/*
 * Copyright 2021 Apollo Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
package com.ctrip.framework.apollo.portal.spi.defaultimpl;

import com.ctrip.framework.apollo.portal.component.config.PortalConfig;
import com.ctrip.framework.apollo.portal.entity.bo.Email;
import com.ctrip.framework.apollo.portal.spi.EmailService;
import com.ctrip.framework.apollo.tracer.Tracer;
import com.sun.mail.smtp.SMTPTransport;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Properties;
import javax.activation.DataHandler;
import javax.activation.DataSource;
import javax.annotation.Resource;
import javax.mail.Message;
import javax.mail.Session;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class DefaultEmailService implements EmailService {

  private final Logger logger = LoggerFactory.getLogger(DefaultEmailService.class);

  @Resource
  private PortalConfig portalConfig;

  @Override
  public void send(Email email) {
    if (!portalConfig.isEmailEnabled()) {
      return;
    }

    SMTPTransport t = null;
    try {
      Properties prop = System.getProperties();
      Session session = Session.getInstance(prop, null);

      Message msg = new MimeMessage(session);
      msg.setFrom(new InternetAddress(email.getSenderEmailAddress()));
      msg.setRecipients(Message.RecipientType.TO, InternetAddress.parse(email.getRecipientsString(), false));
      msg.setSubject(email.getSubject());
      msg.setDataHandler(new DataHandler(new HTMLDataSource(email.getBody())));

      String host = portalConfig.emailConfigHost();
      String user = portalConfig.emailConfigUser();
      String password = portalConfig.emailConfigPassword();

      t = (SMTPTransport) session.getTransport("smtp");
      t.connect(host, user, password);
      msg.saveChanges();
      t.sendMessage(msg, msg.getAllRecipients());
      logger.debug("email response: {}", t.getLastServerResponse());
    } catch (Exception e) {
      logger.error("send email failed.", e);
      Tracer.logError("send email failed.", e);
    } finally {
      if (t != null) {
        try {
          t.close();
        } catch (Exception e) {
          // nothing
        }
      }
    }
  }

  static class HTMLDataSource implements DataSource {

    private String html;

    HTMLDataSource(String htmlString) {
      html = htmlString;
    }

    @Override
    public InputStream getInputStream() throws IOException {
      if (html == null) {
        throw new IOException("html message is null!");
      }
      return new ByteArrayInputStream(html.getBytes());
    }

    @Override
    public OutputStream getOutputStream() throws IOException {
      throw new IOException("This DataHandler cannot write HTML");
    }

    @Override
    public String getContentType() {
      return "text/html";
    }

    @Override
    public String getName() {
      return "HTMLDataSource";
    }
  }
}
