/*
    * 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.internal.PlatformDependent;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.nio.ByteBuffer;
  import java.nio.ByteOrder;
  import java.nio.channels.ClosedChannelException;
  import java.nio.channels.GatheringByteChannel;
  import java.nio.channels.ScatteringByteChannel;
  
  import static io.netty.util.internal.ObjectUtil.checkNotNull;
  
  /**
   * Big endian Java heap buffer implementation. It is recommended to use
   * {@link UnpooledByteBufAllocator#heapBuffer(int, int)}, {@link Unpooled#buffer(int)} and
   * {@link Unpooled#wrappedBuffer(byte[])} instead of calling the constructor explicitly.
   */
  public class UnpooledHeapByteBuf extends AbstractReferenceCountedByteBuf {
  
      private final ByteBufAllocator alloc;
      byte[] array;
      private ByteBuffer tmpNioBuf;
  
      /**
       * Creates a new heap buffer with a newly allocated byte array.
       *
       * @param initialCapacity the initial capacity of the underlying byte array
       * @param maxCapacity the max capacity of the underlying byte array
       */
      public UnpooledHeapByteBuf(ByteBufAllocator alloc, int initialCapacity, int maxCapacity) {
          super(maxCapacity);
  
          checkNotNull(alloc, "alloc");
  
          if (initialCapacity > maxCapacity) {
              throw new IllegalArgumentException(String.format(
                      "initialCapacity(%d) > maxCapacity(%d)", initialCapacity, maxCapacity));
          }
  
          this.alloc = alloc;
          setArray(allocateArray(initialCapacity));
          setIndex(0, 0);
      }
  
      /**
       * Creates a new heap buffer with an existing byte array.
       *
       * @param initialArray the initial underlying byte array
       * @param maxCapacity the max capacity of the underlying byte array
       */
      protected UnpooledHeapByteBuf(ByteBufAllocator alloc, byte[] initialArray, int maxCapacity) {
          super(maxCapacity);
  
          checkNotNull(alloc, "alloc");
          checkNotNull(initialArray, "initialArray");
  
          if (initialArray.length > maxCapacity) {
              throw new IllegalArgumentException(String.format(
                      "initialCapacity(%d) > maxCapacity(%d)", initialArray.length, maxCapacity));
          }
  
          this.alloc = alloc;
          setArray(initialArray);
          setIndex(0, initialArray.length);
      }
  
      byte[] allocateArray(int initialCapacity) {
          return new byte[initialCapacity];
      }
  
      void freeArray(byte[] array) {
          // NOOP
      }
  
      private void setArray(byte[] initialArray) {
          array = initialArray;
          tmpNioBuf = null;
      }
  
      @Override
      public ByteBufAllocator alloc() {
         return alloc;
     }
 
     @Override
     public ByteOrder order() {
         return ByteOrder.BIG_ENDIAN;
     }
 
     @Override
     public boolean isDirect() {
         return false;
     }
 
     @Override
     public int capacity() {
         ensureAccessible();
         return array.length;
     }
 
     @Override
     public ByteBuf capacity(int newCapacity) {
         checkNewCapacity(newCapacity);
 
         int oldCapacity = array.length;
         byte[] oldArray = array;
         if (newCapacity > oldCapacity) {
             byte[] newArray = allocateArray(newCapacity);
             System.arraycopy(oldArray, 0, newArray, 0, oldArray.length);
             setArray(newArray);
             freeArray(oldArray);
         } else if (newCapacity < oldCapacity) {
             byte[] newArray = allocateArray(newCapacity);
             int readerIndex = readerIndex();
             if (readerIndex < newCapacity) {
                 int writerIndex = writerIndex();
                 if (writerIndex > newCapacity) {
                     writerIndex(writerIndex = newCapacity);
                 }
                 System.arraycopy(oldArray, readerIndex, newArray, readerIndex, writerIndex - readerIndex);
             } else {
                 setIndex(newCapacity, newCapacity);
             }
             setArray(newArray);
             freeArray(oldArray);
         }
         return this;
     }
 
     @Override
     public boolean hasArray() {
         return true;
     }
 
     @Override
     public byte[] array() {
         ensureAccessible();
         return array;
     }
 
     @Override
     public int arrayOffset() {
         return 0;
     }
 
     @Override
     public boolean hasMemoryAddress() {
         return false;
     }
 
     @Override
     public long memoryAddress() {
         throw new UnsupportedOperationException();
     }
 
     @Override
     public ByteBuf getBytes(int index, ByteBuf dst, int dstIndex, int length) {
         checkDstIndex(index, length, dstIndex, dst.capacity());
         if (dst.hasMemoryAddress()) {
             PlatformDependent.copyMemory(array, index, dst.memoryAddress() + dstIndex, length);
         } else if (dst.hasArray()) {
             getBytes(index, dst.array(), dst.arrayOffset() + dstIndex, length);
         } else {
             dst.setBytes(dstIndex, array, index, length);
         }
         return this;
     }
 
     @Override
     public ByteBuf getBytes(int index, byte[] dst, int dstIndex, int length) {
         checkDstIndex(index, length, dstIndex, dst.length);
         System.arraycopy(array, index, dst, dstIndex, length);
         return this;
     }
 
     @Override
     public ByteBuf getBytes(int index, ByteBuffer dst) {
         checkIndex(index, dst.remaining());
         dst.put(array, index, dst.remaining());
         return this;
     }
 
     @Override
     public ByteBuf getBytes(int index, OutputStream out, int length) throws IOException {
         ensureAccessible();
         out.write(array, index, length);
         return this;
     }
 
