On the way to multi-tabs support

[vchess.git] / server / sockets.js

const url = require('url');

// Node version in Ubuntu 16.04 does not know about URL class
// NOTE: url is already transformed, without ?xxx=yyy... parts
function getJsonFromUrl(url)
{
  const query = url.substr(2); //starts with "/?"
  let result = {};
  query.split("&").forEach((part) => {
    const item = part.split("=");
    result[item[0]] = decodeURIComponent(item[1]);
  });
  return result;
}

module.exports = function(wss) {
  // Associative array sid --> tmpId --> {socket, page},
  // "page" is either "/" for hall or "/game/some_gid" for Game,
  // tmpId is required if a same user (browser) has different tabs
  let clients = {};
  wss.on("connection", (socket, req) => {
    const query = getJsonFromUrl(req.url);
    const sid = query["sid"];
    const tmpId = query["tmpId"];
    const notifyRoom = (page,code,obj={},excluded=[]) => {
      Object.keys(clients).forEach(k => {
        if (k in excluded)
          return;
        if (k != sid && clients[k].page == page)
        {
          clients[k].sock.send(JSON.stringify(Object.assign(
            {code:code, from:[sid,tmpId]}, obj)));
        }
      });
    };
    const messageListener = (objtxt) => {
      let obj = JSON.parse(objtxt);
      if (!!obj.target && !clients[obj.target])
        return; //receiver not connected, nothing we can do
      switch (obj.code)
      {
        // Wait for "connect" message to notify connection to the room,
        // because if game loading is slow the message listener might
        // not be ready too early.
        case "connect":
        {
          const curPage = clients[sid][tmpId].page;
          notifyRoom(curPage, "connect"); //Hall or Game
          if (curPage.indexOf("/game/") >= 0)
            notifyRoom("/", "gconnect"); //notify main hall
          break;
        }
        case "disconnect":
        {
          const oldPage = obj.page;
          notifyRoom(oldPage, "disconnect"); //Hall or Game
          if (oldPage.indexOf("/game/") >= 0)
            notifyRoom("/", "gdisconnect"); //notify main hall
          break;
        }
        case "pollclients":
        {
          const curPage = clients[sid][tmpId].page;
          let sockIds = {}; //result, object sid ==> [tmpIds]
          Object.keys(clients).forEach(k => {
            Object.keys(clients[k]).forEach(x => {
              if ((k != sid || x != tmpId)
                && clients[k][x].page == curPage)
              {
                if (!sockIds[k])
                  sockIds[k] = [x];
                else
                  sockIds[k].push(x);
              }
            });
          });
          socket.send(JSON.stringify({code:"pollclients", sockIds:sockIds}));
          break;
        }
        case "pollgamers":
        {
          let sockIds = {};
          Object.keys(clients).forEach(k => {
            Object.keys(clients[k]).forEach(x => {
              if ((k != sid || x != tmpId)
                && clients[k][x].page.indexOf("/game/") >= 0)
              {
                if (!sockIds[k])
                  sockIds[k] = [x];
                else
                  sockIds[k].push(x);
              }
            });
          });
          socket.send(JSON.stringify({code:"pollgamers", sockIds:sockIds}));
          break;
        }
        case "askidentity":
        {
          // Identity only depends on sid, so select a tmpId at random
          const tmpIds = Object.keys(clients[obj.target]);
          const tmpId_idx = Math.floor(Math.random() * tmpIds.length);
          clients[obj.target][tmpIds[tmpId_idx]].sock.send(JSON.stringify(
            {code:"askidentity",from:[sid,tmpId]}));
          break;
        }
        case "asklastate":
          clients[obj.target[0]][obj.target[1]].sock.send(JSON.stringify(
            {code:"asklastate",from:[sid,tmpId]}));
          break;
        case "askchallenge":
          clients[obj.target[0]][obj.target[1]].sock.send(JSON.stringify(
            {code:"askchallenge",from:[sid,tmpId]}));
          break;
        case "askgames":
        {
          // Check all clients playing, and send them a "askgame" message
          // game ID --> [ sid1 --> array of tmpIds, sid2 --> array of tmpIds]
          let gameSids = {};
          const regexpGid = /\/[a-zA-Z0-9]+$/;
          Object.keys(clients).forEach(k => {
            Object.keys(clients[k]).forEach(x => {
              if ((k != sid || x != tmpId)
                && clients[k][x].page.indexOf("/game/") >= 0)
            {
              const gid = clients[k][x].page.match(regexpGid)[0];
              if (!gameSids[gid])
                gameSids[gid] = [{k: [x]}];
              else if (k == Object.keys(gameSids[gid][0])[0])
                gameSids[gid][0][k].push(x);
              else if (gameSids[gid].length == 1)
                gameSids[gid].push({k: [x]});
              else
                Object.values(gameSids[gid][1]).push(x);
            }
          });
          // Request only one client out of 2 (TODO: this is a bit heavy)
          // Alt: ask game to all, and filter later?
          Object.keys(gameSids).forEach(gid => {
            const L = gameSids[gid].length;
            const sidIdx = L > 1
              ? Math.floor(Math.random() * Math.floor(L))
              : 0;
            const tmpIdx = Object.values(gameSids[gid][sidIdx]
            const rid = gameSids[gid][sidIdx][tmpIdx];
            clients[sidIdx][tmpIdx].sock.send(JSON.stringify(
              {code:"askgame", from: [sid,tmpId]}));
          });
          break;
        }
        case "askgame":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"askgame", from:sid}));
          break;
        case "askfullgame":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"askfullgame", from:sid}));
          break;
        case "fullgame":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"fullgame", game:obj.game}));
          break;
        case "identity":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"identity",user:obj.user}));
          break;
        case "refusechallenge":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"refusechallenge", cid:obj.cid, from:sid}));
          break;
        case "deletechallenge":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"deletechallenge", cid:obj.cid, from:sid}));
          break;
        case "newgame":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"newgame", gameInfo:obj.gameInfo, cid:obj.cid}));
          break;
        case "challenge":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"challenge", chall:obj.chall, from:sid}));
          break;
        case "game":
          if (!!obj.target)
          {
            clients[obj.target].sock.send(JSON.stringify(
              {code:"game", game:obj.game, from:sid}));
          }
          else
          {
            // Notify all room except opponent and me:
            notifyRoom("/", "game", {game:obj.game}, [obj.oppsid]);
          }
          break;
        case "newchat":
          notifyRoom(clients[sid].page, "newchat", {chat:obj.chat});
          break;
        // TODO: WebRTC instead in this case (most demanding?)
        // --> Or else: at least do a "notifyRoom" (also for draw, resign...)
        case "newmove":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"newmove", move:obj.move}));
          break;
        case "lastate":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"lastate", state:obj.state}));
          break;
        case "resign":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"resign", side:obj.side}));
          break;
        case "abort":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"abort"}));
          break;
        case "drawoffer":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"drawoffer"}));
          break;
        case "draw":
          clients[obj.target].sock.send(JSON.stringify(
            {code:"draw", message:obj.message}));
          break;
      }
    };
    const closeListener = () => {
      delete clients[sid];
    };
    if (!!clients[sid])
    {
      // Turn off old sock through current client:
      clients[sid].sock.send(JSON.stringify({code:"duplicate"}));
    }
    // Potentially replace current connection:
    clients[sid] = {sock: socket, page: query["page"]};
    socket.on("message", messageListener);
    socket.on("close", closeListener);
  });
}