let finalhandler = require('finalhandler');
const async = require('async');
let http = require('http');
let serveStatic = require('serve-static');
const {canonicalHost, defaultHost, dockerHostSwap} = require('../../utils/host');
const opn = require('opn');
require('http-shutdown').extend();

class Server {
  constructor(options) {
    this.buildDir = options.buildDir;
    this.events = options.events;
    this.port = options.port || 8000;
    this.hostname = dockerHostSwap(options.host) || defaultHost;
    this.isFirstStart = true;
    this.opened = false;
  }

  start(callback) {
    if (this.server && this.server.listening) {
      let message = __("a webserver is already running at") + " " +
                      ("http://" + canonicalHost(this.hostname) +
                      ":" + this.port).bold.underline.green;
      return callback(null, message);
    }
    let serve = serveStatic(this.buildDir, {'index': ['index.html', 'index.htm']});

    this.server = http.createServer(function onRequest(req, res) {
      serve(req, res, finalhandler(req, res));
    }).withShutdown();

    const self = this;

    async.waterfall([
      function createPlaceholderPage(next) {
        if (self.isFirstStart) {
          self.isFirstStart = false;
          return self.events.request('embark-building-placeholder', next);
        }
        next();
      },
      function listen(next) {
        self.server.listen(self.port, self.hostname, () => {
          self.port = self.server.address().port;
          next();
        });
      },
      function openBrowser(next) {
        if (!self.opened) {
          self.opened = true;
          const _next = () => { next(); };
          // fail silently, e.g. in a docker container
          return opn(
            `http://${canonicalHost(self.hostname)}:${self.port}`,
            {wait: false}
          ).then(_next, _next);
        }
        next();
      },
      function reportAvailable(next) {
        next(null, __("webserver available at") +
             " " +
             ("http://" + canonicalHost(self.hostname) +
              ":" + self.port).bold.underline.green, self.port);
      }
    ], callback);
  }

  stop(callback) {
    if (!this.server || !this.server.listening) {
      return callback(null, __("no webserver is currently running"));
    }
    this.server.shutdown(function() {
      callback(null, __("Webserver stopped"));
    });
  }

}

module.exports = Server;