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   // or "/mygames" for Mygames page (simpler: no 'people' array).
  25   // tmpId is required if a same user (browser) has different tabs
  26   let clients = {};
  27   let sidToPages = {};
  28   let idToSid = {};
  29   wss.on("connection", (socket, req) => {
  30     const query = getJsonFromUrl(req.url);
  31     const sid = query["sid"];
  32     const id = query["id"];
  33     const tmpId = query["tmpId"];
  34     const page = query["page"];
  35     const notifyRoom = (page,code,obj={}) => {
  36       if (!clients[page]) return;
  37       Object.keys(clients[page]).forEach(k => {
  38         Object.keys(clients[page][k]).forEach(x => {
  39           if (k == sid && x == tmpId) return;
  40           send(
  41             clients[page][k][x].socket,
  42             Object.assign({ code: code, from: sid }, obj)
  43           );
  44         });
  45       });
  46     };
  47     // For focus events: no need to target self
  48     const notifyAllBut = (page,code,obj={},except) => {
  49       if (!clients[page]) return;
  50       Object.keys(clients[page]).forEach(k => {
  51         if (except.includes(k)) return;
  52         Object.keys(clients[page][k]).forEach(x => {
  53           send(
  54             clients[page][k][x].socket,
  55             Object.assign({ code: code, from: sid }, obj)
  56           );
  57         });
  58       });
  59     };
  60     const deleteConnexion = () => {
  61       if (!clients[page] || !clients[page][sid] || !clients[page][sid][tmpId])
  62         return; //job already done
  63       delete clients[page][sid][tmpId];
  64       if (Object.keys(clients[page][sid]).length == 0) {
  65         delete clients[page][sid];
  66         const pgIndex = sidToPages[sid].findIndex(pg => pg == page);
  67         sidToPages[sid].splice(pgIndex, 1);
  68         if (Object.keys(clients[page]).length == 0)
  69           delete clients[page];
  70         // Am I totally offline?
  71         if (sidToPages[sid].length == 0) {
  72           delete sidToPages[sid];
  73           delete idToSid[id];
  74         }
  75       }
  76     };
  77
  78     const doDisconnect = () => {
  79       deleteConnexion();
  80       // Nothing to notify when disconnecting from MyGames page:
  81       if (page != "/mygames" && (!clients[page] || !clients[page][sid])) {
  82         // I effectively disconnected from this page:
  83         notifyRoom(page, "disconnect");
  84         if (page.indexOf("/game/") >= 0)
  85           notifyRoom("/", "gdisconnect", { page:page });
  86       }
  87     };
  88     const messageListener = (objtxt) => {
  89       let obj = JSON.parse(objtxt);
  90       switch (obj.code) {
  91         // Wait for "connect" message to notify connection to the room,
  92         // because if game loading is slow the message listener might
  93         // not be ready too early.
  94         case "connect": {
  95           notifyRoom(page, "connect");
  96           if (page.indexOf("/game/") >= 0)
  97             notifyRoom("/", "gconnect", { page:page });
  98           break;
  99         }
 100         case "disconnect":
 101           // When page changes:
 102           doDisconnect();
 103           break;
 104         case "killme": {
 105           // Self multi-connect: manual removal + disconnect
 106           const doKill = (pg) => {
 107             Object.keys(clients[pg][obj.sid]).forEach(x => {
 108               send(clients[pg][obj.sid][x].socket, { code: "killed" });
 109             });
 110             delete clients[pg][obj.sid];
 111           };
 112           const disconnectFromOtherConnexion = (pg,code,o={}) => {
 113             Object.keys(clients[pg]).forEach(k => {
 114               if (k != obj.sid) {
 115                 Object.keys(clients[pg][k]).forEach(x => {
 116                   send(
 117                     clients[pg][k][x].socket,
 118                     Object.assign({ code: code, from: obj.sid }, o)
 119                   );
 120                 });
 121               }
 122             });
 123           };
 124           Object.keys(clients).forEach(pg => {
 125             if (clients[pg][obj.sid]) {
 126               doKill(pg);
