1 const express = require("express");
2 const cors = require("cors");
3 const body_parser = require("body-parser");
4 const session = require("express-session");
5 const bcrypt = require("bcrypt");
6 const path = require("path");
7 const nunjucks = require("nunjucks");
10 var lmno_config = require("./lmno-config.json");
16 function config_usage() {
17 console.log(`Error: Refusing to run without configuration.
19 Please create a file named lmno-config.json that looks as follows:
22 "session_secret": "<this should be a long string of true-random characters>",
24 "username": "<username>",
25 "password_hash_bcrypt": "<password_hash_made_by_bcrypt>"
29 Note: Of course, change all of <these-parts> to actual values desired.
31 The "node lmno-passwd.js" command can help generate password hashes.`);
34 const app = express();
36 /* This 'trust proxy' option, (and, really? a space in an option
37 * name?!) means that express will grab hostname and IP values from
38 * the X-Forwarded-* header fields. We need that so that our games
39 * will display a proper hostname of https://lmno.games/WXYZ instead
40 * of http://localhost/QFBL which will obviously not be a helpful
41 * thing to share around.
43 app.set('trust proxy', true);
45 app.use(body_parser.urlencoded({ extended: false }));
46 app.use(body_parser.json());
48 secret: lmno_config.session_secret,
50 saveUninitialized: false
53 nunjucks.configure("templates", {
58 /* Load each of our game mini-apps.
60 * Each "engine" we load here must have a property .Game on the
61 * exports object that should be a class that extends the common base
64 * In turn, each engine's Game must have the following properties:
66 * .meta: An object with .name and .identifier properties.
68 * Here, .name is a string giving a human-readable name
69 * for the game, such as "Tic Tac Toe" while .identifier
70 * is the short, single-word, all-lowercase identifier
71 * that is used in the path of the URL, such as
74 * .router: An express Router object
76 * Any game-specific routes should already be on the
77 * router. Then, LMNO will add common routes including:
79 * / Serves <identifier>-game.html template
81 * /player Allows client to set name or team
83 * /events Serves a stream of events. Game can override
84 * the handle_events method, call super() first,
85 * and then have code to add custom events.
87 * /moves Receives move data from clients. This route
88 * is only added if the Game class has an
92 empires: require("./empires").Game,
93 tictactoe: require("./tictactoe").Game,
94 scribe: require("./scribe").Game,
95 empathy: require("./empathy").Game
104 return Array(4).fill(null).map(() => LMNO.letters.charAt(Math.floor(Math.random() * LMNO.letters.length))).join('');
107 create_game(engine_name) {
109 var id = this.generate_id();
110 } while (id in this.games);
112 const engine = engines[engine_name];
114 const game = new engine(id);
116 this.games[id] = game;
122 /* Some letters we don't use in our IDs:
124 * 1. Vowels (AEIOU) to avoid accidentally spelling an unfortunate word
125 * 2. Lowercase letters (replace with corresponding capital on input)
126 * 3. N (replace with M on input)
127 * 4. P (replace with B on input)
128 * 5. S (replace with F on input)
130 LMNO.letters = "BCDFGHJKLMQRTVWXYZ";
132 const lmno = new LMNO();
134 /* Force a game ID into a canonical form as described above. */
135 function lmno_canonize(id) {
137 id = id.toUpperCase();
139 /* Replace unused letters with nearest phonetic match. */
140 id = id.replace(/N/g, 'M');
141 id = id.replace(/P/g, 'B');
142 id = id.replace(/S/g, 'F');
144 /* Replace unused numbers nearest visual match. */
145 id = id.replace(/0/g, 'O');
146 id = id.replace(/1/g, 'I');
147 id = id.replace(/5/g, 'S');
152 app.post('/new/:game_engine', (request, response) => {
153 const game_engine = request.params.game_engine;
154 const game = lmno.create_game(game_engine);
155 response.send(JSON.stringify(game.id));
158 /* Redirect any requests to a game ID at the top-level.
160 * Specifically, after obtaining the game ID (from the path) we simply
161 * lookup the game engine for the corresponding game and then redirect
162 * to the engine- and game-specific path.
