git.cworth.org Git - empires-server/blob - empires.js

   1 const express = require("express");
   2 const Game = require("./game.js");
   3
   4 const engine_name = "empires";
   5
   6 const router = express.Router();
   7
   8 const GameState = {
   9   JOIN:    1,
  10   REVEAL:  2,
  11   CAPTURE: 3,
  12   properties: {
  13     1: {name: "join"},
  14     2: {name: "reveal"},
  15     3: {name: "capture"}
  16   }
  17 };
  18
  19 /**
  20  * Shuffles array in place.
  21  * @param {Array} a items An array containing the items.
  22  */
  23 function shuffle(a) {
  24   if (a === undefined)
  25     return;
  26
  27   var j, x, i;
  28   for (i = a.length - 1; i > 0; i--) {
  29     j = Math.floor(Math.random() * (i + 1));
  30     x = a[i];
  31     a[i] = a[j];
  32     a[j] = x;
  33   }
  34 }
  35
  36 class Empires extends Game {
  37   constructor() {
  38     super(engine_name);
  39     this._spectators = [];
  40     this.next_spectator_id = 1;
  41     this._players = [];
  42     this.next_player_id = 1;
  43     this.characters_to_reveal = null;
  44     this.state = GameState.JOIN;
  45
  46     /* Send a comment to every connected client every 15 seconds. */
  47     setInterval(() => {this.broadcast_string(":");}, 15000);
  48   }
  49
  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);
  54     if (existing >= 0)
  55       return existing.id;
  56
  57     const new_spectator = {id: this.next_spectator_id,
  58                            name: name,
  59                            session_id: session_id
  60                           };
  61     this._spectators.push(new_spectator);
  62     this.next_spectator_id++;
  63     this.broadcast_event("spectator-join", JSON.stringify(new_spectator));
  64
  65     return new_spectator.id;
  66   }
  67
  68   remove_spectator(id) {
  69     const index = this._spectators.findIndex(spectator => spectator.id === id);
  70     this._spectators.splice(index, 1);
  71
  72     this.broadcast_event("spectator-leave", `{"id": ${id}}`);
  73   }
  74
  75   add_player(name, character) {
  76     const new_player = {id: this.next_player_id,
  77                        name: name,
  78                        character: character,
  79                        captures: [],
  80                        };
  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
  85       want. */
  86     const player_data = JSON.stringify((({id, name}) => ({id, name}))(new_player));
  87     this.broadcast_event("player-join", player_data);
  88
  89     return new_player;
  90   }
  91
  92   remove_player(id) {
  93     const index = this._players.findIndex(player => player.id === id);
  94     this._players.splice(index, 1);
  95
  96     this.broadcast_event("player-leave", `{"id": ${id}}`);
  97   }
  98
  99   reset() {
 100     this._players = [];
 101     this.characters_to_reveal = null;
 102     this.next_player_id = 1;
 103
 104     this.change_state(GameState.JOIN);
 105
 106     this.broadcast_event("spectators", "{}");
 107     this.broadcast_event("players", "{}");
 108   }
 109
 110   reveal_next() {
 111     /* Don't try to reveal anything if we aren't in the reveal state. */
 112     if (this.state != GameState.REVEAL) {
 113       clearInterval(this.reveal_interval);
 114       return;
 115     }
 116
 117     if (this.reveal_index >= this.characters_to_reveal.length) {
 118       clearInterval(this.reveal_interval);
 119       this.broadcast_event("character-reveal", '{"character":""}');
 120       return;
 121     }
 122     const character = this.characters_to_reveal[this.reveal_index];
 123     this.reveal_index++;
 124     const character_data = JSON.stringify({"character":character});
 125     this.broadcast_event("character-reveal", character_data);
 126   }
 127
 128   reveal() {
 129     this.change_state(GameState.REVEAL);
 130
 131     if (this.characters_to_reveal === null) {
 132       this.characters_to_reveal = [];
 133       this.characters_to_reveal = this._players.reduce((characters, player) => {
 134         characters.push(player.character);
 135         return characters;
 136       }, []);
 137       shuffle(this.characters_to_reveal);
 138     }
 139
 140     this.reveal_index = 0;
 141
 142     this.reveal_interval = setInterval(this.reveal_next.bind(this), 3000);
 143   }
 144
 145   start() {
 146     this.change_state(GameState.CAPTURE);
 147   }
 148
 149   capture(captor_id, captee_id) {
 150     /* TODO: Fix to fail on already-captured players (or to move the
 151      * captured player from an old captor to a new—need to clarify in
 152      * the API specification which we want here. */
 153     let captor = this._players.find(player => player.id === captor_id);
 154     captor.captures.push(captee_id);
 155
 156     this.broadcast_event("capture", `{"captor": ${captor_id}, "captee": ${captee_id}}`);
 157   }
 158
 159   liberate(captee_id) {
 160     let captor = this._players.find(player => player.captures.includes(captee_id));
 161     captor.captures.splice(captor.captures.indexOf(captee_id), 1);
 162   }
 163
 164   restart() {
 165     for (const player of this._players) {
 166       player.captures = [];
 167     }
 168   }
 169
 170   get characters() {
 171     return this._players.map(player => player.character);
 172   }
 173
 174   get empires() {
 175     return this._players.map(player => ({id: player.id, captures: player.captures}));
 176   }
 177
 178   get spectators() {
 179     /* We return only "id" and "name" here (specifically not session_id!). */
 180     return this._spectators.map(spectator => ({