     @Override
     public int getBytes(int index, GatheringByteChannel out, int length) throws IOException {
         ensureAccessible();
         return getBytes(index, out, length, false);
     }
 
     private int getBytes(int index, GatheringByteChannel out, int length, boolean internal) throws IOException {
         ensureAccessible();
         ByteBuffer tmpBuf;
         if (internal) {
             tmpBuf = internalNioBuffer();
         } else {
             tmpBuf = ByteBuffer.wrap(array);
         }
         return out.write((ByteBuffer) tmpBuf.clear().position(index).limit(index + length));
     }
 
     @Override
     public int readBytes(GatheringByteChannel out, int length) throws IOException {
         checkReadableBytes(length);
         int readBytes = getBytes(readerIndex, out, length, true);
         readerIndex += readBytes;
         return readBytes;
     }
 
     @Override
     public ByteBuf setBytes(int index, ByteBuf src, int srcIndex, int length) {
         checkSrcIndex(index, length, srcIndex, src.capacity());
         if (src.hasMemoryAddress()) {
             PlatformDependent.copyMemory(src.memoryAddress() + srcIndex, array, index, length);
         } else  if (src.hasArray()) {
             setBytes(index, src.array(), src.arrayOffset() + srcIndex, length);
         } else {
             src.getBytes(srcIndex, array, index, length);
         }
         return this;
     }
 
     @Override
     public ByteBuf setBytes(int index, byte[] src, int srcIndex, int length) {
         checkSrcIndex(index, length, srcIndex, src.length);
         System.arraycopy(src, srcIndex, array, index, length);
         return this;
     }
 
     @Override
     public ByteBuf setBytes(int index, ByteBuffer src) {
         ensureAccessible();
         src.get(array, index, src.remaining());
         return this;
     }
 
     @Override
     public int setBytes(int index, InputStream in, int length) throws IOException {
         ensureAccessible();
         return in.read(array, index, length);
     }
 
     @Override
     public int setBytes(int index, ScatteringByteChannel in, int length) throws IOException {
         ensureAccessible();
         try {
             return in.read((ByteBuffer) internalNioBuffer().clear().position(index).limit(index + length));
         } catch (ClosedChannelException ignored) {
             return -1;
         }
     }
 
     @Override
     public int nioBufferCount() {
         return 1;
     }
 
     @Override
     public ByteBuffer nioBuffer(int index, int length) {
         ensureAccessible();
         return ByteBuffer.wrap(array, 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);
         return (ByteBuffer) internalNioBuffer().clear().position(index).limit(index + length);
     }
 
     @Override
     public byte getByte(int index) {
         ensureAccessible();
         return _getByte(index);
     }
 
     @Override
     protected byte _getByte(int index) {
         return HeapByteBufUtil.getByte(array, index);
     }
 
     @Override
     public short getShort(int index) {
         ensureAccessible();
         return _getShort(index);
     }
 
     @Override
     protected short _getShort(int index) {
         return HeapByteBufUtil.getShort(array, index);
     }
 
     @Override
     public int getUnsignedMedium(int index) {
         ensureAccessible();
         return _getUnsignedMedium(index);
     }
 
     @Override
     protected int _getUnsignedMedium(int index) {
         return HeapByteBufUtil.getUnsignedMedium(array, index);
     }
 
     @Override
     public int getInt(int index) {
         ensureAccessible();
         return _getInt(index);
     }
 
     @Override
     protected int _getInt(int index) {
         return HeapByteBufUtil.getInt(array, index);
     }
 
     @Override
     public long getLong(int index) {
         ensureAccessible();
         return _getLong(index);
     }
 
     @Override
     protected long _getLong(int index) {
         return HeapByteBufUtil.getLong(array, index);
     }
 
     @Override
     public ByteBuf setByte(int index, int value) {
         ensureAccessible();
         _setByte(index, value);
         return this;
     }
 
     @Override
     protected void _setByte(int index, int value) {
         HeapByteBufUtil.setByte(array, index, value);
     }
 
     @Override
     public ByteBuf setShort(int index, int value) {
         ensureAccessible();
         _setShort(index, value);
         return this;
     }
 
     @Override
     protected void _setShort(int index, int value) {
         HeapByteBufUtil.setShort(array, index, value);
     }
 
     @Override
     public ByteBuf setMedium(int index, int   value) {
         ensureAccessible();
         _setMedium(index, value);
         return this;
     }
 
     @Override
     protected void _setMedium(int index, int value) {
         HeapByteBufUtil.setMedium(array, index, value);
     }
 
     @Override
     public ByteBuf setInt(int index, int   value) {
         ensureAccessible();
         _setInt(index, value);
         return this;
     }
 
     @Override
     protected void _setInt(int index, int value) {
         HeapByteBufUtil.setInt(array, index, value);
     }
 
     @Override
     public ByteBuf setLong(int index, long  value) {
         ensureAccessible();
         _setLong(index, value);
         return this;
     }
 
     @Override
     protected void _setLong(int index, long value) {
         HeapByteBufUtil.setLong(array, index, value);
     }
 
     @Override
     public ByteBuf copy(int index, int length) {
         checkIndex(index, length);
         byte[] copiedArray = new byte[length];
         System.arraycopy(array, index, copiedArray, 0, length);
         return new UnpooledHeapByteBuf(alloc(), copiedArray, maxCapacity());
     }
 
     private ByteBuffer internalNioBuffer() {
         ByteBuffer tmpNioBuf = this.tmpNioBuf;
         if (tmpNioBuf == null) {
             this.tmpNioBuf = tmpNioBuf = ByteBuffer.wrap(array);
         }
         return tmpNioBuf;
     }
 
     @Override
     protected void deallocate() {
         freeArray(array);
         array = null;
     }
 
     @Override
     public ByteBuf unwrap() {
         return null;
     }
 }