/*
    * Copyright 2012 The Netty Project
    *
    * The Netty Project 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 io.netty.buffer;
  
  import io.netty.util.Recycler;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.nio.ByteBuffer;
  import java.nio.channels.ClosedChannelException;
  import java.nio.channels.GatheringByteChannel;
  import java.nio.channels.ScatteringByteChannel;
  
  final class PooledDirectByteBuf extends PooledByteBuf<ByteBuffer> {
  
      private static final Recycler<PooledDirectByteBuf> RECYCLER = new Recycler<PooledDirectByteBuf>() {
          @Override
          protected PooledDirectByteBuf newObject(Handle handle) {
              return new PooledDirectByteBuf(handle, 0);
          }
      };
  
      static PooledDirectByteBuf newInstance(int maxCapacity) {
          PooledDirectByteBuf buf = RECYCLER.get();
          buf.reuse(maxCapacity);
          return buf;
      }
  
      private PooledDirectByteBuf(Recycler.Handle recyclerHandle, int maxCapacity) {
          super(recyclerHandle, maxCapacity);
      }
  
      @Override
      protected ByteBuffer newInternalNioBuffer(ByteBuffer memory) {
          return memory.duplicate();
      }
  
      @Override
      public boolean isDirect() {
          return true;
      }
  
      @Override
      protected byte _getByte(int index) {
          return memory.get(idx(index));
      }
  
      @Override
      protected short _getShort(int index) {
          return memory.getShort(idx(index));
      }
  
      @Override
      protected int _getUnsignedMedium(int index) {
          index = idx(index);
          return (memory.get(index) & 0xff) << 16 | (memory.get(index + 1) & 0xff) << 8 | memory.get(index + 2) & 0xff;
      }
  
      @Override
      protected int _getInt(int index) {
          return memory.getInt(idx(index));
      }
  
      @Override
      protected long _getLong(int index) {
          return memory.getLong(idx(index));
      }
  
      @Override
      public ByteBuf getBytes(int index, ByteBuf dst, int dstIndex, int length) {
          checkDstIndex(index, length, dstIndex, dst.capacity());
          if (dst.hasArray()) {
              getBytes(index, dst.array(), dst.arrayOffset() + dstIndex, length);
          } else if (dst.nioBufferCount() > 0) {
              for (ByteBuffer bb: dst.nioBuffers(dstIndex, length)) {
                  int bbLen = bb.remaining();
                  getBytes(index, bb);
                  index += bbLen;
              }
          } else {
              dst.setBytes(dstIndex, this, index, length);
          }
          return this;
      }
 
     @Override
     public ByteBuf getBytes(int index, byte[] dst, int dstIndex, int length) {
         getBytes(index, dst, dstIndex, length, false);
         return this;
     }
 
     private void getBytes(int index, byte[] dst, int dstIndex, int length, boolean internal) {
         checkDstIndex(index, length, dstIndex, dst.length);
         ByteBuffer tmpBuf;
         if (internal) {
             tmpBuf = internalNioBuffer();
         } else {
             tmpBuf = memory.duplicate();
         }
         index = idx(index);
         tmpBuf.clear().position(index).limit(index + length);
         tmpBuf.get(dst, dstIndex, length);
     }
 
     @Override
     public ByteBuf readBytes(byte[] dst, int dstIndex, int length) {
         checkReadableBytes(length);
         getBytes(readerIndex, dst, dstIndex, length, true);
         readerIndex += length;
         return this;
     }
 
     @Override
     public ByteBuf getBytes(int index, ByteBuffer dst) {
         getBytes(index, dst, false);
         return this;
     }
 
     private void getBytes(int index, ByteBuffer dst, boolean internal) {
         checkIndex(index, dst.remaining());
         ByteBuffer tmpBuf;
         if (internal) {
             tmpBuf = internalNioBuffer();
         } else {
             tmpBuf = memory.duplicate();
         }
         index = idx(index);
         tmpBuf.clear().position(index).limit(index + dst.remaining());
         dst.put(tmpBuf);
     }
 
     @Override
     public ByteBuf readBytes(ByteBuffer dst) {
         int length = dst.remaining();
         checkReadableBytes(length);
         getBytes(readerIndex, dst, true);
         readerIndex += length;
         return this;
     }
 
     @Override
     public ByteBuf getBytes(int index, OutputStream out, int length) throws IOException {
         getBytes(index, out, length, false);
         return this;
     }
 
     private void getBytes(int index, OutputStream out, int length, boolean internal) throws IOException {
         checkIndex(index, length);
         if (length == 0) {
             return;
         }
 
         byte[] tmp = new byte[length];
         ByteBuffer tmpBuf;
         if (internal) {
             tmpBuf = internalNioBuffer();
         } else {
             tmpBuf = memory.duplicate();
         }
         tmpBuf.clear().position(idx(index));
         tmpBuf.get(tmp);
         out.write(tmp);
     }
 
     @Override
     public ByteBuf readBytes(OutputStream out, int length) throws IOException {
         checkReadableBytes(length);
         getBytes(readerIndex, out, length, true);
         readerIndex += length;
         return this;
     }
 