 181       id: spectator.id,
 182       name: spectator.name
 183     }));
 184   }
 185
 186   get players() {
 187     return this._players.map(player => ({id: player.id, name: player.name }));
 188   }
 189
 190   game_state_event_data(old_state, new_state) {
 191     var old_state_name;
 192     if (old_state)
 193       old_state_name = GameState.properties[old_state].name;
 194     else
 195       old_state_name = "none";
 196     const new_state_name = GameState.properties[new_state].name;
 197
 198     return `{"old_state":"${old_state_name}","new_state":"${new_state_name}"}`;
 199   }
 200
 201   /* Inform clients about a state change. */
 202   broadcast_state_change() {
 203     const event_data = this.game_state_event_data(this.old_state, this.state);
 204     this.broadcast_event("game-state", event_data);
 205   }
 206
 207   /* Change game state and broadcast the change to all clients. */
 208   change_state(state) {
 209     /* Do nothing if there is no actual change happening. */
 210     if (state === this.state)
 211       return;
 212
 213     this.old_state = this.state;
 214     this.state = state;
 215
 216     this.broadcast_state_change();
 217   }
 218
 219   handle_events(request, response) {
 220
 221     super.handle_events(request, response);
 222
 223     /* Now that a client has connected, first we need to stream all of
 224      * the existing spectators and players (if any). */
 225     if (this._spectators.length > 0) {
 226       const spectators_json = JSON.stringify(this.spectators);
 227       const spectators_data = `event: spectators\ndata: ${spectators_json}\n\n`;
 228       response.write(spectators_data);
 229     }
 230
 231     if (this._players.length > 0) {
 232       const players_json = JSON.stringify(this.players);
 233       const players_data = `event: players\ndata: ${players_json}\n\n`;
 234       response.write(players_data);
 235     }
 236
 237     /* And we need to inform the client of the current game state.
 238      *
 239      * In fact, we need to cycle through each state transition from the
 240      * beginning so the client can see each.
 241      */
 242     var old_state = null;
 243     for (var state = GameState.JOIN; state <= this.state; state++) {
 244       var event_data = this.game_state_event_data(old_state, state);
 245       response.write("event: game-state\n" + "data: " + event_data + "\n\n");
 246       old_state = state;
 247     }
 248   }
 249
 250 }
 251
 252 router.post('/spectator', (request, response) => {
 253   const game = request.game;
 254   var name = request.session.nickname;
 255
 256   /* If the request includes a name, that overrides the session nickname. */
 257   if (request.body.name)
 258     name = request.body.name;
 259
 260   const id = game.add_spectator(name, request.session.id);
 261   response.send(JSON.stringify(id));
 262 });
 263
 264 router.delete('/spectator/:id', (request, response) => {
 265   const game = request.game;
 266   game.remove_spectator(parseInt(request.params.id));
 267   response.send();
 268 });
 269
 270 router.post('/register', (request, response) => {
 271   const game = request.game;
 272   var name = request.session.nickname;;
 273
 274   /* If the request includes a name, that overrides the session nickname. */
 275   if (request.body.name)
 276     name = request.body.name;
 277
 278   const player = game.add_player(name, request.body.character);
 279   response.send(JSON.stringify(player.id));
 280 });
 281
 282 router.post('/deregister/:id', (request, response) => {
 283   const game = request.game;
 284   game.remove_player(parseInt(request.params.id));
 285   response.send();
 286 });
 287
 288 router.post('/reveal', (request, response) => {
 289   const game = request.game;
 290   game.reveal();
 291   response.send();
 292 });
 293
 294 router.post('/start', (request, response) => {
 295   const game = request.game;
 296   game.start();
 297   response.send();
 298 });
 299
 300 router.post('/reset', (request, response) => {
 301   const game = request.game;
 302   game.reset();
 303   response.send();
 304 });
 305
 306 router.post('/capture/:captor/:captee', (request, response) => {
 307   const game = request.game;
 308   game.capture(parseInt(request.params.captor), parseInt(request.params.captee));
 309   response.send();
 310 });
 311
 312 router.post('/liberate/:id', (request, response) => {
 313   const game = request.game;
 314   game.liberate(parseInt(request.params.id));
 315   response.send();
 316 });
 317
 318 router.post('/restart', (request, response) => {
 319   const game = request.game;
 320   game.restart(parseInt(request.params.id));
 321     response.send();
 322 });
 323
 324 router.get('/characters', (request, response) => {
 325   const game = request.game;
 326   response.send(game.characters);
 327 });
 328
 329 router.get('/empires', (request, response) => {
 330   const game = request.game;
 331   response.send(game.empires);
 332 });
 333
 334 router.get('/spectators', (request, response) => {
 335   const game = request.game;
 336   response.send(game.spectators);
 337 });
 338
 339 router.get('/players', (request, response) => {
 340   const game = request.game;
 341   response.send(game.players);
 342 });
 343
 344 router.get('/events', (request, response) => {
 345   const game = request.game;
 346   game.handle_events(request, response);
 347 });
 348
 349 exports.router = router;
 350 exports.name = engine_name;
 351 exports.Game = Empires;
 352
 353 Empires.meta = {
 354   name: "Empires",
 355   identifier: "empires"
 356 };
 357
 358 exports.meta = Empires.meta;