/*******************************************************************************
 * Copyright 2014 Federal Chancellery Austria
 * MOA-ID has been developed in a cooperation between BRZ, the Federal
 * Chancellery Austria - ICT staff unit, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 *******************************************************************************/
package at.gv.egovernment.moa.id.configuration.helper;

import java.io.InputStream;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Properties;

import javax.mail.BodyPart;
import javax.mail.Message;
import javax.mail.MessagingException;
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 org.apache.commons.io.IOUtils;

import at.gv.egiz.eaaf.core.impl.utils.FileUtils;
import at.gv.egovernment.moa.id.commons.db.dao.config.UserDatabase;
import at.gv.egovernment.moa.id.config.webgui.exception.ConfigurationException;
import at.gv.egovernment.moa.id.configuration.Constants;
import at.gv.egovernment.moa.id.configuration.config.ConfigurationProvider;
import at.gv.egovernment.moa.util.MiscUtil;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class MailHelper {

  private static final String PATTERN_GIVENNAME = "#GIVENNAME#";
  private static final String PATTERN_FAMILYNAME = "#FAMILYNAME#";
  private static final String PATTERN_URL = "#MANDATE_SERVICE_LINK#";
  private static final String PATTERN_DATE = "#TODAY_DATE#";
  private static final String PATTERN_OPENOAS = "#NUMBER_OAS#";
  private static final String PATTERN_OPENUSERS = "#NUMBER_USERSS#";
  private static final String PATTERN_OANAME = "#OANAME#";

  public static void sendUserMailAddressVerification(UserDatabase userdb) throws ConfigurationException {

    final ConfigurationProvider config = ConfigurationProvider.getInstance();
    final String templateurl = config.getMailUserAcountVerificationTemplate();

    String template = readTemplateFromURL(templateurl, config.getConfigRootDir());

    if (userdb.isIsMandateUser() != null && userdb.isIsMandateUser()) {
      template = template.replace(PATTERN_GIVENNAME, userdb.getInstitut());
      template = template.replace(PATTERN_FAMILYNAME, "");

    } else {
      template = template.replace(PATTERN_GIVENNAME, userdb.getGivenname());
      template = template.replace(PATTERN_FAMILYNAME, userdb.getFamilyname());
    }

    final SimpleDateFormat dateformat = new SimpleDateFormat("dd.MM.yyyy");
    template = template.replace(PATTERN_DATE, dateformat.format(new Date()));

    String verificationURL = config.getPublicUrlPreFix(null);

    if (!verificationURL.endsWith("/")) {
      verificationURL = verificationURL + "/";
    }

    verificationURL = verificationURL + Constants.SERVLET_ACCOUNTVERIFICATION +
        "?" + Constants.REQUEST_USERREQUESTTOKKEN +
        "=" + userdb.getUserRequestTokken();
    template = template.replace(PATTERN_URL, verificationURL);

    sendMail(config, config.getMailUserAcountVerificationSubject(),
        userdb.getMail(), template);

  }

  public static void sendAdminMail(int numOpenOAs, int numOpenUsers) throws ConfigurationException {
    final ConfigurationProvider config = ConfigurationProvider.getInstance();
    final String templateurl = config.getMailAdminTemplate();

    String template = readTemplateFromURL(templateurl, config.getConfigRootDir());
    template = template.replace(PATTERN_OPENOAS, String.valueOf(numOpenOAs));
    template = template.replace(PATTERN_OPENUSERS, String.valueOf(numOpenUsers));

    final SimpleDateFormat dateformat = new SimpleDateFormat("dd.MM.yyyy");
    template = template.replace(PATTERN_DATE, dateformat.format(new Date()));

    sendMail(config, config.getMailAdminSubject(), config.getMailAdminAddress(), template);

  }

  public static void sendUserAccountActivationMail(String givenname, String familyname, String institut,
      String mailurl) throws ConfigurationException {
    final ConfigurationProvider config = ConfigurationProvider.getInstance();
    final String templateurl = config.getMailUserAcountActivationTemplate();

    String template = readTemplateFromURL(templateurl, config.getConfigRootDir());
    if (MiscUtil.isNotEmpty(institut)) {
      template = template.replace(PATTERN_GIVENNAME, institut);
      template = template.replace(PATTERN_FAMILYNAME, "");

    } else {
      template = template.replace(PATTERN_GIVENNAME, givenname);
      template = template.replace(PATTERN_FAMILYNAME, familyname);
    }

    final SimpleDateFormat dateformat = new SimpleDateFormat("dd.MM.yyyy");
    template = template.replace(PATTERN_DATE, dateformat.format(new Date()));

    String verificationURL = config.getPublicUrlPreFix(null);
    if (!verificationURL.endsWith("/")) {
      verificationURL = verificationURL + "/";
    }

    template = template.replace(PATTERN_URL, verificationURL);

    sendMail(config, config.getMailUserAcountActivationSubject(),
        mailurl, template);
  }

  public static void sendUserOnlineApplicationActivationMail(String givenname, String familyname,
      String institut, String oaname, String mailurl) throws ConfigurationException {
    final ConfigurationProvider config = ConfigurationProvider.getInstance();
    final String templateurl = config.getMailOAActivationTemplate();

