var fs = require('fs');
var readline = require('readline');
var google = require('googleapis');
var googleAuth = require('google-auth-library');

require('dotenv').config()

const PEOPLE_DB = process.env.PEOPLE_DB.split('/')[5];
const PAIRS_LIST = process.env.PAIRS_LIST.split('/')[5];

var SCOPES = ['https://www.googleapis.com/auth/spreadsheets.readonly'];
var TOKEN_DIR = (process.env.HOME || process.env.HOMEPATH ||
    process.env.USERPROFILE) + '/.credentials/';
var TOKEN_PATH = TOKEN_DIR + 'sheets.googleapis.com-nodejs-quickstart.json';

var oauth2Client = null;


function executeAPI(callback){
  fs.readFile('client_secret.json', function processClientSecrets(err, content) {
    console.log("reading client secret");
    if (err) {
      console.log('Error loading client secret file: ' + err);
      return;
    }
    // Authorize a client with the loaded credentials, then call the
    // Google Sheets API.
    return authorize(JSON.parse(content), callback);
  });
}

function authorize(credentials, callback){
    var clientSecret = credentials.installed.client_secret;
    var clientId = credentials.installed.client_id;
    var redirectUrl = credentials.installed.redirect_uris[0];
    var auth = new googleAuth();
    
    oauth2Client = new auth.OAuth2(clientId, clientSecret, redirectUrl);
  
    // Check if we have previously stored a token.
    fs.readFile(TOKEN_PATH, function(err, token) {
      console.log(TOKEN_PATH);
      if (err) {
        getNewToken();
        return callback();
      } else {
        oauth2Client.credentials = JSON.parse(token);
        var resultat = callback();
        console.log("resultat");
        console.log(resultat);
        //return callback();
      }
    });
}

function getNewToken() {
    var authUrl = oauth2Client.generateAuthUrl({
      access_type: 'offline',
      scope: SCOPES
    });
    console.log('Authorize this app by visiting this url: ', authUrl);
    var rl = readline.createInterface({
      input: process.stdin,
      output: process.stdout
    });
    rl.question('Enter the code from that page here: ', function(code) {
      rl.close();
      oauth2Client.getToken(code, function(err, token) {
        if (err) {
          console.log('Error while trying to retrieve access token', err);
          return;
        }
        oauth2Client.credentials = token;
        storeToken(token);
      });
    });
}

function storeToken(token) {
  try {
    fs.mkdirSync(TOKEN_DIR);
  } catch (err) {
    if (err.code != 'EEXIST') {
      throw err;
    }
  }
  console.log(JSON.stringify(token));
  fs.writeFile(TOKEN_PATH, JSON.stringify(token));
  console.log('Token stored to ' + TOKEN_PATH);
}

function getPairs(){
    auth=oauth2Client;
    ranges = ['2017!A:A','2017!B:B']; //get all rows with names
    var sheets = google.sheets('v4');
    sheets.spreadsheets.values.batchGet({
      auth: auth,
      spreadsheetId: PAIRS_LIST,
      ranges: ranges
    }, function(err, result) {
     if(err) {
       // Handle error
       console.log(err);
       return null;
     } else {
       const pairs = [];
       
       for (let i=0;i<result.valueRanges[0].values.length;i++){
         let name1 = result.valueRanges[0].values[i][0];
         if (name1){
          let name2 = result.valueRanges[1].values[i][0];
          pairs.push({name1:name1,name2:name2});
         }
       }
       console.log(pairs);
       return pairs;
     }
    });
}

module.exports = {
  getPairs: function{executeAPI(getPairs(callback));}
}