/*******************************************************************************
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library 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.
 *
 *******************************************************************************/

package com.liferay.ide.hook.core.model.internal;

import com.liferay.ide.hook.core.HookCore;

import java.io.File;
import java.util.HashMap;
import java.util.Map;
import java.util.TreeSet;

import javax.xml.parsers.DocumentBuilderFactory;

import org.eclipse.core.runtime.IPath;
import org.eclipse.sapphire.services.Service;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * @author Gregory Amerson
 */
public class StrutsActionPathPossibleValuesCacheService extends Service
{
    private final Map<IPath, TreeSet<String>> possibleValuesMap = new HashMap<IPath, TreeSet<String>>();

    public TreeSet<String> getPossibleValuesForPath( IPath strutsConfigPath )
    {
        TreeSet<String> retval = this.possibleValuesMap.get( strutsConfigPath );

        if( retval == null )
        {
            final File strutsConfigFile = strutsConfigPath.toFile();

            if( strutsConfigFile.exists() )
            {
                final TreeSet<String> possibleValues = new TreeSet<String>();

                try
                {
                    final DocumentBuilderFactory newInstance = DocumentBuilderFactory.newInstance();
                    newInstance.setFeature( "http://apache.org/xml/features/nonvalidating/load-external-dtd", false );
                    newInstance.setValidating( false );
                    final Document doc = newInstance.newDocumentBuilder().parse( strutsConfigFile );

                    final NodeList actions = doc.getElementsByTagName( "action" ); //$NON-NLS-1$

                    if( actions != null )
                    {
                        for( int i = 0; i < actions.getLength(); i++ )
                        {
                            final Node action = actions.item( i );

                            final Node path = action.getAttributes().getNamedItem( "path" ); //$NON-NLS-1$

                            if( path != null )
                            {
                                possibleValues.add( path.getNodeValue() );
                            }
                        }
                    }

                    possibleValuesMap.put( strutsConfigPath, possibleValues );
                    retval = possibleValues;
                }
                catch( Exception e )
                {
                    HookCore.logError( "Unable to parse struts config: " + strutsConfigPath, e );
                }
            }
        }

        if( retval == null )
        {
            retval = new TreeSet<String>();
        }

        return retval;
    }

}