Number(m[1]) > roles.length)
			return res.status(404).send("Invalid role.");
	} else {
		if (!roles.includes(role))
			return res.status(404).send("Invalid role.");
	}
	let info = SQL_INSERT_PLAYER_ROLE.run(game_id, role, req.user.user_id);
	if (info.changes === 1) {
		update_join_clients_players(game_id);
		res.send("SUCCESS");
	} else {
		res.send("Could not join game.");
	}
});

app.get('/part/:game_id/:role', must_be_logged_in, function (req, res) {
	let game_id = req.params.game_id | 0;
	let role = req.params.role;
	SQL_DELETE_PLAYER_ROLE.run(game_id, role);
	update_join_clients_players(game_id);
	res.send("SUCCESS");
});

function assign_random_roles(game, players) {
	function pick_random_item(list) {
		let k = crypto.randomInt(list.length);
		let r = list[k];
		list.splice(k, 1);
		return r;
	}
	let roles = get_game_roles(game.title_id, game.scenario, game.options).slice();
	for (let p of players) {
		let old_role = p.role;
		p.role = pick_random_item(roles);
		console.log("ASSIGN ROLE", "(" + p.name + ")", old_role, "->", p.role);
		SQL_UPDATE_PLAYER_ROLE.run(p.role, game.game_id, old_role, p.user_id);
	}
}

function start_game(game_id, game) {
	let players = SQL_SELECT_PLAYERS.all(game_id);
	if (!RULES[game.title_id].ready(game.scenario, game.options, players))
		return res.send("Invalid scenario/options/player configuration!");
	if (game.is_random) {
		assign_random_roles(game, players);
		players = SQL_SELECT_PLAYERS.all(game_id);
		update_join_clients_players(game_id);
	}
	let options = game.options ? JSON.parse(game.options) : {};
	let seed = random_seed();
	let state = RULES[game.title_id].setup(seed, game.scenario, options, players);
	put_replay(game_id, null, 'setup', [seed, game.scenario, options, players]);
	SQL_UPDATE_GAME_RESULT.run(1, null, game_id);
	SQL_UPDATE_GAME_STATE.run(game_id, JSON.stringify(state), state.active);
	if (is_solo(players))
		SQL_UPDATE_GAME_PRIVATE.run(game_id);
	update_join_clients_game(game_id);
}

app.get('/start/:game_id', must_be_logged_in, function (req, res) {
	let game_id = req.params.game_id | 0;
	let game = SQL_SELECT_GAME.get(game_id);
	if (game.owner_id !== req.user.user_id)
		return res.send("Not authorized to start that game ID.");
	if (game.status !== 0)
		return res.send("The game is already started.");
	start_game(game_id, game);
	res.send("SUCCESS");
});

app.get('/play/:game_id/:role', function (req, res) {
	let game_id = req.params.game_id | 0;
	let role = req.params.role;
	let title = SQL_SELECT_GAME_TITLE.get(game_id);
	if (!title)
		return res.status(404).send("Invalid game ID.");
	res.redirect('/'+title+'/play:'+game_id+':'+role);
});

app.get('/play/:game_id', function (req, res) {
	let game_id = req.params.game_id | 0;
	let user_id = req.user ? req.user.user_id : 0;
	let title = SQL_SELECT_GAME_TITLE.get(game_id);
	if (!title)
		return res.status(404).send("Invalid game ID.");
	let role = SQL_SELECT_PLAYER_ROLE.get(game_id, user_id);
	if (role)
		res.redirect('/'+title+'/play:'+game_id+':'+role);
	else
		res.redirect('/'+title+'/play:'+game_id);
});

app.get('/:title_id/play\::game_id\::role', must_be_logged_in, function (req, res) {
	let user_id = req.user ? req.user.user_id : 0;
	let title_id = req.params.title_id;
	let game_id = req.params.game_id;
	let role = req.params.role;
	if (!SQL_AUTHORIZE_GAME_ROLE.get(title_id, game_id, role, user_id))
		return res.status(404).send("Invalid game ID.");
	return res.sendFile(__dirname + '/public/' + title_id + '/play.html');
});

