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,obj) => {
  25       Object.keys(clients).forEach(k => {
  26         if (k != sid && clients[k].page == page)
  27         {
  28           clients[k].sock.send(JSON.stringify(Object.assign(
  29             {code:code}, obj)));
  30         }
  31       });
  32     };
  33     notifyRoom(query["page"],"connect",{sid:sid});
  34     socket.on("message", objtxt => {
  35       let obj = JSON.parse(objtxt);
  36       if (!!obj.target && !clients[obj.target])
  37         return; //receiver not connected, nothing we can do
  38       switch (obj.code)
  39       {
  40         case "pollclients":
  41           const curPage = clients[sid].page;
  42           socket.send(JSON.stringify({code:"pollclients",
  43             sockIds: Object.keys(clients).filter(k =>
  44               k != sid && clients[k].page == curPage)}));
  45           break;
  46         case "pagechange":
  47           notifyRoom(clients[sid].page, "disconnect", {sid:sid});
  48           clients[sid].page = obj.page;
  49           notifyRoom(obj.page, "connect", {sid:sid});
  50           break;
  51         case "askidentity":
  52           clients[obj.target].sock.send(JSON.stringify(
  53             {code:"askidentity",from:sid}));
  54           break;
  55         case "askchallenge":
  56           clients[obj.target].sock.send(JSON.stringify(
  57             {code:"askchallenge",from:sid}));
  58           break;
  59         case "askgame":
  60           clients[obj.target].sock.send(JSON.stringify(
  61             {code:"askgame",from:sid}));
  62           break;
  63         case "identity":
  64           clients[obj.target].sock.send(JSON.stringify(
  65             {code:"identity",user:obj.user}));
  66           break;
  67         case "refusechallenge":
  68           clients[obj.target].sock.send(JSON.stringify(
  69             {code:"refusechallenge", cid:obj.cid, from:sid}));
  70           break;
  71         case "deletechallenge":
  72           clients[obj.target].sock.send(JSON.stringify(
  73             {code:"deletechallenge", cid:obj.cid, from:sid}));
  74           break;
  75         case "newgame":
  76           clients[obj.target].sock.send(JSON.stringify(
  77             {code:"newgame", gameInfo:obj.gameInfo, cid:obj.cid}));
  78           break;
  79         case "challenge":
  80           clients[obj.target].sock.send(JSON.stringify(
  81             {code:"challenge", chall:obj.chall, from:sid}));
  82           break;
  83         case "game":
  84           clients[obj.target].sock.send(JSON.stringify(
  85             {code:"game", game:obj.game, from:sid}));
  86           break;
  87         case "newchat":
  88           notifyRoom(query["page"], "newchat",
  89             {msg:obj.msg, name:obj.name, sid:sid})
  90           break;
  91         // TODO: WebRTC instead in this case (most demanding?)
  92         case "newmove":
  93           clients[obj.target].sock.send(JSON.stringify(
  94             {code:"newmove",move:obj.move}));
  95           break;
  96         case "lastate":
  97           clients[obj.target].sock.send(JSON.stringify(
  98             {code:"lastate", state:obj.state}));
  99           break;
 100         case "resign":
 101           clients[obj.target].sock.send(JSON.stringify(
 102             {code:"resign"}));
 103           break;
 104         case "abort":
 105           clients[obj.target].sock.send(JSON.stringify(
 106             {code:"abort",msg:obj.msg}));
 107           break;
 108         case "drawoffer":
 109           clients[obj.target].sock.send(JSON.stringify(
 110             {code:"drawoffer"}));
 111           break;
 112         case "draw":
 113           clients[obj.target].sock.send(JSON.stringify(
 114             {code:"draw"}));
 115           break;
 116       }
 117     });
 118     socket.on("close", () => {
 119       const page = clients[sid].page;
 120       delete clients[sid];
 121       notifyRoom(page, "disconnect");
 122     });
 123   });
 124 }