/*
    * ====================================================================
    * 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.reactive;
  
  import org.apache.hc.core5.annotation.Contract;
  import org.apache.hc.core5.annotation.ThreadingBehavior;
  import org.apache.hc.core5.http.ContentType;
  import org.apache.hc.core5.http.nio.AsyncEntityProducer;
  import org.apache.hc.core5.http.nio.DataStreamChannel;
  import org.reactivestreams.Publisher;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  import java.util.Collections;
  import java.util.Objects;
  import java.util.Set;
  
  /**
   * An {@link AsyncEntityProducer} that subscribes to a {@code Publisher}
   * instance, as defined by the Reactive Streams specification.
   *
   * @since 5.0
   */
  @Contract(threading = ThreadingBehavior.SAFE)
  public final class ReactiveEntityProducer implements AsyncEntityProducer {
  
      private final ReactiveDataProducer reactiveDataProducer;
  
      private final long contentLength;
      private final ContentType contentType;
      private final String contentEncoding;
  
      /**
       * Creates a new {@code ReactiveEntityProducer} with the given parameters.
       *
       * @param publisher the publisher of the entity stream.
       * @param contentLength the length of the entity, or -1 if unknown (implies chunked encoding).
       * @param contentType the {@code Content-Type} of the entity, or null if none.
       * @param contentEncoding the {@code Content-Encoding} of the entity, or null if none.
       */
      public ReactiveEntityProducer(
          final Publisher<ByteBuffer> publisher,
          final long contentLength,
          final ContentType contentType,
          final String contentEncoding
      ) {
          this.reactiveDataProducer = new ReactiveDataProducer(publisher);
          this.contentLength = contentLength;
          this.contentType = contentType;
          this.contentEncoding = contentEncoding;
      }
  
      @Override
      public int available() {
          return reactiveDataProducer.available();
      }
  
      @Override
      public void produce(final DataStreamChannel channel) throws IOException {
          reactiveDataProducer.produce(channel);
      }
  
      @Override
      public void releaseResources() {
          reactiveDataProducer.releaseResources();
      }
  
      @Override
      public boolean isRepeatable() {
          return false;
      }
  
      @Override
      public void failed(final Exception cause) {
          releaseResources();
     }
 
     @Override
     public long getContentLength() {
         return contentLength;
     }
 
     @Override
     public String getContentType() {
         return Objects.toString(contentType, null);
     }
 
     @Override
     public String getContentEncoding() {
         return contentEncoding;
     }
 
     @Override
     public boolean isChunked() {
         return contentLength == -1;
     }
 
     @Override
     public Set<String> getTrailerNames() {
         return Collections.emptySet();
     }
 }