/*******************************************************************************
 * Copyright (c) 2009 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 ******************************************************************************/

package org.eclipse.equinox.p2.examples.rcp.prestartupdate;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.OperationCanceledException;
import org.eclipse.core.runtime.SubMonitor;
import org.eclipse.equinox.p2.core.IProvisioningAgent;
import org.eclipse.equinox.p2.operations.ProvisioningJob;
import org.eclipse.equinox.p2.operations.ProvisioningSession;
import org.eclipse.equinox.p2.operations.UpdateOperation;

/**
 * This class shows an example for checking for updates and performing the
 * update synchronously.  It is up to the caller to run this in a job if 
 * a background update check is desired.  This is a reasonable way to run an
 * operation when user intervention is not required.   Another approach is
 * to separately perform the resolution and provisioning steps, deciding
 * whether to perform these synchronously or in a job.
 * 
 * Any p2 operation can be run modally (synchronously), or the job
 * can be requested and scheduled by the caller.
 * 
 * @see UpdateOperation#resolveModal(IProgressMonitor)
 * @see UpdateOperation#getResolveJob(IProgressMonitor)
 * @see UpdateOperation#getProvisioningJob(IProgressMonitor)
 */
public class P2Util {
	// XXX Check for updates to this application and return a status.
	static IStatus checkForUpdates(IProvisioningAgent agent, IProgressMonitor monitor) throws OperationCanceledException {
		ProvisioningSession session = new ProvisioningSession(agent);
		// the default update operation looks for updates to the currently
		// running profile, using the default profile root marker. To change
		// which installable units are being updated, use the more detailed
		// constructors.
		UpdateOperation operation = new UpdateOperation(session);
		SubMonitor sub = SubMonitor.convert(monitor,
				"Checking for application updates...", 200);
		IStatus status = operation.resolveModal(sub.newChild(100));
		if (status.getCode() == UpdateOperation.STATUS_NOTHING_TO_UPDATE) {
			return status;
		}
		if (status.getSeverity() == IStatus.CANCEL)
			throw new OperationCanceledException();
		
		if (status.getSeverity() != IStatus.ERROR) {
			// More complex status handling might include showing the user what updates
			// are available if there are multiples, differentiating patches vs. updates, etc.
			// In this example, we simply update as suggested by the operation.
			ProvisioningJob job = operation.getProvisioningJob(null);
			status = job.runModal(sub.newChild(100));
			if (status.getSeverity() == IStatus.CANCEL)
				throw new OperationCanceledException();
		}
		return status;
	}
}