X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=game.js;h=baf1e557df502cc28f775f3540fa5f14d55102c8;hb=4c810ccb16ea6cfcdcb7f507aea2affc2c36f163;hp=f99ff234fa24c64aa9b9b362a6ad7c475902d5fb;hpb=76e5097689002f03c721c388e2ca71c52abf3354;p=empires-server

diff --git a/game.js b/game.js
index f99ff23..baf1e55 100644
--- a/game.js
+++ b/game.js
@@ -1,30 +1,124 @@
+/* A single player can have multiple connections, (think, multiple
+ * browser windows with a common session cookie). */
+class Player {
+  constructor(id, session_id, name, connection) {
+    this.id = id;
+    this.session_id = session_id;
+    this.name = name;
+    this.connections = [connection];
+  }
+
+  add_connection(connection) {
+    /* Don't add a duplicate connection if this player already has it. */
+    for (let c of this.connections) {
+      if (c === connection)
+        return;
+    }
+
+    this.connections.push(connection);
+  }
+
+  /* Returns the number of remaining connections after this one is removed. */
+  remove_connection(connection) {
+    this.connections.filter(c => c !== connection);
+    return this.connections.length;
+  }
+
+  /* Send a string to all connections for this player. */
+  send(data) {
+    this.connections.forEach(connection => connection.write(data));
+  }
+
+  info_json() {
+    return JSON.stringify({
+      id: this.id,
+      name: this.name,
+    });
+  }
+}
+
 /* Base class providing common code for game engine implementations. */
 class Game {
-  constructor(name) {
-    this.name = name;
-    this.clients = [];
-    this.next_client_id = 1;
+  constructor(id) {
+    this.id = id;
+    this.players = [];
+    this.next_player_id = 1;
+
+    /* Send a comment to every connected client every 15 seconds. */
+    setInterval(() => {this.broadcast_string(":");}, 15000);
+  }
+
+  /* Suport for game meta-data.
+   *
+   * What we want here is an effectively static field that is
+   * accessible through either the class name (SomeGame.meta) or an
+   * instance (some_game.meta). To pull this off we do keep two copies
+   * of the data. But the game classes can just set SomeGame.meta once
+   * and then reference it either way.
+   */
+  static set meta(data) {
+    /* This allows class access (SomeGame.meta) via the get method below. */
+    this._meta = data;
+
+    /* While this allows access via an instance (some_game.meta). */
+    this.prototype.meta = data;
+  }
+
+  static get meta() {
+    return this._meta;
+  }
+
+  add_player(session, connection) {
+    /* First see if we already have a player object for this session. */
+    const existing_index = this.players.findIndex(
+      player => player.session_id === session.id);
+    if (existing_index >= 0) {
+      const player = this.players[existing_index];
+      player.add_connection(connection);
+      return player;
+    }
+
+    /* No existing player. Add a new one. */
+    const id = this.next_player_id;
+    const player = new Player(id, session.id, session.nickname, connection);
+
+    /* Broadcast before adding player to list (to avoid announcing the
+     * new player to itself). */
+    const player_data = JSON.stringify({ id: player.id, name: player.name });
+    this.broadcast_event("player-enter", player_data);
+
+    this.players.push(player);
+    this.next_player_id++;
+
+    return player;
   }
 
-  add_client(response) {
-    const id = this.next_client_id;
-    this.clients.push({id: id,
-                       response: response});
-    this.next_client_id++;
+  find_player(session) {
+    const existing_index = this.players.findIndex(
+      player => player.session_id === session.id);
+    if (existing_index >= 0)
+      return this.players[existing_index];
 
-    return id;
+    return null;
   }
 
-  remove_client(id) {
-    this.clients = this.clients.filter(client => client.id !== id);
+  /* Drop a connection object from a player, and if it's the last one,
+   * then drop that player from the game's list of players. */
+  remove_player_connection(player, connection) {
+    const remaining = player.remove_connection(connection);
+    if (remaining === 0) {
+      const player_data = JSON.stringify({ id: player.id });
+      this.players.filter(p => p !== player);
+      this.broadcast_event("player-exit", player_data);
+    }
   }
 
-  /* Send a string to all clients */
+  /* Send a string to all players */
   broadcast_string(str) {
-    this.clients.forEach(client => client.response.write(str + '\n'));
+    this.players.forEach(player => player.send(str + '\n'));
   }
 
-  /* Send an event to all clients.
+  /* Send an event to all players.
    *
    * 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).
@@ -33,6 +127,42 @@ class Game {
     this.broadcast_string(`event: ${type}\ndata: ${data}\n`);
   }
 
+  handle_events(request, response) {
+    /* 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 player. */
+    const player = this.add_player(request.session, response);
+
+    /* And queue up cleanup to be triggered on client close. */
+    request.on('close', () => {
+      this.remove_player_connection(player, response);
+    });
+
+    /* Give the client the game-info event. */
+    const game_info_json = JSON.stringify({
+      id: this.id,
+      url: `${request.protocol}://${request.hostname}/${this.id}`
+    });
+    response.write(`event: game-info\ndata: ${game_info_json}\n\n`);
+
+    /* Finally, if this game class has a "state" property, stream that
+     * current state to the client. */
+    if (this.state) {
+      const state_json = JSON.stringify(this.state);
+      response.write(`event: game-state\ndata: ${state_json}\n\n`);
+    }
+  }
+
+  broadcast_move(move) {
+    this.broadcast_event("move", move);
+  }
+
 }
 
 module.exports = Game;