//**************************************************************************

//	Filename 	:	ConfigHelper.java, WSSE Toolkit 2005

//

//	Author   	:	Denis Pilipchuk

//

//	Purpose  	:	Helper class for configuration processing. Its static functions 

//                  are thread-safe.

//

//	Disclaimer: This software is provided "as-is" and does not imply

//              any warranty or responsibility.

//****************************************************************************



package wsse.Toolkit.Utils.Config;



import java.util.Enumeration;

import java.util.HashMap;

import java.util.Properties;

import java.util.ResourceBundle;



import wsse.Toolkit.Utils.Xml.XmlFactory;



public class ConfigHelper

{

	// Name of the default config file

	private static final String DefConfig = "WsseToolkit";



	// Supported property names

	private static final String PropXmlFactory = "XmlFactoryImpl";

	private static final String PropUserDirectory = "UserDirImpl";

	private static final String PropSamlGenerator = "SamlGeneratorImpl";



	// Defaults for supported properties

	private static final String DefXmlFactoryImpl = "wsse.Toolkit.Utils.Xml.XmlFactory";

	private static final String DefUserDirImpl = "wsse.Agents.Sample.SampleUserDirectory";

	private static final String DefSamlGenImpl = "wsse.Agents.Sample.SampleAssertionGen";



	public static ConfigHelper GetInstance(String config)

	{

		if (null == m_CachedHelper)

		{

			m_CachedHelper = new ConfigHelper(config);

		}

		return m_CachedHelper;

	}



	public void InitConfig(String config)

	{

		String cfg = null != config ? config : ConfigHelper.DefConfig;

        // Retrieve config file and keep it as properties

        Properties loadProp = ConfigHelper.LoadConfig(cfg);

        m_props = null != loadProp ? loadProp : new Properties();

	}



    //////////////////////////////////////////////////////////////////////////

	// Generic entry getter methods



	public ConfigEntry GetEntry(String entryName)

	{

		return GetEntry(entryName, null);

	}



	public ConfigEntry GetEntry(String entryName, String defValue)

	{

        if (null == entryName || entryName.length() < 1)

        {

            throw new NullPointerException("Null or empty config entry name passed");

        }



		// Use cached enrties, if possible

		ConfigEntry entry = null;

        synchronized (m_cachedEntries)

        {

            if (m_cachedEntries.containsKey(entryName))

            {

                entry = (ConfigEntry)m_cachedEntries.get(entryName);

            }

            else

            {

                String value = m_props.getProperty(entryName, defValue);

                if (null != value)

                {

                    entry = new ConfigEntry(entryName, value);

                    m_cachedEntries.put(entryName, entry);

                }

            }

        }



		return entry;

	}



	//////////////////////////////////////////////////////////////////////////

	// Helper methods

	// Those are just helpers to retrieve well-known configuration entries



	public XmlFactory GetXmlFactory() throws ConfigException

	{

		ConfigEntry entry = GetEntry(ConfigHelper.PropXmlFactory, ConfigHelper.DefXmlFactoryImpl);

		return (XmlFactory)entry.GetAsObject();

	}



	//////////////////////////////////////////////////////////////////////////

	// End of helper methods



	private ConfigHelper(String config)

	{

		InitConfig(config);

	}



    // Retrieve the specified config file

    private static Properties LoadConfig(String name)

    {

        Properties prop = null;

        try

        {

            ResourceBundle bundle = ResourceBundle.getBundle(name);

            //Load Responses Properties file

            prop = new Properties();

            Enumeration enum = bundle.getKeys();

            while (enum.hasMoreElements())

            {

                String key = (String) enum.nextElement();

                prop.put(key, bundle.getObject(key));

            }

        }

        catch (Exception e)

        {

            // Properties file not found on the classpath, use the defaults

        }



        return prop;

    }



	private static ConfigHelper m_CachedHelper;



    private Properties m_props;

    private HashMap m_cachedEntries = new HashMap();

}