const app = express();
app.use(cors());
+const GameState = {
+ JOIN: 1,
+ REVEAL: 2,
+ CAPTURE: 3,
+ properties: {
+ 1: {name: "join"},
+ 2: {name: "reveal"},
+ 3: {name: "capture"}
+ }
+};
+
+/**
+ * Shuffles array in place.
+ * @param {Array} a items An array containing the items.
+ */
+function shuffle(a) {
+ if (a === undefined)
+ return;
+
+ var j, x, i;
+ for (i = a.length - 1; i > 0; i--) {
+ j = Math.floor(Math.random() * (i + 1));
+ x = a[i];
+ a[i] = a[j];
+ a[j] = x;
+ }
+}
+
class Game {
constructor() {
this._players = [];
+ this.characters_to_reveal = null;
this.next_player_id = 1;
this.clients = [];
this.next_client_id = 1;
+ this.state = GameState.JOIN;
+
+ /* Send a comment to every connected client every 15 seconds. */
+ setInterval(() => {this.broadcast_string(":");}, 15000);
}
add_player(name, character) {
/* The syntax here is using an anonymous function to create a new
object from new_player with just the subset of fields that we
want. */
- const player_string = JSON.stringify((({id, name}) => ({id, name}))(new_player));
- this.broadcast("player-register", player_string);
+ const player_data = JSON.stringify((({id, name}) => ({id, name}))(new_player));
+ this.broadcast_event("player-join", player_data);
}
remove_player(id) {
const index = this._players.findIndex(player => player.id === id);
this._players.splice(index, 1);
+
+ this.broadcast_event("player-leave", `{"id": ${id}}`);
}
- remove_all_players() {
+ reset() {
this._players = [];
+ this.characters_to_reveal = null;
this.next_player_id = 1;
+
+ this.change_state(GameState.JOIN);
+
+ this.broadcast_event("players", "{}");
+ }
+
+ reveal_next() {
+ if (this.reveal_index >= this.characters_to_reveal.length) {
+ clearInterval(this.reveal_interval);
+ this.broadcast_event("character-reveal", '{"character":""}');
+ return;
+ }
+ const character = this.characters_to_reveal[this.reveal_index];
+ this.reveal_index++;
+ const character_data = JSON.stringify({"character":character});
+ this.broadcast_event("character-reveal", character_data);
+ }
+
+ reveal() {
+ this.change_state(GameState.REVEAL);
+
+ if (this.characters_to_reveal === null) {
+ this.characters_to_reveal = [];
+ this.characters_to_reveal = this._players.reduce((characters, player) => {
+ characters.push(player.character);
+ return characters;
+ }, []);
+ shuffle(this.characters_to_reveal);
+ }
+
+ this.reveal_index = 0;
+
+ this.reveal_interval = setInterval(this.reveal_next.bind(this), 3000);
+ }
+
+ start() {
+ this.change_state(GameState.CAPTURE);
}
capture(captor_id, captee_id) {
* the API specification which we want here. */
let captor = this._players.find(player => player.id === captor_id);
captor.captures.push(captee_id);
+
+ this.broadcast_event("capture", `{"captor": ${captor_id}, "captee": ${captee_id}}`);
}
liberate(captee_id) {
this.clients = this.clients.filter(client => client.id !== id);
}
- /* Send an event to all clients */
- broadcast(type, data) {
- this.clients.forEach(client => client.response.write(`event: ${type}\ndata: ${data}\n\n`));
+ /* Send a string to all clients */
+ broadcast_string(str) {
+ this.clients.forEach(client => client.response.write(str + '\n'));
+ }
+
+ /* Send an event to all clients.
+ *
+ * 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).
+ */
+ broadcast_event(type, data) {
+ this.broadcast_string(`event: ${type}\ndata: ${data}\n`);
+ }
+
+ game_state_event_data(old_state, new_state) {
+ var old_state_name;
+ if (old_state)
+ old_state_name = GameState.properties[old_state].name;
+ else
+ old_state_name = "none";
+ const new_state_name = GameState.properties[new_state].name;
+
+ return `{"old_state":"${old_state_name}","new_state":"${new_state_name}"}`;
+ }
+
+ /* Inform clients about a state change. */
+ broadcast_state_change() {
+ const event_data = this.game_state_event_data(this.old_state, this.state);
+ this.broadcast_event("game-state", event_data);
+ }
+
+ /* Change game state and broadcast the change to all clients. */
+ change_state(state) {
+ /* Do nothing if there is no actual change happening. */
+ if (state === this.state)
+ return;
+
+ this.old_state = this.state;
+ this.state = state;
+
+ this.broadcast_state_change();
}
}
response.write(players_data);
}
+ /* And we need to inform the client of the current game state.
+ *
+ * In fact, we need to cycle through each state transition from the
+ * beginning so the client can see each.
+ */
+ var old_state = null;
+ for (var state = GameState.JOIN; state <= game.state; state++) {
+ var event_data = game.game_state_event_data(old_state, state);
+ response.write("event: game-state\n" + "data: " + event_data + "\n\n");
+ old_state = state;
+ }
+
/* Add this new client to our list of clients. */
const id = game.add_client(response);
- /* And queue up cleanup to be tirggered on client close. */
+ /* And queue up cleanup to be triggered on client close. */
request.on('close', () => {
game.remove_client(id);
});
response.send();
});
+app.post('/reveal', (request, response) => {
+ game.reveal();
+ response.send();
+});
+
+app.post('/start', (request, response) => {
+ game.start();
+ response.send();
+});
+
app.post('/reset', (request, response) => {
- game.remove_all_players();
+ game.reset();
response.send();
});
app.get('/events', handle_events);
app.listen(3000, function () {
- console.log('Example app listening on port 3000!');
+ console.log('Empires server listening on localhost:3000');
});
projects / empires-server / blobdiff