server/sockets.js

   1 const url = require('url');
   2
   3 // Node version in Ubuntu 16.04 does not know about URL class
   4 function getJsonFromUrl(url)
   5 {
   6   const query = url.substr(2); //starts with "/?"
   7   let result = {};
   8   query.split("&").forEach((part) => {
   9     const item = part.split("=");
  10     result[item[0]] = decodeURIComponent(item[1]);
  11   });
  12   return result;
  13 }
  14
  15 module.exports = function(wss) {
  16   let clients = {}; //associative array sid --> socket
  17   wss.on("connection", (socket, req) => {
  18     const query = getJsonFromUrl(req.url);
  19     const sid = query["sid"];
  20     // TODO: later, allow duplicate connections (shouldn't be much more complicated)
  21     if (!!clients[sid])
  22       return socket.send(JSON.stringify({code:"duplicate"}));
  23     clients[sid] = {sock: socket, page: query["page"]};
  24     const notifyRoom = (page,code) => {
  25       Object.keys(clients).forEach(k => {
  26         if (k != sid && clients[k].page == page)
  27           clients[k].sock.send(JSON.stringify({code:code,sid:sid}));
  28       });
  29     };
  30     notifyRoom(query["page"],"connect");
  31     socket.on("message", objtxt => {
  32       let obj = JSON.parse(objtxt);
  33       if (!!obj.target && !clients[obj.target])
  34         return; //receiver not connected, nothing we can do
  35       switch (obj.code)
  36       {
  37         case "pollclients":
  38           socket.send(JSON.stringify({code:"pollclients",
  39             sockIds: Object.keys(clients).filter(k =>
  40               k != sid && clients[k].page == obj.page)}));
  41           break;
  42         case "pagechange":
  43           notifyRoom(clients[sid].page, "disconnect");
  44           clients[sid].page = obj.page;
  45           notifyRoom(obj.page, "connect");
  46           break;
  47         case "askidentity":
  48           clients[obj.target].sock.send(
  49             JSON.stringify({code:"askidentity",from:sid}));
  50           break;
  51         case "askchallenge":
  52           clients[obj.target].sock.send(
  53             JSON.stringify({code:"askchallenge",from:sid}));
  54           break;
  55         case "askgame":
  56           clients[obj.target].sock.send(
  57             JSON.stringify({code:"askgame",from:sid}));
  58           break;
  59         case "identity":
  60           clients[obj.target].sock.send(
  61             JSON.stringify({code:"identity",user:obj.user}));
  62           break;
  63         case "refusechallenge":
  64           clients[obj.target].sock.send(
  65             JSON.stringify({code:"refusechallenge", cid:obj.cid, from:sid}));
  66           break;
  67         case "deletechallenge":
  68           clients[obj.target].sock.send(
  69             JSON.stringify({code:"deletechallenge", cid:obj.cid, from:sid}));
  70           break;
  71         case "newgame":
  72           clients[obj.target].sock.send(JSON.stringify(
  73             {code:"newgame", gameInfo:obj.gameInfo, cid:obj.cid}));
  74           break;
  75         case "challenge":
  76           clients[obj.target].sock.send(JSON.stringify(
  77             {code:"challenge", chall:obj.chall, from:sid}));
  78           break;
  79         case "game":
  80           clients[obj.target].sock.send(JSON.stringify(
  81             {code:"game", game:obj.game, from:sid}));
  82           break;
  83         case "newchat":
  84           clients[obj.target].sock.send(JSON.stringify({code:"newchat",msg:obj.msg}));
  85           break;
  86         // TODO: WebRTC instead in this case (most demanding?)
  87         case "newmove":
  88           clients[obj.target].sock.send(JSON.stringify({code:"newmove",move:obj.move}));
  89           break;
  90         case "ping":
  91           // If this code is reached, then obj.target is connected
  92           socket.send(JSON.stringify({code:"pong"}));
  93           break;
  94         case "lastate":
  95           const oppId = obj.target;
  96           obj.oppid = sid; //I'm the opponent of my opponent
  97           clients[oppId].sock.send(JSON.stringify(obj));
  98           break;
  99         case "resign":
 100           clients[obj.target].sock.send(JSON.stringify({code:"resign"}));
 101           break;
 102         case "abort":
 103           clients[obj.target].sock.send(JSON.stringify({code:"abort",msg:obj.msg}));
 104           break;
 105         case "drawoffer":
 106           clients[obj.target].sock.send(JSON.stringify({code:"drawoffer"}));
 107           break;
 108         case "draw":
 109           clients[obj.target].sock.send(JSON.stringify({code:"draw"}));
 110           break;
 111       }
 112     });
 113     socket.on("close", () => {
 114       const page = clients[sid].page;
 115       delete clients[sid];
 116       notifyRoom(page, "disconnect");
 117     });
 118   });
 119 }