/*
    * 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.output;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.mockito.Mockito.mock;
  import static org.mockito.Mockito.verify;
  
  import java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  
  import org.apache.commons.io.test.ThrowOnCloseOutputStream;
  import org.junit.jupiter.api.Test;
  
  /**On
   * Tests {@link TeeOutputStream}.
   */
  public class TeeOutputStreamTest {
  
      private void assertByteArrayEquals(final String msg, final byte[] array1, final byte[] array2) {
          assertEquals(array1.length, array2.length, msg + ": array size mismatch");
          for (int i = 0; i < array1.length; i++) {
              assertEquals(array1[i], array2[i], msg + ": array[ " + i + "] mismatch");
          }
      }
  
      /**
       * Tests that the main {@code OutputStream} is closed when closing the branch {@code OutputStream} throws an
       * exception on {@link TeeOutputStream#close()}.
       */
      @Test
      public void testIOExceptionOnClose() throws IOException {
          final OutputStream badOs = new ThrowOnCloseOutputStream();
          final ByteArrayOutputStream goodOs = mock(ByteArrayOutputStream.class);
          final TeeOutputStream tos = new TeeOutputStream(badOs, goodOs);
  
          assertThrows(IOException.class, tos::close);
          verify(goodOs).close();
      }
  
      /**
       * Tests that the branch {@code OutputStream} is closed when closing the main {@code OutputStream} throws an
       * exception on {@link TeeOutputStream#close()}.
       */
      @Test
      public void testIOExceptionOnCloseBranch() throws IOException {
          final OutputStream badOs = new ThrowOnCloseOutputStream();
          final ByteArrayOutputStream goodOs = mock(ByteArrayOutputStream.class);
          final TeeOutputStream tos = new TeeOutputStream(goodOs, badOs);
  
          assertThrows(IOException.class, tos::close);
          verify(goodOs).close();
      }
  
      @Test
      public void testTee() throws IOException {
          final ByteArrayOutputStream baos1 = new ByteArrayOutputStream();
          final ByteArrayOutputStream baos2 = new ByteArrayOutputStream();
          final ByteArrayOutputStream expected = new ByteArrayOutputStream();
  
          try (TeeOutputStream tos = new TeeOutputStream(baos1, baos2)) {
              for (int i = 0; i < 20; i++) {
                  tos.write(i);
                  expected.write(i);
              }
              assertByteArrayEquals("TeeOutputStream.write(int)", expected.toByteArray(), baos1.toByteArray());
              assertByteArrayEquals("TeeOutputStream.write(int)", expected.toByteArray(), baos2.toByteArray());
  
              final byte[] array = new byte[10];
              for (int i = 20; i < 30; i++) {
                  array[i - 20] = (byte) i;
              }
              tos.write(array);
              expected.write(array);
              assertByteArrayEquals("TeeOutputStream.write(byte[])", expected.toByteArray(), baos1.toByteArray());
              assertByteArrayEquals("TeeOutputStream.write(byte[])", expected.toByteArray(), baos2.toByteArray());
  
              for (int i = 25; i < 35; i++) {
                  array[i - 25] = (byte) i;
              }
              tos.write(array, 5, 5);
              expected.write(array, 5, 5);
              assertByteArrayEquals("TeeOutputStream.write(byte[], int, int)", expected.toByteArray(),
                     baos1.toByteArray());
             assertByteArrayEquals("TeeOutputStream.write(byte[], int, int)", expected.toByteArray(),
                     baos2.toByteArray());
 
             expected.flush();
             expected.close();
 
             tos.flush();
         }
     }
 
 }