1 const express = require("express");
2 const Game = require("./game.js");
4 const engine_name = "empires";
6 const router = express.Router();
20 * Shuffles array in place.
21 * @param {Array} a items An array containing the items.
28 for (i = a.length - 1; i > 0; i--) {
29 j = Math.floor(Math.random() * (i + 1));
36 class Empires extends Game {
39 this._spectators = [];
40 this.next_spectator_id = 1;
42 this.next_player_id = 1;
43 this.characters_to_reveal = null;
44 this.state = GameState.JOIN;
46 /* Send a comment to every connected client every 15 seconds. */
47 setInterval(() => {this.broadcast_string(":");}, 15000);
50 add_spectator(name, session_id) {
51 /* Don't add another spectator that matches an existing session. */
52 const existing = this._spectators.findIndex(
53 spectator => spectator.session_id === session_id);
57 const new_spectator = {id: this.next_spectator_id,
59 session_id: session_id
61 this._spectators.push(new_spectator);
62 this.next_spectator_id++;
63 this.broadcast_event("spectator-join", JSON.stringify(new_spectator));
65 return new_spectator.id;
68 remove_spectator(id) {
69 const index = this._spectators.findIndex(spectator => spectator.id === id);
70 this._spectators.splice(index, 1);
72 this.broadcast_event("spectator-leave", `{"id": ${id}}`);
75 add_player(name, character) {
76 const new_player = {id: this.next_player_id,
81 this._players.push(new_player);
82 this.next_player_id++;
83 /* The syntax here is using an anonymous function to create a new
84 object from new_player with just the subset of fields that we
86 const player_data = JSON.stringify((({id, name}) => ({id, name}))(new_player));
87 this.broadcast_event("player-join", player_data);
91 const index = this._players.findIndex(player => player.id === id);
92 this._players.splice(index, 1);
94 this.broadcast_event("player-leave", `{"id": ${id}}`);
99 this.characters_to_reveal = null;
100 this.next_player_id = 1;
102 this.change_state(GameState.JOIN);
104 this.broadcast_event("spectators", "{}");
105 this.broadcast_event("players", "{}");
109 /* Don't try to reveal anything if we aren't in the reveal state. */
110 if (this.state != GameState.REVEAL) {
111 clearInterval(this.reveal_interval);
115 if (this.reveal_index >= this.characters_to_reveal.length) {
116 clearInterval(this.reveal_interval);
117 this.broadcast_event("character-reveal", '{"character":""}');
120 const character = this.characters_to_reveal[this.reveal_index];
122 const character_data = JSON.stringify({"character":character});
123 this.broadcast_event("character-reveal", character_data);
127 this.change_state(GameState.REVEAL);
129 if (this.characters_to_reveal === null) {
130 this.characters_to_reveal = [];
131 this.characters_to_reveal = this._players.reduce((characters, player) => {
132 characters.push(player.character);
135 shuffle(this.characters_to_reveal);
138 this.reveal_index = 0;
140 this.reveal_interval = setInterval(this.reveal_next.bind(this), 3000);
144 this.change_state(GameState.CAPTURE);
147 capture(captor_id, captee_id) {
148 /* TODO: Fix to fail on already-captured players (or to move the
149 * captured player from an old captor to a new—need to clarify in
150 * the API specification which we want here. */
151 let captor = this._players.find(player => player.id === captor_id);
152 captor.captures.push(captee_id);
154 this.broadcast_event("capture", `{"captor": ${captor_id}, "captee": ${captee_id}}`);
157 liberate(captee_id) {
158 let captor = this._players.find(player => player.captures.includes(captee_id));
159 captor.captures.splice(captor.captures.indexOf(captee_id), 1);
163 for (const player of this._players) {
164 player.captures = [];
169 return this._players.map(player => player.character);
173 return this._players.map(player => ({id: player.id, captures: player.captures}));
177 /* We return only "id" and "name" here (specifically not session_id!). */
178 return this._spectators.map(spectator => ({
185 return this._players.map(player => ({id: player.id, name: player.name }));
188 game_state_event_data(old_state, new_state) {
191 old_state_name = GameState.properties[old_state].name;
193 old_state_name = "none";
194 const new_state_name = GameState.properties[new_state].name;
196 return `{"old_state":"${old_state_name}","new_state":"${new_state_name}"}`;
199 /* Inform clients about a state change. */
