/*
    * 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 java.io.ByteArrayOutputStream;
  import java.io.IOException;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.io.input.NullInputStream;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link CountingOutputStream}.
   */
  public class CountingOutputStreamTest {
  
      private void assertByteArrayEquals(final String msg, final byte[] array, final int start, final int end) {
          for (int i = start; i < end; i++) {
              assertEquals(array[i], i-start, msg+": array[" + i + "] mismatch");
          }
      }
  
      @Test
      public void testCounting() throws IOException {
          final ByteArrayOutputStream baos = new ByteArrayOutputStream();
          try (CountingOutputStream cos = new CountingOutputStream(baos)) {
  
              for (int i = 0; i < 20; i++) {
                  cos.write(i);
              }
              assertByteArrayEquals("CountingOutputStream.write(int)", baos.toByteArray(), 0, 20);
              assertEquals(cos.getCount(), 20, "CountingOutputStream.getCount()");
  
              final byte[] array = new byte[10];
              for (int i = 20; i < 30; i++) {
                  array[i - 20] = (byte) i;
              }
              cos.write(array);
              assertByteArrayEquals("CountingOutputStream.write(byte[])", baos.toByteArray(), 0, 30);
              assertEquals(cos.getCount(), 30, "CountingOutputStream.getCount()");
  
              for (int i = 25; i < 35; i++) {
                  array[i - 25] = (byte) i;
              }
              cos.write(array, 5, 5);
              assertByteArrayEquals("CountingOutputStream.write(byte[], int, int)", baos.toByteArray(), 0, 35);
              assertEquals(cos.getCount(), 35, "CountingOutputStream.getCount()");
  
              final int count = cos.resetCount();
              assertEquals(count, 35, "CountingOutputStream.resetCount()");
  
              for (int i = 0; i < 10; i++) {
                  cos.write(i);
              }
              assertByteArrayEquals("CountingOutputStream.write(int)", baos.toByteArray(), 35, 45);
              assertEquals(cos.getCount(), 10, "CountingOutputStream.getCount()");
          }
      }
  
      /*
       * Test for files > 2GB in size - see issue IO-84
       */
      @Test
      public void testLargeFiles_IO84() throws Exception {
          final long size = (long) Integer.MAX_VALUE + (long) 1;
  
          final NullInputStream mock = new NullInputStream(size);
          final CountingOutputStream cos = new CountingOutputStream(NullOutputStream.INSTANCE);
  
          // Test integer methods
          IOUtils.copyLarge(mock, cos);
          assertThrows(ArithmeticException.class, () -> cos.getCount());
          assertThrows(ArithmeticException.class, () -> cos.resetCount());
  
          mock.close();
  
          // Test long methods
          IOUtils.copyLarge(mock, cos);
          assertEquals(size, cos.getByteCount(), "getByteCount()");
          assertEquals(size, cos.resetByteCount(), "resetByteCount()");
      }
  
 }