app.get('/:title_id/play\::game_id', function (req, res) {
	let title_id = req.params.title_id;
	let game_id = req.params.game_id;
	let a_title = SQL_SELECT_GAME_TITLE.get(game_id);
	if (a_title !== title_id)
		return res.status(404).send("Invalid game ID.");
	return res.sendFile(__dirname + '/public/' + title_id + '/play.html');
});

app.get('/:title_id/replay\::game_id', function (req, res) {
	let title_id = req.params.title_id;
	let game_id = req.params.game_id;
	let game = SQL_SELECT_GAME.get(game_id);
	if (!game)
		return res.status(404).send("Invalid game ID.");
	if (game.title_id !== title_id)
		return res.status(404).send("Invalid game ID.");
	if (game.status < 2)
		return res.status(404).send("Invalid game ID.");
	return res.sendFile(__dirname + '/public/' + title_id + '/play.html');
});

app.get('/replay/:game_id', function (req, res) {
	let game_id = req.params.game_id;
	let game = SQL_SELECT_GAME.get(game_id);
	if (game.status < 2)
		return res.status(404).send("Invalid game ID.");
	let players = SQL_SELECT_PLAYERS_JOIN.all(game_id);
	let state = SQL_SELECT_GAME_STATE.get(game_id);
	let replay = SQL_SELECT_REPLAY.all(game_id);
	return res.json({players, state, replay});
});

/*
 * MAIL NOTIFICATIONS
 */

const MAIL_FROM = process.env.MAIL_FROM || "user@localhost";
const MAIL_FOOTER = "\n--\nYou can unsubscribe from notifications on your profile page:\n" + SITE_URL + "/profile\n";

const SQL_SELECT_NOTIFIED = SQL("SELECT datetime('now') < datetime(time,?) FROM last_notified WHERE game_id=? AND user_id=?").pluck();
const SQL_INSERT_NOTIFIED = SQL("INSERT OR REPLACE INTO last_notified (game_id,user_id,time) VALUES (?,?,datetime('now'))");
const SQL_DELETE_NOTIFIED = SQL("DELETE FROM last_notified WHERE game_id=? AND user_id=?");

const QUERY_LIST_YOUR_TURN = SQL("SELECT * FROM your_turn_reminder");

function mail_callback(err, info) {
	if (err)
		console.log("MAIL ERROR", err);
}

function mail_addr(user) {
	return user.name + " <" + user.mail + ">";
}

function mail_game_info(game) {
	let desc = `Game: ${game.title_name}\n`;
	desc += `Scenario: ${game.scenario}\n`;
	desc += `Players: ${game.player_names}\n`;
	if (game.description.length > 0)
		desc += `Description: ${game.description}\n`;
	return desc + "\n";
}

function mail_game_link(game_id, user) {
	return SITE_URL + "/play/" + game_id + "/" + encodeURI(user.role) + "\n";
}

function mail_password_reset_token(user, token) {
	if (mailer) {
		let subject = "Password reset request";
		let body =
			"Your password reset token is: " + token + "\n\n" +
			SITE_URL + "/reset-password/" + user.mail + "/" + token + "\n\n" +
			"If you did not request a password reset you can ignore this mail.\n";
		console.log("SENT MAIL:", mail_addr(user), subject);
		mailer.sendMail({ from: MAIL_FROM, to: mail_addr(user), subject: subject, text: body }, mail_callback);
	}
}

function mail_new_message(user, msg_id, msg_from) {
	if (mailer) {
		let subject = "You have a new message from " + msg_from + ".";
		let body =
			"Read the message here:\n" +
			SITE_URL + "/message/read/" + msg_id + "\n" +
			MAIL_FOOTER;
		console.log("SENT MAIL:", mail_addr(user), subject);
		mailer.sendMail({ from: MAIL_FROM, to: mail_addr(user), subject: subject, text: body }, mail_callback);
	}
}

