/*
    * 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.text.lookup;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertNull;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.net.InetAddress;
  import java.net.UnknownHostException;
  
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link DnsStringLookup}.
   */
  class DnsStringLookupTest {
  
      @Test
      void testAddressFromHostAddress() throws UnknownHostException {
          final InetAddress localHost = InetAddress.getLocalHost();
          assertEquals(localHost.getHostAddress(), DnsStringLookup.INSTANCE.apply("address|" + localHost.getHostAddress()));
      }
  
      @Test
      void testAddressFromHostName() throws UnknownHostException {
          final InetAddress localHost = InetAddress.getLocalHost();
          assertEquals(localHost.getHostAddress(), DnsStringLookup.INSTANCE.apply("address|" + localHost.getHostName()));
      }
  
      @Test
      void testCanonicalNameFromHostAddress() throws UnknownHostException {
          final InetAddress localHost = InetAddress.getLocalHost();
          assertEquals(localHost.getCanonicalHostName(), DnsStringLookup.INSTANCE.apply("canonical-name|" + localHost.getHostAddress()));
      }
  
      @Test
      void testCanonicalNameFromHostName() throws UnknownHostException {
          final InetAddress localHost = InetAddress.getLocalHost();
          assertEquals(localHost.getCanonicalHostName(), DnsStringLookup.INSTANCE.apply("canonical-name|" + localHost.getHostName()));
      }
  
      @Test
      void testDelimiterOnlyKey() {
          // A key that is only delimiter/whitespace splits to an empty array; must not throw.
          assertNull(DnsStringLookup.INSTANCE.apply("|"));
          assertNull(DnsStringLookup.INSTANCE.apply("||"));
          assertNull(DnsStringLookup.INSTANCE.apply("  |  "));
      }
  
      @Test
      void testName() throws UnknownHostException {
          final String address = InetAddress.getLocalHost().getHostAddress();
          final InetAddress[] localHostAll = InetAddress.getAllByName(address);
          boolean matched = false;
          for (final InetAddress localHost : localHostAll) {
              if (localHost.getHostName().equals(DnsStringLookup.INSTANCE.apply("name|" + address + ""))) {
                  matched = true;
              }
          }
          assertTrue(matched);
      }
  
      @Test
      void testNull() {
          assertNull(DnsStringLookup.INSTANCE.apply(null));
      }
  
      @Test
      void testToString() {
          // does not blow up and gives some kind of string.
          assertFalse(DnsStringLookup.INSTANCE.toString().isEmpty());
      }
  }