/*
    * ====================================================================
    * 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.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org/>.
   *
   */
  package org.apache.hc.core5.http.nio.entity;
  
  import java.io.IOException;
  import java.nio.CharBuffer;
  import java.util.concurrent.atomic.AtomicReference;
  
  import org.apache.hc.core5.http.ContentType;
  import org.apache.hc.core5.http.nio.StreamChannel;
  import org.apache.hc.core5.util.Args;
  import org.apache.hc.core5.util.Asserts;
  
  /**
   * Basic {@link org.apache.hc.core5.http.nio.AsyncDataProducer} implementation that
   * generates data stream from content of a string.
   *
   * @since 5.0
   */
  public class StringAsyncEntityProducer extends AbstractCharAsyncEntityProducer {
  
      private final CharBuffer content;
      private final AtomicReference<Exception> exception;
  
      public StringAsyncEntityProducer(
              final CharSequence content,
              final int bufferSize,
              final int fragmentSizeHint,
              final ContentType contentType) {
          super(bufferSize, fragmentSizeHint, contentType);
          Args.notNull(content, "Content");
          this.content = CharBuffer.wrap(content);
          this.exception = new AtomicReference<>(null);
      }
  
      public StringAsyncEntityProducer(final CharSequence content, final int bufferSize, final ContentType contentType) {
          this(content, bufferSize, -1, contentType);
      }
  
      public StringAsyncEntityProducer(final CharSequence content, final ContentType contentType) {
          this(content, 4096, contentType);
      }
  
      public StringAsyncEntityProducer(final CharSequence content) {
          this(content, ContentType.TEXT_PLAIN);
      }
  
      @Override
      public boolean isRepeatable() {
          return true;
      }
  
      @Override
      protected int availableData() {
          return Integer.MAX_VALUE;
      }
  
      @Override
      protected void produceData(final StreamChannel<CharBuffer> channel) throws IOException {
          Asserts.notNull(channel, "Channel");
          channel.write(content);
          if (!content.hasRemaining()) {
              channel.endStream();
          }
      }
  
      @Override
      public void failed(final Exception cause) {
          if (exception.compareAndSet(null, cause)) {
              releaseResources();
          }
      }
  
      public Exception getException() {
          return exception.get();
     }
 
     @Override
     public void releaseResources() {
         this.content.clear();
         super.releaseResources();
     }
 
 }