/*
 * Copyright (c) 2003, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.bundle.http;

import java.util.Dictionary;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;
import javax.servlet.http.HttpSessionContext;


public class HttpSessionImpl implements HttpSession {

  // private fields

  private boolean invalid = true;

  private String id = null;
  private long creationTime = -1;
  private long accessedTime = -1;
  private long lastAccessedTime = -1;
  private int maxInactiveInterval = -1;

  private final Attributes attributes = new Attributes();


  // public methods

  public void init(int count) {

    creationTime = System.currentTimeMillis();
    accessedTime = creationTime;

    id = "session." + count + "." + creationTime;

    invalid = false;
  }

  public void join() {

    lastAccessedTime = accessedTime;
    accessedTime = System.currentTimeMillis();
  }

  public boolean isExpired() {
    return invalid || accessedTime + maxInactiveInterval * 1000 <
        System.currentTimeMillis();
  }

  public void destroy() {

    invalid = true;

    id = null;
    creationTime = -1;
    accessedTime = -1;
    lastAccessedTime = -1;
    maxInactiveInterval = -1;

    attributes.removeAll();
  }


  // implements HttpSession

  public String getId() {
    return id;
  }

  public boolean isNew() {

    if (invalid)
      throw new IllegalStateException("Invalid session");

    return lastAccessedTime == -1;
  }

  public long getCreationTime() {

    if (invalid)
      throw new IllegalStateException("Invalid session");

    return creationTime;
  }

  public long getLastAccessedTime() {
    return lastAccessedTime;
  }

  public int getMaxInactiveInterval() {
    return maxInactiveInterval;
  }

  public void setMaxInactiveInterval(int maxInactiveInterval) {
    this.maxInactiveInterval = maxInactiveInterval;
  }

  public void invalidate() {

    if (invalid)
      throw new IllegalStateException("Invalid session");

    Enumeration names = getAttributeNames();
    while (names.hasMoreElements())
      removeAttribute((String) names.nextElement());

    invalid = true;
  }

  public Object getAttribute(String name) {

    if (invalid)
      throw new IllegalStateException("Invalid session");

    return attributes.getAttribute(name);
  }

  public synchronized Enumeration getAttributeNames() {

    if (invalid)
      throw new IllegalStateException("Invalid session");

    return attributes.getAttributeNames();
  }

  public synchronized void setAttribute(String name, Object value) {

    if (invalid)
      throw new IllegalStateException("Invalid session");

    attributes.setAttribute(name, value);

    if (value instanceof HttpSessionBindingListener) {
      HttpSessionBindingListener listener = (HttpSessionBindingListener) value;
      listener.valueBound(new HttpSessionBindingEvent(this, name));
    }
  }

  public synchronized void removeAttribute(String name) {

    if (invalid)
      throw new IllegalStateException("Invalid session");

    Object value = attributes.removeAttribute(name);

    if (value != null && value instanceof HttpSessionBindingListener) {
      HttpSessionBindingListener listener = (HttpSessionBindingListener) value;
      listener.valueUnbound(new HttpSessionBindingEvent(this, name));
    }
  }

  public synchronized Object getValue(String name) {
    return getAttribute(name); // deprecated
  }

  public synchronized String[] getValueNames() { // deprecated

    Vector v = new Vector();

    Enumeration e = getAttributeNames();
    while (e.hasMoreElements())
      v.addElement(e.nextElement());
    String[] names = new String[v.size()];
    v.copyInto(names);

    return names;
  }

  public void putValue(String name, Object value) {
    setAttribute(name, value); // deprecated
  }

  public void removeValue(String name) {
    removeAttribute(name); // deprecated
  }

  public HttpSessionContext getSessionContext() {
    return null; // deprecated
  }

} // HttpSessionImpl