/*!
* 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.reporting.libraries.css.resolver.function;

import org.pentaho.reporting.libraries.base.config.Configuration;
import org.pentaho.reporting.libraries.base.util.ObjectUtilities;
import org.pentaho.reporting.libraries.css.LibCssBoot;

import java.util.HashMap;
import java.util.Iterator;

/**
 * Creation-Date: 16.04.2006, 14:15:37
 *
 * @author Thomas Morgner
 */
public final class FunctionFactory {
  public static final String VALUE_FUNCTIONS_KEY_RANGE =
    "org.pentaho.reporting.libraries.css.functions.values.";
  public static final String CONTENT_FUNCTIONS_KEY_RANGE =
    "org.pentaho.reporting.libraries.css.functions.content.";

  private HashMap styleFunctions;
  private HashMap contentFunctions;
  private static FunctionFactory instance;

  public static FunctionFactory getInstance() {
    if ( instance == null ) {
      instance = new FunctionFactory();
      instance.registerDefault();
    }
    return instance;
  }

  private FunctionFactory() {
    styleFunctions = new HashMap();
    contentFunctions = new HashMap();
  }

  public void registerDefault() {
    final Configuration config = LibCssBoot.getInstance().getGlobalConfig();
    final Iterator valueKeys = config.findPropertyKeys( VALUE_FUNCTIONS_KEY_RANGE );
    while ( valueKeys.hasNext() ) {
      final String key = (String) valueKeys.next();
      final String value = config.getConfigProperty( key );
      final String name = key.substring( VALUE_FUNCTIONS_KEY_RANGE.length() );
      final Object maybeFunction = ObjectUtilities.loadAndInstantiate
        ( value, FunctionFactory.class, StyleValueFunction.class );
      if ( maybeFunction instanceof StyleValueFunction ) {
        styleFunctions.put( name.toLowerCase(), maybeFunction );
      }
    }

    final Iterator contentKeys = config.findPropertyKeys( CONTENT_FUNCTIONS_KEY_RANGE );
    while ( contentKeys.hasNext() ) {
      final String key = (String) contentKeys.next();
      final String value = config.getConfigProperty( key );
      final String name = key.substring( CONTENT_FUNCTIONS_KEY_RANGE.length() );
      final Object maybeFunction = ObjectUtilities.loadAndInstantiate
        ( value, FunctionFactory.class, ContentFunction.class );
      if ( maybeFunction instanceof ContentFunction ) {
        contentFunctions.put( name.toLowerCase(), maybeFunction );
      }
    }

  }

  public StyleValueFunction getStyleFunction( final String name ) {
    final StyleValueFunction function = (StyleValueFunction) styleFunctions.get( name.toLowerCase() );
    if ( function == null ) {
      //Log.warn ("Unrecognized style function encountered: " + name);
    }
    // todo: Check for null values in all callers ..
    return function;
  }

  public ContentFunction getContentFunction( final String name ) {
    final ContentFunction function = (ContentFunction) contentFunctions.get( name.toLowerCase() );
    if ( function == null ) {
      //Log.warn ("Unrecognized content function encountered: " + name);
    }
    // todo: Check for null values in all callers ..
    return function;
  }
}