/*
 * Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
 *
 * 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.springframework.security.authentication;

import java.util.Collection;

import org.springframework.security.core.GrantedAuthority;
import org.springframework.security.core.SpringSecurityCoreVersion;

/**
 * Represents a remembered <code>Authentication</code>.
 * <p>
 * A remembered <code>Authentication</code> must provide a fully valid
 * <code>Authentication</code>, including the <code>GrantedAuthority</code>s that apply.
 *
 * @author Ben Alex
 * @author Luke Taylor
 */
public class RememberMeAuthenticationToken extends AbstractAuthenticationToken {

	private static final long serialVersionUID = SpringSecurityCoreVersion.SERIAL_VERSION_UID;

	// ~ Instance fields
	// ================================================================================================

	private final Object principal;
	private final int keyHash;

	// ~ Constructors
	// ===================================================================================================

	/**
	 * Constructor.
	 *
	 * @param key         to identify if this object made by an authorised client
	 * @param principal   the principal (typically a <code>UserDetails</code>)
	 * @param authorities the authorities granted to the principal
	 * @throws IllegalArgumentException if a <code>null</code> was passed
	 */
	public RememberMeAuthenticationToken(String key, Object principal,
										Collection<? extends GrantedAuthority> authorities) {
		super(authorities);

		if ((key == null) || ("".equals(key)) || (principal == null)
				|| "".equals(principal)) {
			throw new IllegalArgumentException(
					"Cannot pass null or empty values to constructor");
		}

		this.keyHash = key.hashCode();
		this.principal = principal;
		setAuthenticated(true);
	}

	/**
	 * Private Constructor to help in Jackson deserialization.
	 *
	 * @param keyHash     hashCode of above given key.
	 * @param principal   the principal (typically a <code>UserDetails</code>)
	 * @param authorities the authorities granted to the principal
	 * @since 4.2
	 */
	private RememberMeAuthenticationToken(Integer keyHash, Object principal, Collection<? extends GrantedAuthority> authorities) {
		super(authorities);

		this.keyHash = keyHash;
		this.principal = principal;
		setAuthenticated(true);
	}

	// ~ Methods
	// ========================================================================================================

	/**
	 * Always returns an empty <code>String</code>
	 *
	 * @return an empty String
	 */
	public Object getCredentials() {
		return "";
	}

	public int getKeyHash() {
		return this.keyHash;
	}

	public Object getPrincipal() {
		return this.principal;
	}

	public boolean equals(Object obj) {
		if (!super.equals(obj)) {
			return false;
		}

		if (obj instanceof RememberMeAuthenticationToken) {
			RememberMeAuthenticationToken test = (RememberMeAuthenticationToken) obj;

			if (this.getKeyHash() != test.getKeyHash()) {
				return false;
			}

			return true;
		}

		return false;
	}

}
