/*******************************************************************************
 * Copyright (c) 2008, 2012 Wind River Systems 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:
 *     Wind River Systems - initial API and implementation
 *******************************************************************************/
package org.eclipse.cdt.dsf.debug.internal.ui.viewmodel.actions;

import org.eclipse.cdt.dsf.debug.ui.viewmodel.actions.VMHandlerUtils;
import org.eclipse.cdt.dsf.ui.viewmodel.IVMContext;
import org.eclipse.cdt.dsf.ui.viewmodel.IVMProvider;
import org.eclipse.cdt.dsf.ui.viewmodel.update.ICachingVMProvider;
import org.eclipse.cdt.dsf.ui.viewmodel.update.IVMUpdatePolicy;
import org.eclipse.core.expressions.PropertyTester;
import org.eclipse.debug.ui.IDebugView;
import org.eclipse.ui.IWorkbenchPart;

/**
 * Property tester for update policy information available through the given
 * object.  The object being tested should be either an {@link IVMContext},
 * through which an instance of {@link ICachingVMProvider} could be obtained.
 * Or it could be an {@link IWorkbenchPart}, which is tested to see if it
 * is a debug view through which a caching VM provider can be obtained.
 * The Caching View Model provider is used to test the given property.
 * <p>
 * Three properties are supported:
 * <ul>
 * <li> "areUpdatePoliciesSupported" - Checks whether update policies are
 * available at all given the receiver.</li>
 * <li> "isUpdatePolicyAvailable" - Checks whether the update policy in the
 * expected value is available for the given receiver.</li>
 * <li> "isUpdatePolicyActive" - Checks whether the policy given in the expected
 * value is the currently active policy for the given receiver.</li>
 * </ul>
 * </p>
 */
public class UpdatePoliciesPropertyTester extends PropertyTester {

	private static final String SUPPORTED = "areUpdatePoliciesSupported"; //$NON-NLS-1$
	private static final String AVAILABLE = "isUpdatePolicyAvailable"; //$NON-NLS-1$
	private static final String ACTIVE = "isUpdatePolicyActive"; //$NON-NLS-1$

	@Override
	public boolean test(Object receiver, String property, Object[] args, Object expectedValue) {
		if (receiver instanceof IVMContext) {
			IVMProvider provider = ((IVMContext) receiver).getVMNode().getVMProvider();
			if (provider instanceof ICachingVMProvider) {
				return testProvider((ICachingVMProvider) provider, property, expectedValue);
			}
		} else if (receiver instanceof IDebugView) {
			IVMProvider provider = VMHandlerUtils.getVMProviderForPart((IDebugView) receiver);
			if (provider instanceof ICachingVMProvider) {
				return testProvider((ICachingVMProvider) provider, property, expectedValue);
			}
		}
		return false;
	}

	private boolean testProvider(ICachingVMProvider provider, String property, Object expectedValue) {
		if (SUPPORTED.equals(property)) {
			return true;
		} else if (AVAILABLE.equals(property)) {
			for (IVMUpdatePolicy policy : provider.getAvailableUpdatePolicies()) {
				if (policy.getID().equals(expectedValue)) {
					return true;
				}
				return false;
			}
		} else if (ACTIVE.equals(property)) {
			return expectedValue != null && expectedValue.equals(provider.getActiveUpdatePolicy().getID());
		}
		return false;
	}

}
