/*
    * 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.eclipse.aether.transport.jetty;
  
  import java.io.EOFException;
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.nio.channels.Channels;
  import java.nio.channels.ReadableByteChannel;
  import java.nio.file.Files;
  import java.nio.file.StandardOpenOption;
  
  import org.eclipse.aether.spi.connector.transport.PutTask;
  import org.eclipse.jetty.client.util.AbstractRequestContent;
  import org.eclipse.jetty.io.ByteBufferPool;
  import org.eclipse.jetty.util.BufferUtil;
  import org.eclipse.jetty.util.Callback;
  import org.eclipse.jetty.util.IO;
  
  class PutTaskRequestContent extends AbstractRequestContent {
      private final PutTask putTask;
      private final int bufferSize;
      private ByteBufferPool bufferPool;
      private boolean useDirectByteBuffers = true;
  
      @SuppressWarnings("checkstyle:MagicNumber")
      PutTaskRequestContent(PutTask putTask) {
          this(putTask, 4096);
      }
  
      PutTaskRequestContent(PutTask putTask, int bufferSize) {
          super("application/octet-stream");
          this.putTask = putTask;
          this.bufferSize = bufferSize;
      }
  
      @Override
      public long getLength() {
          return putTask.getDataLength();
      }
  
      @Override
      public boolean isReproducible() {
          return true;
      }
  
      public ByteBufferPool getByteBufferPool() {
          return bufferPool;
      }
  
      public void setByteBufferPool(ByteBufferPool byteBufferPool) {
          this.bufferPool = byteBufferPool;
      }
  
      public boolean isUseDirectByteBuffers() {
          return useDirectByteBuffers;
      }
  
      public void setUseDirectByteBuffers(boolean useDirectByteBuffers) {
          this.useDirectByteBuffers = useDirectByteBuffers;
      }
  
      @Override
      protected Subscription newSubscription(Consumer consumer, boolean emitInitialContent) {
          return new SubscriptionImpl(consumer, emitInitialContent);
      }
  
      private class SubscriptionImpl extends AbstractSubscription {
          private ReadableByteChannel channel;
          private long readTotal;
  
          private SubscriptionImpl(Consumer consumer, boolean emitInitialContent) {
              super(consumer, emitInitialContent);
          }
  
          @Override
          protected boolean produceContent(Producer producer) throws IOException {
              ByteBuffer buffer;
              boolean last;
              if (channel == null) {
                  if (putTask.getDataPath() != null) {
                      channel = Files.newByteChannel(putTask.getDataPath(), StandardOpenOption.READ);
                  } else {
                     channel = Channels.newChannel(putTask.newInputStream());
                 }
             }
 
             buffer = bufferPool == null
                     ? BufferUtil.allocate(bufferSize, isUseDirectByteBuffers())
                     : bufferPool.acquire(bufferSize, isUseDirectByteBuffers());
 
             BufferUtil.clearToFill(buffer);
             int read = channel.read(buffer);
             BufferUtil.flipToFlush(buffer, 0);
             if (!channel.isOpen() && read < 0) {
                 throw new EOFException("EOF reached for " + putTask);
             }
             if (read > 0) {
                 readTotal += read;
             }
             last = readTotal == getLength();
             if (last) {
                 IO.close(channel);
             }
             return producer.produce(buffer, last, Callback.from(() -> release(buffer)));
         }
 
         private void release(ByteBuffer buffer) {
             if (bufferPool != null) {
                 bufferPool.release(buffer);
             }
         }
 
         @Override
         public void fail(Throwable failure) {
             super.fail(failure);
             IO.close(channel);
         }
     }
 }