/*!
 * 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) 2002-2013 Pentaho Corporation..  All rights reserved.
 */

package org.pentaho.platform.config;

import org.dom4j.Element;
import org.dom4j.Node;
import org.apache.commons.lang.StringUtils;
import org.pentaho.platform.api.engine.IConfiguration;
import org.pentaho.platform.api.engine.ISystemSettings;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.util.List;
import java.util.Properties;

/**
 * User: nbaker Date: 4/2/13
 */
public class SystemSettingsConfiguration implements IConfiguration {
  private String id;
  private Logger logger = LoggerFactory.getLogger( getClass() );
  private ISystemSettings settings;

  public SystemSettingsConfiguration( String id, ISystemSettings settings ) {
    if ( id == null ) {
      throw new IllegalArgumentException( "id cannot be null" );
    }
    if ( settings == null ) {
      throw new IllegalArgumentException( "SystemSettings is null" );
    }
    this.id = id;
    this.settings = settings;
  }

  @Override
  public String getId() {
    return "system";
  }

  @Override
  public Properties getProperties() throws IOException {
    Properties props = new Properties();
    List elements = settings.getSystemSettings( "pentaho-system" );
    if ( elements == null ) {
      return null;
    }
    elements = ( (Element) elements.get( 0 ) ).content();
    addElementsToProperties( elements, props, "" );

    return props;
  }

  private void addElementsToProperties( List elements, Properties props, String parentPath ) {

    for ( java.lang.Object o : elements ) {
      Node ele = (Node) o;
      if ( ele.getNodeType() != 1 ) { // text
        continue;
      }
      String contents = ele.getText().trim();

      String newParentPath = "";

      if ( !StringUtils.isEmpty( parentPath ) ) {
        newParentPath = parentPath + ".";
      }
      newParentPath += ele.getName();

      if ( !StringUtils.isEmpty( contents ) ) {
        props.setProperty( newParentPath, contents );
      }
      if ( ele instanceof Element ) {
        List children = ( (Element) ele ).content();

        addElementsToProperties( children, props, newParentPath );
      }

    }
  }

  @Override
  public void update( Properties properties ) throws IOException {
    throw new UnsupportedOperationException( "SystemSettings does not support write-back" );
  }
}