//#region REQUIRE
const path = require('path');
const express = require('express')
//const cookieParser = require('cookie-parser');
const axios = require('axios');
const queryString = require('querystring');
const pg = require('pg');
//#endregion

//#region CONSTANTS
const staticDir = path.join(__dirname, '../public');
const port = 80
const clientId = process.env.CLIENT_ID;
const clientSecret = process.env.CLIENT_SECRET;
const redirectUri = 'https://codefirst.iut.uca.fr/containers/felixmielcarek-bigbrotherwebapp/callback';
const scope = 'user-read-private user-read-email user-library-read user-library-modify';
const { Client } = pg
const client = new Client({
  user: process.env.POSTGRES_USER,
  host: 'felixmielcarek-bigbrotherdb',
  database: process.env.POSTGRES_DATABASE,
  password: process.env.POSTGRES_PASSWORD,
  port: 5432
})
//#endregion

//#region VARIABLES
let state = '';
//#endregion

//#region APP INIT
const app = express()
//app.use(cookieParser());
app.use(express.static(staticDir));
app.get(['/',''], function (req, res) {
  /*req.cookies['account'] == 'true'
    ? res.sendFile(staticDir + '/home.html')
    :*/ res.sendFile(staticDir + '/login.html');
});

app.listen(port, () => {
  console.log(`Big brother is listening on port ${port}`);
})
//#endregion

//#region USER AUTHORIZATION
function generateRandomString(length) {
  const charset = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
  let randomString = '';
  for (let i = 0; i < length; i++) {
    const randomIndex = Math.floor(Math.random() * charset.length);
    randomString += charset[randomIndex];
  }
  return randomString;
}

app.get('/login', function (req, res) {
  state = generateRandomString(16);

  res.redirect('https://accounts.spotify.com/authorize?' +
    queryString.stringify({
      response_type: 'code',
      client_id: clientId,
      scope: scope,
      redirect_uri: redirectUri,
      state: state
    }));
});
//#endregion

//#region ACCESS TOKEN
app.get('/callback', (req, res) => {
  //res.cookie('account', 'true', { maxAge: 360000 });

  const code = req.query.code;
  if(state != req.query.state) {
    console.error("Spotify state error.")
    return
  }

  res.redirect('/');

  var authOptions = {
    url: 'https://accounts.spotify.com/api/token',
    method: 'post',
    data: {
      code: code,
      redirect_uri: redirectUri,
      grant_type: 'authorization_code'
    },
    headers: {
      'content-type': 'application/x-www-form-urlencoded',
      'Authorization': 'Basic ' + (new Buffer.from(clientId + ':' + clientSecret).toString('base64'))
    },
    json: true
  };

  axios(authOptions)
    .then(async response => {
      const accessToken = response.data.access_token
      const refreshToken = response.data.refresh_token

      try {
        const response = await axios.get(`https://api.spotify.com/v1/me`, { headers: { 'Authorization': 'Bearer ' + accessToken, } });
        
        const data = {
          SpotifyId: response.data.id,
          AccessToken: accessToken,
          RefreshToken: refreshToken
        };

        await client.connect()

        const sqlQuery = `
          INSERT INTO public.users (spotifyid,accesstoken,refreshtoken)
          VALUES ($1,$2,$3)
          ON CONFLICT (spotifyid) DO UPDATE SET
          accesstoken = EXCLUDED.accesstoken,
          refreshtoken = EXCLUDED.refreshtoken
        `;
        
        client.query(sqlQuery, [data.SpotifyId, data.AccessToken, data.RefreshToken], (err, res) => {
          if (err) {
            console.error('Error executing query', err);
            return;
          }
          console.log('Data inserted/updated successfully');
          client.end();
        });
      } catch (error) { console.log('Error getting user Spotify id') }
    })
    .catch(error => {
      console.log('Error:', error);
    });
});
//#endregion