/*
    * 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.
   */
  package org.apache.maven.plugins.assembly.io;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.nio.ByteBuffer;
  import java.nio.channels.FileChannel;
  
  /**
   * file location implementation.
   *
   */
  class FileLocation implements Location {
  
      private File file;
      private FileChannel channel;
      private final String specification;
      private FileInputStream stream;
  
      /**
       * @param file {@link File}
       * @param specification spec
       */
      FileLocation(File file, String specification) {
          this.file = file;
          this.specification = specification;
      }
  
      /**
       * @param specification spec
       */
      FileLocation(String specification) {
          this.specification = specification;
      }
  
      @Override
      public void close() {
          if ((channel != null) && channel.isOpen()) {
              try {
                  channel.close();
              } catch (IOException e) {
                  // swallow it.
              }
          }
  
          if (stream != null) {
              try {
                  stream.close();
              } catch (IOException e) {
                  // swallow it.
              }
          }
      }
  
      @Override
      public File getFile() throws IOException {
          initFile();
  
          return unsafeGetFile();
      }
  
      /**
       * @return {@link File}
       */
      File unsafeGetFile() {
          return file;
      }
  
      /**
       * initialize file.
       * @throws IOException in case of error
       */
      protected void initFile() throws IOException {
          if (file == null) {
              file = new File(specification);
          }
      }
  
      /**
       * @param file {@link File}
      */
     protected void setFile(File file) {
         if (channel != null) {
             throw new IllegalStateException("Location is already open; cannot setFile(..).");
         }
 
         this.file = file;
     }
 
     @Override
     public String getSpecification() {
         return specification;
     }
 
     @Override
     public void open() throws IOException {
         if (stream == null) {
             initFile();
 
             stream = new FileInputStream(file);
             channel = stream.getChannel();
         }
     }
 
     @Override
     public int read(ByteBuffer buffer) throws IOException {
         open();
         return channel.read(buffer);
     }
 
     @Override
     public int read(byte[] buffer) throws IOException {
         open();
         return channel.read(ByteBuffer.wrap(buffer));
     }
 
     @Override
     public InputStream getInputStream() throws IOException {
         open();
         return stream;
     }
 }