function mail_your_turn_notification(user, game_id, interval) {
	if (mailer) {
		let too_soon = SQL_SELECT_NOTIFIED.get(interval, game_id, user.user_id);
		if (!too_soon) {
			SQL_INSERT_NOTIFIED.run(game_id, user.user_id);
			let game = SQL_SELECT_GAME_FULL_VIEW.get(game_id);
			let subject = `${game.title_name} #${game_id} (${user.role}) - Your turn!`;
			let body = mail_game_info(game) +
				"It's your turn.\n\n" +
				mail_game_link(game_id, user) +
				MAIL_FOOTER;
			console.log("SENT MAIL:", mail_addr(user), subject);
			mailer.sendMail({ from: MAIL_FROM, to: mail_addr(user), subject: subject, text: body }, mail_callback);
		}
	}
}

function reset_your_turn_notification(user, game_id) {
	SQL_DELETE_NOTIFIED.run(game_id, user.user_id);
}

function mail_ready_to_start_notification(user, game_id, interval) {
	if (mailer) {
		let too_soon = SQL_SELECT_NOTIFIED.get(interval, game_id, user.user_id);
		if (!too_soon) {
			SQL_INSERT_NOTIFIED.run(game_id, user.user_id);
			let game = SQL_SELECT_GAME_FULL_VIEW.get(game_id);
			let subject = `${game.title_name} #${game_id} - Ready to start!`;
			let body = mail_game_info(game) +
				"Your game is ready to start.\n\n" +
				SITE_URL + "/join/" + game_id + "\n" +
				MAIL_FOOTER;
			console.log("SENT MAIL:", mail_addr(user), subject);
			mailer.sendMail({ from: MAIL_FROM, to: mail_addr(user), subject: subject, text: body }, mail_callback);
		}
	}
}

function mail_your_turn_notification_to_offline_users(game_id, old_active, active) {
	function is_online(game_id, user_id) {
		for (let other of clients[game_id])
			if (other.user && other.user.user_id === user_id)
				return true;
		return false;
	}

	// Only send notifications when the active player changes or if it's a simultaneous move.
	if (old_active === active && active !== 'Both' && active !== 'All')
		return;

	let players = SQL_SELECT_PLAYERS.all(game_id);
	for (let p of players) {
		if (p.notify) {
			if (active === p.role || active === 'Both' || active === 'All') {
				if (is_online(game_id, p.user_id)) {
					reset_your_turn_notification(p, game_id);
				} else {
					mail_your_turn_notification(p, game_id, '+15 minutes');
				}
			} else {
				reset_your_turn_notification(p, game_id);
			}
		}
	}
}

function notify_your_turn_reminder() {
	for (let item of QUERY_LIST_YOUR_TURN.all()) {
		mail_your_turn_notification(item, item.game_id, '+25 hours');
	}
}

function notify_ready_to_start_reminder() {
	for (let game of SQL_SELECT_OPEN_GAMES.all()) {
		let players = SQL_SELECT_PLAYERS.all(game.game_id);
		let rules = RULES[game.title_id];
		if (rules && rules.ready(game.scenario, game.options, players)) {
			let owner = SQL_OFFLINE_USER.get(game.owner_id, '+3 minutes');
			if (owner) {
				if (owner.notify)
					mail_ready_to_start_notification(owner, game.game_id, '+25 hours');
			}
		}
	}
}

// Check and send daily 'your turn' reminders every 15 minutes.
setInterval(notify_your_turn_reminder, 15 * 60 * 1000);

// Check and send ready to start notifications every 5 minutes.
setInterval(notify_ready_to_start_reminder, 5 * 60 * 1000);

