/* (c) 2014 Open Source Geospatial Foundation - all rights reserved
 * (c) 2001 - 2013 OpenPlans
 * This code is licensed under the GPL 2.0 license, available at the root
 * application directory.
 */
package org.geoserver.security;

import java.util.logging.Level;

import javax.servlet.http.HttpServletRequest;

import org.springframework.security.authentication.AuthenticationProvider;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.core.userdetails.UsernameNotFoundException;

/**
 * Authentication provider that wraps a regular {@link AuthenticationProvider} in the 
 * {@link GeoServerAuthenticationProvider} interface. 
 * 
 * @author Justin Deoliveira, OpenGeo
 *
 */
public class DelegatingAuthenticationProvider extends GeoServerAuthenticationProvider {

    AuthenticationProvider authProvider;

    public DelegatingAuthenticationProvider(AuthenticationProvider authProvider) {
        this.authProvider = authProvider;
    }

    @Override
    public boolean supports(Class<? extends Object> authentication, HttpServletRequest request) {
        return authProvider.supports(authentication);
    }

    @Override
    public final Authentication authenticate(Authentication authentication, HttpServletRequest request) {
        try {
            return doAuthenticate(authentication, request);
        } catch (AuthenticationException ex) {
            log(ex);

            // pass request to next provider in the chain
            return null; 
        }
    }

    /**
     * Does the actual authentication.
     * <p>
     * Subclasses should override this method, the default implementation simply delegages to the
     * underlying {@link AuthenticationProvider#authenticate(Authentication)}.
     * </p>
     * <p>
     * This method does not need to worry about handling any {@link AuthenticationException}, they
     * should be thrown back.
     * </p>
     */
    protected Authentication doAuthenticate(Authentication authentication, HttpServletRequest request) 
        throws AuthenticationException { 
        return authProvider.authenticate(authentication);
    }
}