/*******************************************************************************
 * Copyright (c) 2004, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - Initial API and implementation
 *******************************************************************************/

package org.eclipse.wst.common.core.search;

import java.util.Map;

import org.eclipse.core.runtime.Plugin;
import org.eclipse.wst.common.core.search.internal.SearchParticipantRegistry;
import org.eclipse.wst.common.core.search.internal.SearchParticipantRegistryReader;
import org.eclipse.wst.common.core.search.pattern.SearchPattern;
import org.osgi.framework.BundleContext;

/**
 * The main plugin class to be used in the desktop.
 * <p>
 * <b>Note:</b> This class/interface is part of an interim API that is still under development and expected to
 * change significantly before reaching stability. It is being made available at this early stage to solicit feedback
 * from pioneering adopters on the understanding that any code that uses this API will almost certainly be broken
 * (repeatedly) as the API evolves.
 * </p>
 */
public class SearchPlugin extends Plugin implements ISearchOptions
{

	private SearchParticipantRegistry searchParticipantRegistry;

	// The shared instance.
	private static SearchPlugin plugin;

	/**
	 * The constructor.
	 */
	public SearchPlugin()
	{
		plugin = this;
	}

	/**
	 * This method is called upon plug-in activation
	 */
	public void start(BundleContext context) throws Exception
	{
		super.start(context);
	}

	/**
	 * This method is called when the plug-in is stopped
	 */
	public void stop(BundleContext context) throws Exception
	{
		super.stop(context);
		plugin = null;
	}

	/**
	 * Returns the shared instance.
	 */
	public static SearchPlugin getDefault()
	{
		return plugin;
	}

	private SearchParticipantRegistry getSearchParticipantRegistry()
	{
		if (searchParticipantRegistry == null)
		{
			searchParticipantRegistry = new SearchParticipantRegistry();
			new SearchParticipantRegistryReader(searchParticipantRegistry)
					.readRegistry();
		}
		return searchParticipantRegistry;
	}


	public SearchParticipant getSearchParticipant(String id)
	{
		return getSearchParticipantRegistry().getSearchParticipant(id);
	}

	/**
	 * Returns the registered search participants that support the specified search
	 * pattern and options, loading and creating the search participants if necessary.
	 * @param pattern The pattern representing a search request
	 * @param searchOptions Map of options and values defining behavior of the search;
	 *         <code>null</code> if no options are specified;
	 *         some options and values are provided by {@link ISearchOptions}
	 * @return Array of search participants that support the specified search request 
	 */
	SearchParticipant[] loadSearchParticipants(SearchPattern pattern, Map searchOptions)
	{
		return getSearchParticipantRegistry().getParticipants(pattern, searchOptions);
	}

}