/*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License, version 2.1 as published by the Free Software
* Foundation.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU Lesser General Public License for more details.
*
* Copyright (c) 2001 - 2013 Object Refinery Ltd, Pentaho Corporation and Contributors..  All rights reserved.
*/

package org.pentaho.reporting.libraries.serializer.methods;

import org.pentaho.reporting.libraries.serializer.SerializeMethod;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.text.AttributedCharacterIterator;
import java.text.AttributedString;
import java.text.CharacterIterator;
import java.util.HashMap;
import java.util.Map;

/**
 * A serializer-method to serialize and deserialize attributed-strings.
 *
 * @author Thomas Morgner
 */
public class AttributedStringSerializer implements SerializeMethod {
  /**
   * Default constructor.
   */
  public AttributedStringSerializer() {
  }

  /**
   * Writes a serializable object description to the given object output stream.
   *
   * @param o      the to be serialized object.
   * @param stream the outputstream that should receive the object.
   * @throws IOException if an I/O error occured.
   */
  public void writeObject( final Object o, final ObjectOutputStream stream ) throws IOException {
    final AttributedString as = (AttributedString) o;
    final AttributedCharacterIterator aci = as.getIterator();
    // build a plain string from aci
    // then write the string
    StringBuffer plainStr = new StringBuffer( 100 );
    char current = aci.first();
    while ( current != CharacterIterator.DONE ) {
      plainStr = plainStr.append( current );
      current = aci.next();
    }
    stream.writeObject( plainStr.toString() );

    // then write the attributes and limits for each run
    current = aci.first();
    final int begin = aci.getBeginIndex();
    while ( current != CharacterIterator.DONE ) {
      // write the current character - when the reader sees that this
      // is not CharacterIterator.DONE, it will know to read the
      // run limits and attributes
      stream.writeChar( current );

      // now write the limit, adjusted as if beginIndex is zero
      final int limit = aci.getRunLimit();
      stream.writeInt( limit - begin );

      // now write the attribute set
      final Map<AttributedCharacterIterator.Attribute, Object> atts =
        new HashMap<AttributedCharacterIterator.Attribute, Object>( aci.getAttributes() );
      stream.writeObject( atts );
      current = aci.setIndex( limit );
    }
    // write a character that signals to the reader that all runs
    // are done...
    stream.writeChar( CharacterIterator.DONE );

  }

  /**
   * Reads the object from the object input stream.
   *
   * @param stream the object input stream from where to read the serialized data.
   * @return the generated object.
   * @throws IOException            if reading the stream failed.
   * @throws ClassNotFoundException if serialized object class cannot be found.
   */
  public Object readObject( final ObjectInputStream stream )
    throws IOException, ClassNotFoundException {
    // read string and attributes then create result
    final String plainStr = (String) stream.readObject();
    final AttributedString result = new AttributedString( plainStr );
    char c = stream.readChar();
    int start = 0;
    while ( c != CharacterIterator.DONE ) {
      final int limit = stream.readInt();
      final Map<AttributedCharacterIterator.Attribute, Object> atts =
        (Map<AttributedCharacterIterator.Attribute, Object>) stream.readObject();
      result.addAttributes( atts, start, limit );
      start = limit;
      c = stream.readChar();
    }
    return result;
  }

  /**
   * The class of the object, which this object can serialize.
   *
   * @return the class of the object type, which this method handles.
   */
  public Class getObjectClass() {
    return AttributedString.class;
  }
}