package br.net.eds.integracao.mail.util;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import java.util.List;

import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.activation.MimetypesFileTypeMap;

import javax.mail.Address;
import javax.mail.Message;
import javax.mail.Multipart;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.mail.internet.MimeUtility;

public class MailSender {

    /**
     * Envia email
     *
     * @param mailSession javax.mail.Session
     * @param to          destinatários
     * @param subject     assunto
     * @param message     mensagem em formato text/html
     * @param attachments
     *          lista de arquivos em anexo.
     *          Quando um anexo for utilizado no corpo de um email, o mesmo deve ser mencionado da seguinte forma:
     *          <img src="cid:[NOME_DO_ARQUIVO]" />
     * @throws Exception em caso de erro inesperado
     */
    public static void doIt(Session mailSession,
                            String[] to,
                            String subject,
                            String message,
                            List<File> attachments) throws Exception {

        if (mailSession == null) {

            throw new Exception("Erro ao injetar mail session.");
        }

        mailSession.setDebug(true);

        //Objeto que contém a mensagem
        Message msg = null;

        try {
//            final String user = mailSession.getProperty("mail.smtp.user");
//            final String password = mailSession.getProperty("mail.smtp.password");
//
//            mailSession = Session.getInstance(mailSession.getProperties(),
//                new javax.mail.Authenticator(){
//                    protected PasswordAuthentication getPasswordAuthentication() {
//                        // Specify the Username and the PassWord
//                        return new PasswordAuthentication(user, password);
//                    }
//                }
//            );

            msg = new MimeMessage(mailSession);
            msg.setHeader("Content-Type", "text/html; charset=\"UTF-8\"");
            msg.addHeader("Cache-Control", "no-cache");

            /* ************************
             * Informando destinatários
             * ************************/
            Address[] recipients = new InternetAddress[to.length];
            for (int i = 0; i < to.length; i++) {
                recipients[i] = new InternetAddress(to[i]);
            }
            msg.setRecipients(Message.RecipientType.TO, recipients);

            /* ***************************
             * Informando email de origem
             * ***************************/
            msg.setFrom(new InternetAddress(mailSession.getProperty("mail.smtp.user")));

            /* ***************************
             * Informando assunto do email
             * ***************************/
            msg.setSubject(MimeUtility.encodeText(subject, "UTF-8", "B"));

            /* ****************************
             * Preparando corpo da mensagem
             * ****************************/
            MimeBodyPart messageBodyPart = new MimeBodyPart();
            messageBodyPart.setContent(message, "text/html; charset=\"UTF-8\"");

            /* ********************************
             * Adicionando anexos as mensagens
             * ********************************/
            Multipart multipart = new MimeMultipart();
            multipart.addBodyPart(messageBodyPart);


            if (attachments != null) {
                MimetypesFileTypeMap types = new MimetypesFileTypeMap();
                for (int count = 0; count < attachments.size(); count++) {
                    File file = attachments.get(count);

                    String fileName = file.getName();
                    String fileContentType = types.getContentType(file);

                    messageBodyPart = new MimeBodyPart();
                    messageBodyPart.setDataHandler(
                        new DataHandler(
                            new InputStreamDataSource(
                                fileName,
                                fileContentType,
                                new FileInputStream(file)
                            )
                        )
                    );

                    messageBodyPart.setFileName(fileName);
                    messageBodyPart.setHeader("Content-ID", String.format("<%s>", fileName));

                    multipart.addBodyPart(messageBodyPart);
                }
            }
            msg.setContent(multipart);
        } catch (Exception e) {
            throw new Exception("Erro ao completar mensagem.", e);
        }

        // Objeto encarregado de enviar os dados para o email
        try {
            Transport.send(msg, msg.getAllRecipients());
        } catch (Exception e) {
            throw new Exception("Erro ao enviar mensagem.", e);
        }
    }

