Copyright (c) 2006, 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) 2006, 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.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.mapping.ResourceTraversal;
import org.eclipse.core.runtime.IPath;

Helper class that accumulates several traversals in order
to generate a final set of traversals and to perform certain
queries on a set of traversals.
/**
 * Helper class that accumulates several traversals in order
 * to generate a final set of traversals and to perform certain
 * queries on a set of traversals.
 */
public class CompoundResourceTraversal {

	private Set<IResource> deepFolders = new HashSet<>();
	private Set<IResource> shallowFolders = new HashSet<>();
	private Set<IResource> zeroFolders = new HashSet<>();
	private Set<IResource> files = new HashSet<>();

	public synchronized void addTraversals(ResourceTraversal[] traversals) {
		for (ResourceTraversal traversal : traversals) {
			addTraversal(traversal);
		}
	}

	public synchronized void addTraversal(ResourceTraversal traversal) {
		IResource[] resources = traversal.getResources();
		for (IResource resource : resources) {
			addResource(resource, traversal.getDepth());
		}
	}

	public synchronized void addResource(IResource resource, int depth) {
		if (resource.getType() == IResource.FILE) {
			if (!isCovered(resource, IResource.DEPTH_ZERO))
				files.add(resource);
		}
		switch (depth) {
		case IResource.DEPTH_INFINITE:
			addDeepFolder(resource);
			break;
		case IResource.DEPTH_ONE:
			addShallowFolder(resource);
			break;
		case IResource.DEPTH_ZERO:
			addZeroFolder(resource);
			break;
		}
	}

	private void addShallowFolder(IResource resource) {
		if (!isCovered(resource, IResource.DEPTH_ONE)) {
			shallowFolders.add(resource);
			removeDescendants(resource, IResource.DEPTH_ONE);
		}
	}

	public synchronized boolean isCovered(IResource resource, int depth) {
		IPath fullPath = resource.getFullPath();
		// Regardless of the depth, look for a deep folder that covers the resource
		for (Iterator iter = deepFolders.iterator(); iter.hasNext();) {
			IResource deepFolder = (IResource) iter.next();
			if (deepFolder.getFullPath().isPrefixOf(fullPath)) {
				return true;
			}
		}
		// For files, look in the shallow folders and files
		if (resource.getType() == IResource.FILE) {
			return (shallowFolders.contains(resource.getParent()) || files.contains(resource));
		}
		// For folders, look in appropriate sets
		switch (depth) {
		case IResource.DEPTH_ONE:
			return (shallowFolders.contains(resource));
		case IResource.DEPTH_ZERO:
			return (shallowFolders.contains(resource.getParent()) || zeroFolders.contains(resource));
		}
		return false;
	}

	private void addZeroFolder(IResource resource) {
		if (!isCovered(resource, IResource.DEPTH_ZERO))
			zeroFolders.add(resource);
	}

	private void addDeepFolder(IResource resource) {
		if (!isCovered(resource, IResource.DEPTH_INFINITE)) {
			deepFolders.add(resource);
			removeDescendants(resource, IResource.DEPTH_INFINITE);
		}
	}

	private void removeDescendants(IResource resource, int depth) {
		IPath fullPath = resource.getFullPath();
		// First, remove any files that are now covered
		for (Iterator iter = files.iterator(); iter.hasNext();) {
			IResource child = (IResource) iter.next();
			switch (depth) {
			case IResource.DEPTH_INFINITE:
				if (fullPath.isPrefixOf(child.getFullPath())) {
					iter.remove();
				}
				break;
			case IResource.DEPTH_ONE:
				if (fullPath.equals(child.getFullPath().removeLastSegments(1))) {
					iter.remove();
				}
				break;
			}
		}
		// Now, remove any shallow folders
		if (depth == IResource.DEPTH_INFINITE) {
			for (Iterator iter = shallowFolders.iterator(); iter.hasNext();) {
				IResource child = (IResource) iter.next();
				if (fullPath.isPrefixOf(child.getFullPath())) {
					iter.remove();
				}
			}
		}
		// Finally, remove any zero folders
		for (Iterator iter = zeroFolders.iterator(); iter.hasNext();) {
			IResource child = (IResource) iter.next();
			switch (depth) {
			case IResource.DEPTH_INFINITE:
				if (fullPath.isPrefixOf(child.getFullPath())) {
					iter.remove();
				}
				break;
			case IResource.DEPTH_ONE:
				// TODO: Is a zero folder covered by a shallow folder?
				if (fullPath.equals(child.getFullPath().removeLastSegments(1))) {
					iter.remove();
				}
				break;
			}
		}
	}

	public synchronized void add(CompoundResourceTraversal compoundTraversal) {
		// Technically, this code should synchronize on compoundTraversal.
		// However, this makes deadlock possible and, in practive, I don't think that
		// the provided traversal will be modified after it is passed to this method.
		addResources(
				compoundTraversal.deepFolders.toArray(new IResource[compoundTraversal.deepFolders.size()]),
				IResource.DEPTH_INFINITE);
		addResources(
				compoundTraversal.shallowFolders.toArray(new IResource[compoundTraversal.shallowFolders.size()]),
				IResource.DEPTH_ONE);
		addResources(
				compoundTraversal.zeroFolders.toArray(new IResource[compoundTraversal.zeroFolders.size()]),
				IResource.DEPTH_ZERO);
		addResources(
				compoundTraversal.files.toArray(new IResource[compoundTraversal.files.size()]),
				IResource.DEPTH_ZERO);
	}

	public synchronized void addResources(IResource[] resources, int depth) {
		for (IResource resource : resources) {
			addResource(resource, depth);
		}