/*
 * GAME SERVER
 */

let clients = {};

function send_message(socket, cmd, arg) {
	socket.send(JSON.stringify([cmd, arg]));
}

function send_state(socket, state) {
	try {
		let view = socket.rules.view(state, socket.role);
		if (socket.seen < view.log.length)
			view.log_start = socket.seen;
		else
			view.log_start = view.log.length;
		socket.seen = view.log.length;
		view.log = view.log.slice(view.log_start);
		if (state.state === 'game_over')
			view.game_over = 1;
		view = JSON.stringify(['state', view]);
		if (socket.last_view !== view) {
			socket.send(view);
			socket.last_view = view;
		}
	} catch (err) {
		console.log(err);
		return send_message(socket, 'error', err.toString());
	}
}

function get_game_state(game_id) {
	let game_state = SQL_SELECT_GAME_STATE.get(game_id);
	if (!game_state)
		throw new Error("No game with that ID");
	return JSON.parse(game_state);
}

function put_game_state(game_id, state, old_active) {
	if (state.state === 'game_over') {
		SQL_UPDATE_GAME_RESULT.run(2, state.result, game_id);
	}
	SQL_UPDATE_GAME_STATE.run(game_id, JSON.stringify(state), state.active);
	for (let other of clients[game_id])
		send_state(other, state);
	update_join_clients_game(game_id);
	mail_your_turn_notification_to_offline_users(game_id, old_active, state.active);
}

function put_replay(game_id, role, action, args) {
	if (args !== undefined && args !== null)
		args = JSON.stringify(args);
	SQL_INSERT_REPLAY.run(game_id, role, action, args);
}

function on_action(socket, action, arg) {
	if (arg !== undefined)
		SLOG(socket, "ACTION", action, JSON.stringify(arg));
	else
		SLOG(socket, "ACTION", action);
	try {
		let state = get_game_state(socket.game_id);
		let old_active = state.active;
		state = socket.rules.action(state, socket.role, action, arg);
		put_game_state(socket.game_id, state, old_active);
		put_replay(socket.game_id, socket.role, action, arg);
	} catch (err) {
		console.log(err);
		return send_message(socket, 'error', err.toString());
	}
}

function on_query(socket, q) {
	let params = undefined;
	if (Array.isArray(q)) {
		params = q[1];
		q = q[0];
	}
	if (params !== undefined)
		SLOG(socket, "QUERY", q, JSON.stringify(params));
	else
		SLOG(socket, "QUERY", q);
	try {
		if (socket.rules.query) {
			let state = get_game_state(socket.game_id);
			let reply = socket.rules.query(state, socket.role, q, params);
			send_message(socket, 'reply', [q, reply]);
		}
	} catch (err) {
		console.log(err);
		return send_message(socket, 'error', err.toString());
	}
}

function on_resign(socket) {
	SLOG(socket, "RESIGN");
	try {
		let state = get_game_state(socket.game_id);
		let old_active = state.active;
		// TODO: shared "resign" function
		state = socket.rules.resign(state, socket.role);
		put_game_state(socket.game_id, state, old_active);
		put_replay(socket.game_id, socket.role, 'resign', null);
	} catch (err) {
		console.log(err);
		return send_message(socket, 'error', err.toString());
	}
}

function on_getchat(socket, seen) {
	try {
		let chat = SQL_SELECT_GAME_CHAT.all(socket.game_id, seen);
		if (chat.length > 0)
			SLOG(socket, "GETCHAT", seen, chat.length);
		for (let i = 0; i < chat.length; ++i)
			send_message(socket, 'chat', chat[i]);
	} catch (err) {
		console.log(err);
		return send_message(socket, 'error', err.toString());
	}
}

function on_chat(socket, message) {
	message = message.substring(0,4000);
	try {
		let chat = SQL_INSERT_GAME_CHAT.get(socket.game_id, socket.user.user_id, message);
		chat[2] = socket.user.name;
		SLOG(socket, "CHAT");
		for (let other of clients[socket.game_id])
			if (other.role !== "Observer")
				send_message(other, 'chat', chat);
	} catch (err) {
		console.log(err);
		return send_message(socket, 'error', err.toString());
	}
}

