+/* A single player can have multiple connections, (think, multiple
+ * browser windows with a common session cookie). */
+class Player {
+ constructor(id, name, connection) {
+ this.id = id;
+ this.name = name;
+ this.connections = [connection];
+ this.team = "";
+ }
+
+ 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,
+ team: this.team
+ });
+ }
+}
+
/* 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;
+ this.teams = [];
+ this.state = {
+ team_to_play: ""
+ };
+
+ /* 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;
+ }
+
+ /* 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) {
+ /* 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 };
}
- add_client(response) {
- const id = this.next_client_id;
- this.clients.push({id: id,
- response: response});
- this.next_client_id++;
+ add_player(session, connection) {
+ /* First see if we already have a player object for this session. */
+ const existing = this.players[session.id];
+ if (existing) {
+ existing.add_connection(connection);
+ return existing;
+ }
+
+ /* No existing player. Add a new one. */
+ const id = this.next_player_id;
+ const player = new Player(id, session.nickname, connection);
- return id;
+ /* 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[session.id] = player;
+ this.next_player_id++;
+
+ return player;
}
- 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'));
+ for (let [session_id, player] of Object.entries(this.players))
+ 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).
};
response.writeHead(200, headers);
- /* Add this new client to our list of clients. */
- const id = this.add_client(response);
+ /* 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_client(id);
+ 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`);
+
+ /* And the player-info event. */
+ response.write(`event: player-info\ndata: ${player.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`);
+ }
+ }
+
+ handle_player(request, response) {
+ const player = this.players[request.session.id];
+ const name = request.body.name;
+ const team = request.body.team;
+ var updated = false;
+ if (! player) {
+ response.sendStatus(404);
+ return;
+ }
+
+ if (name && (player.name !== name)) {
+ player.name = name;
+
+ /* In addition to setting the name within this game's player
+ * object, also set the name in the session. */
+ request.session.nickname = name;
+ request.session.save();
+
+ updated = true;
+ }
+
+ if (team !== null && (player.team !== team) &&
+ (team === "" || this.teams.includes(team)))
+ {
+ player.team = team;
+
+ updated = true;
+ }
+
+ if (updated)
+ this.broadcast_event("player-update", player.info_json());
+
+ response.send("");
+ }
+
+ broadcast_move(move) {
+ this.broadcast_event("move", move);
}
}
projects / empires-server / blobdiff