/*
 * Copyright (C) 2007-2012 Argeo GmbH
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.argeo.security;

import java.security.AccessController;
import java.security.Principal;
import java.security.acl.Group;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import javax.security.auth.Subject;
import javax.security.auth.x500.X500Principal;

import org.argeo.ArgeoException;

/** Static utilities */
public final class SecurityUtils {
	private SecurityUtils() {
	}

	/** Whether the current thread has the admin role */
	public static boolean hasCurrentThreadAuthority(String authority) {
		return roles().contains(authority);
	}

	/**
	 * @return the authenticated username or null if not authenticated /
	 *         anonymous
	 */
	public static String getCurrentThreadUsername() {
		return getUsername();
	}

	public final static String getUsername() {
		Subject subject = Subject.getSubject(AccessController.getContext());
		if (subject == null)
			return null;
		if (subject.getPrincipals(X500Principal.class).size() != 1)
			return null;
		Principal principal = subject.getPrincipals(X500Principal.class)
				.iterator().next();
		return principal.getName();

	}

	public final static Set<String> roles() {
		Set<String> roles = Collections.synchronizedSet(new HashSet<String>());
		Subject subject = Subject.getSubject(AccessController.getContext());
		if (subject == null)
			throw new ArgeoException("Not authenticated.");
		X500Principal userPrincipal = subject
				.getPrincipals(X500Principal.class).iterator().next();
		roles.add(userPrincipal.getName());
		for (Principal group : subject.getPrincipals(Group.class)) {
			roles.add(group.getName());
		}
		return roles;
	}
}