    /**
     * Envia email
     *
     * @param transport javax.mail.Session
     * @param to          destinatários
     * @param subject     assunto
     * @param message     mensagem em formato text/html
     * @param attachments
     *          lista de arquivos em anexo.
     *          Quando um anexo for utilizado no corpo de um email, o mesmo deve ser mencionado da seguinte forma:
     *          &lt;img src="cid:[NOME_DO_ARQUIVO]" /&gt;
     * @throws Exception em caso de erro inesperado
     */
    public static void doIt(Session mailSession,
                            Transport mainTransport,
                            String[] to,
                            String subject,
                            String message,
                            List<File> attachments) throws Exception {

        //Objeto que contém a mensagem
        Message msg = null;
        try {
            msg = new MimeMessage(mailSession);
            msg.setHeader("Content-Type", "text/html; charset=\"UTF-8\"");
            msg.addHeader("Cache-Control", "no-cache");

            /* ************************
             * Informando destinatários
             * ************************/
            Address[] recipients = new InternetAddress[to.length];
            for (int i = 0; i < to.length; i++) {
                recipients[i] = new InternetAddress(to[i]);
            }
            msg.setRecipients(Message.RecipientType.TO, recipients);

            /* ***************************
             * Informando email de origem
             * ***************************/
            msg.setFrom(new InternetAddress(mailSession.getProperty("mail.smtp.user")));

            /* ***************************
             * Informando assunto do email
             * ***************************/
            msg.setSubject(MimeUtility.encodeText(subject, "UTF-8", "B"));

            /* ****************************
             * Preparando corpo da mensagem
             * ****************************/
            MimeBodyPart messageBodyPart = new MimeBodyPart();
            messageBodyPart.setContent(message, "text/html; charset=\"UTF-8\"");

            /* ********************************
             * Adicionando anexos as mensagens
             * ********************************/
            Multipart multipart = new MimeMultipart();
            multipart.addBodyPart(messageBodyPart);


            if (attachments != null) {
                MimetypesFileTypeMap types = new MimetypesFileTypeMap();
                for (int count = 0; count < attachments.size(); count++) {
                    File file = attachments.get(count);

                    String fileName = file.getName();
                    String fileContentType = types.getContentType(file);

                    messageBodyPart = new MimeBodyPart();
                    messageBodyPart.setDataHandler(
                        new DataHandler(
                            new InputStreamDataSource(
                                fileName,
                                fileContentType,
                                new FileInputStream(file)
                            )
                        )
                    );

                    messageBodyPart.setFileName(fileName);
                    messageBodyPart.setHeader("Content-ID", String.format("<%s>", fileName));

                    multipart.addBodyPart(messageBodyPart);
                }
            }
            msg.setContent(multipart);
            msg.saveChanges();
        } catch (Exception e) {
            throw new Exception("Erro ao completar mensagem.", e);
        }

        // ####################################################
        // OBJETO ENCARREGADO DE ENVIAR OS DADOS PARA O EMAIL #
        // ####################################################
        try {
            mainTransport.sendMessage(msg, msg.getAllRecipients());
        } catch (Exception e) {
            throw new Exception("Erro ao enviar mensagem.", e);
        }
    }

    private static class InputStreamDataSource implements DataSource {

        private String name;
        private String contentType;
        private ByteArrayOutputStream baos;

        @SuppressWarnings("oracle.jdeveloper.java.nested-assignment")
        InputStreamDataSource(String name, String contentType, InputStream inputStream) throws IOException {
            this.name = name;
            this.contentType = contentType;

            baos = new ByteArrayOutputStream();
            int read = 0;
            byte[] buff = new byte[256];
            while ((read = inputStream.read(buff)) != -1) {
                baos.write(buff, 0, read);
            }
            baos.close();
        }

        public String getContentType() {
            return contentType;
        }

        public InputStream getInputStream() throws IOException {
            return new ByteArrayInputStream(baos.toByteArray());
        }

        public String getName() {
            return name;
        }

        public OutputStream getOutputStream() throws IOException {
            throw new IOException("Cannot write to this read-only resource");
        }
    }
}