     @Override
     public int getBytes(int index, GatheringByteChannel out, int length) throws IOException {
         return getBytes(index, out, length, false);
     }
 
     private int getBytes(int index, GatheringByteChannel out, int length, boolean internal) throws IOException {
         checkIndex(index, length);
         if (length == 0) {
             return 0;
         }
 
         ByteBuffer tmpBuf;
         if (internal) {
             tmpBuf = internalNioBuffer();
         } else {
             tmpBuf = memory.duplicate();
         }
         index = idx(index);
         tmpBuf.clear().position(index).limit(index + length);
         return out.write(tmpBuf);
     }
 
     @Override
     public int readBytes(GatheringByteChannel out, int length) throws IOException {
         checkReadableBytes(length);
         int readBytes = getBytes(readerIndex, out, length, true);
         readerIndex += readBytes;
         return readBytes;
     }
 
     @Override
     protected void _setByte(int index, int value) {
         memory.put(idx(index), (byte) value);
     }
 
     @Override
     protected void _setShort(int index, int value) {
         memory.putShort(idx(index), (short) value);
     }
 
     @Override
     protected void _setMedium(int index, int value) {
         index = idx(index);
         memory.put(index, (byte) (value >>> 16));
         memory.put(index + 1, (byte) (value >>> 8));
         memory.put(index + 2, (byte) value);
     }
 
     @Override
     protected void _setInt(int index, int value) {
         memory.putInt(idx(index), value);
     }
 
     @Override
     protected void _setLong(int index, long value) {
         memory.putLong(idx(index), value);
     }
 
     @Override
     public ByteBuf setBytes(int index, ByteBuf src, int srcIndex, int length) {
         checkSrcIndex(index, length, srcIndex, src.capacity());
         if (src.hasArray()) {
             setBytes(index, src.array(), src.arrayOffset() + srcIndex, length);
         } else if (src.nioBufferCount() > 0) {
             for (ByteBuffer bb: src.nioBuffers(srcIndex, length)) {
                 int bbLen = bb.remaining();
                 setBytes(index, bb);
                 index += bbLen;
             }
         } else {
             src.getBytes(srcIndex, this, index, length);
         }
         return this;
     }
 
     @Override
     public ByteBuf setBytes(int index, byte[] src, int srcIndex, int length) {
         checkSrcIndex(index, length, srcIndex, src.length);
         ByteBuffer tmpBuf = internalNioBuffer();
         index = idx(index);
         tmpBuf.clear().position(index).limit(index + length);
         tmpBuf.put(src, srcIndex, length);
         return this;
     }
 
     @Override
     public ByteBuf setBytes(int index, ByteBuffer src) {
         checkIndex(index, src.remaining());
         ByteBuffer tmpBuf = internalNioBuffer();
         if (src == tmpBuf) {
             src = src.duplicate();
         }
 
         index = idx(index);
         tmpBuf.clear().position(index).limit(index + src.remaining());
         tmpBuf.put(src);
         return this;
     }
 
     @Override
     public int setBytes(int index, InputStream in, int length) throws IOException {
         checkIndex(index, length);
         byte[] tmp = new byte[length];
         int readBytes = in.read(tmp);
         if (readBytes <= 0) {
             return readBytes;
         }
         ByteBuffer tmpBuf = internalNioBuffer();
         tmpBuf.clear().position(idx(index));
         tmpBuf.put(tmp, 0, readBytes);
         return readBytes;
     }
 
     @Override
     public int setBytes(int index, ScatteringByteChannel in, int length) throws IOException {
         checkIndex(index, length);
         ByteBuffer tmpBuf = internalNioBuffer();
         index = idx(index);
         tmpBuf.clear().position(index).limit(index + length);
         try {
             return in.read(tmpBuf);
         } catch (ClosedChannelException ignored) {
             return -1;
         }
     }
 
     @Override
     public ByteBuf copy(int index, int length) {
         checkIndex(index, length);
         ByteBuf copy = alloc().directBuffer(length, maxCapacity());
         copy.writeBytes(this, index, length);
         return copy;
     }
 
     @Override
     public int nioBufferCount() {
         return 1;
     }
 
     @Override
     public ByteBuffer nioBuffer(int index, int length) {
         checkIndex(index, length);
         index = idx(index);
         return ((ByteBuffer) memory.duplicate().position(index).limit(index + length)).slice();
     }
 
     @Override
     public ByteBuffer[] nioBuffers(int index, int length) {
         return new ByteBuffer[] { nioBuffer(index, length) };
     }
 
     @Override
     public ByteBuffer internalNioBuffer(int index, int length) {
         checkIndex(index, length);
         index = idx(index);
         return (ByteBuffer) internalNioBuffer().clear().position(index).limit(index + length);
     }
 
     @Override
     public boolean hasArray() {
         return false;
     }
 
     @Override
     public byte[] array() {
         throw new UnsupportedOperationException("direct buffer");
     }
 
     @Override
     public int arrayOffset() {
         throw new UnsupportedOperationException("direct buffer");
     }
 
     @Override
     public boolean hasMemoryAddress() {
         return false;
     }
 
     @Override
     public long memoryAddress() {
         throw new UnsupportedOperationException();
     }
 
     @Override
     protected Recycler<?> recycler() {
         return RECYCLER;
     }
 }