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

   1 const express = require("express");
   2 const cors = require("cors");
   3 const body_parser = require("body-parser");
   4
   5 const app = express();
   6 app.use(cors());
   7
   8 class Game {
   9   constructor() {
  10     this._players = [];
  11     this.next_player_id = 1;
  12     this.clients = [];
  13     this.next_client_id = 1;
  14   }
  15
  16   add_player(name, character) {
  17     const new_player = {id: this.next_player_id,
  18                        name: name,
  19                        character: character,
  20                        captures: [],
  21                        };
  22     this._players.push(new_player);
  23     this.next_player_id++;
  24     /* The syntax here is using an anonymous function to create a new
  25       object from new_player with just the subset of fields that we
  26       want. */
  27     const player_string = JSON.stringify((({id, name}) => ({id, name}))(new_player));
  28     this.broadcast("player-register", player_string);
  29   }
  30
  31   remove_player(id) {
  32     const index = this._players.findIndex(player => player.id === id);
  33     this._players.splice(index, 1);
  34   }
  35
  36   remove_all_players() {
  37     this._players = [];
  38     this.next_player_id = 1;
  39   }
  40
  41   capture(captor_id, captee_id) {
  42     /* TODO: Fix to fail on already-captured players (or to move the
  43      * captured player from an old captor to a new—need to clarify in
  44      * the API specification which we want here. */
  45     let captor = this._players.find(player => player.id === captor_id);
  46     captor.captures.push(captee_id);
  47   }
  48
  49   liberate(captee_id) {
  50     let captor = this._players.find(player => player.captures.includes(captee_id));
  51     captor.captures.splice(captor.captures.indexOf(captee_id), 1);
  52   }
  53
  54   restart() {
  55     for (const player of this._players) {
  56       player.captures = [];
  57     }
  58   }
  59
  60   get characters() {
  61     return this._players.map(player => player.character);
  62   }
  63
  64   get empires() {
  65     return this._players.map(player => ({id: player.id, captures: player.captures}));
  66   }
  67
  68   get players() {
  69     return this._players.map(player => ({id: player.id, name: player.name }));
  70   }
  71
  72   add_client(response) {
  73     const id = this.next_client_id;
  74     this.clients.push({id: id,
  75                        response: response});
  76     this.next_client_id++;
  77
  78     return id;
  79   }
  80
  81   remove_client(id) {
  82     this.clients = this.clients.filter(client => client.id !== id);
  83   }
  84
  85   /* Send an event to all clients */
  86   broadcast(type, data) {
  87     this.clients.forEach(client => client.response.write(`event: ${type}\ndata: ${data}\n\n`));
  88   }
  89 }
  90
  91 const game = new Game();
  92
  93 app.use(body_parser.urlencoded({ extended: false }));
  94 app.use(body_parser.json());
  95
  96 function handle_events(request, response) {
  97   /* These headers will keep the connection open so we can stream events. */
  98   const headers = {
  99     "Content-type": "text/event-stream",
 100     "Connection": "keep-alive",
 101     "Cache-Control": "no-cache"
 102   };
 103   response.writeHead(200, headers);
 104
 105   /* Now that a client has connected, first we need to stream all of
 106    * the existing players (if any). */
 107   if (game._players.length > 0) {
 108     const players_json = JSON.stringify(game.players);
 109     const players_data = `event: players\ndata: ${players_json}\n\n`;
 110     response.write(players_data);
 111   }
 112
 113   /* Add this new client to our list of clients. */
 114   const id = game.add_client(response);
 115
 116   /* And queue up cleanup to be tirggered on client close. */
 117   request.on('close', () => {
 118     game.remove_client(id);
 119   });
 120 }
 121
 122 app.get('/', (request, response) => {
 123   response.send('Hello World!');
 124 });
 125
 126 app.post('/register', (request, response) => {
 127   game.add_player(request.body.name, request.body.character);
 128   response.send();
 129 });
 130
 131 app.post('/deregister/:id', (request, response) => {
 132   game.remove_player(parseInt(request.params.id));
 133   response.send();
 134 });
 135
 136 app.post('/reset', (request, response) => {
 137   game.remove_all_players();
 138   response.send();
 139 });
 140
 141 app.post('/capture/:captor/:captee', (request, response) => {
 142   game.capture(parseInt(request.params.captor), parseInt(request.params.captee));
 143   response.send();
 144 });
 145
 146 app.post('/liberate/:id', (request, response) => {
 147   game.liberate(parseInt(request.params.id));
 148   response.send();
 149 });
 150
 151 app.post('/restart', (request, response) => {
 152   game.restart(parseInt(request.params.id));
 153     response.send();
 154 });
 155
 156 app.get('/characters', (request, response) => {
 157   response.send(game.characters);
 158 });
 159
 160 app.get('/empires', (request, response) => {
 161   response.send(game.empires);
 162 });
 163
 164 app.get('/players', (request, response) => {
 165   response.send(game.players);
 166 });
 167
 168 app.get('/events', handle_events);
 169
 170 app.listen(3000, function () {
 171   console.log('Example app listening on port 3000!');
 172 });