+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 });
+ else
+ response.render(`${game.meta.identifier}-game.html`);
+ });
+
+ router.put('/player', (request, response) => {
+ const game = request.game;
+
+ game.handle_player(request, response);
+ });
+
+ router.get('/events', (request, response) => {
+ const game = request.game;
+
+ game.handle_events(request, response);
+ });
+
+ /* Further, add some routes conditionally depending on whether the
+ * engine provides specific, necessary methods for the routes. */
+
+ /* Note: We have to use hasOwnProperty here since the base Game
+ * class has a geeric add_move function, and we don't want that to
+ * have any influence on our decision. Only if the child has
+ * overridden that do we want to create a "/move" route. */
+ if (engine.prototype.hasOwnProperty("add_move")) {
+ router.post('/move', (request, response) => {
+ const game = request.game;
+ const move = request.body.move;
+ const player = game.players_by_session[request.session.id];
+
+ /* Reject move if there is no player for this session. */
+ if (! player) {
+ response.json({legal: false, message: "No valid player from session"});
+ return;
+ }
+
+ const result = game.add_move(player, move);
+
+ /* Feed move response back to the client. */
+ response.json(result);
+
+ /* And only if legal, inform all clients. */
+ if (! result.legal)
+ return;
+
+ game.broadcast_move(move);
+ });
+ }
+
+ /* And mount the whole router at the path for the game. */
+ app.use(`/${engine.meta.identifier}/[a-zA-Z0-9]{4}/`, router);
+}