/* Copyright 2012 Acegi Technology
 * auth jiangww
 */
package com.jeeww.core.security;

import org.springframework.security.authentication.AuthenticationProvider;
import org.springframework.security.authentication.AuthenticationServiceException;
import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
import org.springframework.security.authentication.dao.SaltSource;
import org.springframework.security.authentication.encoding.PasswordEncoder;
import org.springframework.security.authentication.encoding.PlaintextPasswordEncoder;
import org.springframework.security.core.AuthenticationException;
import org.springframework.security.core.userdetails.UserDetails;
import org.springframework.security.core.userdetails.UserDetailsService;
import org.springframework.security.core.userdetails.UsernameNotFoundException;
import org.springframework.util.Assert;

/**
 * An {@link AuthenticationProvider} implementation that retrieves user details
 * from a {@link UserDetailsService}.
 * 
 * @author jiangww
 */
public class CustomerDaoAuthenticationProvider extends CustomerAbstractUserDetailsAuthenticationProvider {
	// ~ Static fields/initializers
	// =====================================================================================
	/**
	 * The plaintext password used to perform
	 * {@link PasswordEncoder#isPasswordValid(String, String, Object)} on when
	 * the user is not found to avoid SEC-2056.
	 */
	private static final String	USER_NOT_FOUND_PASSWORD	= "userNotFoundPassword";

	// ~ Instance fields
	// ================================================================================================

	private PasswordEncoder		passwordEncoder;

	/**
	 * The password used to perform
	 * {@link PasswordEncoder#isPasswordValid(String, String, Object)} on when
	 * the user is not found to avoid SEC-2056. This is necessary, because some
	 * {@link PasswordEncoder} implementations will short circuit if the
	 * password is not in a valid format.
	 */
	private String				userNotFoundEncodedPassword;

	private SaltSource			saltSource;

	private UserDetailsService	userDetailsService;

	public CustomerDaoAuthenticationProvider() {
		setPasswordEncoder(new PlaintextPasswordEncoder());
	}

	// ~ Methods
	// ========================================================================================================

	@SuppressWarnings("deprecation")
	protected void additionalAuthenticationChecks(UserDetails userDetails, UsernamePasswordAuthenticationToken authentication) throws AuthenticationException {
		Object salt = null;

		if (this.saltSource != null) {
			salt = this.saltSource.getSalt(userDetails);
		}

		if (authentication.getCredentials() == null || authentication.getCredentials().equals("")) {
			logger.debug("Authentication failed: no credentials provided");

			throw new BadCredentialsException(messages.getMessage("AbstractUserDetailsAuthenticationProvider.badCredentials", "Bad credentials"), userDetails);
		}
		// sessionFactory.getCurrentSession();
//		String pass = passwordEncoder.encodePassword(presentedPassword, salt);
		String presentedPassword = authentication.getCredentials().toString();
		if (userDetails.getPassword() == null) {
			logger.debug("Authentication failed: password does not match stored value");
			throw new BadCredentialsException(messages.getMessage("AbstractUserDetailsAuthenticationProvider.badCredentials", "Bad credentials"), userDetails);
		}
		if (!passwordEncoder.isPasswordValid(userDetails.getPassword().toLowerCase(), presentedPassword, null)) {
			logger.debug("Authentication failed: password does not match stored value");
			throw new BadCredentialsException(messages.getMessage("AbstractUserDetailsAuthenticationProvider.badCredentials", "Bad credentials"), userDetails);
		}
	}

	protected void doAfterPropertiesSet() throws Exception {
		Assert.notNull(this.userDetailsService, "A UserDetailsService must be set");
	}

	protected final UserDetails retrieveUser(String username, UsernamePasswordAuthenticationToken authentication) throws AuthenticationException {
		UserDetails loadedUser;

		try {
			loadedUser = this.getUserDetailsService().loadUserByUsername(username);
		} catch (UsernameNotFoundException notFound) {
			if (authentication.getCredentials() != null) {
				String presentedPassword = authentication.getCredentials().toString();
				passwordEncoder.isPasswordValid(userNotFoundEncodedPassword, presentedPassword, null);
			}
			throw notFound;
		} catch (Exception repositoryProblem) {
			throw new AuthenticationServiceException(repositoryProblem.getMessage(), repositoryProblem);
		}

		if (loadedUser == null) {
			throw new AuthenticationServiceException("UserDetailsService returned null, which is an interface contract violation");
		}
		return loadedUser;
	}

	/**
	 * Sets the PasswordEncoder instance to be used to encode and validate
	 * passwords. If not set, the password will be compared as plain text.
	 * <p>
	 * For systems which are already using salted password which are encoded
	 * with a previous release, the encoder should be of type
	 * {@code org.springframework.security.authentication.encoding.PasswordEncoder}
	 * . Otherwise, the recommended approach is to use
	 * {@code org.springframework.security.crypto.password.PasswordEncoder}.
	 * 
	 * @param passwordEncoder
	 *            must be an instance of one of the {@code PasswordEncoder}
	 *            types.
	 */
	public void setPasswordEncoder(Object passwordEncoder) {
		Assert.notNull(passwordEncoder, "passwordEncoder cannot be null");

		if (passwordEncoder instanceof PasswordEncoder) {
			setPasswordEncoder((PasswordEncoder) passwordEncoder);
			return;
		}

		if (passwordEncoder instanceof org.springframework.security.crypto.password.PasswordEncoder) {
			final org.springframework.security.crypto.password.PasswordEncoder delegate = (org.springframework.security.crypto.password.PasswordEncoder) passwordEncoder;
			setPasswordEncoder(new PasswordEncoder() {
				public String encodePassword(String rawPass, Object salt) {
					checkSalt(salt);
					return delegate.encode(rawPass);
				}

				public boolean isPasswordValid(String encPass, String rawPass, Object salt) {
					checkSalt(salt);
					return delegate.matches(rawPass, encPass);
				}

				private void checkSalt(Object salt) {
					Assert.isNull(salt, "Salt value must be null when used with crypto module PasswordEncoder");
				}
			});

			return;
		}

		throw new IllegalArgumentException("passwordEncoder must be a PasswordEncoder instance");
	}

	private void setPasswordEncoder(PasswordEncoder passwordEncoder) {
		Assert.notNull(passwordEncoder, "passwordEncoder cannot be null");

		this.userNotFoundEncodedPassword = passwordEncoder.encodePassword(USER_NOT_FOUND_PASSWORD, null);
		this.passwordEncoder = passwordEncoder;
	}

	protected PasswordEncoder getPasswordEncoder() {
		return passwordEncoder;
	}

	/**
	 * The source of salts to use when decoding passwords. <code>null</code> is
	 * a valid value, meaning the <code>DaoAuthenticationProvider</code> will
	 * present <code>null</code> to the relevant <code>PasswordEncoder</code>.
	 * <p>
	 * Instead, it is recommended that you use an encoder which uses a random
	 * salt and combines it with the password field. This is the default
	 * approach taken in the
	 * {@code org.springframework.security.crypto.password} package.
	 * 
	 * @param saltSource
	 *            to use when attempting to decode passwords via the
	 *            <code>PasswordEncoder</code>
	 */
	public void setSaltSource(SaltSource saltSource) {
		this.saltSource = saltSource;
	}

	protected SaltSource getSaltSource() {
		return saltSource;
	}

	public void setUserDetailsService(UserDetailsService userDetailsService) {
		this.userDetailsService = userDetailsService;
	}

	protected UserDetailsService getUserDetailsService() {
		return userDetailsService;
	}
}
