/*

* Copyright (c) 2006 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.s60tools.apiquery.shared.searchmethodregistry;

import java.util.Collection;

import java.util.Collections;

import java.util.HashMap;

import java.util.Map;

import com.nokia.s60tools.apiquery.shared.resources.Messages;

import com.nokia.s60tools.apiquery.shared.searchmethod.ISearchMethodExtension;

import com.nokia.s60tools.apiquery.shared.searchmethod.ISearchMethodExtensionInfo;

import com.nokia.s60tools.apiquery.shared.util.console.APIQueryConsole;

import com.nokia.s60tools.util.console.IConsolePrintUtility;

import com.nokia.s60tools.util.debug.DbgUtility;

/**

 * Singleton class that is created on plugin

 * startup, and is kept active as long as plugin is active.

 * 

 * The purpose of this class is to store search method

 * extensions that were found from the system.

 */

public class SearchMethodExtensionRegistry {

	/**

	 * Singleton instance.

	 */

	static private SearchMethodExtensionRegistry instance = null;

	/**

	 * Listeners interested in job completions operations.

	 */

	private static Map<String, ISearchMethodExtension> extensions = Collections.synchronizedMap(new HashMap<String, ISearchMethodExtension>());

	/**

	 * Public Singleton instance accessor.

	 * @return Returns instance of this singleton class-

	 */

	public static SearchMethodExtensionRegistry getInstance(){

		if( instance == null ){

			instance = new SearchMethodExtensionRegistry();

		}

		return instance;		

	}	

	/**

	 * Private default constructor.

	 */

	private SearchMethodExtensionRegistry() {

		DbgUtility.println(DbgUtility.PRIORITY_CLASS, "-- <<create>> --> " + getClass().getName()); //$NON-NLS-1$

	}	

	/**

	 * Add a new Search Method

	 * @param extension

	 */

	public void addExtension(ISearchMethodExtension extension){

		synchronized(extensions){

			ISearchMethodExtensionInfo info = extension.getExtensionInfo();

			String id = info.getId();

			ISearchMethodExtension possibleDuplicate = extensions.get(id);			

			if( possibleDuplicate != null ){				

				String errMsg = Messages.getString("SearchMethodExtensionRegistry.Failed_To_Add_Ext_ConsoleMsg")  //$NON-NLS-1$

						+ Messages.getString("SearchMethodExtensionRegistry.Extension_Prefix") //$NON-NLS-1$

						+ id

						+ Messages.getString("SearchMethodExtensionRegistry.Is_Registered_Already_MsgPostfix"); //$NON-NLS-1$

				APIQueryConsole.getInstance().println(errMsg, IConsolePrintUtility.MSG_ERROR);

				throw new RuntimeException(errMsg);

			}

			extensions.put(id, extension);

		} // synchronized

	}

	/**

	 * Remove a Search Method

	 * @param extension

	 */

	public void removeExtension(ISearchMethodExtension extension){

		synchronized(extensions){

			ISearchMethodExtensionInfo info = extension.getExtensionInfo();

			String id = info.getId();

			ISearchMethodExtension possibleDuplicate = extensions.get(id);			

			if( possibleDuplicate == null ){				

				String errMsg = Messages.getString("SearchMethodExtensionRegistry.Failed_To_Remove_Ext_ConsoleMsg")  //$NON-NLS-1$

					+ Messages.getString("SearchMethodExtensionRegistry.Extension_Prefix") //$NON-NLS-1$

					+ id

					+ Messages.getString("SearchMethodExtensionRegistry.Is_Registered_Already_MsgPostfix"); //$NON-NLS-1$

				APIQueryConsole.getInstance().println(errMsg, IConsolePrintUtility.MSG_ERROR);

				throw new RuntimeException(errMsg);

			}

			extension.notifyExtensionShutdown();

			extensions.remove(extension);

		} // synchronized

	}

	/**

	 * Called before host plugin shutdown.  

	 */

	public void notifyPluginShutdown(){

		for (ISearchMethodExtension ext : getExtensions()) {

			ext.notifyExtensionShutdown();						

		}

	}

	/**

	 * Returns the iterator for the currently registered extensions.

	 * @return Returns the currently registered extensions.

	 */

	public Collection<ISearchMethodExtension> getExtensions(){

		return extensions.values();

	}

	/**

	 * Gets the amount of currently registered extensions.

	 * @return Returns the amount of currently registered extensions.

	 */

	public int getExtensionCount(){

		return getExtensions().size();

	}

	/**

	 * Gets the extension that matches with the given description.

	 * @param extensionDescription Description of the search method.

	 * @return The extension matching the description or <code>null</code> if not found.

	 */

	public ISearchMethodExtension getByDescription(String extensionDescription) {

		for (ISearchMethodExtension ext : getExtensions()) {

			ISearchMethodExtensionInfo extInfo = ext.getExtensionInfo();

			if(extInfo.getDescription().equals(extensionDescription)){

				return ext;

			}

		}

		return null;

	}

	/**

	 * Gets the extension that matches with the given id.

	 * @param id Id of the search method.

	 * @return The extension matching the id or <code>null</code> if not found.

	 */

	public ISearchMethodExtension getById(String id) {

		for (ISearchMethodExtension ext : getExtensions()) {

			ISearchMethodExtensionInfo extInfo = ext.getExtensionInfo();

			if(extInfo.getId().equals(id)){

				return ext;

			}

		}

		return null;

	}

}