game: Allow either player to play the first move

[empires-server] / game.js

diff --git a/game.js b/game.js
index de77148aa3ed58888930d4b872da8e0c92a28644..24e36adbc4106db5df835ddcfcc3ea403f575988 100644 (file)
--- a/game.js
+++ b/game.js
@@ -44,8 +44,13 @@ class Game {
   constructor(id) {
     this.id = id;
     this.players = [];
+    this.players_by_session = {};
     this.next_player_id = 1;
     this.teams = [];
+    this.state = {
+      team_to_play: ""
+    };
+    this.first_move = true;
 
     /* Send a comment to every connected client every 15 seconds. */
     setInterval(() => {this.broadcast_string(":");}, 15000);
@@ -71,14 +76,82 @@ class Game {
     return this._meta;
   }
 
+  /* Just performs some checks for whether a move is definitely not
+   * legal (such as not the player's turn). A child class is expected
+   * to override this (and call super.add_move early!) to implement
+   * the actual logic for a move. */
+  add_move(player, move) {
+
+    /* The checks here don't apply on the first move. */
+    if (! this.first_move) {
+
+      /* Discard any move asserting to be the first move if it's no
+       * longer the first move. This resolves the race condition if
+       * multiple players attempt to make the first move. */
+      if (move.assert_first_move) {
+        return { legal: false,
+                 message: "Your opponent beat you to the first move" };
+      }
+
+      /* Cannot move if you are not on a team. */
+      if (player.team === "")
+      {
+        return { legal: false,
+                 message: "You must be on a team to take a turn" };
+      }
+
+      /* Cannot move if it's not this player's team's turn. */
+      if (player.team !== this.state.team_to_play)
+      {
+        return { legal: false,
+                 message: "It's not your turn to move" };
+      }
+    }
+
+    return { legal: true };
+  }
+
+  /* Assign team only if player is unassigned.
+   * Return true if assignment made, false otherwise. */
+  assign_player_to_team_perhaps(player, team)
+  {
+    if (player.team !== "")
+      return false;
+
+    player.team = team;
+    this.broadcast_event("player-update", player.info_json());
+
+    return true;
+  }
+
+  /* This function is called after the child add_move has returned
+   * 'result' so that any generic processing can happen.
+   *
+   * In particular, we assign teams for a two-player game where a
+   * player assumed a team by making the first move. */
+  post_move(player, result)
+  {
+    if (this.first_move && result.legal) {
+      this.first_move = false;
+
+      this.assign_player_to_team_perhaps(player, this.teams[0]);
+
+      /* Yes, start at 1 to skip teams[0] which we just assigned. */
+      for (let i = 1; i < this.teams.length; i++) {
+        const other = this.players.find(p => p !== player && p.team === "");
+        if (!other)
+          return;
+        this.assign_player_to_team_perhaps(other, this.teams[i]);
+      }
+    }
+  }
+
   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;
+    const existing = this.players_by_session[session.id];
+    if (existing) {
+      existing.add_connection(connection);
+      return existing;
     }
 
     /* No existing player. Add a new one. */
@@ -91,20 +164,12 @@ class Game {
     this.broadcast_event("player-enter", player_data);
 
     this.players.push(player);
+    this.players_by_session[session.id] = player;
     this.next_player_id++;
 
     return player;
   }
 
-  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 null;
-  }
-
   /* 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) {
@@ -112,6 +177,7 @@ class Game {
     if (remaining === 0) {
       const player_data = JSON.stringify({ id: player.id });
       this.players.filter(p => p !== player);
+      delete this.players_by_session[player.session_id];
       this.broadcast_event("player-exit", player_data);
     }
   }
@@ -166,7 +232,7 @@ class Game {
   }
 
   handle_player(request, response) {
-    const player = this.find_player(request.session);
+    const player = this.players_by_session[request.session.id];
     const name = request.body.name;
     const team = request.body.team;
     var updated = false;