/* Gun Multi-WS Monster */
/* Spawn multiple Gun WebSockets from the same HTTP/HTTPS server
 * Each Gun is scoped to its ws.path and intended for ephemeral usage
 * MIT Licensed (C) QXIP 2020
 */

const url = require('url');
var rimraf = require("rimraf");
const Gun = require('gun/gun');
require('./gun-ws.js');
const http = require('http');
const WebSocket = require('ws');
var server = http.createServer();

// LRU with last used sockets
const QuickLRU = require('quick-lru');
var evict = function(key,value){
  console.log('!!!!!!!!!!!!!!! Garbage Collect',key);
  var uuid = value.gun.opt()._.opt.ws.uuid;
  if(uuid) rimraf("/tmp/"+uuid, function () { console.log("Cleaned up ID",uuid); });
}
const lru = new QuickLRU({maxSize: 10, onEviction: evict });

server.on('upgrade', async function (request, socket, head) {
  var pathname = url.parse(request.url).pathname || '/gun';
  console.log('Got WS request',pathname);
  var gun = { gun: false, server: false};
  if (pathname){
      if (lru.has(pathname)){
        // Existing Node
        console.log('Recycle id',pathname);
        gun = await lru.get(pathname);
      } else {
        // Create Node
        console.log('Create id',pathname);
        // NOTE: Only works with lib/ws.js shim allowing a predefined WS as ws.web parameter in Gun constructor
        var uuid = Math.random().toString(36).substring(7);
        gun.server = new WebSocket.Server({ noServer: true, path: pathname});
        console.log('set peer',request.headers.host+pathname);
        gun.gun = new Gun({ 
            peers:[], // should we use self as peer?
            localStorage: false,
            uuid: uuid,
            file: "tmp/"+uuid,
            multicast: false,
            ws: { noServer: true, path: pathname, web: gun.server }, 
            web: gun.server 
        });
        // gun.gun.on("in", function(msg) { console.log('got',msg ) });
        lru.set(pathname,gun);
      }
  }
  if (gun.server){
      // Handle Request
      gun.server.handleUpgrade(request, socket, head, function (ws) {
              console.log('connecting to gun instance', gun.gun.opt()._.opt.ws.path )
              gun.server.emit('connection', ws, request);     
      });
    
  } else {
      socket.destroy();
  }
});

// 
server.listen(3000);