function on_debug(socket) {
	if (!DEBUG)
		send_message(socket, 'error', "Debugging is not enabled on this server.");
	SLOG(socket, "DEBUG");
	try {
		let game_state = SQL_SELECT_GAME_STATE.get(socket.game_id);
		if (!game_state)
			return send_message(socket, 'error', "No game with that ID.");
		send_message(socket, 'debug', game_state);
	} catch (err) {
		console.log(err);
		return send_message(socket, 'error', err.toString());
	}
}

function on_save(socket) {
	if (!DEBUG)
		send_message(socket, 'error', "Debugging is not enabled on this server.");
	SLOG(socket, "SAVE");
	try {
		let game_state = SQL_SELECT_GAME_STATE.get(socket.game_id);
		if (!game_state)
			return send_message(socket, 'error', "No game with that ID.");
		send_message(socket, 'save', game_state);
	} catch (err) {
		console.log(err);
		return send_message(socket, 'error', err.toString());
	}
}

function on_restore(socket, state_text) {
	if (!DEBUG)
		send_message(socket, 'error', "Debugging is not enabled on this server.");
	SLOG(socket, "RESTORE");
	try {
		let state = JSON.parse(state_text);
		state.seed = random_seed(); // reseed!
		state_text = JSON.stringify(state);
		SQL_UPDATE_GAME_RESULT.run(1, null, socket.game_id);
		SQL_UPDATE_GAME_STATE.run(socket.game_id, state_text, state.active);
		put_replay(socket.game_id, null, 'restore', state_text);
		for (let other of clients[socket.game_id])
			send_state(other, state);
	} catch (err) {
		console.log(err);
		return send_message(socket, 'error', err.toString());
	}
}

function broadcast_presence(game_id) {
	let presence = {};
	for (let socket of clients[game_id])
		presence[socket.role] = true;
	for (let socket of clients[game_id])
		send_message(socket, 'presence', presence);
}

function on_restart(socket, scenario) {
	if (!DEBUG)
		send_message(socket, 'error', "Debugging is not enabled on this server.");
	try {
		let seed = random_seed();
		let options = JSON.parse(SQL_SELECT_GAME.get(socket.game_id).options);
		let state = socket.rules.setup(seed, scenario, options, socket.players);
		put_replay(socket.game_id, null, 'setup', [seed, scenario, options, socket.players]);
		for (let other of clients[socket.game_id]) {
			other.seen = 0;
			send_state(other, state);
		}
		let state_text = JSON.stringify(state);
		SQL_UPDATE_GAME_RESULT.run(1, null, socket.game_id);
		SQL_UPDATE_GAME_STATE.run(socket.game_id, state_text, state.active);
	} catch (err) {
		console.log(err);
		return send_message(socket, 'error', err.toString());
	}
}

function handle_player_message(socket, cmd, arg) {
	switch (cmd) {
	case 'action': on_action(socket, arg[0], arg[1]); break;
	case 'query': on_query(socket, arg); break;
	case 'resign': on_resign(socket); break;
	case 'getchat': on_getchat(socket, arg); break;
	case 'chat': on_chat(socket, arg); break;
	case 'debug': on_debug(socket); break;
	case 'save': on_save(socket); break;
	case 'restore': on_restore(socket, arg); break;
	case 'restart': on_restart(socket, arg); break;
	}
}

function handle_observer_message(socket, cmd, arg) {
	switch (cmd) {
	case 'query': on_query(socket, arg); break;
	}
}

wss.on('connection', (socket, req, client) => {
	let u = url.parse(req.url, true);
	if (u.pathname !== '/play-socket')
		return setTimeout(() => socket.close(1000, "Invalid request."), 30000);
	req.query = u.query;

	let user_id = 0;
	let sid = login_cookie(req);
	if (sid)
		user_id = login_sql_select.get(sid);
	if (user_id)
		socket.user = SQL_SELECT_USER_INFO.get(user_id);

	socket.ip = req.ip || req.connection.remoteAddress || "0.0.0.0";
	socket.title_id = req.query.title || "unknown";
	socket.game_id = req.query.game | 0;
	socket.role = req.query.role;
	socket.seen = req.query.seen | 0;
	socket.rules = RULES[socket.title_id];

