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           const curPage = clients[sid].page;
  39           socket.send(JSON.stringify({code:"pollclients",
  40             sockIds: Object.keys(clients).filter(k =>
  41               k != sid && clients[k].page == curPage)}));
  42           break;
  43         case "pagechange":
  44           notifyRoom(clients[sid].page, "disconnect");
  45           clients[sid].page = obj.page;
  46           notifyRoom(obj.page, "connect");
  47           break;
  48         case "askidentity":
  49           clients[obj.target].sock.send(JSON.stringify(
  50             {code:"askidentity",from:sid}));
  51           break;
  52         case "askchallenge":
  53           clients[obj.target].sock.send(JSON.stringify(
  54             {code:"askchallenge",from:sid}));
  55           break;
  56         case "askgame":
  57           clients[obj.target].sock.send(JSON.stringify(
  58             {code:"askgame",from:sid}));
  59           break;
  60         case "identity":
  61           clients[obj.target].sock.send(JSON.stringify(
  62             {code:"identity",user:obj.user}));
  63           break;
  64         case "refusechallenge":
  65           clients[obj.target].sock.send(JSON.stringify(
  66             {code:"refusechallenge", cid:obj.cid, from:sid}));
  67           break;
  68         case "deletechallenge":
  69           clients[obj.target].sock.send(JSON.stringify(
  70             {code:"deletechallenge", cid:obj.cid, from:sid}));
  71           break;
  72         case "newgame":
  73           clients[obj.target].sock.send(JSON.stringify(
  74             {code:"newgame", gameInfo:obj.gameInfo, cid:obj.cid}));
  75           break;
  76         case "challenge":
  77           clients[obj.target].sock.send(JSON.stringify(
  78             {code:"challenge", chall:obj.chall, from:sid}));
  79           break;
  80         case "game":
  81           clients[obj.target].sock.send(JSON.stringify(
  82             {code:"game", game:obj.game, from:sid}));
  83           break;
  84         case "newchat":
  85           clients[obj.target].sock.send(JSON.stringify(
  86             {code:"newchat",msg:obj.msg}));
  87           break;
  88         // TODO: WebRTC instead in this case (most demanding?)
  89         case "newmove":
  90           clients[obj.target].sock.send(JSON.stringify(
  91             {code:"newmove",move:obj.move}));
  92           break;
  93         case "lastate":
  94           clients[obj.target].sock.send(JSON.stringify(
  95             {code:"lastate", state:obj.state}));
  96           break;
  97         case "resign":
  98           clients[obj.target].sock.send(JSON.stringify(
  99             {code:"resign"}));
 100           break;
 101         case "abort":
 102           clients[obj.target].sock.send(JSON.stringify(
 103             {code:"abort",msg:obj.msg}));
 104           break;
 105         case "drawoffer":
 106           clients[obj.target].sock.send(JSON.stringify(
 107             {code:"drawoffer"}));
 108           break;
 109         case "draw":
 110           clients[obj.target].sock.send(JSON.stringify(
 111             {code:"draw"}));
 112           break;
 113       }
 114     });
 115     socket.on("close", () => {
 116       const page = clients[sid].page;
 117       delete clients[sid];
 118       notifyRoom(page, "disconnect");
 119     });
 120   });
 121 }