/*

  * 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.shindig.social.core.util.xstream;

 import com.thoughtworks.xstream.io.HierarchicalStreamDriver;

 import com.thoughtworks.xstream.io.HierarchicalStreamReader;

 import com.thoughtworks.xstream.io.HierarchicalStreamWriter;

 import java.io.InputStream;

 import java.io.OutputStream;

 import java.io.Reader;

 import java.io.Writer;

 import java.util.Map;

 /**

  * A StackDriver wraps other forms of Drivers and updates a WriterStack with the

  * path into the writer hierarchy.

  */

 public class StackDriver implements HierarchicalStreamDriver {

   /**

    * The parent Stream Driver that does the work.

    */

   private HierarchicalStreamDriver parent;

   /**

    * A Writer Stack implementation that records where the writer is.

    */

   private WriterStack writerStack;

   private Map<String, NamespaceSet> namespaces;

   /**

    * Create a {@link StackDriver}, wrapping a {@link HierarchicalStreamDriver}

    * and updating a {@link WriterStack}.

    * 

    * @param parent

    *          the driver to be wrapped

    * @param writerStack

    *          the thread safe writer stack that records where the writer is.

    * @param map

    */

   public StackDriver(HierarchicalStreamDriver parent, WriterStack writerStack,

       Map<String, NamespaceSet> map) {

     this.parent = parent;

     this.writerStack = writerStack;

     this.namespaces = map;

   }

   /**

    * Create a {@link HierarchicalStreamReader}, using the wrapped

    * {@link HierarchicalStreamDriver}.

    * 

    * @param reader

    *          the Reader that will be used to read from the underlying stream

    * @return the reader

    * @see com.thoughtworks.xstream.io.HierarchicalStreamDriver#createReader(java.

    *      io.Reader)

    */

   public HierarchicalStreamReader createReader(Reader reader) {

     return parent.createReader(reader);

   }

   /**

    * Create a {@link HierarchicalStreamReader}, using the wrapped

    * {@link HierarchicalStreamDriver}.

    * 

    * @param inputStream

    *          the input stream that will be used to read from the underlying

    *          stream

    * @return the reader

    * @see com.thoughtworks.xstream.io.HierarchicalStreamDriver#createReader(java.

    *      io.InputStream)

    */

   public HierarchicalStreamReader createReader(InputStream inputStream) {

     return parent.createReader(inputStream);

   }

   /**

    * Create a {@link HierarchicalStreamWriter} that tracks the path to the

    * current element based on a {@link Writer}.

    * 

    * @param writer

    *          the underlying writer that will perform the writes.

    * @return the writer

    * @see com.thoughtworks.xstream.io.HierarchicalStreamDriver#createWriter(java.

    *      io.Writer)

    */

   public HierarchicalStreamWriter createWriter(Writer writer) {

     HierarchicalStreamWriter parentWriter = parent.createWriter(writer);

     return new StackWriterWrapper(parentWriter, writerStack, namespaces);

   }

   /**

    * Create a {@link HierarchicalStreamWriter} that tracks the path to the

    * current element based on a {@link OutputStream}.

    * 

    * @param outputStream

    *          the underlying output stream that will perform the writes.

    * @return the writer

    * @see com.thoughtworks.xstream.io.HierarchicalStreamDriver#createWriter(java.

    *      io.Writer)

    */

   public HierarchicalStreamWriter createWriter(OutputStream outputStream) {

     HierarchicalStreamWriter parentWriter = parent.createWriter(outputStream);

     return new StackWriterWrapper(parentWriter, writerStack, namespaces);

   }

 }