package com.tabuleapp.SendGrid;

import javax.mail.Authenticator;
import javax.mail.BodyPart;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.Multipart;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;

import java.io.UnsupportedEncodingException;
import java.util.Properties;

/**
 * Creates an email object for sending via SendGrid.
 * Be sure to update Sendgrid credentials.
 *
 * Usage:
 * 	SGEmail email = new SGEmail();
 * 	email.to("neil@tabuleapp.com, "Neil Gupta");
 * 	email.from("contact@tabuleapp.com", "Tabule");
 * 	email.subject("This is a subject");
 * 	email.text("This is a plain text body.");
 * 	email.html("This is an html body.");
 * 	email.send();
 *
 * @author Neil Gupta. Copyright 2012 Tabule, Inc.
 * @version 1.0
 */
public class SGEmail {

    private static final String SMTP_AUTH_USER = "YOUR SENDGRID USERNAME";
    private static final String SMTP_AUTH_PWD  = "YOUR SENDGRID PASSWORD";
    private static final String SMTP_HOST_NAME = "smtp.sendgrid.net";

    private InternetAddress to;
    private InternetAddress from;
	private String subject;
	private String html;
	private String text;

	public void to(String email, String name) {
		try {
			to = new InternetAddress(email, name);
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
	}

	public void to(String email) {
		try {
			to = new InternetAddress(email);
		} catch (AddressException e) {
			e.printStackTrace();
		}
	}

	public void from(String email, String name) {
		try {
			from = new InternetAddress(email, name);
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
	}

	public void from(String email) {
		try {
			from = new InternetAddress(email);
		} catch (AddressException e) {
			e.printStackTrace();
		}
	}

	public void subject(String subject) {
		this.subject = subject;
	}

	public void html(String html) {
		this.html = html;
	}

	public void text(String text) {
		this.text = text;
	}

	public void send() {
		try {
	        Properties props = new Properties();
	        props.put("mail.transport.protocol", "smtp");
	        props.put("mail.smtp.host", SMTP_HOST_NAME);
	        props.put("mail.smtp.port", 587);
	        props.put("mail.smtp.auth", "true");

	        Authenticator auth = new SMTPAuthenticator();
	        Session mailSession = Session.getInstance(props, auth);
	        Transport transport = mailSession.getTransport();

	        MimeMessage message = new MimeMessage(mailSession);

	        Multipart multipart = new MimeMultipart("alternative");

	        if (text != null) {
		        BodyPart part1 = new MimeBodyPart();
		        part1.setText(text);
		        multipart.addBodyPart(part1);
	        }

	        if (html != null) {
		        BodyPart part2 = new MimeBodyPart();
		        part2.setContent(html, "text/html");
		        multipart.addBodyPart(part2);
	        }

	        message.setContent(multipart);
	        message.setFrom(from);
	        message.setSubject(subject);
	        message.addRecipient(Message.RecipientType.TO, to);

	        transport.connect();
	        transport.sendMessage(message,
	            message.getRecipients(Message.RecipientType.TO));
	        transport.close();
		} catch(MessagingException e) {
			e.printStackTrace();
		}
	}

    private class SMTPAuthenticator extends javax.mail.Authenticator {
        public PasswordAuthentication getPasswordAuthentication() {
           String username = SMTP_AUTH_USER;
           String password = SMTP_AUTH_PWD;
           return new PasswordAuthentication(username, password);
        }
    }
}