Copyright (c) 2005, 2012 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) 2005, 2012 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.loader.buddy;

import java.io.IOException;
import java.net.URL;
import java.util.Enumeration;
import org.eclipse.osgi.internal.loader.BundleLoader;
import org.osgi.service.packageadmin.ExportedPackage;
import org.osgi.service.packageadmin.PackageAdmin;

Global policy is an implementation of a buddy policy. It is responsible
for looking up a class within the global set of exported classes. If multiple
version of the same package are exported in the system, the exported package
with the highest version will be returned.
/**
 * Global policy is an implementation of a buddy policy. It is responsible
 * for looking up a class within the global set of exported classes. If multiple
 * version of the same package are exported in the system, the exported package
 * with the highest version will be returned.
 */
@SuppressWarnings("deprecation")
public class GlobalPolicy implements IBuddyPolicy {
	private PackageAdmin admin;

	public GlobalPolicy(PackageAdmin admin) {
		this.admin = admin;
	}

	@Override
	public Class<?> loadClass(String name) {
		ExportedPackage pkg = admin.getExportedPackage(BundleLoader.getPackageName(name));
		if (pkg == null)
			return null;
		try {
			return pkg.getExportingBundle().loadClass(name);
		} catch (ClassNotFoundException e) {
			return null;
		}
	}

	@Override
	public URL loadResource(String name) {
		//get all exported packages that match the resource's package
		ExportedPackage pkg = admin.getExportedPackage(BundleLoader.getResourcePackageName(name));
		if (pkg == null)
			return null;
		return pkg.getExportingBundle().getResource(name);
	}

	@Override
	public Enumeration<URL> loadResources(String name) {
		//get all exported packages that match the resource's package
		ExportedPackage[] pkgs = admin.getExportedPackages(BundleLoader.getResourcePackageName(name));
		if (pkgs == null || pkgs.length == 0)
			return null;

		//get all matching resources for each package
		Enumeration<URL> results = null;
		for (ExportedPackage pkg : pkgs) {
			try {
				results = BundleLoader.compoundEnumerations(results, pkg.getExportingBundle().getResources(name));
			}catch (IOException e) {
				//ignore IO problems and try next package
			}
		}

		return results;
	}
}