 127               disconnectFromOtherConnexion(pg, "disconnect");
 128               if (pg.indexOf("/game/") >= 0 && clients["/"])
 129                 disconnectFromOtherConnexion("/", "gdisconnect", { page: pg });
 130             }
 131           });
 132           break;
 133         }
 134         case "pollclients": {
 135           // From Hall or Game
 136           let sockIds = [];
 137           Object.keys(clients[page]).forEach(k => {
 138             // Avoid polling myself: no new information to get
 139             if (k != sid) sockIds.push(k);
 140           });
 141           send(socket, { code: "pollclients", sockIds: sockIds });
 142           break;
 143         }
 144         case "pollclientsandgamers": {
 145           // From Hall
 146           let sockIds = [];
 147           Object.keys(clients["/"]).forEach(k => {
 148             // Avoid polling myself: no new information to get
 149             if (k != sid) sockIds.push({sid:k});
 150           });
 151           // NOTE: a "gamer" could also just be an observer
 152           Object.keys(clients).forEach(p => {
 153             if (p.indexOf("/game/") >= 0) {
 154               Object.keys(clients[p]).forEach(k => {
 155                 // 'page' indicator is needed for gamers
 156                 if (k != sid) sockIds.push({ sid:k, page:p });
 157               });
 158             }
 159           });
 160           send(socket, { code: "pollclientsandgamers", sockIds: sockIds });
 161           break;
 162         }
 163
 164         // Asking something: from is fully identified,
 165         // but the requested resource can be from any tmpId (except current!)
 166         case "askidentity":
 167         case "asklastate":
 168         case "askchallenges":
 169         case "askgame":
 170         case "askfullgame": {
 171           const pg = obj.page || page; //required for askidentity and askgame
 172           // In cas askfullgame to wrong SID for example, would crash:
 173           if (!!clients[pg] && !!clients[pg][obj.target]) {
 174             const tmpIds = Object.keys(clients[pg][obj.target]);
 175             if (obj.target == sid) {
 176               // Targetting myself
 177               const idx_myTmpid = tmpIds.findIndex(x => x == tmpId);
 178               if (idx_myTmpid >= 0) tmpIds.splice(idx_myTmpid, 1);
 179             }
 180             const tmpId_idx = Math.floor(Math.random() * tmpIds.length);
 181             send(
 182               clients[pg][obj.target][tmpIds[tmpId_idx]].socket,
 183               { code: obj.code, from: [sid,tmpId,page] }
 184             );
 185           }
 186           break;
 187         }
 188
 189         // Some Hall events: target all tmpId's (except mine),
 190         case "refusechallenge":
 191         case "startgame":
 192           Object.keys(clients[page][obj.target]).forEach(x => {
 193             if (obj.target != sid || x != tmpId)
 194               send(
 195                 clients[page][obj.target][x].socket,
 196                 { code: obj.code, data: obj.data }
 197               );
 198           });
 199           break;
 200
 201         // Notify all room: mostly game events
 202         case "newchat":
 203         case "newchallenge":
 204         case "deletechallenge_s":
 205         case "newgame":
 206         case "resign":
 207         case "abort":
 208         case "drawoffer":
 209         case "rematchoffer":
 210         case "draw":
 211           if (!!obj.oppsid)
 212             // "newgame" message from Hall: do not target players
 213             notifyAllBut(page, "newgame", {data: obj.data}, [sid, obj.oppsid]);
 214           else notifyRoom(page, obj.code, {data: obj.data});
 215           break;
 216
 217         case "rnewgame":
 218           // A rematch game started: players are already informed
 219           notifyAllBut(page, "newgame", {data: obj.data}, [sid]);
 220           notifyAllBut("/", "newgame", {data: obj.data}, [sid, obj.oppsid]);
 221           notifyRoom("/mygames", "newgame", {data: obj.data});
 222           break;
 223
 224         case "newmove": {
 225           const dataWithFrom = { from: [sid,tmpId], data: obj.data };
 226           // Special case re-send newmove only to opponent:
