const express = require("express");
const cors = require("cors");
const body_parser = require("body-parser");
+const session = require("express-session");
+const bcrypt = require("bcrypt");
+const path = require("path");
+const nunjucks = require("nunjucks");
+
+try {
+ var lmno_config = require("./lmno-config.json");
+} catch (err) {
+ config_usage();
+ process.exit(1);
+}
+
+function config_usage() {
+ console.log(`Error: Refusing to run without configuration.
+
+Please create a file named lmno-config.json that looks as follows:
+
+{
+ "session_secret": "<this should be a long string of true-random characters>",
+ "users": {
+ "username": "<username>",
+ "password_hash_bcrypt": "<password_hash_made_by_bcrypt>"
+ }
+}
+
+Note: Of course, change all of <these-parts> to actual values desired.
+
+The "node lmno-passwd.js" command can help generate password hashes.`);
+}
const app = express();
+
+/* This 'trust proxy' option, (and, really? a space in an option
+ * name?!) means that express will grab hostname and IP values from
+ * the X-Forwarded-* header fields. We need that so that our games
+ * will display a proper hostname of https://lmno.games/WXYZ instead
+ * of http://localhost/QFBL which will obviously not be a helpful
+ * thing to share around.
+ */
+app.set('trust proxy', true);
app.use(cors());
+app.use(body_parser.urlencoded({ extended: false }));
+app.use(body_parser.json());
+app.use(session({
+ secret: lmno_config.session_secret,
+ resave: false,
+ saveUninitialized: false
+}));
+
+const njx = nunjucks.configure("templates", {
+ autoescape: true,
+ express: app
+});
+
+njx.addFilter('active', function(list) {
+ if (list)
+ return list.filter(e => e.active === true);
+ else
+ return [];
+});
+
+njx.addFilter('idle', function(list) {
+ if (list)
+ return list.filter(e => e.active === false);
+ else
+ return [];
+});
+
+njx.addFilter('map_prop', function(list, prop) {
+ if (list)
+ return list.map(e => e[prop]);
+ else
+ return [];
+});
+
+/* Load each of our game mini-apps.
+ *
+ * Each "engine" we load here must have a property .Game on the
+ * exports object that should be a class that extends the common base
+ * class Game.
+ *
+ * In turn, each engine's Game must have the following properties:
+ *
+ * .meta: An object with .name and .identifier properties.
+ *
+ * Here, .name is a string giving a human-readable name
+ * for the game, such as "Tic Tac Toe" while .identifier
+ * is the short, single-word, all-lowercase identifier
+ * that is used in the path of the URL, such as
+ * "tictactoe".
+ *
+ * .router: An express Router object
+ *
+ * Any game-specific routes should already be on the
+ * router. Then, LMNO will add common routes including:
+ *
+ * / Serves <identifier>-game.html template
+ *
+ * /player Allows client to set name or team
+ *
+ * /events Serves a stream of events. Game can override
+ * the handle_events method, call super() first,
+ * and then have code to add custom events.
+ *
+ * /moves Receives move data from clients. This route
+ * is only added if the Game class has an
+ * add_move method.
