const nodemailer = require ('nodemailer');
const emailConfig = require('../config/email');

module.exports = {
  transformEmailFromAlexaResponse: function (email) {
    //email from alexa response will contain words instead of symbols, like :
    //at = @
    //underscore = _
    //dash = -
    //dot = .
    //TODO: This list should be longer
    let transformedEmail = email
      .replace (/\s/g, '') //remove all spaces
      .replace (/at/gi, '@')
      .replace (/underscore/gi, '_')
      .replace (/dash/gi, '-')
      .replace (/dot/gi, '.');

    return transformedEmail;
  },

  isEmailValid: function (email) {
    console.log ('Email to validate : ' + email);
    let validEmailRegex = /^(([^<>()\[\]\\.,;:\s@"]+(\.[^<>()\[\]\\.,;:\s@"]+)*)|(".+"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;

    return validEmailRegex.test (email);
  },

  sendEmail: function (name, fromEmail, message, toEmail) {
    return new Promise ((resolve, reject) => {
      fromEmail = this.transformEmailFromAlexaResponse(fromEmail);
      let messageBody =
        'Hello. User left you a message on Saburly service using Alexa skill. \r\nMessage : ' +
        message +
        '\r\nName : ' +
        name +
        '\r\nEmail : ' +
        fromEmail +
        '\r\nYour Saburly team';

      let messageBodyHTML =
        '<p>Hello. User left you a message on Saburly service using Alexa skill.</p><br/><b>Message : </b><br/><p>' +
        message +
        '</p><br/><b>Name : </b>' +
        name +
        '<br/><b>Email : </b>' +
        fromEmail +
        '<br/><br/><b>Your Saburly team</b>';

      let transporter = nodemailer.createTransport ({
        host: emailConfig.SMTP_HOST,
        port: emailConfig.PORT,
        secure: emailConfig.SECURE,
        auth: emailConfig.AUTH,
      });

      var mailOptions = {
        from: emailConfig.FROM_EMAIL,
        replyTo: fromEmail,
        to: toEmail,
        subject: emailConfig.SUBJECT,
        text: messageBody,
        html: messageBodyHTML,
      };

      transporter.sendMail (mailOptions, (error, info) => {
        if (error) {
          reject (error);
        } else {
          resolve (info);
        }
      });
    });
  },
};