server/sockets.js

   1 const url = require('url');
   2
   3 // Node version in Ubuntu 16.04 does not know about URL class
   4 // NOTE: url is already transformed, without ?xxx=yyy... parts
   5 function getJsonFromUrl(url) {
   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 // Helper to safe-send some message through a (web-)socket:
  16 function send(socket, message) {
  17   if (!!socket && socket.readyState == 1)
  18     socket.send(JSON.stringify(message));
  19 }
  20
  21 module.exports = function(wss) {
  22   // Associative array page --> sid --> tmpId --> socket
  23   // "page" is either "/" for hall or "/game/some_gid" for Game,
  24   // tmpId is required if a same user (browser) has different tabs
  25   let clients = {};
  26   wss.on("connection", (socket, req) => {
  27     const query = getJsonFromUrl(req.url);
  28     const sid = query["sid"];
  29     const tmpId = query["tmpId"];
  30     const page = query["page"];
  31     const notifyRoom = (page,code,obj={}) => {
  32       if (!clients[page]) return;
  33       Object.keys(clients[page]).forEach(k => {
  34         Object.keys(clients[page][k]).forEach(x => {
  35           if (k == sid && x == tmpId) return;
  36           send(
  37             clients[page][k][x],
  38             Object.assign({code: code, from: sid}, obj)
  39           );
  40         });
  41       });
  42     };
  43     const deleteConnexion = () => {
  44       if (!clients[page] || !clients[page][sid] || !clients[page][sid][tmpId])
  45         return; //job already done
  46       delete clients[page][sid][tmpId];
  47       if (Object.keys(clients[page][sid]).length == 0) {
  48         delete clients[page][sid];
  49         if (Object.keys(clients[page]).length == 0)
  50           delete clients[page];
  51       }
  52     };
  53
  54     const doDisconnect = () => {
  55       deleteConnexion();
  56       if (!clients[page] || !clients[page][sid]) {
  57         // I effectively disconnected from this page:
  58         notifyRoom(page, "disconnect");
  59         if (page.indexOf("/game/") >= 0)
  60           notifyRoom("/", "gdisconnect", {page:page});
  61       }
  62     };
  63     const messageListener = (objtxt) => {
  64       let obj = JSON.parse(objtxt);
  65       switch (obj.code) {
  66         // Wait for "connect" message to notify connection to the room,
  67         // because if game loading is slow the message listener might
  68         // not be ready too early.
  69         case "connect": {
  70           notifyRoom(page, "connect");
  71           if (page.indexOf("/game/") >= 0)
  72             notifyRoom("/", "gconnect", {page:page});
  73           break;
  74         }
  75         case "disconnect":
  76           // When page changes:
  77           doDisconnect();
  78           break;
  79         case "killme": {
  80           // Self multi-connect: manual removal + disconnect
  81           const doKill = (pg) => {
  82             Object.keys(clients[pg][obj.sid]).forEach(x => {
  83               send(clients[pg][obj.sid][x], {code: "killed"});
  84             });
  85             delete clients[pg][obj.sid];
  86           };
  87           const disconnectFromOtherConnexion = (pg,code,o={}) => {
  88             Object.keys(clients[pg]).forEach(k => {
  89               if (k != obj.sid) {
  90                 Object.keys(clients[pg][k]).forEach(x => {
  91                   send(
  92                     clients[pg][k][x],
  93                     Object.assign({code: code, from: obj.sid}, o)
  94                   );
  95                 });
  96               }
  97             });
  98           };
  99           Object.keys(clients).forEach(pg => {
 100             if (clients[pg][obj.sid]) {
 101               doKill(pg);
 102               disconnectFromOtherConnexion(pg, "disconnect");
 103               if (pg.indexOf("/game/") >= 0 && clients["/"])
 104                 disconnectFromOtherConnexion("/", "gdisconnect", {page: pg});
 105             }
 106           });
 107           break;
 108         }
 109         case "pollclients": {
 110           // From Hall or Game
 111           let sockIds = [];
 112           Object.keys(clients[page]).forEach(k => {
 113             // Avoid polling myself: no new information to get
 114             if (k != sid) sockIds.push(k);
 115           });
 116           send(socket, {code: "pollclients", sockIds: sockIds});
 117           break;
 118         }
 119         case "pollclientsandgamers": {
 120           // From Hall
 121           let sockIds = [];
 122           Object.keys(clients["/"]).forEach(k => {
 123             // Avoid polling myself: no new information to get
 124             if (k != sid) sockIds.push({sid:k});
 125           });
 126           // NOTE: a "gamer" could also just be an observer
 127           Object.keys(clients).forEach(p => {
 128             if (p != "/") {
 129               Object.keys(clients[p]).forEach(k => {
 130                 // 'page' indicator is needed for gamers
 131                 if (k != sid) sockIds.push({sid:k, page:p});
 132               });
 133             }
 134           });
 135           send(socket, {code: "pollclientsandgamers", sockIds: sockIds});
 136           break;
 137         }
 138
 139         // Asking something: from is fully identified,
 140         // but the requested resource can be from any tmpId (except current!)
