/*******************************************************************************
 *
 * Copyright (c) 2004-2009 Oracle Corporation.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * 
 *    Kohsuke Kawaguchi
 *
 *
 *******************************************************************************/ 

package hudson.security;

import org.springframework.security.authentication.AuthenticationManager;
import org.springframework.security.authentication.DisabledException;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;


/**
 * {@link AuthenticationManager} proxy that delegates to another instance.
 *
 * <p> This is used so that we can set up servlet filters first (which requires
 * a reference to {@link AuthenticationManager}), then later change the actual
 * authentication manager (and its set up) at runtime.
 *
 * @author Kohsuke Kawaguchi
 */
public class AuthenticationManagerProxy implements AuthenticationManager {

    private volatile AuthenticationManager delegate;

    public Authentication authenticate(Authentication authentication) throws AuthenticationException {
        AuthenticationManager m = delegate; // fix the reference we are working with

        if (m == null) {
            throw new DisabledException("Authentication service is still not ready yet");
        } else {
            return m.authenticate(authentication);
        }
    }

    public void setDelegate(AuthenticationManager manager) {
        this.delegate = manager;
    }
}