const VoxeetSecret = require('../VoxeetSecret.json');
const admin = require('firebase-admin');
const fetch = require('node-fetch');

module.exports = async (req, res) => {
  const bodyData = JSON.parse(req.body);
  const { key, secret } = VoxeetSecret;
  const credentials = Buffer.from(encodeURI(key) + ':' + encodeURI(secret)).toString('base64');
  const headers = {
    'Content-Type': 'application/json',
    'Cache-Control': 'no-cache',
    Authorization: 'Basic ' + credentials,
  };
  const oauth = await fetch(VoxeetSecret.validateURL, {
    method: 'POST',
    headers,
    body: JSON.stringify({
      grant_type: 'client_credentials',
    }),
  }).then((oauthResponse) => oauthResponse.json())
    .catch((err) => res.status(500).send({err, message: 'Unable to generate token for call'}));

  const [exists, conferencePending, conference, adminOnly, adminUid] = await admin
  .firestore()
  .collection('rooms')
  .doc(req.params.partyName)
  .get()
  .then(snap => {
    const data = snap.exists ? snap.data() : {};
    return [snap.exists, data.conferencePending, data.conference, data.adminOnly, data.adminUid];
  });

  if (exists === true) {
    if (conference === undefined || conference === null) {
      if (conferencePending === undefined || conferencePending === null) {
        if (!adminOnly || (adminOnly && (adminUid === bodyData.uid)) ) {
          await admin
          .firestore()
          .collection('rooms')
          .doc(req.params.partyName)
          .update({
            conferencePending: bodyData.uid
          });
          await admin
            .firestore()
            .collection('rooms')
            .doc(req.params.partyName)
            .collection('messages')
            .add({
              uid: '<system>',
              name: '',
              text: 'A call session is being created (will be available soon).',
              time: new Date(),
          });
        }
      }
    }
    if (oauth) res.status(200).send(oauth);
  } else {
    res.status(400).send({ message: 'Unable to get party for call.' });
  }

  return;
};