Add dependencies for the prompt-sync module

[empires-server] / lmno.js

diff --git a/lmno.js b/lmno.js
index f79da3afd653cf1d7b89219aada1546d97aff036..65c317d05f37bb1b964781dd84b1b6d0f3b0f1ab 100644 (file)
--- a/lmno.js
+++ b/lmno.js
@@ -1,9 +1,35 @@
 const express = require("express");
 const cors = require("cors");
 const body_parser = require("body-parser");
+const session = require("express-session");
+
+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>";
+}
+
+Note: Don't use the exact text above, but instead replace the string
+with what it describes: a long string of random characters.`);
+}
 
 const app = express();
 app.use(cors());
+app.use(session({
+  secret: lmno_config.session_secret,
+  resave: false,
+  saveUninitialized: false
+}));
 
 /* Load each of our game mini-apps. */
 var empires = require("./empires");
@@ -46,6 +72,24 @@ LMNO.letters = "BCDFGHJKLMQRTVWXYZ";
 
 const lmno = new LMNO();
 
+/* 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(/P/g, 'B');
+  id = id.replace(/S/g, 'F');
+
+  /* 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_id = lmno.create_game(game_engine);
@@ -60,6 +104,13 @@ app.post('/new/:game_engine', (request, response) =>  {
  */
 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.ids[game_id];
   if (game === undefined) {
@@ -71,11 +122,26 @@ app.get('/[a-zA-Z0-9]{4}', (request, response) => {
 
 /* LMNO middleware to lookup the game. */
 app.use('/empires/:game_id([a-zA-Z0-9]{4})', (request, response, next) => {
-  request.game = lmno.ids[request.params.game_id].game;
-  if (request.game === undefined) {
+  const game_id = request.params.game_id;
+  const canon_id = lmno_canonize(game_id);
+
+  /* Redirect user to page with the canonical ID in it. */
+  if (game_id !== canon_id) {
+    const new_url = request.originalUrl.replace("/empires/" + game_id,
+                                                "/empires/" + canon_id);
+    response.redirect(301, new_url);
+    return;
+  }
+
+  /* See if there is any game with this ID. */
+  const game = lmno.ids[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.game;
   next();
 });