	}

	
Return the resources contained in the given traversals that are not covered by this traversal
Params:
traversals – the traversals being testes
Returns:
the resources contained in the given traversals that are not covered by this traversal/**
	 * Return the resources contained in the given traversals that are not covered by this traversal
	 * @param traversals the traversals being testes
	 * @return the resources contained in the given traversals that are not covered by this traversal
	 */
	public synchronized IResource[] getUncoveredResources(ResourceTraversal[] traversals) {
		CompoundResourceTraversal newTraversals = new CompoundResourceTraversal();
		newTraversals.addTraversals(traversals);
		return getUncoveredResources(newTraversals);
	}

	/*
	 * Return any resources in the other traversal that are not covered by this traversal
	 */
	private IResource[] getUncoveredResources(CompoundResourceTraversal otherTraversal) {
		Set<IResource> result = new HashSet<>();
		for (Iterator iter = otherTraversal.files.iterator(); iter.hasNext();) {
			IResource resource = (IResource) iter.next();
			if (!isCovered(resource, IResource.DEPTH_ZERO)) {
				result.add(resource);
			}
		}
		for (Iterator iter = otherTraversal.zeroFolders.iterator(); iter.hasNext();) {
			IResource resource = (IResource) iter.next();
			if (!isCovered(resource, IResource.DEPTH_ZERO)) {
				result.add(resource);
			}
		}
		for (Iterator iter = otherTraversal.shallowFolders.iterator(); iter.hasNext();) {
			IResource resource = (IResource) iter.next();
			if (!isCovered(resource, IResource.DEPTH_ONE)) {
				result.add(resource);
			}
		}
		for (Iterator iter = otherTraversal.deepFolders.iterator(); iter.hasNext();) {
			IResource resource = (IResource) iter.next();
			if (!isCovered(resource, IResource.DEPTH_INFINITE)) {
				result.add(resource);
			}
		}
		return result.toArray(new IResource[result.size()]);
	}

	public synchronized ResourceTraversal[] asTraversals() {
		List<ResourceTraversal> result = new ArrayList<>();
		if (!files.isEmpty() || ! zeroFolders.isEmpty()) {
			Set<IResource> combined = new HashSet<>();
			combined.addAll(files);
			combined.addAll(zeroFolders);
			result.add(new ResourceTraversal(combined.toArray(new IResource[combined.size()]), IResource.DEPTH_ZERO, IResource.NONE));
		}
		if (!shallowFolders.isEmpty()) {
			result.add(new ResourceTraversal(shallowFolders.toArray(new IResource[shallowFolders.size()]), IResource.DEPTH_ONE, IResource.NONE));
		}
		if (!deepFolders.isEmpty()) {
			result.add(new ResourceTraversal(deepFolders.toArray(new IResource[deepFolders.size()]), IResource.DEPTH_INFINITE, IResource.NONE));
		}
		return result.toArray(new ResourceTraversal[result.size()]);
	}

	public synchronized IResource[] getRoots() {
		List<IResource> result = new ArrayList<>();
		result.addAll(files);
		result.addAll(zeroFolders);
		result.addAll(shallowFolders);
		result.addAll(deepFolders);
		return result.toArray(new IResource[result.size()]);
	}

	public synchronized ResourceTraversal[] getUncoveredTraversals(ResourceTraversal[] traversals) {
		CompoundResourceTraversal other = new CompoundResourceTraversal();
		other.addTraversals(traversals);
		return getUncoveredTraversals(other);
	}

	public ResourceTraversal[] getUncoveredTraversals(CompoundResourceTraversal otherTraversal) {
		synchronized (otherTraversal) {
			CompoundResourceTraversal uncovered = new CompoundResourceTraversal();
			for (Iterator iter = otherTraversal.files.iterator(); iter.hasNext();) {
				IResource resource = (IResource) iter.next();
				if (!isCovered(resource, IResource.DEPTH_ZERO)) {
					uncovered.addResource(resource, IResource.DEPTH_ZERO);
				}
			}
			for (Iterator iter = otherTraversal.zeroFolders.iterator(); iter.hasNext();) {
				IResource resource = (IResource) iter.next();
				if (!isCovered(resource, IResource.DEPTH_ZERO)) {
					uncovered.addResource(resource, IResource.DEPTH_ZERO);
				}
			}
			for (Iterator iter = otherTraversal.shallowFolders.iterator(); iter.hasNext();) {
				IResource resource = (IResource) iter.next();
				if (!isCovered(resource, IResource.DEPTH_ONE)) {
					uncovered.addResource(resource, IResource.DEPTH_ONE);
				}
			}
			for (Iterator iter = otherTraversal.deepFolders.iterator(); iter.hasNext();) {
				IResource resource = (IResource) iter.next();
				if (!isCovered(resource, IResource.DEPTH_INFINITE)) {
					uncovered.addResource(resource, IResource.DEPTH_INFINITE);
				}
			}
			return uncovered.asTraversals();
		}
	}

	public synchronized void clear() {
		deepFolders.clear();
		shallowFolders.clear();
		zeroFolders.clear();
		files.clear();
	}

}