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 sid --> socket
  33     wss.on("connection", (socket, req) => {
  34         const query = getJsonFromUrl(req.url);
  35         const sid = query["sid"];
  36     // Ignore duplicate connections (on the same live game that we play):
  37         if (!!clients[sid])
  38             return socket.send(JSON.stringify({code:"duplicate"}));
  39         clients[sid] = socket;
  40         // Notify room:
  41     Object.keys(clients).forEach(k => {
  42       if (k != sid)
  43         clients[k].send(JSON.stringify({code:"connect",sid:sid}));
  44     });
  45     socket.on("message", objtxt => {
  46             let obj = JSON.parse(objtxt);
  47       if (!!obj.target && !clients[obj.target])
  48         return; //receiver not connected, nothing we can do
  49       //console.log(obj.code);
  50             switch (obj.code)
  51             {
  52         case "pollclients":
  53           socket.send(JSON.stringify({code:"pollclients",
  54             sockIds:Object.keys(clients).filter(k => k != sid)}));
  55           break;
  56         case "askidentity":
  57           clients[obj.target].send(
  58             JSON.stringify({code:"askidentity",from:sid}));
  59           break;
  60         case "askchallenge":
  61           clients[obj.target].send(
  62             JSON.stringify({code:"askchallenge",from:sid}));
  63           break;
  64         case "askgame":
  65           clients[obj.target].send(
  66             JSON.stringify({code:"askgame",from:sid}));
  67           break;
  68         case "identity":
  69           clients[obj.target].send(
  70             JSON.stringify({code:"identity",user:obj.user}));
  71           break;
  72         case "challenge":
  73           // Relay challenge to other player
  74           clients[obj.target].send(
  75             JSON.stringify({code:"challenge", chall:obj.chall, from:sid}));
  76           break;
  77         case "acceptchallenge":
  78           clients[obj.target].send(
  79             JSON.stringify({code:"acceptchallenge", cid:obj.cid, from:sid}));
  80           break;
  81         case "withdrawchallenge":
  82           clients[obj.target].send(
  83             JSON.stringify({code:"withdrawchallenge", cid:obj.cid, from:sid}));
  84           break;
  85         case "newgame":
  86           clients[obj.target].send(JSON.stringify(
  87             {code:"newgame", gameInfo:obj.gameInfo}));
  88           break;
  89         case "game":
  90           // TODO: relay (live) game to other player
  91           break;
  92                 case "newchat":
  93           clients[obj.target].send(JSON.stringify({code:"newchat",msg:obj.msg}));
  94                     break;
  95                 // Transmit chats and moves to current room
  96                 // TODO: WebRTC instead in this case (most demanding?)
  97                 case "newmove":
  98           clients[obj.target].send(JSON.stringify({code:"newmove",move:obj.move}));
  99                     break;
 100                 // TODO: generalize that for several opponents
 101                 case "ping":
 102                     socket.send(JSON.stringify({code:"pong",gameId:obj.gameId}));
 103                     break;
 104                 case "lastate":
 105           const oppId = obj.target;
 106           obj.oppid = sid; //I'm the opponent of my opponent(s)
 107           clients[oppId].send(JSON.stringify(obj));
 108                     break;
 109                 // TODO: moreover, here, game info should be sent (through challenge; not stored here)
 110                 // TODO: also other challenge events
 111                 case "resign":
 112           clients[obj.target].send(JSON.stringify({code:"resign"}));
 113                     break;
 114                 // TODO: case "challenge" (get ID) --> send to all, "acceptchallenge" (with ID) --> send to all, "cancelchallenge" --> send to all
 115                 // also, "sendgame" (give current game info, if any) --> to new connections, "sendchallenges" (same for challenges) --> to new connections
 116             }
 117         });
 118         socket.on("close", () => {
 119             delete clients[sid];
 120       // Notify every other connected client
 121       Object.keys(clients).forEach( k => {
 122         clients[k].send(JSON.stringify({code:"disconnect",sid:sid}));
 123       });
 124         });
 125     });
 126 }