/*******************************************************************************
 * Copyright (c) 2000, 2008 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.jdt.internal.ui.search;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;

import org.eclipse.jdt.internal.corext.util.Messages;

import org.eclipse.jdt.ui.search.IQueryParticipant;

import org.eclipse.jdt.internal.ui.JavaPlugin;

/**
 */
public class SearchParticipantDescriptor {
		private static final String CLASS= "class"; //$NON-NLS-1$
		private static final String NATURE= "nature"; //$NON-NLS-1$
		private static final String ID= "id"; //$NON-NLS-1$

		private IConfigurationElement fConfigurationElement;
		private boolean fEnabled; //

		protected SearchParticipantDescriptor(IConfigurationElement configElement) {
			fConfigurationElement= configElement;
			fEnabled= true;
		}

	/**
	 * checks whether a participant has all the proper attributes.
	 *
	 * @return returns a status describing the result of the validation
	 */
	protected IStatus checkSyntax() {
		if (fConfigurationElement.getAttribute(ID) == null) {
			String format= SearchMessages.SearchParticipant_error_noID;
			String message= Messages.format(format,  new String[] { fConfigurationElement.getDeclaringExtension().getUniqueIdentifier() });
			return new Status(IStatus.ERROR, JavaPlugin.getPluginId(), 0, message, null);
		}
		if (fConfigurationElement.getAttribute(NATURE) == null) {
			String format= SearchMessages.SearchParticipant_error_noNature;
			String message= Messages.format(format,  new String[] { fConfigurationElement.getAttribute(ID)});
			return new Status(IStatus.ERROR, JavaPlugin.getPluginId(), 0, message, null);
		}

		if (fConfigurationElement.getAttribute(CLASS) == null) {
			String format= SearchMessages.SearchParticipant_error_noClass;
			String message= Messages.format(format,  new String[] { fConfigurationElement.getAttribute(ID)});
			return new Status(IStatus.ERROR, JavaPlugin.getPluginId(), 0, message, null);
		}
		return Status.OK_STATUS;
	}

	public String getID() {
		return fConfigurationElement.getAttribute(ID);
	}

	public void disable() {
		fEnabled= false;
	}

	public boolean isEnabled() {
		return fEnabled;
	}

	protected IQueryParticipant create() throws CoreException {
		try {
			return (IQueryParticipant) fConfigurationElement.createExecutableExtension(CLASS);
		} catch (ClassCastException e) {
			throw new CoreException(new Status(IStatus.ERROR, JavaPlugin.getPluginId(), 0, SearchMessages.SearchParticipant_error_classCast, e));
		}
	}

	protected String getNature() {
		return fConfigurationElement.getAttribute(NATURE);
	}


}