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

[empires-server] / tictactoe.js

diff --git a/tictactoe.js b/tictactoe.js
index 766c1e4ed569cf9d2efb52bae9e7d70ffc6ce6fa..7b91a9bc34461158d41fd1d1495cdc84d33600c0 100644 (file)
--- a/tictactoe.js
+++ b/tictactoe.js
@@ -1,69 +1,50 @@
 const express = require("express");
-
-const app = express.Router();
-
-class TicTacToe {
-  constructor() {
-    this.moves = [];
-    this.board = Array(9).fill(null);
-    this.clients = [];
-    this.next_client_id = 1;
+const Game = require("./game.js");
+
+const router = express.Router();
+
+class TicTacToe extends Game {
+  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);
-
-    return true;
-  }
-
-  add_client(response) {
-    const id = this.next_client_id;
-    this.clients.push({id: id,
-                       response: response});
-    this.next_client_id++;
-
-    return id;
-  }
-
-  remove_client(id) {
-    this.clients = this.clients.filter(client => client.id !== id);
-  }
+    this.state.board[square] = this.state.next_player;
+    this.state.moves.push(square);
 
-  /* Send a string to all clients */
-  broadcast_string(str) {
-    this.clients.forEach(client => client.response.write(str + '\n'));
-  }
+    if (this.state.next_player === "X")
+      this.state.next_player = "O";
+    else
+      this.state.next_player = "X";
 
-  /* Send an event to all clients.
-   *
-   * An event has both a declared type and a separate data block.
-   * It also ends with two newlines (to mark the end of the event).
-   */
-  broadcast_event(type, data) {
-    this.broadcast_string(`event: ${type}\ndata: ${data}\n`);
+    return true;
   }
 
   broadcast_move(square) {
     this.broadcast_event("move", square);
   }
-}
 
-app.get('/', (request, response) => {
-  const game = request.game;
+  handle_events(request, response) {
+    super.handle_events(request, response);
 
-  if (! request.session.nickname)
-    response.render('choose-nickname.html', { game_name: "Tic Tac Toe" });
-  else
-    response.render('tictactoe-game.html');
-});
+    /* 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`);
+  }
+}
 
-app.post('/move', (request, response) => {
+router.post('/move', (request, response) => {
   const game = request.game;
   const square = request.body.square;
 
@@ -79,26 +60,16 @@ app.post('/move', (request, response) => {
   game.broadcast_move(square);
 });
 
-app.get('/events', (request, response) => {
+router.get('/events', (request, response) => {
   const game = request.game;
 
-  /* These headers will keep the connection open so we can stream events. */
-  const headers = {
-    "Content-type": "text/event-stream",
-    "Connection": "keep-alive",
-    "Cache-Control": "no-cache"
-  };
-  response.writeHead(200, headers);
-
-  /* Add this new client to our list of clients. */
-  const id = game.add_client(response);
-
-  /* And queue up cleanup to be triggered on client close. */
-  request.on('close', () => {
-    game.remove_client(id);
-  });
+  game.handle_events(request, response);
 });
 
-exports.app = app;
-exports.name = "tictactoe";
+exports.router = router;
 exports.Game = TicTacToe;
+
+TicTacToe.meta = {
+  name: "Tic Tac Toe",
+  identifier: "tictactoe"
+};