-const cors = require("cors");
-const body_parser = require("body-parser");
-const path = require("path");
-const nunjucks = require("nunjucks");
-
-const app = express();
-app.use(cors());
-app.use(body_parser.urlencoded({ extended: false }));
-app.use(body_parser.json());
-
-nunjucks.configure("templates", {
- autoescape: true,
- express: app
+const Game = require("./game.js");
+
+const router = express.Router();
+
+class TicTacToe extends Game {
+ constructor() {
+ super();
+ this.moves = [];
+ this.board = Array(9).fill(null);
+ }
+
+ /* Returns Boolean indicating whether move was legal and added. */
+ add_move(square) {
+ /* Cannot move to an occupied square. */
+ if (this.board[square])
+ return false;
+
+ this.board[square] = 'X';
+ this.moves.push(square);
+
+ return true;
+ }
+
+ broadcast_move(square) {
+ this.broadcast_event("move", square);
+ }
+
+ handle_events(request, response) {
+ super.handle_events(request, response);
+
+ /* When a new client joins, replay all previous moves to it. */
+ for (let move of this.moves) {
+ response.write(`event: move\ndata: ${move}\n\n`);
+ }
+ }
+}
+
+router.post('/move', (request, response) => {
+ const game = request.game;
+ const square = request.body.square;
+
+ const legal = game.add_move(square);
+
+ /* Inform this client whether the move was legal. */
+ response.send(JSON.stringify(legal));
+
+ /* And only if legal, inform all clients. */
+ if (! legal)
+ return;
+
+ game.broadcast_move(square);