Copyright (c) 2007, 2017 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
/*******************************************************************************
 * Copyright (c) 2007, 2017 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.team.internal.core.mapping;

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.core.resources.mapping.ResourceMapping;
import org.eclipse.core.resources.mapping.ResourceTraversal;
import org.eclipse.team.core.mapping.ISynchronizationScope;

public class ScopeChangeEvent {

	private final ISynchronizationScope scope;
	private final ResourceMapping[] originalMappings;
	private final ResourceTraversal[] originalTraversals;
	private boolean expanded;
	private boolean contracted;

	public ScopeChangeEvent(ISynchronizationScope scope) {
		this.scope = scope;
		originalMappings = scope.getMappings();
		originalTraversals = scope.getTraversals();
	}

	public boolean hasAdditionalMappings() {
		return scope.getMappings().length > originalMappings.length;
	}

	public ResourceTraversal[] getUncoveredTraversals(CompoundResourceTraversal traversal) {
		CompoundResourceTraversal originals = new CompoundResourceTraversal();
		originals.addTraversals(originalTraversals);
		return originals.getUncoveredTraversals(traversal);
	}

	public void setExpanded(boolean expanded) {
		this.expanded = expanded;
	}

	public boolean isExpanded() {
		return expanded;
	}

	public void setContracted(boolean contracted) {
		this.contracted = contracted;
	}

	public boolean isContracted() {
		return contracted;
	}

	public ResourceMapping[] getChangedMappings() {
		ResourceMapping[] currentMappings = scope.getMappings();
		ResourceMapping[] changedMappings;
		if (currentMappings.length > originalMappings.length) {
			// The number of mappings has increased so we should report the new mappings
			Set<ResourceMapping> originalSet = new HashSet<>();
			List<ResourceMapping> result = new ArrayList<>();
			Collections.addAll(originalSet, originalMappings);
			for (ResourceMapping mapping : currentMappings) {
				if (!originalSet.contains(mapping)) {
					result.add(mapping);
				}
			}
			changedMappings = result.toArray(new ResourceMapping[result.size()]);
		} else if (isContracted()) {
			// The number of mappings may be smaller so report the removed mappings
			Set<ResourceMapping> finalSet = new HashSet<>();
			List<ResourceMapping> result = new ArrayList<>();
			Collections.addAll(finalSet, currentMappings);
			for (ResourceMapping mapping : originalMappings) {
				if (!finalSet.contains(mapping)) {
					result.add(mapping);
				}
			}
			changedMappings = result.toArray(new ResourceMapping[result.size()]);
		} else {
			changedMappings = new ResourceMapping[0];
		}
		return changedMappings;
	}

	public ResourceTraversal[] getChangedTraversals(CompoundResourceTraversal refreshTraversals) {
		ResourceTraversal[] changesTraversals;
		if (isExpanded()) {
			changesTraversals = getUncoveredTraversals(refreshTraversals);
		} else if (isContracted()) {
			CompoundResourceTraversal finalTraversals = new CompoundResourceTraversal();
			finalTraversals.addTraversals(scope.getTraversals());
			changesTraversals = finalTraversals.getUncoveredTraversals(originalTraversals);
		} else {
			changesTraversals = new ResourceTraversal[0];
		}
		return changesTraversals;
	}

	public boolean shouldFireChange() {
		return isExpanded() || isContracted() || hasAdditionalMappings();
	}
}