/*
    * 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.io.output;
  
  import java.io.FilterOutputStream;
  import java.io.IOException;
  import java.io.OutputStream;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.io.build.AbstractStreamBuilder;
  
  /**
   * OutputStream which breaks larger output blocks into chunks. Native code may need to copy the input array; if the write buffer is very large this can cause
   * OOME.
   * <p>
   * To build an instance, see {@link Builder}
   * </p>
   *
   * @see Builder
   * @since 2.5
   */
  public class ChunkedOutputStream extends FilterOutputStream {
  
      // @formatter:off
      /**
       * Builds a new {@link UnsynchronizedByteArrayOutputStream}.
       *
       * <p>
       * Using File IO:
       * </p>
       * <pre>{@code
       * ChunkedOutputStream s = ChunkedOutputStream.builder()
       *   .setPath("over/there.out")
       *   .setBufferSize(8192)
       *   .get();
       * }
       * </pre>
       * <p>
       * Using NIO Path:
       * </p>
       * <pre>{@code
       * ChunkedOutputStream s = ChunkedOutputStream.builder()
       *   .setPath("over/there.out")
       *   .setBufferSize(8192)
       *   .get();
       * }
       * </pre>
       *
       * @see #get()
       * @since 2.13.0
       */
      // @formatter:on
      public static class Builder extends AbstractStreamBuilder<ChunkedOutputStream, Builder> {
  
          /**
           * Constructs a new builder of {@link ChunkedOutputStream}.
           */
          public Builder() {
              // empty
          }
  
          /**
           * Builds a new {@link ChunkedOutputStream}.
           * <p>
           * This builder uses the following aspects:
           * </p>
           * <ul>
           * <li>{@link #getOutputStream()} is the target aspect.</li>
           * <li>{@link #getBufferSize()} is used for the chunk size.</li>
           * </ul>
           *
           * @return a new instance.
           * @throws IllegalStateException         if the {@code origin} is {@code null}.
           * @throws UnsupportedOperationException if the origin cannot be converted to an {@link OutputStream}.
           * @throws IOException                   if an I/O error occurs converting to an {@link OutputStream} using {@link #getOutputStream()}.
           * @see #getOutputStream()
           * @see #getBufferSize()
           * @see #getUnchecked()
           */
          @Override
          public ChunkedOutputStream get() throws IOException {
              return new ChunkedOutputStream(this);
          }
  
      }
 
     /**
      * Constructs a new {@link Builder}.
      *
      * @return a new {@link Builder}.
      * @since 2.13.0
      */
     public static Builder builder() {
         return new Builder();
     }
 
     /**
      * The maximum chunk size to us when writing data arrays
      */
     private final int chunkSize;
 
     /**
      * Constructs a new stream that uses the specified chunk size.
      *
      * @param builder holds contruction data.
      * @throws IOException if an I/O error occurs.
      */
     @SuppressWarnings("resource") // caller closes.
     private ChunkedOutputStream(final Builder builder) throws IOException {
         super(builder.getOutputStream());
         final int bufferSize = builder.getBufferSize();
         if (bufferSize <= 0) {
             throw new IllegalArgumentException("chunkSize <= 0");
         }
         this.chunkSize = bufferSize;
     }
 
     /**
      * Constructs a new stream that uses a chunk size of {@link IOUtils#DEFAULT_BUFFER_SIZE}.
      *
      * @param stream the stream to wrap
      * @deprecated Use {@link #builder()}, {@link Builder}, and {@link Builder#get()}
      */
     @Deprecated
     public ChunkedOutputStream(final OutputStream stream) {
         this(stream, IOUtils.DEFAULT_BUFFER_SIZE);
     }
 
     /**
      * Constructs a new stream that uses the specified chunk size.
      *
      * @param stream    the stream to wrap
      * @param chunkSize the chunk size to use; must be a positive number.
      * @throws IllegalArgumentException if the chunk size is &lt;= 0
      * @deprecated Use {@link #builder()}, {@link Builder}, and {@link Builder#get()}
      */
     @Deprecated
     public ChunkedOutputStream(final OutputStream stream, final int chunkSize) {
         super(stream);
         if (chunkSize <= 0) {
             throw new IllegalArgumentException("chunkSize <= 0");
         }
         this.chunkSize = chunkSize;
     }
 
     /* Package-private for testing. */
     int getChunkSize() {
         return chunkSize;
     }
 
     /**
      * Writes the data buffer in chunks to the underlying stream
      *
      * @param data      the data to write
      * @param srcOffset the offset
      * @param length    the length of data to write
      * @throws IOException if an I/O error occurs.
      */
     @Override
     public void write(final byte[] data, final int srcOffset, final int length) throws IOException {
         int bytes = length;
         int dstOffset = srcOffset;
         while (bytes > 0) {
             final int chunk = Math.min(bytes, chunkSize);
             out.write(data, dstOffset, chunk);
             bytes -= chunk;
             dstOffset += chunk;
         }
     }
 
 }