const functions = require('firebase-functions');
const admin = require('firebase-admin');
const secret = require('./FirebaseSecret.json');
const express = require('express');
const cors = require('cors');

const authenticator = (req, res, next) => {
  if (req.method === 'OPTIONS') {
    res.status(200).send();
    return next();
  }

  const token = req.headers.authorization.split(' ')[1];
  const reqToken = token.split(':')[0];
  const reqUid = token.split(':')[1];
  admin
    .auth()
    .verifyIdToken(reqToken)
    .then((user) => {
      if (user.uid === reqUid) {
        console.log('Verified Token - UID - ', reqUid);
        if (req.method === 'POST') {
          const bodydata = JSON.parse(req.body);
          bodydata.uid = user.uid;
          req.body = JSON.stringify(bodydata);
        }
        if (req.method === 'GET' || req.method === 'DELETE') {
          req.body = JSON.stringify({ uid: user.uid });
        }
        return next();
      } else {
        return res.status(401).send('Unauthorized');
      }
    })
    .catch((err) => {
      console.log('Failed Auth - ', req.headers.authorization, '\n', err);
      return res.status(500).send(err);
    });
  return null;
};

const createRoom = async (req, res) => {
  const bodydata = JSON.parse(req.body);
  console.log('Requested Create - UID - ', bodydata.uid);
  if (!bodydata.userName) res.status(400).send('Missing user name');
  const roomId = await admin
    .firestore()
    .collection('rooms')
    .add({
      name: bodydata.roomName,
      player: bodydata.player,
      createdAt: new Date().toISOString(),
      updatedAt: new Date().toISOString(),
    })
    .then((ref) => ref.id)
    .catch((err) => {
      console.error(err);
    });
  await admin
    .firestore()
    .collection('rooms')
    .doc(roomId)
    .collection('messages')
    .add({
      uid: '<system>',
      name: '',
      text: `${bodydata.userName} started the party.`,
      time: new Date().toISOString(),
    });
  await admin
    .firestore()
    .collection('rooms')
    .doc(roomId)
    .collection('users')
    .doc(bodydata.uid)
    .set({
      admin: true,
      name: bodydata.userName,
    });
  res.status(201).send({ roomId });
};

const joinRoom = async (req, res) => {
  const bodydata = JSON.parse(req.body);
  console.log('Requested Join - UID - ', bodydata.uid, '\n\tRoom - ', bodydata.roomId);
  const exists = await admin
    .firestore()
    .collection('rooms')
    .doc(bodydata.roomId)
    .get()
    .then((roomSnap) => roomSnap.exists);
  const userExists = await admin
    .firestore()
    .collection('rooms')
    .doc(bodydata.roomId)
    .collection('users')
    .doc(bodydata.uid)
    .get()
    .then((userSnap) => userSnap.exists);
  if (userExists) return res.status(200).send({ roomId: bodydata.roomId });
  if (exists && bodydata.roomId && bodydata.userName) {
    await admin
      .firestore()
      .collection('rooms')
      .doc(bodydata.roomId)
      .collection('messages')
      .add({
        uid: '<system>',
        name: '',
        text: `${bodydata.userName} joined the party.`,
        time: new Date().toISOString(),
      });
    await admin
      .firestore()
      .collection('rooms')
      .doc(bodydata.roomId)
      .collection('users')
      .doc(bodydata.uid)
      .set({
        admin: false,
        name: bodydata.userName,
      });
    await admin.firestore().collection('rooms').doc(bodydata.roomId).update({
      updatedAt: new Date().toISOString(),
    });
    res.status(200).send({ roomId: bodydata.roomId });
  }
  if (!bodydata.userName) res.status(400).send('Missing user name');
  else res.status(404).send('Party Not Found');
};

const sendMessage = async (req, res) => {
  const { name, text, time, uid, roomId } = JSON.parse(req.body);
  await admin
    .firestore()
    .collection('rooms')
    .doc(roomId)
    .collection('messages')
    .add({
      name,
      text,
      time,
      uid,
    })
    .catch((messageErr) => res.status(500).send(messageErr));
  await admin.firestore().collection('rooms').doc(bodydata.roomId).update({
    updatedAt: new Date().toISOString(),
  });
};

const leaveRoom = async (req, res) => {
  console.log('Requested Leave - UID - ', req.params.uid, '\n\tRoom - ', req.params.rid);
  await admin
    .firestore()
    .collection('rooms')
    .doc(req.params.rid)
    .collection('users')
    .doc(req.params.uid)
    .delete()
    .catch((err) => res.status(500).send(err));
  res.status(200).send();
};

const deleteRoom = async (req, res) => {
  console.log('Requested Delete - Room - ', req.params.rid);
  console.log(req.body);
  const isAdmin = await admin
    .firestore()
    .collection('rooms')
    .doc(req.params.rid)
    .collection('users')
    .doc(JSON.parse(req.body).uid)
    .get()
    .then((v) => {
      if (v.exists) {
        return v.data().admin;
      }
      return false;
    });
  if (!isAdmin) {
    console.log('[UNAUTHORIZED] Requested Delete - Room - ', req.params.rid);
    res.status(401).send();
    return;
  }
  await admin
    .firestore()
    .collection('rooms')
    .doc(req.params.rid)
    .collection('messages')
    .listDocuments()
    .then((messages) => messages.forEach((message) => message.delete()))
    .catch((err) => res.status(500).send(err));
  await admin
    .firestore()
    .collection('rooms')
    .doc(req.params.rid)
    .collection('users')
    .listDocuments()
    .then((users) => users.forEach((user) => user.delete()))
    .catch((err) => res.status(500).send(err));
  await admin
    .firestore()
    .collection('rooms')
    .doc(req.params.rid)
    .delete()
    .catch((err) => res.status(500).send(err));
  res.status(200).send();
};

const updatePlayer = async (req, res) => {
  const { player, roomId, uid } = JSON.parse(req.body);
  const userExists = await admin
    .firestore()
    .collection('rooms')
    .doc(roomId)
    .collection('users')
    .doc(uid)
    .get()
    .then((userSnap) => userSnap.exists);
  if (userExists) {
    await admin
      .firestore()
      .collection('rooms')
      .doc(roomId)
      .update({
        player,
      })
      .catch((err) => res.status(500).send(err));
    res.status(200).send();
  } else {
    res.status(401).send('Not in room to sync');
  }
};

const app = express();
app.use(cors({ origin: true }));
app.use(authenticator);

admin.initializeApp({
  credential: admin.credential.cert(secret),
  databaseURL: 'https://watch-party-crx.firebaseio.com',
});

app.post('/create', createRoom);
app.post('/join', joinRoom);
app.post('/message', sendMessage);
app.delete('/leave/:rid/users/:uid', leaveRoom);
app.delete('/delete/:rid', deleteRoom);
app.post('/updatePlayer', updatePlayer);

exports.widgets = functions.https.onRequest(app);