+ */
+const engines = {
+ empires: require("./empires").Game,
+ tictactoe: require("./tictactoe").Game,
+ scribe: require("./scribe").Game,
+ empathy: require("./empathy").Game
+};
class LMNO {
constructor() {
- this.ids = {};
+ this.games = {};
}
generate_id() {
- return [null,null,null,null].map(() => LMNO.letters.charAt(Math.floor(Math.random() * LMNO.letters.length))).join('');
+ /* Note: The copy from Array(4) to [...Array(4)] is necessary so
+ * that map() will actually work, (which it doesn't on an array
+ * from Array(N) which is in this strange state of having "empty"
+ * items rather than "undefined" as we get after [...Array(4)] */
+ return [...Array(4)].map(() => LMNO.letters.charAt(Math.floor(Math.random() * LMNO.letters.length))).join('');
}
- create_game(engine) {
- do {
- var id = this.generate_id();
- } while (id in this.ids);
+ create_game_with_id(engine_name, id) {
+ if (this.games[id])
+ return null;
+
+ const engine = engines[engine_name];
- const game = {
- id: id,
- engine: engine,
- };
+ const game = new engine(id);
- this.ids[id] = game;
+ this.games[id] = game;
return game;
}
+
+ create_game(engine_name) {
+ do {
+ var id = this.generate_id();
+ } while (id in this.games);
+
+ return this.create_game_with_id(engine_name, id);
+ }
}
/* Some letters we don't use in our IDs:
* 1. Vowels (AEIOU) to avoid accidentally spelling an unfortunate word
* 2. Lowercase letters (replace with corresponding capital on input)
* 3. N (replace with M on input)
- * 4. P (replace with B on input)
- * 5. S (replace with F on input)
+ * 4. B (replace with P on input)
+ * 5. F,X (replace with S on input)
*/
-LMNO.letters = "BCDFGHJKLMQRTVWXYZ";
+LMNO.letters = "CCDDDGGGHHJKLLLLMMMMPPPPQRRRSSSTTTVVWWYYZ";
const lmno = new LMNO();
+/* Pre-allocate an empires game with ID QRST.
+ * This is for convenience in the development of the flempires
+ * client which would like to have stable API endpoints across
+ * server restarts.
+ */
+lmno.create_game_with_id("empires", "QRST");
+
+/* Force a game ID into a canonical form as described above. */
+function lmno_canonize(id) {
+ /* Capitalize */
+ id = id.toUpperCase();
+
+ /* Replace unused letters with nearest phonetic match. */
+ id = id.replace(/N/g, 'M');
+ id = id.replace(/B/g, 'P');
+ id = id.replace(/F/g, 'S');
+ id = id.replace(/X/g, 'S');
+
+ /* Replace unused numbers nearest visual match. */
+ id = id.replace(/0/g, 'O');
+ id = id.replace(/1/g, 'I');
+ id = id.replace(/5/g, 'S');
+
+ return id;
+}
+
app.post('/new/:game_engine', (request, response) => {
const game_engine = request.params.game_engine;
const game = lmno.create_game(game_engine);
response.send(JSON.stringify(game.id));
});
+/* Redirect any requests to a game ID at the top-level.
+ *
+ * Specifically, after obtaining the game ID (from the path) we simply
+ * lookup the game engine for the corresponding game and then redirect
+ * to the engine- and game-specific path.
+ */
+app.get('/[a-zA-Z0-9]{4}', (request, response) => {
+ const game_id = request.path.replace(/\//g, "");
+ const canon_id = lmno_canonize(game_id);
+
+ /* Redirect user to page with the canonical ID in it. */
+ if (game_id !== canon_id) {
+ response.redirect(301, `/${canon_id}/`);
+ return;
+ }
+
+ const game = lmno.games[game_id];
+ if (game === undefined) {
+ response.sendStatus(404);
+ return;
+ }
+ response.redirect(301, `/${game.meta.identifier}/${game.id}/`);
+});
+
+/* LMNO middleware to lookup the game. */
+app.use('/:engine([^/]+)/:game_id([a-zA-Z0-9]{4})', (request, response, next) => {
+ const engine = request.params.engine;
+ const game_id = request.params.game_id;
+ const canon_id = lmno_canonize(game_id);
+
+ /* Redirect user to page with the canonical ID in it, also ensuring
+ * that the game ID is _always_ followed by a slash. */
+ const has_slash = new RegExp(`^/${engine}/${game_id}/`);
+ if (game_id !== canon_id ||
+ ! has_slash.test(request.originalUrl))
+ {
+ const old_path = new RegExp(`/${engine}/${game_id}/?`);
+ const new_path = `/${engine}/${canon_id}/`;
+ const new_url = request.originalUrl.replace(old_path, new_path);
+ response.redirect(301, new_url);
+ return;
+ }
+
+ /* See if there is any game with this ID. */
+ const game = lmno.games[game_id];
+ if (game === undefined) {
+ response.sendStatus(404);
+ return;
+ }
+
+ /* Stash the game onto the request to be used by the game-specific code. */
+ request.game = game;
+ next();
+});
+
+function auth_admin(request, response, next) {
+ /* If there is no user associated with this session, redirect to the login
+ * page (and set a "next" query parameter so we can come back here).