	SLOG(socket, "OPEN " + socket.seen);

	try {
		let title_id = SQL_SELECT_GAME_TITLE.get(socket.game_id);
		if (title_id !== socket.title_id)
			return socket.close(1000, "Invalid game ID.");

		let players = socket.players = SQL_SELECT_PLAYERS_JOIN.all(socket.game_id);

		if (socket.role !== "Observer") {
			if (!socket.user)
				return socket.close(1000, "You are not logged in!");
			if (socket.role && socket.role !== 'undefined' && socket.role !== 'null') {
				let me = players.find(p => p.user_id === socket.user.user_id && p.role === socket.role);
				if (!me)
					return socket.close(1000, "You aren't assigned that role!");
			} else {
				let me = players.find(p => p.user_id === socket.user.user_id);
				socket.role = me ? me.role : "Observer";
			}
		}

		if (socket.seen === 0)
			send_message(socket, 'players', [socket.role, players]);

		if (clients[socket.game_id])
			clients[socket.game_id].push(socket);
		else
			clients[socket.game_id] = [ socket ];

		socket.on('close', (code, reason) => {
			SLOG(socket, "CLOSE " + code);
			clients[socket.game_id].splice(clients[socket.game_id].indexOf(socket), 1);
			broadcast_presence(socket.game_id);
		});

		socket.on('message', (data) => {
			try {
				let [ cmd, arg ] = JSON.parse(data);
				if (socket.role !== "Observer")
					handle_player_message(socket, cmd, arg);
				else
					handle_observer_message(socket, cmd, arg);
			} catch (err) {
				send_message(socket, 'error', err);
			}
		});

		broadcast_presence(socket.game_id);
		send_state(socket, get_game_state(socket.game_id));
	} catch (err) {
		console.log(err);
		socket.close(1000, err.message);
	}
});

/*
 * HIDDEN EXTRAS
 */

const SQL_GAME_STATS = SQL(`
	select
		title_id, scenario, options,
		group_concat(result) as result_role,
		group_concat(n) as result_count,
		sum(n) as total
	from
		(
			select
				title_id, scenario, options,
				result,
				count(1) as n
			from
				opposed_games
				natural join game_state
			where
				status=2
			group by
				title_id,
				scenario,
				options,
				result
		)
	group by
		title_id, scenario, options
	having
		total > 12
	`);

app.get('/stats', function (req, res) {
	let stats = SQL_GAME_STATS.all();
	stats.forEach(row => {
		row.title_name = TITLES[row.title_id].title_name;
		row.options = format_options(row.options);
		row.result_role = row.result_role.split(",");
		row.result_count = row.result_count.split(",").map(Number);
	});
	res.render('stats.pug', {
		user: req.user,
		stats: stats,
	});
});

const SQL_USER_STATS = SQL(`
	select
		title_name,
		scenario,
		role,
		sum(role=result) as won,
		count(*) as total
	from
		players
		natural join games
		natural join titles
	where
		user_id = ?
		and status = 2
		and game_id in (select game_id from opposed_games)
	group by
		title_name,
		scenario,
		role
	`);

app.get('/user-stats/:who_name', function (req, res) {
	let who = SQL_SELECT_USER_BY_NAME.get(req.params.who_name);
	if (who) {
		let stats = SQL_USER_STATS.all(who.user_id);
		res.render('user_stats.pug', { user: req.user, who: who, stats: stats });
	} else {
		return res.status(404).send("Invalid user name.");
	}
});