 227           if (!!obj.target && !!clients[page][obj.target]) {
 228             Object.keys(clients[page][obj.target]).forEach(x => {
 229               send(
 230                 clients[page][obj.target][x].socket,
 231                 Object.assign({ code: "newmove" }, dataWithFrom)
 232               );
 233             });
 234           } else {
 235             // NOTE: data.from is useful only to opponent
 236             notifyRoom(page, "newmove", dataWithFrom);
 237           }
 238           break;
 239         }
 240         case "gotmove":
 241           if (
 242             !!clients[page][obj.target[0]] &&
 243             !!clients[page][obj.target[0]][obj.target[1]]
 244           ) {
 245             send(
 246               clients[page][obj.target[0]][obj.target[1]].socket,
 247               { code: "gotmove" }
 248             );
 249           }
 250           break;
 251
 252         case "result":
 253           // Special case: notify all, 'transroom': Game --> Hall
 254           notifyRoom("/", "result", { gid: obj.gid, score: obj.score });
 255           break;
 256
 257         case "mabort": {
 258           const gamePg = "/game/" + obj.gid;
 259           if (!!clients[gamePg] && !!clients[gamePg][obj.target]) {
 260             Object.keys(clients[gamePg][obj.target]).forEach(x => {
 261               send(
 262                 clients[gamePg][obj.target][x].socket,
 263                 { code: "abort" }
 264               );
 265             });
 266           }
 267           break;
 268         }
 269
 270         case "notifyscore":
 271         case "notifyturn":
 272         case "notifynewgame":
 273           if (!!clients["/mygames"]) {
 274             obj.targets.forEach(t => {
 275               const k = t.sid || idToSid[t.uid];
 276               if (!!clients["/mygames"][k]) {
 277                 Object.keys(clients["/mygames"][k]).forEach(x => {
 278                   send(
 279                     clients["/mygames"][k][x].socket,
 280                     { code: obj.code, data: obj.data }
 281                   );
 282                 });
 283               }
 284             });
 285           }
 286           break;
 287
 288         case "getfocus":
 289         case "losefocus":
 290           if (page == "/") notifyAllBut("/", obj.code, { page: "/" }, [sid]);
 291           else {
 292             // Notify game room + Hall:
 293             notifyAllBut(page, obj.code, {}, [sid]);
 294             notifyAllBut("/", obj.code, { page: page }, [sid]);
 295           }
 296           break;
 297
 298         // Passing, relaying something: from isn't needed,
 299         // but target is fully identified (sid + tmpId)
 300         case "challenges":
 301         case "fullgame":
 302         case "game":
 303         case "identity":
 304         case "lastate":
 305         {
 306           const pg = obj.target[2] || page; //required for identity and game
 307           // NOTE: if in game we ask identity to opponent still in Hall,
 308           // but leaving Hall, clients[pg] or clients[pg][target] could be undefined
 309           if (!!clients[pg] && !!clients[pg][obj.target[0]]) {
 310             send(
 311               clients[pg][obj.target[0]][obj.target[1]].socket,
 312               { code:obj.code, data:obj.data }
 313             );
 314           }
 315           break;
 316         }
 317       }
 318     };
 319     const closeListener = () => {
 320       // For browser or tab closing (including page reload):
 321       doDisconnect();
 322     };
 323     // Update clients object: add new connexion
 324     const newElt = { socket: socket, focus: true };
 325     if (!clients[page])
 326       clients[page] = { [sid]: {[tmpId]: newElt } };
 327     else if (!clients[page][sid])
 328       clients[page][sid] = { [tmpId]: newElt };
 329     else
 330       clients[page][sid][tmpId] = newElt;
 331     // Also update helper correspondances
 332     if (!idToSid[id]) idToSid[id] = sid;
 333     if (!sidToPages[sid]) sidToPages[sid] = [];
 334     const pgIndex = sidToPages[sid].findIndex(pg => pg == page);
 335     if (pgIndex === -1) sidToPages[sid].push(page);
 336     socket.on("message", messageListener);
 337     socket.on("close", closeListener);
 338   });
 339 }