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, curPath}
  33     let pages = {}; //associative array path --> array of client sid
  34     // No-op function as a callback when sending messages
  35     const noop = () => { };
  36     wss.on("connection", (socket, req) => {
  37         const query = getJsonFromUrl(req.url);
  38         const sid = query["sid"];
  39         // Ignore duplicate connections (on the same live game that we play):
  40         if (!!clients[sid])
  41             return socket.send(JSON.stringify({code:"duplicate"}));
  42         // We don't know yet on which page the user will be
  43         clients[sid] = {socket: socket, path: ""};
  44
  45         socket.on("message", objtxt => {
  46             let obj = JSON.parse(objtxt);
  47             switch (obj.code)
  48             {
  49                 case "enter":
  50                     if (clients[sid].path.length > 0)
  51                         remInArray(pages[clients[sid].path], sid);
  52                     clients[sid].path = obj.path;
  53                     pages[obj.path].push(sid);
  54                     // TODO also: notify "old" sub-room that I left (if it was not index)
  55                     if (obj.path == "/")
  56                     {
  57                         // Send counting info
  58                         let countings = {};
  59                         Object.keys(pages).forEach(
  60                             path => { countings[path] = pages[path].length; });
  61                         socket.send(JSON.stringify({code:"counts",counts:countings}));
  62                     }
  63                     else
  64                     {
  65                         // Send to every client connected on index an update message for counts
  66                         pages["/"].forEach((id) => {
  67                             clients[id].socket.send(
  68                                 JSON.stringify({code:"increase",path:obj.path}), noop);
  69                         });
  70                         // TODO: do not notify anything in rules and problems sections (no socket required)
  71                         // --> in fact only /Atomic (main hall) and inside a game: /Atomic/392f3ju
  72                         // Also notify the (sub-)room (including potential opponents):
  73                         Object.keys(clients[page]).forEach( k => {
  74                             clients[page][k].send(JSON.stringify({code:"connect",id:sid}), noop);
  75                         });
  76                         // Finally, receive (sub-)room composition
  77                         // TODO.
  78                     }
  79 // NOTE: no "leave" counterpart (because it's always to enter somewhere else)
  80 //              case "leave":
  81 //                  break;
  82                 // Transmit chats and moves to current room
  83                 // TODO: WebRTC instead in this case (most demanding?)
  84                 case "newchat":
  85                     if (!!clients[page][obj.oppid])
  86                     {
  87                         clients[page][obj.oppid].send(
  88                             JSON.stringify({code:"newchat",msg:obj.msg}), noop);
  89                     }
  90                     break;
  91                 case "newmove":
  92                     if (!!clients[page][obj.oppid])
  93                     {
  94                         clients[page][obj.oppid].send(
  95                             JSON.stringify({code:"newmove",move:obj.move}), noop);
  96                     }
  97                     break;
  98
  99
 100                 // TODO: generalize that for several opponents
 101                 case "ping":
 102                     if (!!clients[page][obj.oppid])
 103                         socket.send(JSON.stringify({code:"pong",gameId:obj.gameId}));
 104                     break;
 105                 case "lastate":
 106                     if (!!clients[page][obj.oppid])
 107                     {
 108                         const oppId = obj.oppid;
 109                         obj.oppid = sid; //I'm oppid for my opponent
 110                         clients[page][oppId].send(JSON.stringify(obj), noop);
 111                     }
 112                     break;
 113                 // TODO: moreover, here, game info should be sent (through challenge; not stored here)
 114                 case "newgame":
 115                     if (!!games[page])
 116                     {
 117                         // Start a new game
 118                         const oppId = games[page]["id"];
 119                         const fen = games[page]["fen"];
 120                         const gameId = games[page]["gameid"];
 121                         delete games[page];
 122                         const mycolor = (Math.random() < 0.5 ? 'w' : 'b');
 123                         socket.send(JSON.stringify(
 124                             {code:"newgame",fen:fen,oppid:oppId,color:mycolor,gameid:gameId}));
 125                         if (!!clients[page][oppId])
 126                         {
 127                             clients[page][oppId].send(
 128                                 JSON.stringify(
 129                                     {code:"newgame",fen:fen,oppid:sid,color:mycolor=="w"?"b":"w",gameid:gameId}),
 130                                 noop);
 131                         }
 132                     }
 133                     else
 134                         games[page] = {id:sid, fen:obj.fen, gameid:obj.gameid}; //wait for opponent
 135                     break;
 136                 case "cancelnewgame": //if a user cancel his seek
 137                     // TODO: just transmit event
 138                     //delete games[page];
 139                     break;
 140                 // TODO: also other challenge events
 141                 case "resign":
 142                     if (!!clients[page][obj.oppid])
 143                         clients[page][obj.oppid].send(JSON.stringify({code:"resign"}), noop);
 144                     break;
 145                 // TODO: case "challenge" (get ID) --> send to all, "acceptchallenge" (with ID) --> send to all, "cancelchallenge" --> send to all
 146                 // also, "sendgame" (give current game info, if any) --> to new connections, "sendchallenges" (same for challenges) --> to new connections
 147             }
 148         });
 149         socket.on("close", () => {
 150             delete clients[sid];
 151             // TODO: carefully delete pages[.........]
 152             // + adapt below:
 153             if (page != "/")
 154             {
 155                 // Send to every client connected on index an update message for counts
 156                 Object.keys(clients["index"]).forEach( k => {
 157                     clients["index"][k].send(
 158                         JSON.stringify({code:"decrease",vid:page}), noop);
 159                 });
 160             }
 161             // Also notify potential opponents:
 162             // hit all clients which check if sid corresponds
 163             Object.keys(clients[page]).forEach( k => {
 164                 clients[page][k].send(JSON.stringify({code:"disconnect",id:sid}), noop);
 165             });
 166         });
 167     });
 168 }