/*
    * 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.assertArrayEquals;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.io.file.TempFile;
  import org.apache.commons.lang3.ArrayFill;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests {@link ChunkedOutputStream}.
   */
  public class ChunkedOutputStreamTest {
  
      private ByteArrayOutputStream newByteArrayOutputStream(final AtomicInteger numWrites) {
          return new ByteArrayOutputStream() {
              @Override
              public void write(final byte[] b, final int off, final int len) {
                  numWrites.incrementAndGet();
                  super.write(b, off, len);
              }
          };
      }
  
      /**
       * Tests the default chunk size with a ByteArrayOutputStream.
       *
       * @throws IOException
       */
      @Test
      public void testBuildSetByteArrayOutputStream() throws IOException {
          final AtomicInteger numWrites = new AtomicInteger();
          try (ByteArrayOutputStream baos = newByteArrayOutputStream(numWrites);
                  final ChunkedOutputStream chunked = ChunkedOutputStream.builder().setOutputStream(baos).get()) {
              chunked.write(new byte[IOUtils.DEFAULT_BUFFER_SIZE + 1]);
              assertEquals(2, numWrites.get());
          }
          assertThrows(IllegalStateException.class, () -> ChunkedOutputStream.builder().get());
      }
  
      /**
       * Tests the default chunk size with a Path.
       *
       * @throws IOException
       */
      @Test
      public void testBuildSetPath() throws IOException {
          try (TempFile tempFile = TempFile.create("test-", ".txt")) {
              final byte[] fill = ArrayFill.fill(new byte[IOUtils.DEFAULT_BUFFER_SIZE + 1], (byte) 'a');
              final Path tempPath = tempFile.get();
              try (ChunkedOutputStream chunked = ChunkedOutputStream.builder().setPath(tempPath).get()) {
                  chunked.write(fill);
              }
              assertArrayEquals(fill, Files.readAllBytes(tempPath));
          }
      }
  
      @Test
      public void testDefaultConstructor() throws IOException {
          final AtomicInteger numWrites = new AtomicInteger();
          try (ByteArrayOutputStream baos = newByteArrayOutputStream(numWrites);
                  final ChunkedOutputStream chunked = new ChunkedOutputStream(baos)) {
              chunked.write(new byte[IOUtils.DEFAULT_BUFFER_SIZE + 1]);
              assertEquals(2, numWrites.get());
          }
      }
  
      @Test
      public void testNegativeChunkSize() throws IOException {
          assertThrows(IllegalArgumentException.class, () -> new ChunkedOutputStream(new ByteArrayOutputStream(), -1));
          // Builder resets invalid input to the default.
          try (ChunkedOutputStream os = ChunkedOutputStream.builder().setOutputStream(new ByteArrayOutputStream()).setBufferSize(-1).get()) {
              assertEquals(IOUtils.DEFAULT_BUFFER_SIZE, os.getChunkSize());
          }
      }
  
     @Test
     public void testWriteFourChunks() throws Exception {
         final AtomicInteger numWrites = new AtomicInteger();
         try (ByteArrayOutputStream baos = newByteArrayOutputStream(numWrites);
                 final ChunkedOutputStream chunked = new ChunkedOutputStream(baos, 10)) {
             chunked.write("0123456789012345678901234567891".getBytes());
             assertEquals(4, numWrites.get());
         }
     }
 
     @Test
     public void testZeroChunkSize() throws IOException {
         assertThrows(IllegalArgumentException.class, () -> new ChunkedOutputStream(new ByteArrayOutputStream(), 0));
         // Builder resets invalid input to the default.
         try (ChunkedOutputStream os = ChunkedOutputStream.builder().setOutputStream(new ByteArrayOutputStream()).setBufferSize(0).get()) {
             assertEquals(IOUtils.DEFAULT_BUFFER_SIZE, os.getChunkSize());
         }
     }
 
 }