/*
 * Copyright (C) 2005-2007 Alfresco Software Limited.
 *
 * This program 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.

 * This program 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.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 * As a special exception to the terms and conditions of version 2.0 of 
 * the GPL, you may redistribute this Program in connection with Free/Libre 
 * and Open Source Software ("FLOSS") applications as described in Alfresco's 
 * FLOSS exception.  You should have recieved a copy of the text describing 
 * the FLOSS exception, and it is also available here: 
 * http://www.alfresco.com/legal/licensing"
 */
package org.alfresco.repo.security.authentication;

import java.util.ArrayList;
import java.util.List;

import org.alfresco.service.cmr.security.AuthenticationService;

/**
 * This class implements a simple chaining authentication service. It chains together other authentication services so
 * that authentication can happen against more than one authentication service. The authentication services it uses are
 * stored as a list. Each authentication service must belong to the same domain. This is checked at configuration time.
 * Authentication will try each authentication service in order. If any allow authentication given the user name and
 * password then the user will be accepted. Additions, deletions and password changes are made to one special
 * authentication service. This service will be tried first for authentication. Users can not be created if they exist
 * in another authentication service. To avoid transactional issues in chaining, the services registered with this
 * service must not have transactional wrappers. If not, errors will mark the transaction for roll back and we can not
 * chain down the list of authentication services.
 * 
 * @author Andy Hind
 */
public class ChainingAuthenticationServiceImpl extends AbstractChainingAuthenticationService
{

    List<AuthenticationService> authenticationServices;

    AuthenticationService mutableAuthenticationService;

    public ChainingAuthenticationServiceImpl()
    {
        super();
    }

    public void setAuthenticationServices(List<AuthenticationService> authenticationServices)
    {
        this.authenticationServices = authenticationServices;
    }

    @Override
    public AuthenticationService getMutableAuthenticationService()
    {
        return this.mutableAuthenticationService;
    }

    public void setMutableAuthenticationService(AuthenticationService mutableAuthenticationService)
    {
        this.mutableAuthenticationService = mutableAuthenticationService;
    }

    @Override
    protected List<AuthenticationService> getUsableAuthenticationServices()
    {
        if (this.mutableAuthenticationService == null)
        {
            return this.authenticationServices;
        }
        else
        {
            ArrayList<AuthenticationService> services = new ArrayList<AuthenticationService>(
                    this.authenticationServices == null ? 1 : this.authenticationServices.size() + 1);
            services.add(this.mutableAuthenticationService);
            if (this.authenticationServices != null)
            {
                services.addAll(this.authenticationServices);
            }
            return services;
        }
    }
}