/*******************************************************************************
 * Copyright (c) 2003, 2010 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.equinox.p2.testserver;

import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import java.security.AccessControlContext;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import org.osgi.framework.Bundle;

/**
 * Utility class to execute common privileged code.
 */
public class SecureAction {
	// make sure we use the correct controlContext;
	private final AccessControlContext controlContext;

	/**
	 * Constructs a new SecureAction object. The constructed SecureAction object
	 * uses the caller's AccessControlContext to perform security checks
	 */
	public SecureAction() {
		// save the control context to be used.
		this.controlContext = AccessController.getContext();
	}

	/**
	 * Gets a resource from a bundle.
	 *
	 * @param bundle the bundle to get the resource from
	 * @param name   The name of the resource
	 * @return The URL of the resource
	 */

	public URL getBundleResource(final Bundle bundle, final String name) {
		if (System.getSecurityManager() == null)
			return bundle.getResource(name);
		return AccessController.doPrivileged((PrivilegedAction<URL>) () -> bundle.getResource(name), controlContext);
	}

	public URLConnection openURL(final URL url) throws IOException {
		if (System.getSecurityManager() == null)
			return open(url);
		try {
			return AccessController.doPrivileged((PrivilegedExceptionAction<URLConnection>) () -> open(url),
					controlContext);
		} catch (PrivilegedActionException ex) {
			throw (IOException) ex.getException();
		}
	}

	URLConnection open(final URL url) throws IOException {
		URLConnection connection = url.openConnection();
		connection.connect(); /* establish connection to check permissions */
		return connection;
	}

	/**
	 * Returns a system property. Same as calling System.getProperty(String,String).
	 *
	 * @param property the property key.
	 * @param def      the default value if the property key does not exist.
	 * @return the value of the property or the def value if the property does not
	 *         exist.
	 */
	public String getProperty(final String property, final String def) {
		if (System.getSecurityManager() == null)
			return System.getProperty(property, def);
		return AccessController.doPrivileged((PrivilegedAction<String>) () -> System.getProperty(property, def),
				controlContext);
	}

}