/**
 * Try to unlock the door with auth mode
 */

exports.handler = async function(context, event, callback) {
  const response = new Twilio.Response();

  let door = event.door;
  let pin = event.key;

  if (!door || !pin) {
    response.setStatusCode(400);
    return callback(null, response);
  }

  const ddbPath = Runtime.getFunctions()['common/ddb'].path;
  const ddb = require(ddbPath);
  const client = ddb.createDDBClient(context);

  const config = await client.send(ddb.getDoorConfigCommand(door));

  if (!config.Item) {
    response.setStatusCode(404);
    return callback(null, response);
  }

  let correctPin = config.Item.pin.S;

  if (correctPin !== pin) {
    response.setStatusCode(401);
    return callback(null, response);
  }

  const fingerprint = { 
    method: "PIN",
    userAgent: event.request.headers['user-agent'],
    ip: event.ip,
  };

  // take timeout from the query string
  const timeout = event.timeout ? parseInt(event.timeout) : config.Item.timeout.N;

  // check lock status if locked, then unlock. If unlocked then lock
  await client.send(ddb.getLockStatusCommand(door))
    .then(async (lock) => {
      const isOpen = ddb.isLockOpen(lock);

      if (isOpen) {
        const fingerprint = JSON.parse(lock.Item.fingerprint.S);

        response
          .setStatusCode(200)
          .appendHeader('Content-Type', 'application/json')
          .setBody({
            status: "CLOSED",
            fingerprint,
          });

        await client.send(ddb.clearLockStatusCommand(lock));
        return;
      }

      await client.send(ddb.setLockStatusCommand(door, timeout, fingerprint))
        .then(async (item) => {    
          response
            .setStatusCode(200)
            .appendHeader('Content-Type', 'application/json')
            .setBody({ msg: `Opened the door "${door}" for ${timeout}s` });
        }).catch((e) => {
          console.log(e);
          response
            .setStatusCode(500)
            .appendHeader('Content-Type', 'application/json')
            .setBody({ err: e });
        });
    });

  await client.destroy();
  return callback(null, response);
};