//READ, MARKSEEN, DOWNLOAD ATTACHMENT ON MAIL WITH NODEJS
//HOW TO USE
// INSTALL : NODEJS. NPM
// CREATE DIRECTORY AND INSTALL PACKAGE NODEJS
// npm install imap-simple
// npm install simple-excel-to-json
// RUN SCRIPT : node your_script.js

const fs = require('fs')
var imaps = require('imap-simple');
var Parser = require('simple-excel-to-json');
var parser = new Parser.XlsParser()

var config = {
    imap: {
        user: 'account123@gmail.com',
        password: 'xxx',
        host: 'imap.gmail.com',
        port: 993,
        tls: true,
        authTimeout: 3000
    }
};

imaps.connect(config).then(function (connection) {

  connection.openBox('INBOX').then(function () {

    var searchCriteria = ['UNSEEN', ['SUBJECT', 'EMPAS'], ['FROM', 'sender123@gmail.com']];
      var fetchOptions = {
          bodies: ['HEADER'],
          struct: true,
          markSeen: false
        };

      // retrieve only the headers of the messages
      return connection.search(searchCriteria, fetchOptions);
  }).then(function (messages) {

    console.log('messages-----',messages)
      var attachments = [];

      messages.forEach(function (message) {
          var parts = imaps.getParts(message.attributes.struct);
          var x = imaps.getParts(message.parts);
        //   console.log(x)
          attachments = attachments.concat(parts.filter(function (part) {
              return part.disposition && part.disposition.type.toUpperCase() === 'ATTACHMENT';
          }).map(function (part) {
              // retrieve the attachments only of the messages with attachments
              return connection.getPartData(message, part)
              .then(function (partData) {
                  return {
                      filename: part.disposition.params.filename,
                      data: partData
                    };
                });
            }));
        });

			return Promise.all(attachments);
	}).then(function (attachments) {
      var dir = 'files';
      console.log('create directory files')
      if (!fs.existsSync(dir)){
        fs.mkdirSync(dir);
      }
      for (let i = 0; i < attachments.length; i++) {
        const el = attachments[i];
        var chk = el.data

        fs.writeFileSync("files/test.xlsx", chk, function(err) {
          if(err) {
              return console.log(err);
          }
        });

        var doc = parser.parseXls2Json('files/test.xlsx')
        console.log('-----doc----', doc)
      }
      connection.end()
  });
});