Copyright (c) 2000, 2008 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) 2000, 2008 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.ltk.internal.core.refactoring.resource;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;

public class ResourceProcessors {

	public static String[] computeAffectedNatures(IResource resource) throws CoreException {
		IProject project= resource.getProject();
		Set<String> result= new HashSet<>();
		Set<IProject> visitedProjects= new HashSet<>();
		computeNatures(result, visitedProjects, project);
		return result.toArray(new String[result.size()]);
	}

	public static String[] computeAffectedNatures(IResource[] resources) throws CoreException {
		Set<String> result= new HashSet<>();
		Set<IProject> visitedProjects= new HashSet<>();
		for (IResource resource : resources) {
			computeNatures(result, visitedProjects, resource.getProject());
		}
		return result.toArray(new String[result.size()]);
	}

	private static void computeNatures(Set<String> result, Set<IProject> visitedProjects, IProject focus) throws CoreException {
		if (visitedProjects.contains(focus))
			return;
		String[] pns= focus.getDescription().getNatureIds();
		result.addAll(Arrays.asList(pns));
		visitedProjects.add(focus);
		IProject[] referencing= focus.getReferencingProjects();
		for (IProject r : referencing) {
			computeNatures(result, visitedProjects, r);
		}
	}

	public static IPath handleToResourcePath(final String project, final String handle) {
		final IPath path= Path.fromPortableString(handle);
		if (project != null && project.length() > 0 && !path.isAbsolute())
			return new Path(project).append(path).makeAbsolute();
		return path;
	}

	public static String resourcePathToHandle(final String project, final IPath resourcePath) {
		if (project != null && project.length() > 0 && resourcePath.segmentCount() != 1)
			if (resourcePath.segment(0).equals(project)) {
				return resourcePath.removeFirstSegments(1).toPortableString();
			}
		return resourcePath.toPortableString();
	}
}