/* 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.core.session;

import org.springframework.security.core.SpringSecurityCoreVersion;
import org.springframework.util.Assert;

import java.util.Date;
import java.io.Serializable;


/**
 * Represents a record of a session within the Spring Security framework.
 * <p>
 * This is primarily used for concurrent session support.
 * <p>
 * Sessions have three states: active, expired, and destroyed. A session can that is invalidated by
 * <code>session.invalidate()</code> or via Servlet Container management is considered "destroyed". An "expired"
 * session, on the other hand, is a session that Spring Security wants to end because it was selected for removal for
 * some reason (generally as it was the least recently used session and the maximum sessions for the user were
 * reached). An "expired" session is removed as soon as possible by a <code>Filter</code>.
 *
 * @author Ben Alex
 */
public class SessionInformation implements Serializable {

    private static final long serialVersionUID = SpringSecurityCoreVersion.SERIAL_VERSION_UID;

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

    private Date lastRequest;
    private final Object principal;
    private final String sessionId;
    private boolean expired = false;

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

    public SessionInformation(Object principal, String sessionId, Date lastRequest) {
        Assert.notNull(principal, "Principal required");
        Assert.hasText(sessionId, "SessionId required");
        Assert.notNull(lastRequest, "LastRequest required");
        this.principal = principal;
        this.sessionId = sessionId;
        this.lastRequest = lastRequest;
    }

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

    public void expireNow() {
        this.expired = true;
    }

    public Date getLastRequest() {
        return lastRequest;
    }

    public Object getPrincipal() {
        return principal;
    }

    public String getSessionId() {
        return sessionId;
    }

    public boolean isExpired() {
        return expired;
    }

    /**
     * Refreshes the internal lastRequest to the current date and time.
     */
    public void refreshLastRequest() {
        this.lastRequest = new Date();
    }
}
