/*
    * ====================================================================
    * 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.http.nio.util;
  
  import java.io.IOException;
  
  import org.apache.http.annotation.NotThreadSafe;
  import org.apache.http.nio.ContentDecoder;
  
  /**
   * Basic implementation of the {@link ContentInputBuffer} interface.
   * <p>
   * This class is not thread safe.
   *
   * @since 4.0
   */
  @NotThreadSafe
  public class SimpleInputBuffer extends ExpandableBuffer implements ContentInputBuffer {
  
      private boolean endOfStream = false;
  
      public SimpleInputBuffer(final int buffersize, final ByteBufferAllocator allocator) {
          super(buffersize, allocator);
      }
  
      /**
       * @since 4.3
       */
      public SimpleInputBuffer(final int buffersize) {
          this(buffersize, HeapByteBufferAllocator.INSTANCE);
      }
  
      public void reset() {
          this.endOfStream = false;
          super.clear();
      }
  
      public int consumeContent(final ContentDecoder decoder) throws IOException {
          setInputMode();
          int totalRead = 0;
          int bytesRead;
          while ((bytesRead = decoder.read(this.buffer)) != -1) {
              if (bytesRead == 0) {
                  if (!this.buffer.hasRemaining()) {
                      expand();
                  } else {
                      break;
                  }
              } else {
                  totalRead += bytesRead;
              }
          }
          if (bytesRead == -1 || decoder.isCompleted()) {
              this.endOfStream = true;
          }
          return totalRead;
      }
  
      public boolean isEndOfStream() {
          return !hasData() && this.endOfStream;
      }
  
      public int read() throws IOException {
          if (isEndOfStream()) {
              return -1;
          }
          setOutputMode();
          return this.buffer.get() & 0xff;
      }
  
      public int read(final byte[] b, final int off, final int len) throws IOException {
          if (isEndOfStream()) {
              return -1;
          }
          if (b == null) {
             return 0;
         }
         setOutputMode();
         int chunk = len;
         if (chunk > this.buffer.remaining()) {
             chunk = this.buffer.remaining();
         }
         this.buffer.get(b, off, chunk);
         return chunk;
     }
 
     public int read(final byte[] b) throws IOException {
         if (isEndOfStream()) {
             return -1;
         }
         if (b == null) {
             return 0;
         }
         return read(b, 0, b.length);
     }
 
     public void shutdown() {
         this.endOfStream = true;
     }
 
 }