164 app.get('/[a-zA-Z0-9]{4}', (request, response) => {
165 const game_id = request.path.replace(/\//g, "");
166 const canon_id = lmno_canonize(game_id);
168 /* Redirect user to page with the canonical ID in it. */
169 if (game_id !== canon_id) {
170 response.redirect(301, `/${canon_id}/`);
174 const game = lmno.games[game_id];
175 if (game === undefined) {
176 response.sendStatus(404);
179 response.redirect(301, `/${game.meta.identifier}/${game.id}/`);
182 /* LMNO middleware to lookup the game. */
183 app.use('/:engine([^/]+)/:game_id([a-zA-Z0-9]{4})', (request, response, next) => {
184 const engine = request.params.engine;
185 const game_id = request.params.game_id;
186 const canon_id = lmno_canonize(game_id);
188 /* Redirect user to page with the canonical ID in it, also ensuring
189 * that the game ID is _always_ followed by a slash. */
190 const has_slash = new RegExp(`^/${engine}/${game_id}/`);
191 if (game_id !== canon_id ||
192 ! has_slash.test(request.originalUrl))
194 const old_path = new RegExp(`/${engine}/${game_id}/?`);
195 const new_path = `/${engine}/${canon_id}/`;
196 const new_url = request.originalUrl.replace(old_path, new_path);
197 response.redirect(301, new_url);
201 /* See if there is any game with this ID. */
202 const game = lmno.games[game_id];
203 if (game === undefined) {
204 response.sendStatus(404);
208 /* Stash the game onto the request to be used by the game-specific code. */
213 function auth_admin(request, response, next) {
214 /* If there is no user associated with this session, redirect to the login
215 * page (and set a "next" query parameter so we can come back here).
217 if (! request.session.user) {
218 response.redirect(302, "/login?next=" + request.path);
222 /* If the user is logged in but not authorized to view the page then
223 * we return that error. */
224 if (request.session.user.role !== "admin") {
225 response.status(401).send("Unauthorized");
231 app.get('/logout', (request, response) => {
232 request.session.user = undefined;
233 request.session.destroy();
235 response.send("You are now logged out.");
238 app.get('/login', (request, response) => {
239 if (request.session.user) {
240 response.send("Welcome, " + request.session.user + ".");
244 response.render('login.html');
247 app.post('/login', async (request, response) => {
248 const username = request.body.username;
249 const password = request.body.password;
250 const user = lmno_config.users[username];
252 response.sendStatus(404);
255 const match = await bcrypt.compare(password, user.password_hash_bcrypt);
257 response.sendStatus(404);
260 request.session.user = { username: user.username, role: user.role };
261 response.sendStatus(200);
265 /* API to set uer profile information */
266 app.put('/profile', (request, response) => {
267 const nickname = request.body.nickname;
269 request.session.nickname = nickname;
270 request.session.save();
275 /* An admin page (only available to admin users, of course) */
276 app.get('/admin/', auth_admin, (request, response) => {
280 for (let id in lmno.games) {
281 if (lmno.games[id].players.length)
282 active.push(lmno.games[id]);
284 idle.push(lmno.games[id]);
286 response.render('admin.html', { test: "foobar", games: { active: active, idle: idle}});
290 /* Mount sub apps. only _after_ we have done all the middleware we need. */
291 for (let key in engines) {
292 const engine = engines[key];
293 const router = engine.router;
295 /* Add routes that are common to all games. */
296 router.get('/', (request, response) => {
297 const game = request.game;
299 if (! request.session.nickname) {
300 response.render('choose-nickname.html', {
301 game_name: game.meta.name,
302 options: game.meta.options
305 response.render(`${game.meta.identifier}-game.html`);
309 router.put('/player', (request, response) => {
310 const game = request.game;
312 game.handle_player(request, response);
315 router.get('/events', (request, response) => {
316 const game = request.game;
318 game.handle_events(request, response);
321 /* Further, add some routes conditionally depending on whether the
322 * engine provides specific, necessary methods for the routes. */
324 /* Note: We have to use hasOwnProperty here since the base Game
325 * class has a geeric add_move function, and we don't want that to
326 * have any influence on our decision. Only if the child has
327 * overridden that do we want to create a "/move" route. */
328 if (engine.prototype.hasOwnProperty("add_move")) {
329 router.post('/move', (request, response) => {
330 const game = request.game;
331 const move = request.body.move;
332 const player = game.players_by_session[request.session.id];
334 /* Reject move if there is no player for this session. */
336 response.json({legal: false, message: "No valid player from session"});
340 const result = game.add_move(player, move);
342 /* Take care of any generic post-move work. */
343 game.post_move(player, result);
345 /* Feed move response back to the client. */
346 response.json(result);
348 /* And only if legal, inform all clients. */
352 game.broadcast_move(move);
356 /* And mount the whole router at the path for the game. */
357 app.use(`/${engine.meta.identifier}/[a-zA-Z0-9]{4}/`, router);
360 app.listen(4000, function () {
361 console.log('LMNO server listening on localhost:4000');