/*
    * 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
    *
    *      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 org.apache.commons.io;
  
  import static org.junit.jupiter.api.Assertions.assertArrayEquals;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.io.IOException;
  import java.io.RandomAccessFile;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.Arrays;
  
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link RandomAccessFiles}.
   */
  public class RandomAccessFilesTest {
  
      private static final String FILE_NAME_RO_20 = "src/test/resources/org/apache/commons/io/test-file-20byteslength.bin";
      private static final String FILE_NAME_RO_0 = "src/test/resources/org/apache/commons/io/test-file-empty.bin";
      private static final String FILE_NAME_RO_0_BIS = "src/test/resources/org/apache/commons/io/test-file-empty2.bin";
  
      @Test
      public void testContentEquals() throws IOException {
          try (RandomAccessFile raf1 = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_20)) {
              assertEquals(raf1, raf1);
              assertTrue(RandomAccessFiles.contentEquals(raf1, raf1));
          }
          // as above, to make sure resources are OK
          try (RandomAccessFile raf1 = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_20)) {
              assertEquals(raf1, raf1);
              assertTrue(RandomAccessFiles.contentEquals(raf1, raf1));
          }
          // same 20 bytes
          try (RandomAccessFile raf1 = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_20);
                  RandomAccessFile raf2 = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_20)) {
              assertTrue(RandomAccessFiles.contentEquals(raf1, raf2));
          }
          // same empty file
          try (RandomAccessFile raf1 = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_0);
                  RandomAccessFile raf2 = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_0)) {
              assertTrue(RandomAccessFiles.contentEquals(raf1, raf2));
              assertTrue(RandomAccessFiles.contentEquals(RandomAccessFiles.reset(raf2), RandomAccessFiles.reset(raf1)));
          }
          // diff empty file
          try (RandomAccessFile raf1 = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_0);
                  RandomAccessFile raf2 = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_0_BIS)) {
              assertTrue(RandomAccessFiles.contentEquals(raf1, raf2));
              assertTrue(RandomAccessFiles.contentEquals(RandomAccessFiles.reset(raf2), RandomAccessFiles.reset(raf1)));
          }
          try (RandomAccessFile raf1 = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_0);
                  RandomAccessFile raf2 = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_20)) {
              assertFalse(RandomAccessFiles.contentEquals(raf1, raf2));
              assertFalse(RandomAccessFiles.contentEquals(RandomAccessFiles.reset(raf2), RandomAccessFiles.reset(raf1)));
          }
          //
          final Path bigFile1 = Files.createTempFile(getClass().getSimpleName(), "-1.bin");
          final Path bigFile2 = Files.createTempFile(getClass().getSimpleName(), "-2.bin");
          final Path bigFile3 = Files.createTempFile(getClass().getSimpleName(), "-3.bin");
          try {
              final int newLength = 1_000_000;
              final byte[] bytes1 = new byte[newLength];
              final byte[] bytes2 = new byte[newLength];
              Arrays.fill(bytes1, (byte) 1);
              Arrays.fill(bytes2, (byte) 2);
              Files.write(bigFile1, bytes1);
              Files.write(bigFile2, bytes2);
              try (RandomAccessFile raf1 = RandomAccessFileMode.READ_ONLY.create(bigFile1);
                      RandomAccessFile raf2 = RandomAccessFileMode.READ_ONLY.create(bigFile2)) {
                  assertFalse(RandomAccessFiles.contentEquals(raf1, raf2));
                  assertFalse(RandomAccessFiles.contentEquals(RandomAccessFiles.reset(raf2), RandomAccessFiles.reset(raf1)));
                  assertTrue(RandomAccessFiles.contentEquals(RandomAccessFiles.reset(raf1), RandomAccessFiles.reset(raf1)));
              }
              // Make the last byte different
              final byte[] bytes3 = bytes1.clone();
              bytes3[bytes3.length - 1] = 9;
              Files.write(bigFile3, bytes3);
              try (RandomAccessFile raf1 = RandomAccessFileMode.READ_ONLY.create(bigFile1);
                      RandomAccessFile raf3 = RandomAccessFileMode.READ_ONLY.create(bigFile3)) {
                 assertFalse(RandomAccessFiles.contentEquals(raf1, raf3));
                 assertFalse(RandomAccessFiles.contentEquals(RandomAccessFiles.reset(raf3), RandomAccessFiles.reset(raf1)));
             }
         } finally {
             // Delete ASAP
             Files.deleteIfExists(bigFile1);
             Files.deleteIfExists(bigFile2);
             Files.deleteIfExists(bigFile3);
         }
     }
 
     @Test
     public void testRead() throws IOException {
         try (final RandomAccessFile raf = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_20)) {
             final byte[] buffer = RandomAccessFiles.read(raf, 0, 0);
             assertArrayEquals(new byte[] {}, buffer);
         }
         try (final RandomAccessFile raf = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_20)) {
             final byte[] buffer = RandomAccessFiles.read(raf, 1, 0);
             assertArrayEquals(new byte[] {}, buffer);
         }
         try (final RandomAccessFile raf = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_20)) {
             final byte[] buffer = RandomAccessFiles.read(raf, 0, 1);
             assertArrayEquals(new byte[] { '1' }, buffer);
         }
         try (final RandomAccessFile raf = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_20)) {
             final byte[] buffer = RandomAccessFiles.read(raf, 1, 1);
             assertArrayEquals(new byte[] { '2' }, buffer);
         }
         try (final RandomAccessFile raf = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_20)) {
             final byte[] buffer = RandomAccessFiles.read(raf, 0, 20);
             assertEquals(20, buffer.length);
         }
         try (final RandomAccessFile raf = RandomAccessFileMode.READ_ONLY.create(FILE_NAME_RO_20)) {
             assertThrows(IOException.class, () -> RandomAccessFiles.read(raf, 0, 21));
         }
     }
 }