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 // Removal in array of strings (socket IDs)
  16 function remInArray(arr, item)
  17 {
  18     const idx = arr.indexOf(item);
  19     if (idx >= 0)
  20         arr.splice(idx, 1);
  21 }
  22
  23 // TODO: empêcher multi-log du même user (envoyer le user ID + secret en même temps que name et...)
  24 // --> si secret ne matche pas celui trouvé en DB, stop
  25 // TODO: this file "in the end" would be much simpler, essentially just tracking connect/disconnect
  26 // (everything else using WebRTC)
  27 // TODO: lorsque challenge accepté, seul le dernier joueur à accepter envoi message "please start game"
  28 // avec les coordonnées des participants. Le serveur renvoit alors les détails de la partie (couleurs, position)
  29 //TODO: programmatic re-navigation on current game if we receive a move and are not there
  30
  31 module.exports = function(wss) {
  32     let clients = {}; //associative array client sid --> socket
  33     // No-op function as a callback when sending messages
  34     const noop = () => { };
  35     wss.on("connection", (socket, req) => {
  36         const query = getJsonFromUrl(req.url);
  37         const sid = query["sid"];
  38         // Ignore duplicate connections (on the same live game that we play):
  39         if (!!clients[sid])
  40             return socket.send(JSON.stringify({code:"duplicate"}));
  41         clients[sid] = socket;
  42         socket.on("message", objtxt => {
  43             let obj = JSON.parse(objtxt);
  44       if (!!obj.oppid && !clients[oppid])
  45         return; //receiver not connected, nothing we can do
  46             switch (obj.code)
  47             {
  48                 // Transmit chats and moves to current room
  49                 // TODO: WebRTC instead in this case (most demanding?)
  50                 case "newchat":
  51           clients[obj.oppid].send(JSON.stringify({code:"newchat",msg:obj.msg}), noop);
  52                     break;
  53                 case "newmove":
  54           clients[obj.oppid].send(JSON.stringify({code:"newmove",move:obj.move}), noop);
  55                     break;
  56                 // TODO: generalize that for several opponents
  57                 case "ping":
  58                     socket.send(JSON.stringify({code:"pong",gameId:obj.gameId}));
  59                     break;
  60                 case "lastate":
  61           const oppId = obj.oppid;
  62           obj.oppid = sid; //I'm oppid for my opponent
  63           clients[oppId].send(JSON.stringify(obj), noop);
  64                     break;
  65                 // TODO: moreover, here, game info should be sent (through challenge; not stored here)
  66                 case "newgame":
  67           clients[oppId].send(
  68             JSON.stringify(
  69               {code:"newgame",fen:fen,oppid:sid,color:"w",gameid:"TODO"}),
  70             noop);
  71                     break;
  72                 case "cancelnewgame": //if a user cancel his seek
  73                     // TODO: just transmit event
  74                     //delete games[page];
  75                     break;
  76                 // TODO: also other challenge events
  77                 case "resign":
  78           clients[obj.oppid].send(JSON.stringify({code:"resign"}), noop);
  79                     break;
  80                 // TODO: case "challenge" (get ID) --> send to all, "acceptchallenge" (with ID) --> send to all, "cancelchallenge" --> send to all
  81                 // also, "sendgame" (give current game info, if any) --> to new connections, "sendchallenges" (same for challenges) --> to new connections
  82         case "newchallenge":
  83           console.log("challenge received");
  84           console.log(obj.sender);
  85           console.log(obj);
  86           break;
  87             }
  88         });
  89         socket.on("close", () => {
  90             delete clients[sid];
  91       // Notify every other connected client
  92       Object.keys(clients).forEach( k => {
  93         clients[k].send(JSON.stringify({code:"disconnect",sid:sid}), noop);
  94       });
  95         });
  96     });
  97 }