 141         case "askidentity":
 142         case "asklastate":
 143         case "askchallenge":
 144         case "askgame":
 145         case "askfullgame": {
 146           const pg = obj.page || page; //required for askidentity and askgame
 147           // In cas askfullgame to wrong SID for example, would crash:
 148           if (!!clients[pg] && !!clients[pg][obj.target]) {
 149             const tmpIds = Object.keys(clients[pg][obj.target]);
 150             if (obj.target == sid) {
 151               // Targetting myself
 152               const idx_myTmpid = tmpIds.findIndex(x => x == tmpId);
 153               if (idx_myTmpid >= 0) tmpIds.splice(idx_myTmpid, 1);
 154             }
 155             const tmpId_idx = Math.floor(Math.random() * tmpIds.length);
 156             send(
 157               clients[pg][obj.target][tmpIds[tmpId_idx]],
 158               {code: obj.code, from: [sid,tmpId,page]}
 159             );
 160           }
 161           break;
 162         }
 163
 164         // Some Hall events: target all tmpId's (except mine),
 165         case "refusechallenge":
 166         case "startgame":
 167           Object.keys(clients[page][obj.target]).forEach(x => {
 168             if (obj.target != sid || x != tmpId)
 169               send(
 170                 clients[page][obj.target][x],
 171                 {code: obj.code, data: obj.data}
 172               );
 173           });
 174           break;
 175
 176         // Notify all room: mostly game events
 177         case "newchat":
 178         case "newchallenge":
 179         case "newgame":
 180         case "deletechallenge":
 181         case "newmove":
 182         case "resign":
 183         case "abort":
 184         case "drawoffer":
 185         case "draw":
 186           // TODO: if newmove, change "from" field to fully specified sid + tmpId
 187           // ==> allow "gotmove" messages to be fully targetted
 188           // Special case re-send newmove only to opponent:
 189           if (!!obj.target) {
 190             Object.keys(clients[page][obj.target]).forEach(x => {
 191               send(
 192                 clients[page][obj.target][x],
 193                 {code: "newmove", data: obj.data}
 194               );
 195             });
 196           }
 197           else notifyRoom(page, obj.code, {data: obj.data});
 198           break;
 199
 200         case "gotmove":
 201           // TODO: should fully specify the target and be included in the last case below
 202           if (!!clients[page][obj.target]) {
 203             Object.keys(clients[page][obj.target]).forEach(x => {
 204               send(
 205                 clients[pg][obj.target][x],
 206                 {code: "gotmove", data: obj.data}
 207               );
 208             });
 209           }
 210           break;
 211
 212         case "result":
 213           // Special case: notify all, 'transroom': Game --> Hall
 214           notifyRoom("/", "result", {gid: obj.gid, score: obj.score});
 215           break;
 216
 217         case "mconnect":
 218           // Special case: notify some game rooms that
 219           // I'm watching game state from MyGames
 220           // TODO: this code is ignored for now
 221           obj.gids.forEach(gid => {
 222             const pg = "/game/" + gid;
 223             Object.keys(clients[pg]).forEach(s => {
 224               Object.keys(clients[pg][s]).forEach(x => {
 225                 send(
 226                   clients[pg][s][x],
 227                   {code: "mconnect", data: obj.data}
 228                 );
 229               });
 230             });
 231           });
 232           break;
 233         case "mdisconnect":
 234           // TODO
 235           // Also TODO: pass newgame to MyGames, and gameover (result)
 236           break;
 237
 238         // Passing, relaying something: from isn't needed,
 239         // but target is fully identified (sid + tmpId)
 240         case "challenge":
 241         case "fullgame":
 242         case "game":
 243         case "identity":
 244         case "lastate":
 245         {
 246           const pg = obj.target[2] || page; //required for identity and game
 247           // NOTE: if in game we ask identity to opponent still in Hall,
 248           // but leaving Hall, clients[pg] or clients[pg][target] could be undefined
 249           if (!!clients[pg] && !!clients[pg][obj.target[0]])
 250             send(clients[pg][obj.target[0]][obj.target[1]], {code:obj.code, data:obj.data});
 251           break;
 252         }
 253       }
 254     };
 255     const closeListener = () => {
 256       // For browser or tab closing (including page reload):
 257       doDisconnect();
 258     };
 259     // Update clients object: add new connexion
 260     if (!clients[page])
 261       clients[page] = {[sid]: {[tmpId]: socket}};
 262     else if (!clients[page][sid])
 263       clients[page][sid] = {[tmpId]: socket};
 264     else
 265       clients[page][sid][tmpId] = socket;
 266     socket.on("message", messageListener);
 267     socket.on("close", closeListener);
 268   });
 269 }