'use strict';

module.exports.create = function (deps, conf) {
  var network = deps.PromiseA.promisify(deps.recase.camelCopy(require('network')));
  var loopback = require('./loopback').create(deps, conf);
  var dnsCtrl = require('./dns-ctrl').create(deps, conf);

  var localAddr, gateway;
  var tunnelActive = false;
  async function checkNetworkEnv() {
    // Since we can't detect the OS level events when a user plugs in an ethernet cable to recheck
    // what network environment we are in we check our local network address and the gateway to
    // determine if we need to run the loopback check and router configuration again.
    var gw = await network.getGatewayIpAsync();
    var addr = await network.getPrivateIpAsync();
    if (localAddr === addr && gateway === gw) {
      return;
    }

    localAddr = addr;
    gateway = gw;
    var loopResult = await loopback('seth.daplie.me');
    var notLooped = Object.keys(loopResult.ports).filter(function (port) {
      return !loopResult.ports[port];
    });

    // if (notLooped.length) {
    //   // TODO: try to automatically configure router to forward ports to us.
    // }

    // If we are on a public accress or all ports we are listening on are forwarded to us then
    // we don't need the tunnel and we can set the DNS records for all our domains to our public
    // address. Otherwise we need to use the tunnel to accept traffic.
    if (!notLooped.length) {
      if (tunnelActive) {
        deps.tunnelClients.disconnect();
        tunnelActive = false;
      }
    } else {
      if (!tunnelActive) {
        var session = await getSession();
        await deps.tunnelClients.start(session, conf.dns.domains);
        tunnelActive = true;
      }
    }
  }

  async function getSession() {
    var sessions = await deps.storage.owners.all();
    var session = sessions.filter(function (sess) {
      return sess.token.scp.indexOf('dns') >= 0;
    })[0];

    if (!session) {
      throw new Error('no sessions with DNS grants');
    }

    // The OAUTH3 library stores some things on the root session object that we usually
    // just leave inside the token, but we need to pull those out before we use it here
    session.provider_uri = session.provider_uri || session.token.provider_uri || session.token.iss;
    session.client_uri = session.client_uri || session.token.azp;
    session.scope = session.scope || session.token.scp;
    return session;
  }

  var publicAddress;
  async function recheckPubAddr() {
    if (!conf.ddns.enabled) {
      return;
    }

    await checkNetworkEnv();
    if (tunnelActive) {
      return;
    }
    var session = await getSession();
    var directives = await deps.OAUTH3.discover(session.token.aud);
    var addr = await loopback.checkPublicAddr(directives.api);

    if (publicAddress === addr) {
      return;
    }

    if (conf.debug) {
      console.log('previous public address',publicAddress, 'does not match current public address', addr);
    }

    await dnsCtrl.setDeviceAddress(session, addr, conf.ddns.domains);
    publicAddress = addr;
  }

  recheckPubAddr();
  setInterval(recheckPubAddr, 5*60*1000);

  return {
    loopbackServer:     loopback.server
  , setDeviceAddress:   dnsCtrl.setDeviceAddress
  , getDeviceAddresses: dnsCtrl.getDeviceAddresses
  , recheckPubAddr:     recheckPubAddr
  };
};