Copyright (c) 2012, 2013 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) 2012, 2013 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.osgi.internal.container;

import java.security.Permission;
import java.util.*;
import org.osgi.framework.*;
import org.osgi.framework.namespace.*;
import org.osgi.framework.wiring.*;
import org.osgi.resource.*;

public class InternalUtils {

	
Coerce the generic type of a list from List
to List
Params:
l – List to be coerced.
Returns:
l coerced to List/**
	 * Coerce the generic type of a list from List<BundleCapability>
	 * to List<Capability>
	 * @param l List to be coerced.
	 * @return l coerced to List<Capability>
	 */
	@SuppressWarnings("unchecked")
	public static List<Capability> asListCapability(List<? extends Capability> l) {
		return (List<Capability>) l;
	}

	
Coerce the generic type of a list from List
to List
Params:
l – List to be coerced.
Returns:
l coerced to List/**
	 * Coerce the generic type of a list from List<BundleRequirement>
	 * to List<Requirement>
	 * @param l List to be coerced.
	 * @return l coerced to List<Requirement>
	 */
	@SuppressWarnings("unchecked")
	public static List<Requirement> asListRequirement(List<? extends Requirement> l) {
		return (List<Requirement>) l;
	}

	
Coerce the generic type of a list from List
to List
Params:
l – List to be coerced.
Returns:
l coerced to List/**
	 * Coerce the generic type of a list from List<? extends BundleCapability>
	 * to List<BundleCapability>
	 * @param l List to be coerced.
	 * @return l coerced to List<BundleCapability>
	 */
	@SuppressWarnings("unchecked")
	public static List<BundleCapability> asListBundleCapability(List<? extends BundleCapability> l) {
		return (List<BundleCapability>) l;
	}

	
Coerce the generic type of a list from List
to List
Params:
l – List to be coerced.
Returns:
l coerced to List/**
	 * Coerce the generic type of a list from List<? extends BundleRequirement>
	 * to List<BundleRequirement>
	 * @param l List to be coerced.
	 * @return l coerced to List<BundleRequirement>
	 */
	@SuppressWarnings("unchecked")
	public static List<BundleRequirement> asListBundleRequirement(List<? extends BundleRequirement> l) {
		return (List<BundleRequirement>) l;
	}

	
Coerce the generic type of a list from List
to List
Params:
l – List to be coerced.
Returns:
l coerced to List/**
	 * Coerce the generic type of a list from List<? extends BundleWire>
	 * to List<BundleWire>
	 * @param l List to be coerced.
	 * @return l coerced to List<BundleWire>
	 */
	@SuppressWarnings("unchecked")
	public static List<BundleWire> asListBundleWire(List<? extends BundleWire> l) {
		return (List<BundleWire>) l;
	}

	
Coerce the generic type of a list from List
to List
Params:
l – List to be coerced.
Returns:
l coerced to List/**
	 * Coerce the generic type of a list from List<? extends BundleWire>
	 * to List<BundleWire>
	 * @param l List to be coerced.
	 * @return l coerced to List<BundleWire>
	 */
	@SuppressWarnings("unchecked")
	public static List<Wire> asListWire(List<? extends Wire> l) {
		return (List<Wire>) l;
	}

	
Coerce the generic type of a list from List
to List
Params:
l – List to be coerced.
Returns:
l coerced to List/**
	 * Coerce the generic type of a list from List<? extends BundleRevision>
	 * to List<BundleRevision>
	 * @param l List to be coerced.
	 * @return l coerced to List<BundleRevision>
	 */
	@SuppressWarnings("unchecked")
	public static List<BundleRevision> asListBundleRevision(List<? extends BundleRevision> l) {
		return (List<BundleRevision>) l;
	}

	
Coerce the generic type of a collection from Collection
to Collection
Params:
c – List to be coerced.
Returns:
c coerced to Collection/**
	 * Coerce the generic type of a collection from Collection<? extends Resource>
	 * to Collection<Resource>
	 * @param c List to be coerced.
	 * @return c coerced to Collection<Resource>
	 */
	@SuppressWarnings("unchecked")
	public static Collection<Resource> asCollectionResource(Collection<? extends Resource> c) {
		return (Collection<Resource>) c;
	}

	
Coerce the generic type of a collection from Collection
to Collection
Params:
c – List to be coerced.
Returns:
c coerced to Collection/**
	 * Coerce the generic type of a collection from Collection<? extends BundleWiring>
	 * to Collection<BundleWiring>
	 * @param c List to be coerced.
	 * @return c coerced to Collection<BundleWiring>
	 */
	@SuppressWarnings("unchecked")
	public static Collection<BundleWiring> asCollectionBundleWiring(Collection<? extends BundleWiring> c) {
		return (Collection<BundleWiring>) c;
	}

	public static void filterCapabilityPermissions(Collection<? extends BundleCapability> capabilities) {
		if (System.getSecurityManager() == null) {
			return;
		}
		for (Iterator<? extends BundleCapability> iCapabilities = capabilities.iterator(); iCapabilities.hasNext();) {
			BundleCapability capability = iCapabilities.next();
			Permission permission = getProvidePermission(capability);
			Bundle provider = capability.getRevision().getBundle();
			if (provider != null && !provider.hasPermission(permission)) {
				iCapabilities.remove();
			}
		}
	}

	public static Permission getRequirePermission(BundleCapability candidate) {
		String name = candidate.getNamespace();
		if (PackageNamespace.PACKAGE_NAMESPACE.equals(name)) {
			return new PackagePermission(getPermisionName(candidate), candidate.getRevision().getBundle(), PackagePermission.IMPORT);
		}
		if (HostNamespace.HOST_NAMESPACE.equals(name)) {
			return new BundlePermission(getPermisionName(candidate), BundlePermission.FRAGMENT);
		}
		if (BundleNamespace.BUNDLE_NAMESPACE.equals(name)) {
			return new BundlePermission(getPermisionName(candidate), BundlePermission.REQUIRE);
		}
		return new CapabilityPermission(name, candidate.getAttributes(), candidate.getRevision().getBundle(), CapabilityPermission.REQUIRE);
	}

	public static Permission getProvidePermission(BundleCapability candidate) {
		String name = candidate.getNamespace();
		if (PackageNamespace.PACKAGE_NAMESPACE.equals(name)) {
			return new PackagePermission(getPermisionName(candidate), PackagePermission.EXPORTONLY);
		}
		if (HostNamespace.HOST_NAMESPACE.equals(name)) {
			return new BundlePermission(getPermisionName(candidate), BundlePermission.HOST);
		}
		if (BundleNamespace.BUNDLE_NAMESPACE.equals(name)) {
			return new BundlePermission(getPermisionName(candidate), BundlePermission.PROVIDE);
		}
		return new CapabilityPermission(name, CapabilityPermission.PROVIDE);
	}

	private static String getPermisionName(BundleCapability candidate) {
		Object name = candidate.getAttributes().get(candidate.getNamespace());
		if (name instanceof String) {
			return (String) name;
		}
		if (name instanceof Collection) {
			Collection<?> names = (Collection<?>) name;
			return names.isEmpty() ? "unknown" : names.iterator().next().toString(); //$NON-NLS-1$
		}
		return "unknown"; //$NON-NLS-1$
	}

}