+ */
+ if (! request.session.user) {
+ response.redirect(302, "/login?next=" + request.path);
+ return;
+ }
+
+ /* If the user is logged in but not authorized to view the page then
+ * we return that error. */
+ if (request.session.user.role !== "admin") {
+ response.status(401).send("Unauthorized");
+ return;
+ }
+ next();
+}
+
+app.get('/logout', (request, response) => {
+ request.session.user = undefined;
+ request.session.destroy();
+
+ response.send("You are now logged out.");
+});
+
+app.get('/login', (request, response) => {
+ if (request.session.user) {
+ response.send("Welcome, " + request.session.user + ".");
+ return;
+ }
+
+ response.render('login.html');
+});
+
+app.post('/login', async (request, response) => {
+ const username = request.body.username;
+ const password = request.body.password;
+ const user = lmno_config.users[username];
+ if (! user) {
+ response.sendStatus(404);
+ return;
+ }
+ const match = await bcrypt.compare(password, user.password_hash_bcrypt);
+ if (! match) {
+ response.sendStatus(404);
+ return;
+ }
+ request.session.user = { username: user.username, role: user.role };
+ response.sendStatus(200);
+ return;
+});
+
+/* API to set user profile information */
+app.put('/profile', (request, response) => {
+ const nickname = request.body.nickname;
+ if (nickname) {
+ request.session.nickname = nickname;
+ request.session.save();
+ }
+ response.send();
+});
+
+/* An admin page (only available to admin users, of course) */
+app.get('/admin/', auth_admin, (request, response) => {
+ let active = [];
+ let idle = [];
+
+ for (let id in lmno.games) {
+ if (lmno.games[id].players.filter(p => p.active).length > 0)
+ active.push(lmno.games[id]);
+ else
+ idle.push(lmno.games[id]);
+ }
+ response.render('admin.html', { games: { active: active, idle: idle}});
+});
+
+
+/* Mount sub apps. only _after_ we have done all the middleware we need. */
+for (let key in engines) {
+ const engine = engines[key];
+ const router = engine.router;
+
+ /* Add routes that are common to all games. */
+ router.get('/', (request, response) => {
+ const game = request.game;
+
+ if (! request.session.nickname) {
+ response.render('choose-nickname.html', {
+ game_name: game.meta.name,
+ options: game.meta.options
+ });
+ } else {
+ response.render(`${game.meta.identifier}-game.html`);
+ }
+ });
+
+ router.put('/player', (request, response) => {
+ const game = request.game;
+
+ game.handle_player(request, response);
+ });
+
+ router.get('/events', (request, response) => {
+ const game = request.game;
+
+ game.handle_events(request, response);
+ });
+
+ /* Further, add some routes conditionally depending on whether the
+ * engine provides specific, necessary methods for the routes. */
+
+ /* Note: We have to use hasOwnProperty here since the base Game
+ * class has a geeric add_move function, and we don't want that to
+ * have any influence on our decision. Only if the child has
+ * overridden that do we want to create a "/move" route. */
+ if (engine.prototype.hasOwnProperty("add_move")) {
+ router.post('/move', (request, response) => {
+ const game = request.game;
+ const move = request.body.move;
+ const player = game.players_by_session[request.session.id];
+
+ /* Reject move if there is no player for this session. */
+ if (! player) {
+ response.json({legal: false, message: "No valid player from session"});
+ return;
+ }
+
+ const result = game.add_move(player, move);
+
+ /* Take care of any generic post-move work. */
+ game.post_move(player, result);
+
+ /* Feed move response back to the client. */
+ response.json(result);
+
+ /* And only if legal, inform all clients. */
+ if (! result.legal)
+ return;
+
+ game.broadcast_move(move);
+ });
+ }
+
+ /* And mount the whole router at the path for the game. */
+ app.use(`/${engine.meta.identifier}/[a-zA-Z0-9]{4}/`, router);
+}
+
app.listen(4000, function () {
console.log('LMNO server listening on localhost:4000');
});
projects / empires-server / blobdiff