sockets.js

   1 const url = require('url');
   2 const sqlite3 = require('sqlite3');
   3 const db = new sqlite3.Database('db/vchess.sqlite');
   4
   5 module.exports = function(wss) {
   6     db.serialize(function() {
   7         db.all("SELECT * FROM Variants", (err,variants) => {
   8             let clients = { "index": {} };
   9             let games = {}; //pending games (player sid)
  10             for (const v of variants)
  11                 clients[v.name] = {};
  12             // No-op function as a callback when sending messages
  13             const noop = () => { };
  14             wss.on("connection", (socket, req) => {
  15                 const params = new URL("http://localhost" + req.url).searchParams;
  16                 const sid = params.get("sid");
  17                 const page = params.get("page");
  18                 // Ignore duplicate connections:
  19                 if (!!clients[page][sid])
  20                 {
  21                     socket.send(JSON.stringify({code:"duplicate"}));
  22                     return;
  23                 }
  24                 clients[page][sid] = socket;
  25                 if (page == "index")
  26                 {
  27                     // Send counting info
  28                     const countings = {};
  29                     for (const v of variants)
  30                         countings[v.name] = Object.keys(clients[v.name]).length;
  31                     socket.send(JSON.stringify({code:"counts",counts:countings}));
  32                 }
  33                 else
  34                 {
  35                     // Send to every client connected on index an update message for counts
  36                     Object.keys(clients["index"]).forEach( k => {
  37                         clients["index"][k].send(
  38                             JSON.stringify({code:"increase",vname:page}), noop);
  39                     });
  40                     // Also notify potential opponents:
  41                     // hit all clients which check if sid corresponds
  42                     Object.keys(clients[page]).forEach( k => {
  43                         clients[page][k].send(JSON.stringify({code:"connect",id:sid}), noop);
  44                     });
  45                     socket.on("message", objtxt => {
  46                         let obj = JSON.parse(objtxt);
  47                         switch (obj.code)
  48                         {
  49                             case "newmove":
  50                                 if (!!clients[page][obj.oppid])
  51                                 {
  52                                     clients[page][obj.oppid].send(
  53                                         JSON.stringify({code:"newmove",move:obj.move}), noop);
  54                                 }
  55                                 break;
  56                             case "ping":
  57                                 if (!!clients[page][obj.oppid])
  58                                     socket.send(JSON.stringify({code:"pong"}));
  59                                 break;
  60                             case "lastate":
  61                                 if (!!clients[page][obj.oppid])
  62                                 {
  63                                     const oppId = obj.oppid;
  64                                     obj.oppid = sid; //I'm oppid for my opponent
  65                                     clients[page][oppId].send(JSON.stringify(obj), noop);
  66                                 }
  67                                 break;
  68                             case "newgame":
  69                                 if (!!games[page])
  70                                 {
  71                                     // Start a new game
  72                                     const oppId = games[page]["id"];
  73                                     const fen = games[page]["fen"];
  74                                     delete games[page];
  75                                     const mycolor = Math.random() < 0.5 ? 'w' : 'b';
  76                                     socket.send(JSON.stringify(
  77                                         {code:"newgame",fen:fen,oppid:oppId,color:mycolor}));
  78                                     if (!!clients[page][oppId])
  79                                     {
  80                                         clients[page][oppId].send(
  81                                             JSON.stringify(
  82                                                 {code:"newgame",fen:fen,oppid:sid,color:mycolor=="w"?"b":"w"}),
  83                                             noop);
  84                                     }
  85                                 }
  86                                 else
  87                                     games[page] = {id:sid, fen:obj.fen}; //wait for opponent
  88                                 break;
  89                             case "cancelnewgame": //if a user cancel his seek
  90                                 delete games[page];
  91                                 break;
  92                             case "resign":
  93                                 if (!!clients[page][obj.oppid])
  94                                     clients[page][obj.oppid].send(JSON.stringify({code:"resign"}), noop);
  95                                 break;
  96                         }
  97                     });
  98                 }
  99                 socket.on("close", () => {
 100                     delete clients[page][sid];
 101                     // Remove potential pending game
 102                     if (!!games[page] && games[page]["id"] == sid)
 103                         delete games[page];
 104                     if (page != "index")
 105                     {
 106                         // Send to every client connected on index an update message for counts
 107                         Object.keys(clients["index"]).forEach( k => {
 108                             clients["index"][k].send(
 109                                 JSON.stringify({code:"decrease",vname:page}), noop);
 110                         });
 111                     }
 112                     // Also notify potential opponents:
 113                     // hit all clients which check if sid corresponds
 114                     Object.keys(clients[page]).forEach( k => {
 115                         clients[page][k].send(JSON.stringify({code:"disconnect",id:sid}), noop);
 116                     });
 117                 });
 118             });
 119         });
 120     });
 121 }