/*

* Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies). 

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description: 

 *

*/

package com.nokia.tools.themeinstaller.odtconverter;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.net.URL;

import java.util.Properties;

/**

 * Properties for ODT to XML converter

 * @author jutarhon

 */

public class ConverterProperties extends Properties

    {

    /**

     * Default serial version UID

     */

    private static final long serialVersionUID = 1L;

    private static final String PROPERTY_FILE =

        "data" + File.separatorChar + "ThemeInstaller.prop";

    private static ConverterProperties sInstance = null;

    private static String sPropFileName = null;

    /**

     * Default constructor, loads the properties from default place

     * @throws IOException If default file is not found or some other IO error occurs

     */

    public ConverterProperties() throws IOException

        {

        // Get the execution location

        URL resource =

                getClass().getProtectionDomain().getCodeSource().getLocation();

        File bin = new File( resource.getPath() );

        // Load properties from the Theme Installation directory

        loadProperties( new File(

                bin.getParent() + File.separatorChar + PROPERTY_FILE ) );

        }

    /**

     * Constructor with specified properties file

     * @param aFile File to read

     * @throws IOException If given file is not found or some other IO error occurs

     */

    public ConverterProperties( File aFile ) throws IOException

        {

        loadProperties( aFile );

        }

    /**

     * Constructor with default values

     * @param aDefaults Default properties values

     * @throws IOException  If default file is not found or some other IO error occurs

     */

    public ConverterProperties( Properties aDefaults ) throws IOException

        {

        super( aDefaults );

        loadProperties( new File( PROPERTY_FILE ) );

        }

    /**

     * Loads the properties from file

     * @param aFile File to read

     * @throws IOException  If given file is not found or some other IO error occurs

     */

    protected void loadProperties( File aFile ) throws IOException

        {

        FileInputStream file = null;

        try

            {

            file = new FileInputStream( aFile );

            load( file );

            }

        finally

            {

            if( file != null )

                {

                file.close();

                }

            }

        }

    /**

     * Singleton method for getting the ConverterProperties instance. Note that

     * the initialize method must be called before this one.

     * @return ConverterProperties instance

     * @throws IllegalStateException if this method has been called before

     * initialize has been called.

     */

    public static ConverterProperties getInstance()

        {

        if( sInstance == null )

            {

            throw new IllegalStateException( "Converter Properties: " +

                    "Initialize must be called before the properties " +

                    "can be used" );

            }

        return sInstance;

        }

    /**

     * Initialize method for constructing and reading the properties. The

     * properties are re-initialized only if the given property file differs

     * from the one used in the previous initialization.

     * @param aPropFile Properties file

     * @throws IOException If required properties can not be read from the

     * property file.

     */

    public static void initialize( File aPropFile )

        throws IOException

        {

        // Already initialized if:

        // sInstance is not null AND

        // sPropFileName equals with aPropFile

        if( sInstance != null &&

          ( sPropFileName != null && aPropFile != null && sPropFileName.equals( aPropFile.getPath() ) ||

          ( sPropFileName == null && aPropFile == null ) ) )

            {

            return;

            }

        // Create a new instance

        if( aPropFile == null )

            {

            sInstance = new ConverterProperties();

            sPropFileName = null;

            }

        else

            {

            sInstance = new ConverterProperties( aPropFile );

            sPropFileName = aPropFile.getPath();

            }

        }

    }