/*
 * Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
 *
 * This file is part of Resin(R) Open Source
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * Resin Open Source is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Resin Open Source is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
 * of NON-INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Resin Open Source; if not, write to the
 *
 *   Free Software Foundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Scott Ferguson
 */

package com.caucho.security;

import java.security.Principal;
import java.util.ArrayList;

import javax.ejb.Startup;
import javax.inject.Singleton;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Used to allow multiple login types in a priority list.
 *
 * @since Resin 4.0.2
 */
@Singleton
@Startup
public class LoginList implements Login {
  private final ArrayList<Login> _loginList = new ArrayList<Login>();

  /**
   * Adds the next login in the list.
   */
  public void add(Login login)
  {
    _loginList.add(login);
  }

  /**
   * Returns the login list.
   */
  public ArrayList<Login> getLoginList()
  {
    return _loginList;
  }

  /**
   * Returns the authentication type.  <code>getAuthType</code> is called
   * by <code>HttpServletRequest.getAuthType</code>.
   */
  public String getAuthType()
  {
    if (_loginList.size() == 0)
      return null;

    return _loginList.get(0).getAuthType();
  }

  /**
   * Returns the configured authenticator
   */
  public Authenticator getAuthenticator()
  {
    if (_loginList.size() == 0)
      return null;

    return _loginList.get(0).getAuthenticator();
  }

  /**
   * Returns true if the login is used for this request
   */
  public boolean isLoginUsedForRequest(HttpServletRequest request)
  {
    for (int i = 0; i < _loginList.size(); i++) {
      if (_loginList.get(i).isLoginUsedForRequest(request))
        return true;
    }

    return false;
  }

  /**
   * Returns the Principal associated with the current request.
   * getUserPrincipal is called in response to the Request.getUserPrincipal
   * call.  Login.getUserPrincipal can't modify the response or return
   * an error page.
   *
   * @param request servlet request
   *
   * @return the logged in principal on success, null on failure.
   */
  public Principal getUserPrincipal(HttpServletRequest request)
  {
    for (int i = 0; i < _loginList.size(); i++) {
      Principal user = _loginList.get(i).getUserPrincipal(request);

      if (user != null)
        return user;
    }

    return null;
  }

  /**
   * Logs a user in.  The authenticate method is called during the
   * security check.  If the user does not exist, <code>authenticate</code>
   * sets the reponse error page and returns null.
   *
   * @param request servlet request
   * @param response servlet response for a failed authentication.
   * @param isFail true if the authorization has failed
   *
   * @return the logged in principal on success, null on failure.
   */
  public Principal login(HttpServletRequest request,
                         HttpServletResponse response,
                         boolean isFail)
  {
    for (int i = 0; i < _loginList.size(); i++) {
      Login login = _loginList.get(i);

      if (login.isLoginUsedForRequest(request)) {
        Principal user = login.login(request, response, isFail);

        if (user != null)
          return user;
      }
    }

    // if none match, use first

    if (_loginList.size() > 0) {
      Login login = _loginList.get(0);

      Principal user = login.login(request, response, isFail);

      return user;
    }

    return null;
  }

  /**
   * Returns true if username and password based authentication is supported.
   * @see BasicLogin
   * @return
   */
  public boolean isPasswordBased()
  {
    for (int i = 0; i < _loginList.size(); i++) {
      if (_loginList.get(i).isPasswordBased())
        return true;
    }

    return false;
  }

  /**
   * Returns true if the current user plays the named role.
   * <code>isUserInRole</code> is called in response to the
   * <code>HttpServletRequest.isUserInRole</code> call.
   *
   * @param user the logged in user
   * @param role the role to check
   *
   * @return true if the user plays the named role
   */
  public boolean isUserInRole(Principal user, String role)
  {
    for (int i = 0; i < _loginList.size(); i++) {
      if (_loginList.get(i).isUserInRole(user, role))
        return true;
    }

    return false;
  }

  /**
   * Logs the user out from the given request.
   *
   * <p>Since there is no servlet API for logout, this must be called
   * directly from user code.  Resin stores the web-app's login object
   * in the ServletContext attribute "caucho.login".
   */
  public void logout(Principal user,
                     HttpServletRequest request,
                     HttpServletResponse response)
  {
    for (int i = 0; i < _loginList.size(); i++) {
      _loginList.get(i).logout(user, request, response);
    }
  }

  /**
   * Called when the session invalidates.
   */
  public void sessionInvalidate(HttpSession session,
                                boolean isTimeout)
  {
    for (int i = 0; i < _loginList.size(); i++) {
      _loginList.get(i).sessionInvalidate(session, isTimeout);
    }
  }

  public String toString()
  {
    return getClass().getSimpleName() + _loginList;
  }
}