// $codepro.audit.disable com.instantiations.assist.eclipse.analysis.audit.rule.effectivejava.alwaysOverridetoString.alwaysOverrideToString, com.instantiations.assist.eclipse.analysis.deserializeabilitySecurity, com.instantiations.assist.eclipse.analysis.disallowReturnMutable, com.instantiations.assist.eclipse.analysis.enforceCloneableUsageSecurity
/*******************************************************************************
 * Copyright (c) 2011, 2012 Ericsson AB 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
 * 
 * Description:
 * 
 * This class implements the command to regress the element (Review/Anomaly)
 * to its previous state
 * 
 * Contributors:
 *   Sebastien Dubois - Created for Mylyn Review R4E project
 *   
 ******************************************************************************/
package org.eclipse.mylyn.reviews.r4e.ui.internal.commands.handlers;

import java.util.Iterator;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.mylyn.reviews.r4e.core.model.R4EAnomalyState;
import org.eclipse.mylyn.reviews.r4e.core.model.R4EReviewPhase;
import org.eclipse.mylyn.reviews.r4e.core.model.serial.impl.CompatibilityException;
import org.eclipse.mylyn.reviews.r4e.core.model.serial.impl.ResourceHandlingException;
import org.eclipse.mylyn.reviews.r4e.ui.R4EUIPlugin;
import org.eclipse.mylyn.reviews.r4e.ui.internal.model.IR4EUIModelElement;
import org.eclipse.mylyn.reviews.r4e.ui.internal.model.R4EUIAnomalyExtended;
import org.eclipse.mylyn.reviews.r4e.ui.internal.model.R4EUIModelController;
import org.eclipse.mylyn.reviews.r4e.ui.internal.model.R4EUIPostponedAnomaly;
import org.eclipse.mylyn.reviews.r4e.ui.internal.model.R4EUIReviewBasic;
import org.eclipse.mylyn.reviews.r4e.ui.internal.model.R4EUIReviewExtended;
import org.eclipse.mylyn.reviews.r4e.ui.internal.utils.R4EUIConstants;
import org.eclipse.mylyn.reviews.r4e.ui.internal.utils.UIUtils;
import org.eclipse.ui.handlers.HandlerUtil;

/**
 * @author Sebastien Dubois
 * @version $Revision: 1.0 $
 */
public class PreviousStateHandler extends AbstractHandler {

	// ------------------------------------------------------------------------
	// Constants
	// ------------------------------------------------------------------------

	/**
	 * Field COMMAND_MESSAGE. (value is ""Regressing element to its Previous State..."")
	 */
	private static final String COMMAND_MESSAGE = "Regressing element to its Previous State...";

	// ------------------------------------------------------------------------
	// Methods
	// ------------------------------------------------------------------------

	/**
	 * Method execute.
	 * 
	 * @param aEvent
	 *            ExecutionEvent
	 * @return Object
	 * @see org.eclipse.core.commands.IHandler#execute(ExecutionEvent)
	 */
	public Object execute(final ExecutionEvent aEvent) {
		final Job job = new Job(COMMAND_MESSAGE) {

			public String familyName = R4EUIConstants.R4E_UI_JOB_FAMILY;

			@Override
			public boolean belongsTo(Object family) {
				return familyName.equals(family);
			}

			@Override
			public IStatus run(IProgressMonitor monitor) {
				final ISelection selection = HandlerUtil.getCurrentSelection(aEvent);
				if (selection instanceof IStructuredSelection) {
					if (!selection.isEmpty()) {
						monitor.beginTask(COMMAND_MESSAGE, ((IStructuredSelection) selection).size());
						R4EUIModelController.setJobInProgress(true);

						IR4EUIModelElement element = null;
						for (final Iterator<?> iterator = ((IStructuredSelection) selection).iterator(); iterator.hasNext();) {
							element = (IR4EUIModelElement) iterator.next();
							R4EUIPlugin.Ftracer.traceInfo("Regressing State for element " + element.getName()); //$NON-NLS-1$

							if (element instanceof R4EUIReviewExtended) {
								R4EReviewPhase newPhase = ((R4EUIReviewExtended) element).getPreviousPhase();
								UIUtils.changeReviewPhase(element, newPhase);

							} else if (element instanceof R4EUIReviewBasic) {
								R4EReviewPhase newPhase = ((R4EUIReviewBasic) element).getPhaseFromString(R4EUIConstants.REVIEW_PHASE_STARTED);
								UIUtils.changeReviewPhase(element, newPhase);
							} else if (element instanceof R4EUIPostponedAnomaly) {
								try {
									if (((R4EUIPostponedAnomaly) element).checkCompatibility()) {
										R4EAnomalyState newState = ((R4EUIPostponedAnomaly) element).getPreviousState();
										UIUtils.changeAnomalyState(element, newState);
									}
								} catch (ResourceHandlingException e) {
									UIUtils.displayResourceErrorDialog(e);
								} catch (CompatibilityException e) {
									UIUtils.displayCompatibilityErrorDialog(e);
								}
							} else if (element instanceof R4EUIAnomalyExtended) {
								R4EAnomalyState newState = ((R4EUIAnomalyExtended) element).getPreviousState();
								UIUtils.changeAnomalyState(element, newState);
							}
							monitor.worked(1);
							if (monitor.isCanceled()) {
								R4EUIModelController.setJobInProgress(false);
								UIUtils.setNavigatorViewFocus(element, 0);
								return Status.CANCEL_STATUS;
							}
						}
						R4EUIModelController.setJobInProgress(false);
						UIUtils.setNavigatorViewFocus(element, 0);
					}
				}
				R4EUIModelController.setJobInProgress(false);
				monitor.done();
				return Status.OK_STATUS;
			}
		};
		job.setUser(true);
		job.schedule();
		return null;
	}
}