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     this.broadcast("player-deregister", `{"id": ${id}}`);
  36   }
  37
  38   remove_all_players() {
  39     this._players = [];
  40     this.next_player_id = 1;
  41   }
  42
  43   capture(captor_id, captee_id) {
  44     /* TODO: Fix to fail on already-captured players (or to move the
  45      * captured player from an old captor to a new—need to clarify in
  46      * the API specification which we want here. */
  47     let captor = this._players.find(player => player.id === captor_id);
  48     captor.captures.push(captee_id);
  49
  50     this.broadcast("capture", `{"captor": ${captor_id}, "captee": ${captee_id}}`);
  51   }
  52
  53   liberate(captee_id) {
  54     let captor = this._players.find(player => player.captures.includes(captee_id));
  55     captor.captures.splice(captor.captures.indexOf(captee_id), 1);
  56   }
  57
  58   restart() {
  59     for (const player of this._players) {
  60       player.captures = [];
  61     }
  62   }
  63
  64   get characters() {
  65     return this._players.map(player => player.character);
  66   }
  67
  68   get empires() {
  69     return this._players.map(player => ({id: player.id, captures: player.captures}));
  70   }
  71
  72   get players() {
  73     return this._players.map(player => ({id: player.id, name: player.name }));
  74   }
  75
  76   add_client(response) {
  77     const id = this.next_client_id;
  78     this.clients.push({id: id,
  79                        response: response});
  80     this.next_client_id++;
  81
  82     return id;
  83   }
  84
  85   remove_client(id) {
  86     this.clients = this.clients.filter(client => client.id !== id);
  87   }
  88
  89   /* Send an event to all clients */
  90   broadcast(type, data) {
  91     this.clients.forEach(client => client.response.write(`event: ${type}\ndata: ${data}\n\n`));
  92   }
  93 }
  94
  95 const game = new Game();
  96
  97 app.use(body_parser.urlencoded({ extended: false }));
  98 app.use(body_parser.json());
  99
 100 function handle_events(request, response) {
 101   /* These headers will keep the connection open so we can stream events. */
 102   const headers = {
 103     "Content-type": "text/event-stream",
 104     "Connection": "keep-alive",
 105     "Cache-Control": "no-cache"
 106   };
 107   response.writeHead(200, headers);
 108
 109   /* Now that a client has connected, first we need to stream all of
 110    * the existing players (if any). */
 111   if (game._players.length > 0) {
 112     const players_json = JSON.stringify(game.players);
 113     const players_data = `event: players\ndata: ${players_json}\n\n`;
 114     response.write(players_data);
 115   }
 116
 117   /* Add this new client to our list of clients. */
 118   const id = game.add_client(response);
 119
 120   /* And queue up cleanup to be tirggered on client close. */
 121   request.on('close', () => {
 122     game.remove_client(id);
 123   });
 124 }
 125
 126 app.get('/', (request, response) => {
 127   response.send('Hello World!');
 128 });
 129
 130 app.post('/register', (request, response) => {
 131   game.add_player(request.body.name, request.body.character);
 132   response.send();
 133 });
 134
 135 app.post('/deregister/:id', (request, response) => {
 136   game.remove_player(parseInt(request.params.id));
 137   response.send();
 138 });
 139
 140 app.post('/reset', (request, response) => {
 141   game.remove_all_players();
 142   response.send();
 143 });
 144
 145 app.post('/capture/:captor/:captee', (request, response) => {
 146   game.capture(parseInt(request.params.captor), parseInt(request.params.captee));
 147   response.send();
 148 });
 149
 150 app.post('/liberate/:id', (request, response) => {
 151   game.liberate(parseInt(request.params.id));
 152   response.send();
 153 });
 154
 155 app.post('/restart', (request, response) => {
 156   game.restart(parseInt(request.params.id));
 157     response.send();
 158 });
 159
 160 app.get('/characters', (request, response) => {
 161   response.send(game.characters);
 162 });
 163
 164 app.get('/empires', (request, response) => {
 165   response.send(game.empires);
 166 });
 167
 168 app.get('/players', (request, response) => {
 169   response.send(game.players);
 170 });
 171
 172 app.get('/events', handle_events);
 173
 174 app.listen(3000, function () {
 175   console.log('Example app listening on port 3000!');
 176 });