Saving state

[vchess.git] / server / sockets.js

const url = require('url');

// Node version in Ubuntu 16.04 does not know about URL class
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;
}

// Removal in array of strings (socket IDs)
function remInArray(arr, item)
{
	const idx = arr.indexOf(item);
	if (idx >= 0)
		arr.splice(idx, 1);
}

// TODO: empêcher multi-log du même user (envoyer le user ID + secret en même temps que name et...)
// --> si secret ne matche pas celui trouvé en DB, stop
// TODO: this file "in the end" would be much simpler, essentially just tracking connect/disconnect
// (everything else using WebRTC)
// TODO: lorsque challenge accepté, seul le dernier joueur à accepter envoi message "please start game"
// avec les coordonnées des participants. Le serveur renvoit alors les détails de la partie (couleurs, position)
//TODO: programmatic re-navigation on current game if we receive a move and are not there

module.exports = function(wss) {
	let clients = {}; //associative array sid --> socket
	wss.on("connection", (socket, req) => {
		const query = getJsonFromUrl(req.url);
		const sid = query["sid"];
    // Ignore duplicate connections (on the same live game that we play):
		if (!!clients[sid])
			return socket.send(JSON.stringify({code:"duplicate"}));
		clients[sid] = socket;
		// Notify room:
    Object.keys(clients).forEach(k => {
      if (k != sid)
        clients[k].send(JSON.stringify({code:"connect",sid:sid}));
    });
    socket.on("message", objtxt => {
			let obj = JSON.parse(objtxt);
      if (!!obj.target && !clients[obj.target])
        return; //receiver not connected, nothing we can do
      //console.log(obj.code);
			switch (obj.code)
			{
        case "pollclients":
          socket.send(JSON.stringify({code:"pollclients",
            sockIds:Object.keys(clients).filter(k => k != sid)}));
          break;
        case "askidentity":
          clients[obj.target].send(
            JSON.stringify({code:"askidentity",from:sid}));
          break;
        case "askchallenge":
          clients[obj.target].send(
            JSON.stringify({code:"askchallenge",from:sid}));
          break;
        case "askgame":
          clients[obj.target].send(
            JSON.stringify({code:"askgame",from:sid}));
          break;
        case "identity":
          clients[obj.target].send(
            JSON.stringify({code:"identity",user:obj.user}));
          break;
        case "challenge":
          // Relay challenge to other player
          clients[obj.target].send(
            JSON.stringify({code:"challenge", chall:obj.chall, from:sid}));
          break;
        case "acceptchallenge":
          clients[obj.target].send(
            JSON.stringify({code:"acceptchallenge", cid:obj.cid, from:sid}));
          break;
        case "withdrawchallenge":
          clients[obj.target].send(
            JSON.stringify({code:"withdrawchallenge", cid:obj.cid, from:sid}));
          break;
        case "newgame":
          clients[obj.target].send(JSON.stringify(
            {code:"newgame", gameInfo:obj.gameInfo}));
          break;
        case "game":
          // TODO: relay (live) game to other player
          break;
				case "newchat":
          clients[obj.target].send(JSON.stringify({code:"newchat",msg:obj.msg}));
					break;
				// Transmit chats and moves to current room
				// TODO: WebRTC instead in this case (most demanding?)
				case "newmove":
          clients[obj.target].send(JSON.stringify({code:"newmove",move:obj.move}));
					break;
				// TODO: generalize that for several opponents
				case "ping":
					socket.send(JSON.stringify({code:"pong",gameId:obj.gameId}));
					break;
				case "lastate":
          const oppId = obj.target;
          obj.oppid = sid; //I'm the opponent of my opponent(s)
          clients[oppId].send(JSON.stringify(obj));
					break;
				// TODO: moreover, here, game info should be sent (through challenge; not stored here)
				// TODO: also other challenge events
				case "resign":
          clients[obj.target].send(JSON.stringify({code:"resign"}));
					break;
				// TODO: case "challenge" (get ID) --> send to all, "acceptchallenge" (with ID) --> send to all, "cancelchallenge" --> send to all
				// also, "sendgame" (give current game info, if any) --> to new connections, "sendchallenges" (same for challenges) --> to new connections
			}
		});
		socket.on("close", () => {
			delete clients[sid];
      // Notify every other connected client
      Object.keys(clients).forEach( k => {
        clients[k].send(JSON.stringify({code:"disconnect",sid:sid}));
      });
		});
	});
}