+ /* 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 === no_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 !== no_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 === no_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 = this.players_by_session[session.id];
+ if (existing) {
+ existing.add_connection(connection);
+ return existing;
+ }
+
+ /* No existing player. Add a new one. */
+ const id = this.next_player_id;
+ let nickname = session.nickname;
+ if (nickname === "")
+ nickname = "Guest";
+ const nickname_orig = nickname;
+
+ /* Ensure we don't have a name collision with a previous player. */
+ let unique_suffix = 1;
+ while (this.players.find(player => player.name === nickname))
+ {
+ nickname = `${nickname_orig}${unique_suffix.toString().padStart(2, '0')}`;
+ unique_suffix++;
+ }
+
+ const player = new Player(id, session.id, nickname, connection);