/**
 *  Doorman entrypoint
 */
const fetch = require('node-fetch');

async function getConfig(context, buzzer) {
  return await fetch(context.DOORMAN_URL + `/api/door/info?buzzer=${buzzer}`)
    .then(res => res.json())
    .catch(err => {
      return undefined;
    });
}

function notifyDiscord(context, msg, u, optionalJsonStr) {
  return fetch(context.DOORMAN_URL + 
    `/api/door/notify?discordUser=${u}&msg=${encodeURIComponent(msg)}&json=${encodeURIComponent(optionalJsonStr)}`
  ).catch(err => console.log(err))
}

function notifyAllDiscord(context, config, msg, optionalJsonStr) {
  return Promise.all(config.discordUsers.map((u) => 
    notifyDiscord(context, msg, u, optionalJsonStr)
  ));
}

function doorOpenTwiml(twiml, config) {
  twiml.play('https://buzzer-2439-prod.twil.io/buzzing_up_boosted.mp3');
  twiml.play({ digits: config.pressKey }); // configured in doorman what button to click and passed into this function
  twiml.pause({ length: 1 });
  twiml.hangup();
}

function dialFallbackTwiml(twiml, config) {
  let dial = twiml.dial({
    timeLimit: 20, 
    timeout: 20
  });

  config.fallbackNumbers.forEach(number => {
    dial.number(number);
  });
}

exports.handler = async function(context, event, callback) {
  let twiml = new Twilio.twiml.VoiceResponse();

  let config = event.config;

  // get by api or parse it out from query
  if (!config) {
    config = await getConfig(context, event.From);
  } else {
    try {
      config = JSON.parse(config);
    } catch(e) {
      config = await getConfig(context, event.From);
    }
  }

  // reject the call if this is not configured
  if (!config || !config.door) {
    twiml.reject();
    callback(null, twiml);
    return;
  }

  // TODO: await on this?
  // let users know someone is currently buzzing, and allow unlock by discord user
  let msg = `🔔 Someone is dialing right now @ Door "${config.door}" [Click to unlock](${context.DOORMAN_URL}/api/door/auth?door=${config.door}&key=`;
  let discordNotifs = Promise.all(config.discordUsers.map((u) => 
    notifyDiscord(context, msg + u + ')', u)
  ));

  // poll Doorman, to see if we should unlock
  const interval = setInterval(() => {
    fetch(context.DOORMAN_URL + `/api/door/status?door=${config.door}`)
      .then(async res => {
        if (res.status === 200) {
          clearInterval(interval);
          // put this before awaiting notify
          // so it would be appended above any dial Verb from fallback
          doorOpenTwiml(twiml, config);

          const body = await res.json();
          await notifyAllDiscord(context, config, `🔓 Doorman buzzed someone up @ Door "${config.door}"`, JSON.stringify(body.fingerprint));
          callback(null, twiml);
        }
      })
      .catch(err => console.log(err));
  }, 500);

  // redirect to call after 6s
  setTimeout(async () => {
    dialFallbackTwiml(twiml, config);
    await notifyAllDiscord(
      context, 
      config, 
      `📞 Somebody buzzed the door and it dialed through to fallback phone numbers @ Door "${config.door}"`
    );

    callback(null, twiml);
  }, 6000);
};