tictactoe: Use a "game-state" event instead of a series of "move" events

[lmno-server] / tictactoe.js

diff --git a/tictactoe.js b/tictactoe.js
index 6d4b0148a4a12afa4a5e8046fd3c8447d9d6729d..7b91a9bc34461158d41fd1d1495cdc84d33600c0 100644 (file)
--- a/tictactoe.js
+++ b/tictactoe.js
@@ -1,25 +1,31 @@
 const express = require("express");
 const Game = require("./game.js");
 
-const engine_name = "tictactoe";
-
 const router = express.Router();
 
 class TicTacToe extends Game {
-  constructor() {
-    super(engine_name);
-    this.moves = [];
-    this.board = Array(9).fill(null);
+  constructor(id) {
+    super(id);
+    this.state = {
+      moves: [],
+      board: Array(9).fill(""),
+      next_player: "X",
+    };
   }
 
   /* Returns Boolean indicating whether move was legal and added. */
   add_move(square) {
     /* Cannot move to an occupied square. */
-    if (this.board[square])
+    if (this.state.board[square])
       return false;
 
-    this.board[square] = 'X';
-    this.moves.push(square);
+    this.state.board[square] = this.state.next_player;
+    this.state.moves.push(square);
+
+    if (this.state.next_player === "X")
+      this.state.next_player = "O";
+    else
+      this.state.next_player = "X";
 
     return true;
   }
@@ -31,22 +37,13 @@ class TicTacToe extends Game {
   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`);
-    }
+    /* When a new client joins, give them the current game state,
+     * (which includes the history of moves). */
+    const state_json = JSON.stringify(this.state);
+    response.write(`event: game-state\ndata: ${state_json}\n\n`);
   }
 }
 
-router.get('/', (request, response) => {
-  const game = request.game;
-
-  if (! request.session.nickname)
-    response.render('choose-nickname.html', { game_name: "Tic Tac Toe" });
-  else
-    response.render('tictactoe-game.html');
-});
-
 router.post('/move', (request, response) => {
   const game = request.game;
   const square = request.body.square;
@@ -70,5 +67,9 @@ router.get('/events', (request, response) => {
 });
 
 exports.router = router;
-exports.name = engine_name;
 exports.Game = TicTacToe;
+
+TicTacToe.meta = {
+  name: "Tic Tac Toe",
+  identifier: "tictactoe"
+};