200 broadcast_state_change() {
201 const event_data = this.game_state_event_data(this.old_state, this.state);
202 this.broadcast_event("game-state", event_data);
205 /* Change game state and broadcast the change to all clients. */
206 change_state(state) {
207 /* Do nothing if there is no actual change happening. */
208 if (state === this.state)
211 this.old_state = this.state;
214 this.broadcast_state_change();
218 function handle_events(request, response) {
219 const game = request.game;
220 /* These headers will keep the connection open so we can stream events. */
222 "Content-type": "text/event-stream",
223 "Connection": "keep-alive",
224 "Cache-Control": "no-cache"
226 response.writeHead(200, headers);
228 /* Now that a client has connected, first we need to stream all of
229 * the existing spectators and players (if any). */
230 if (game._spectators.length > 0) {
231 const spectators_json = JSON.stringify(game.spectators);
232 const spectators_data = `event: spectators\ndata: ${spectators_json}\n\n`;
233 response.write(spectators_data);
236 if (game._players.length > 0) {
237 const players_json = JSON.stringify(game.players);
238 const players_data = `event: players\ndata: ${players_json}\n\n`;
239 response.write(players_data);
242 /* And we need to inform the client of the current game state.
244 * In fact, we need to cycle through each state transition from the
245 * beginning so the client can see each.
247 var old_state = null;
248 for (var state = GameState.JOIN; state <= game.state; state++) {
249 var event_data = game.game_state_event_data(old_state, state);
250 response.write("event: game-state\n" + "data: " + event_data + "\n\n");
254 /* Add this new client to our list of clients. */
255 const id = game.add_client(response);
257 /* And queue up cleanup to be triggered on client close. */
258 request.on('close', () => {
259 game.remove_client(id);
263 router.get('/', (request, response) => {
264 if (! request.session.nickname)
265 response.render('choose-nickname.html', { game_name: "Empires" });
267 response.render('empires-game.html');
270 router.post('/spectator', (request, response) => {
271 const game = request.game;
272 var name = request.session.nickname;
274 /* If the request includes a name, that overrides the session nickname. */
275 if (request.body.name)
276 name = request.body.name;
278 const id = game.add_spectator(name, request.session.id);
279 response.send(JSON.stringify(id));
282 router.delete('/spectator/:id', (request, response) => {
283 const game = request.game;
284 game.remove_spectator(parseInt(request.params.id));
288 router.post('/register', (request, response) => {
289 const game = request.game;
290 var name = request.session.nickname;;
292 /* If the request includes a name, that overrides the session nickname. */
293 if (request.body.name)
294 name = request.body.name;
296 game.add_player(name, request.body.character);
300 router.post('/deregister/:id', (request, response) => {
301 const game = request.game;
302 game.remove_player(parseInt(request.params.id));
306 router.post('/reveal', (request, response) => {
307 const game = request.game;
312 router.post('/start', (request, response) => {
313 const game = request.game;
318 router.post('/reset', (request, response) => {
319 const game = request.game;
324 router.post('/capture/:captor/:captee', (request, response) => {
325 const game = request.game;
326 game.capture(parseInt(request.params.captor), parseInt(request.params.captee));
330 router.post('/liberate/:id', (request, response) => {
331 const game = request.game;
332 game.liberate(parseInt(request.params.id));
336 router.post('/restart', (request, response) => {
337 const game = request.game;
338 game.restart(parseInt(request.params.id));
342 router.get('/characters', (request, response) => {
343 const game = request.game;
344 response.send(game.characters);
347 router.get('/empires', (request, response) => {
348 const game = request.game;
349 response.send(game.empires);
352 router.get('/spectators', (request, response) => {
353 const game = request.game;
354 response.send(game.spectators);
357 router.get('/players', (request, response) => {
358 const game = request.game;
359 response.send(game.players);
362 router.get('/events', handle_events);
364 exports.router = router;
365 exports.name = engine_name;
366 exports.Game = Empires;