/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.apache.harmony.auth;

import java.io.Serializable;
import java.security.Principal;

import org.apache.harmony.auth.internal.nls.Messages;

/**
 * This class represents a unix groups by its group id.
 */
public class UnixNumericGroupPrincipal implements Serializable, Principal {

	private static final long serialVersionUID = -535408497353506159L;

	// Group id
	private final long gid;
	// Group name
	private String gname;

	/**
	 * Creates the object using gid passed.
	 * 
	 * @param gid
	 *            gid
	 * @param primary
	 *            shows whether the group is primary
	 */
	public UnixNumericGroupPrincipal(long gid, boolean primary) {
		this.gid = gid;
	}

	/**
	 * Creates the object using gid and group's name passed.
	 * 
	 * @param gid
	 *            gid
	 * @param gname
	 *            group name
	 * @param primary
	 *            shows whether the group is primary
	 */
	public UnixNumericGroupPrincipal(long gid, String gname, boolean primary) {
		this.gid = gid;
		this.gname = gname;
	}

	/**
	 * Creates the object using a String representation of gid.
	 * 
	 * @param gid
	 *            string representation of gid
	 * @param primary
	 *            shows whether the group is primary throws NullPointerException
	 *            if gid is null
	 */
	public UnixNumericGroupPrincipal(String gid, boolean primary) {
		if (gid == null) {
			throw new NullPointerException(Messages.getString("auth.07")); //$NON-NLS-1$
		}
		this.gid = Long.parseLong(gid);
	}

	/**
	 * Tests objects for equality.<br>
	 * The objects are considered equals if they both are of type
	 * UnixNumericGroupPrincipal and have the same gid.
	 */
	@Override
	public boolean equals(Object o) {
		if (o instanceof UnixNumericGroupPrincipal) {
			return ((UnixNumericGroupPrincipal) o).gid == gid;
		}
		return false;
	}

	/**
	 * Returns String representation of the stored GID.
	 */
	@Override
	public String getName() {
		return Long.toString(gid);
	}

	/**
	 * Returns group name.
	 */
	public String getObjectName() {
		return gname;
	}

	/**
	 * Returns hash code of this object.
	 */
	@Override
	public int hashCode() {
		return (int) gid;
	}

	/**
	 * Returns numeric representation of the stored gid.
	 */
	public long longValue() {
		return gid;
	}

	/**
	 * Returns String representation of this object.
	 */
	@Override
	public String toString() {
		if (gname == null) {
			return "UnixNumericGroupPrincipal, gid=" + gid; //$NON-NLS-1$
		}
		return "UnixNumericGroupPrincipal, gid=" + gid + "; name=" + gname; //$NON-NLS-1$ //$NON-NLS-2$
	}
}