/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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
    *
    *      https://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 org.apache.commons.net.smtp;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.fail;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  import java.text.ParseException;
  import java.text.SimpleDateFormat;
  import java.util.Date;
  import java.util.Locale;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.junit.Before;
  import org.junit.Test;
  
  /**
   * Tests {@link SimpleSMTPHeader}.
   */
  public class SimpleSMTPHeaderTestCase {
  
      private Date beforeDate;
  
      /** Returns the msg without a date. */
      private String checkDate(final String msg) {
          final Pattern pat = Pattern.compile("^(Date: (.+))$", Pattern.MULTILINE);
          final Matcher m = pat.matcher(msg);
          if (m.find()) {
              final String date = m.group(2);
              final String pattern = "EEE, dd MMM yyyy HH:mm:ss Z"; // Fri, 21 Nov 1997 09:55:06 -0600
              final SimpleDateFormat format = new SimpleDateFormat(pattern, Locale.ENGLISH);
              try {
                  final Date sentDate = format.parse(date);
                  // Round to nearest second because the text format does not include ms
                  final long sentSecs = sentDate.getTime() / 1000;
                  final long beforeDateSecs = beforeDate.getTime() / 1000;
                  final Date afterDate = new Date();
                  final long afterDateSecs = afterDate.getTime() / 1000;
                  if (sentSecs < beforeDateSecs) {
                      fail(sentDate + " should be after " + beforeDate);
                  }
                  if (sentSecs > afterDateSecs) {
                      fail(sentDate + " should be before " + afterDate);
                  }
              } catch (final ParseException e) {
                  fail("" + e);
              }
  
              final int start = m.start(1);
              final int end = m.end(1);
              if (start == 0) {
                  return msg.substring(end + 1);
              }
              return msg.substring(0, start) + msg.substring(end + 1);
          }
          fail("Expecting Date header in " + msg);
          return null;
      }
  
      @Before
      public void setUp() {
          beforeDate = new Date();
      }
  
      @Test
      public void testToString() {
          // Note that the DotTerminatedMessageWriter converts LF to CRLF
          final SimpleSMTPHeader header = new SimpleSMTPHeader("from@here.invalid", "to@there.invalid", "Test email");
          assertEquals("From: from@here.invalid\nTo: to@there.invalid\nSubject: Test email\n\n", checkDate(header.toString()));
      }
  
      @Test
      public void testToStringAddHeader() {
          final SimpleSMTPHeader header = new SimpleSMTPHeader("from@here.invalid", null, null);
          assertNotNull(header);
          header.addHeaderField("X-Header1", "value 1");
          header.addHeaderField("X-Header2", "value 2");
          // Note that the DotTerminatedMessageWriter converts LF to CRLF
          assertEquals("X-Header1: value 1\nX-Header2: value 2\nFrom: from@here.invalid\n\n", checkDate(header.toString()));
      }
  
      @Test
     public void testToStringAddHeaderDate() {
         final SimpleSMTPHeader header = new SimpleSMTPHeader("from@here.invalid", null, null);
         assertNotNull(header);
         header.addHeaderField("Date", "dummy date");
         // does not replace the Date field
         assertEquals("Date: dummy date\nFrom: from@here.invalid\n\n", header.toString());
     }
 
     @Test
     public void testToStringNoFrom() {
         assertThrows(IllegalArgumentException.class, () -> new SimpleSMTPHeader(null, null, null));
     }
 
     @Test
     public void testToStringNoSubject() {
         final SimpleSMTPHeader header = new SimpleSMTPHeader("from@here.invalid", "to@there.invalid", null);
         assertNotNull(header);
         // Note that the DotTerminatedMessageWriter converts LF to CRLF
         assertEquals("From: from@here.invalid\nTo: to@there.invalid\n\n", checkDate(header.toString()));
     }
 
     @Test
     public void testToStringNoTo() {
         final SimpleSMTPHeader header = new SimpleSMTPHeader("from@here.invalid", null, null);
         assertNotNull(header);
         // Note that the DotTerminatedMessageWriter converts LF to CRLF
         assertEquals("From: from@here.invalid\n\n", checkDate(header.toString()));
     }
 }