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 aba043c65eba8c1dbe04ef6034c6d54b8fa8fee1..7b91a9bc34461158d41fd1d1495cdc84d33600c0 100644 (file)
--- a/tictactoe.js
+++ b/tictactoe.js
@@ -6,18 +6,26 @@ const router = express.Router();
 class TicTacToe extends Game {
   constructor(id) {
     super(id);
-    this.moves = [];
-    this.board = Array(9).fill(null);
+    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;
   }
@@ -29,10 +37,10 @@ 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`);
   }
 }
 
@@ -65,5 +73,3 @@ TicTacToe.meta = {
   name: "Tic Tac Toe",
   identifier: "tictactoe"
 };
-
-exports.meta = TicTacToe.meta;