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) => {
  res.set('Access-Control-Allow-Origin', ['*']);
  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) res.status(200).send({ roomId: bodydata.roomId });
  else if (!userExists && 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 });
  } else if (!userExists && !bodydata.userName)
    res.status(400).send({ message: 'Missing user name' });
  else res.status(404).send({ message: '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(roomId).update({
    updatedAt: new Date().toISOString(),
  });
  res.status(200).send({ message: 'Sent a message' });
};

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({ message: 'Left the party' });
};

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({ message: 'Not authorized to end this party.' });
    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({ message: 'Ended the party' });
};

const updatePlayer = async (req, res) => {
  const { player, roomId, uid, showChanged, userName } = JSON.parse(req.body);
  const statusString =
    player.status === 'PLAYING'
      ? 'started playing from'
      : player.status === 'PAUSED'
      ? 'paused at'
      : player.status === 'NOT_PLAYING'
      ? 'stopped at'
      : 'is at';
  const timeString =
    player.time > 3600
      ? new Date(player.time * 1000).toISOString().substr(11, 8)
      : new Date(player.time * 1000).toISOString().substr(14, 5);
  const [roomExists, roomData] = await admin
    .firestore()
    .collection('rooms')
    .doc(roomId)
    .get()
    .then((docSnap) => [docSnap.exists, docSnap.data()]);
  if (!roomExists) return res.status(404).send({ message: 'Party not found.' });
  const userExists = await admin
    .firestore()
    .collection('rooms')
    .doc(roomId)
    .collection('users')
    .doc(uid)
    .get()
    .then((userSnap) => userSnap.exists);
  if (userExists) {
    if (showChanged === true) {
      await admin
        .firestore()
        .collection('rooms')
        .doc(roomId)
        .collection('messages')
        .add({
          uid: '<system>',
          name: '',
          text: `${userName} changed show to \n${player.showName}`,
          time: new Date().toISOString(),
        });
    }
    if (roomData.status !== player.status) {
      await admin
        .firestore()
        .collection('rooms')
        .doc(roomId)
        .update({
          player,
        })
        .catch((err) => res.status(500).send(err));
      await admin
        .firestore()
        .collection('rooms')
        .doc(roomId)
        .collection('messages')
        .add({
          uid: '<system>',
          name: '',
          text: `${userName} ${statusString} ${timeString}`,
          time: new Date().toISOString(),
        });
      return res.status(200).send({ message: 'Synced party player' });
    } else {
      return res.status(208).send({ message: 'Player already up to date' });
    }
  } else {
    return 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);