/*
    * 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.handler.codec.http.multipart;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.buffer.CompositeByteBuf;
  import io.netty.handler.codec.http.HttpConstants;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.nio.ByteBuffer;
  import java.nio.channels.FileChannel;
  import java.nio.charset.Charset;
  
  import static io.netty.buffer.Unpooled.*;
  
  /**
   * Abstract Memory HttpData implementation
   */
  public abstract class AbstractMemoryHttpData extends AbstractHttpData {
  
      private ByteBuf byteBuf;
      private int chunkPosition;
      protected boolean isRenamed;
  
      protected AbstractMemoryHttpData(String name, Charset charset, long size) {
          super(name, charset, size);
      }
  
      @Override
      public void setContent(ByteBuf buffer) throws IOException {
          if (buffer == null) {
              throw new NullPointerException("buffer");
          }
          long localsize = buffer.readableBytes();
          if (definedSize > 0 && definedSize < localsize) {
              throw new IOException("Out of size: " + localsize + " > " +
                      definedSize);
          }
          if (byteBuf != null) {
              byteBuf.release();
          }
          byteBuf = buffer;
          size = localsize;
          completed = true;
      }
  
      @Override
      public void setContent(InputStream inputStream) throws IOException {
          if (inputStream == null) {
              throw new NullPointerException("inputStream");
          }
          ByteBuf buffer = buffer();
          byte[] bytes = new byte[4096 * 4];
          int read = inputStream.read(bytes);
          int written = 0;
          while (read > 0) {
              buffer.writeBytes(bytes, 0, read);
              written += read;
              read = inputStream.read(bytes);
          }
          size = written;
          if (definedSize > 0 && definedSize < size) {
              throw new IOException("Out of size: " + size + " > " + definedSize);
          }
          if (byteBuf != null) {
              byteBuf.release();
          }
          byteBuf = buffer;
          completed = true;
      }
  
      @Override
      public void addContent(ByteBuf buffer, boolean last)
              throws IOException {
          if (buffer != null) {
              long localsize = buffer.readableBytes();
              if (definedSize > 0 && definedSize < size + localsize) {
                  throw new IOException("Out of size: " + (size + localsize) +
                          " > " + definedSize);
              }
              size += localsize;
              if (byteBuf == null) {
                 byteBuf = buffer;
             } else if (byteBuf instanceof CompositeByteBuf) {
                 CompositeByteBuf cbb = (CompositeByteBuf) byteBuf;
                 cbb.addComponent(true, buffer);
             } else {
                 CompositeByteBuf cbb = compositeBuffer(Integer.MAX_VALUE);
                 cbb.addComponents(true, byteBuf, buffer);
                 byteBuf = cbb;
             }
         }
         if (last) {
             completed = true;
         } else {
             if (buffer == null) {
                 throw new NullPointerException("buffer");
             }
         }
     }
 
     @Override
     public void setContent(File file) throws IOException {
         if (file == null) {
             throw new NullPointerException("file");
         }
         long newsize = file.length();
         if (newsize > Integer.MAX_VALUE) {
             throw new IllegalArgumentException(
                     "File too big to be loaded in memory");
         }
         FileInputStream inputStream = new FileInputStream(file);
         FileChannel fileChannel = inputStream.getChannel();
         byte[] array = new byte[(int) newsize];
         ByteBuffer byteBuffer = ByteBuffer.wrap(array);
         int read = 0;
         while (read < newsize) {
             read += fileChannel.read(byteBuffer);
         }
         fileChannel.close();
         inputStream.close();
         byteBuffer.flip();
         if (byteBuf != null) {
             byteBuf.release();
         }
         byteBuf = wrappedBuffer(Integer.MAX_VALUE, byteBuffer);
         size = newsize;
         completed = true;
     }
 
     @Override
     public void delete() {
         if (byteBuf != null) {
             byteBuf.release();
             byteBuf = null;
         }
     }
 
     @Override
     public byte[] get() {
         if (byteBuf == null) {
             return EMPTY_BUFFER.array();
         }
         byte[] array = new byte[byteBuf.readableBytes()];
         byteBuf.getBytes(byteBuf.readerIndex(), array);
         return array;
     }
 
     @Override
     public String getString() {
         return getString(HttpConstants.DEFAULT_CHARSET);
     }
 
     @Override
     public String getString(Charset encoding) {
         if (byteBuf == null) {
             return "";
         }
         if (encoding == null) {
             encoding = HttpConstants.DEFAULT_CHARSET;
         }
         return byteBuf.toString(encoding);
     }
 
     /**
      * Utility to go from a In Memory FileUpload
      * to a Disk (or another implementation) FileUpload
      * @return the attached ByteBuf containing the actual bytes
      */
     @Override
     public ByteBuf getByteBuf() {
         return byteBuf;
     }
 
     @Override
     public ByteBuf getChunk(int length) throws IOException {
         if (byteBuf == null || length == 0 || byteBuf.readableBytes() == 0) {
             chunkPosition = 0;
             return EMPTY_BUFFER;
         }
         int sizeLeft = byteBuf.readableBytes() - chunkPosition;
         if (sizeLeft == 0) {
             chunkPosition = 0;
             return EMPTY_BUFFER;
         }
         int sliceLength = length;
         if (sizeLeft < length) {
             sliceLength = sizeLeft;
         }
         ByteBuf chunk = byteBuf.slice(chunkPosition, sliceLength).retain();
         chunkPosition += sliceLength;
         return chunk;
     }
 
     @Override
     public boolean isInMemory() {
         return true;
     }
 
     @Override
     public boolean renameTo(File dest) throws IOException {
         if (dest == null) {
             throw new NullPointerException("dest");
         }
         if (byteBuf == null) {
             // empty file
             dest.createNewFile();
             isRenamed = true;
             return true;
         }
         int length = byteBuf.readableBytes();
         FileOutputStream outputStream = new FileOutputStream(dest);
         FileChannel fileChannel = outputStream.getChannel();
         int written = 0;
         if (byteBuf.nioBufferCount() == 1) {
             ByteBuffer byteBuffer = byteBuf.nioBuffer();
             while (written < length) {
                 written += fileChannel.write(byteBuffer);
             }
         } else {
             ByteBuffer[] byteBuffers = byteBuf.nioBuffers();
             while (written < length) {
                 written += fileChannel.write(byteBuffers);
             }
         }
 
         fileChannel.force(false);
         fileChannel.close();
         outputStream.close();
         isRenamed = true;
         return written == length;
     }
 
     @Override
     public File getFile() throws IOException {
         throw new IOException("Not represented by a file");
     }
 }