// Copyright 2019 The Nomulus Authors. All Rights Reserved.
//
// 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 google.registry.util;

import static com.google.common.truth.Truth.assertThat;
import static google.registry.testing.JUnitBackports.assertThrows;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.doThrow;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;

import com.google.common.net.MediaType;
import google.registry.testing.FakeClock;
import google.registry.testing.FakeSleeper;
import google.registry.util.EmailMessage.Attachment;
import javax.mail.BodyPart;
import javax.mail.Message;
import javax.mail.Message.RecipientType;
import javax.mail.MessagingException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMultipart;
import org.junit.Rule;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import org.mockito.ArgumentCaptor;
import org.mockito.Captor;
import org.mockito.junit.MockitoJUnit;
import org.mockito.junit.MockitoRule;

/** Unit tests for {@link SendEmailService}. */
@RunWith(JUnit4.class)
public class SendEmailServiceTest {

  @Rule
  public final MockitoRule mocks = MockitoJUnit.rule();

  private final Retrier retrier = new Retrier(new FakeSleeper(new FakeClock()), 2);
  private final TransportEmailSender wrapper = mock(TransportEmailSender.class);
  private final SendEmailService sendEmailService = new SendEmailService(retrier, wrapper);

  @Captor private ArgumentCaptor<Message> messageCaptor;

  @Test
  public void testSuccess_simple() throws Exception {
    EmailMessage content = createBuilder().build();
    sendEmailService.sendEmail(content);
    Message message = getMessage();
    assertThat(message.getAllRecipients())
        .asList()
        .containsExactly(new InternetAddress("fake@example.com"));
    assertThat(message.getFrom())
        .asList()
        .containsExactly(new InternetAddress("registry@example.com"));
    assertThat(message.getRecipients(RecipientType.BCC)).isNull();
    assertThat(message.getSubject()).isEqualTo("Subject");
    assertThat(message.getContentType()).startsWith("multipart/mixed");
    assertThat(getInternalContent(message).getContent().toString()).isEqualTo("body");
    assertThat(getInternalContent(message).getContentType()).isEqualTo("text/plain; charset=utf-8");
    assertThat(((MimeMultipart) message.getContent()).getCount()).isEqualTo(1);
  }

  @Test
  public void testSuccess_bcc() throws Exception {
    EmailMessage content = createBuilder().setBcc(new InternetAddress("bcc@example.com")).build();
    sendEmailService.sendEmail(content);
    Message message = getMessage();
    assertThat(message.getRecipients(RecipientType.BCC))
        .asList()
        .containsExactly(new InternetAddress("bcc@example.com"));
  }

  @Test
  public void testSuccess_contentType() throws Exception {
    EmailMessage content = createBuilder().setContentType(MediaType.HTML_UTF_8).build();
    sendEmailService.sendEmail(content);
    Message message = getMessage();
    assertThat(getInternalContent(message).getContentType())
        .isEqualTo("text/html; charset=utf-8");
  }

  @Test
  public void testSuccess_attachment() throws Exception {
    EmailMessage content =
        createBuilder()
            .setAttachment(
                Attachment.newBuilder()
                    .setFilename("filename")
                    .setContent("foo,bar\nbaz,qux")
                    .setContentType(MediaType.CSV_UTF_8)
                    .build())
            .build();
    sendEmailService.sendEmail(content);
    Message message = getMessage();
    assertThat(((MimeMultipart) message.getContent()).getCount()).isEqualTo(2);
    BodyPart attachment = ((MimeMultipart) message.getContent()).getBodyPart(1);
    assertThat(attachment.getContent()).isEqualTo("foo,bar\nbaz,qux");
    assertThat(attachment.getContentType()).endsWith("name=filename");
  }

  @Test
  public void testSuccess_retry() throws Exception {
    doThrow(new MessagingException("hi"))
        .doNothing()
        .when(wrapper)
        .sendMessage(messageCaptor.capture());
    EmailMessage content = createBuilder().build();
    sendEmailService.sendEmail(content);
    assertThat(messageCaptor.getValue().getSubject()).isEqualTo("Subject");
  }

  @Test
  public void testFailure_wrongExceptionType() throws Exception {
    doThrow(new RuntimeException("this is a runtime exception")).when(wrapper).sendMessage(any());
    EmailMessage content = createBuilder().build();
    RuntimeException thrown =
        assertThrows(RuntimeException.class, () -> sendEmailService.sendEmail(content));
    assertThat(thrown).hasMessageThat().isEqualTo("this is a runtime exception");
  }

  @Test
  public void testFailure_tooManyTries() throws Exception {
    doThrow(new MessagingException("hi"))
        .doThrow(new MessagingException("second"))
        .when(wrapper)
        .sendMessage(any());
    EmailMessage content = createBuilder().build();
    RuntimeException thrown =
        assertThrows(RuntimeException.class, () -> sendEmailService.sendEmail(content));
    assertThat(thrown).hasCauseThat().hasMessageThat().isEqualTo("second");
    assertThat(thrown).hasCauseThat().isInstanceOf(MessagingException.class);
  }

  private EmailMessage.Builder createBuilder() throws Exception {
    return EmailMessage.newBuilder()
        .setFrom(new InternetAddress("registry@example.com"))
        .addRecipient(new InternetAddress("fake@example.com"))
        .setSubject("Subject")
        .setBody("body");
  }

  private Message getMessage() throws MessagingException {
    verify(wrapper).sendMessage(messageCaptor.capture());
    return messageCaptor.getValue();
  }

  private BodyPart getInternalContent(Message message) throws Exception {
    return ((MimeMultipart) message.getContent()).getBodyPart(0);
  }
}