    String template = readTemplateFromURL(templateurl, config.getConfigRootDir());
    if (MiscUtil.isNotEmpty(institut)) {
      template = template.replace(PATTERN_GIVENNAME, institut);
      template = template.replace(PATTERN_FAMILYNAME, "");

    } else {
      template = template.replace(PATTERN_GIVENNAME, givenname);
      template = template.replace(PATTERN_FAMILYNAME, familyname);
    }

    template = template.replace(PATTERN_OANAME, oaname);

    final SimpleDateFormat dateformat = new SimpleDateFormat("dd.MM.yyyy");
    template = template.replace(PATTERN_DATE, dateformat.format(new Date()));

    String verificationURL = config.getPublicUrlPreFix(null);
    if (!verificationURL.endsWith("/")) {
      verificationURL = verificationURL + "/";
    }

    template = template.replace(PATTERN_URL, verificationURL);

    sendMail(config, config.getMailOAActivationSubject(),
        mailurl, template);
  }

  public static void sendUserAccountRevocationMail(UserDatabase userdb) throws ConfigurationException {
    final ConfigurationProvider config = ConfigurationProvider.getInstance();
    final String templateurl = config.getMailUserAcountRevocationTemplate();

    String template = readTemplateFromURL(templateurl, config.getConfigRootDir());

    if (userdb.isIsMandateUser() != null && userdb.isIsMandateUser()) {
      template = template.replace(PATTERN_GIVENNAME, userdb.getInstitut());
      template = template.replace(PATTERN_FAMILYNAME, "");

    } else {
      template = template.replace(PATTERN_GIVENNAME, userdb.getGivenname());
      template = template.replace(PATTERN_FAMILYNAME, userdb.getFamilyname());
    }

    final SimpleDateFormat dateformat = new SimpleDateFormat("dd.MM.yyyy");
    template = template.replace(PATTERN_DATE, dateformat.format(new Date()));

    sendMail(config, config.getMailUserAcountActivationSubject(),
        userdb.getMail(), template);
  }

  private static String readTemplateFromURL(String templateurl, String rootDir)
      throws ConfigurationException {
    InputStream input;
    try {

      final URL keystoreURL = new URL(FileUtils.makeAbsoluteURL(templateurl, rootDir));
      input = keystoreURL.openStream();
      final StringWriter writer = new StringWriter();
      IOUtils.copy(input, writer);
      input.close();
      return writer.toString();

    } catch (final Exception e) {
      log.warn("Mailtemplate can not be read from source" + templateurl);
      throw new ConfigurationException("Mailtemplate can not be read from source" + templateurl);

    }
  }

  private static void sendMail(ConfigurationProvider config, String subject, String recipient, String content)
      throws ConfigurationException {
    try {
      log.debug("Sending mail.");
      MiscUtil.assertNotNull(subject, "subject");
      MiscUtil.assertNotNull(recipient, "recipient");
      MiscUtil.assertNotNull(content, "content");

      final Properties props = new Properties();
      props.setProperty("mail.transport.protocol", "smtp");
      props.setProperty("mail.host", config.getSMTPMailHost());
      log.trace("Mail host: " + config.getSMTPMailHost());
      if (config.getSMTPMailPort() != null) {
        log.trace("Mail port: " + config.getSMTPMailPort());
        props.setProperty("mail.port", config.getSMTPMailPort());
      }
      if (config.getSMTPMailUsername() != null) {
        log.trace("Mail user: " + config.getSMTPMailUsername());
        props.setProperty("mail.user", config.getSMTPMailUsername());
      }
      if (config.getSMTPMailPassword() != null) {
        log.trace("Mail password: " + config.getSMTPMailPassword());
        props.setProperty("mail.password", config.getSMTPMailPassword());
      }

      final Session mailSession = Session.getDefaultInstance(props, null);
      final Transport transport = mailSession.getTransport();

      final MimeMessage message = new MimeMessage(mailSession);
      message.setSubject(subject);
      log.trace("Mail from: " + config.getMailFromName() + "/" + config.getMailFromAddress());
      message.setFrom(new InternetAddress(config.getMailFromAddress(), config.getMailFromName()));
      log.trace("Recipient: " + recipient);
      message.addRecipient(Message.RecipientType.TO, new InternetAddress(recipient));

      log.trace("Creating multipart content of mail.");
      final MimeMultipart multipart = new MimeMultipart("related");

      log.trace("Adding first part (html)");
      final BodyPart messageBodyPart = new MimeBodyPart();
      messageBodyPart.setContent(content, "text/html; charset=ISO-8859-15");
      multipart.addBodyPart(messageBodyPart);

//			log.trace("Adding mail images");
//			messageBodyPart = new MimeBodyPart();
//			for (Image image : images) {
//				messageBodyPart.setDataHandler(new DataHandler(image));
//				messageBodyPart.setHeader("Content-ID", "<" + image.getContentId() + ">");
//				multipart.addBodyPart(messageBodyPart);
//			}

      message.setContent(multipart);
      transport.connect();
      log.trace("Sending mail message.");
      transport.sendMessage(message, message.getRecipients(Message.RecipientType.TO));
      log.trace("Successfully sent.");
      transport.close();

    } catch (final MessagingException e) {
      throw new ConfigurationException(e);

    } catch (final UnsupportedEncodingException e) {
      throw new ConfigurationException(e);

    }
  }
}