package org.argeo.security.equinox;

import java.util.Map;

import javax.security.auth.Subject;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.NameCallback;
import javax.security.auth.callback.PasswordCallback;
import javax.security.auth.callback.TextOutputCallback;
import javax.security.auth.login.LoginException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.argeo.security.SiteAuthenticationToken;
import org.springframework.security.Authentication;
import org.springframework.security.AuthenticationManager;
import org.springframework.security.context.SecurityContextHolder;
import org.springframework.security.providers.jaas.SecurityContextLoginModule;

/** Login module which caches one subject per thread. */
public class SpringLoginModule extends SecurityContextLoginModule {
	private final static Log log = LogFactory.getLog(SpringLoginModule.class);

	private AuthenticationManager authenticationManager;

	private CallbackHandler callbackHandler;

	private Subject subject;

	public SpringLoginModule() {

	}

	@SuppressWarnings("rawtypes")
	public void initialize(Subject subject, CallbackHandler callbackHandler,
			Map sharedState, Map options) {
		super.initialize(subject, callbackHandler, sharedState, options);
		this.callbackHandler = callbackHandler;
		this.subject = subject;
	}

	public boolean login() throws LoginException {
		// try to retrieve Authentication from Subject
		// Set<Authentication> auths =
		// subject.getPrincipals(Authentication.class);
		// if (auths.size() > 0)
		// SecurityContextHolder.getContext().setAuthentication(
		// auths.iterator().next());

		// thread already logged in
		if (SecurityContextHolder.getContext().getAuthentication() != null)
			return super.login();

		// reset all principals and credentials
		if (log.isTraceEnabled())
			log.trace("Resetting all principals and credentials of " + subject);
		if (subject.getPrincipals() != null)
			subject.getPrincipals().clear();
		if (subject.getPrivateCredentials() != null)
			subject.getPrivateCredentials().clear();
		if (subject.getPublicCredentials() != null)
			subject.getPublicCredentials().clear();

		// ask for username and password
		Callback label = new TextOutputCallback(TextOutputCallback.INFORMATION,
				"Required login");
		NameCallback nameCallback = new NameCallback("User");
		PasswordCallback passwordCallback = new PasswordCallback("Password",
				false);

		// NameCallback urlCallback = new NameCallback("Site URL");

		if (callbackHandler == null) {
			throw new LoginException("No call back handler available");
			// return false;
		}
		try {
			callbackHandler.handle(new Callback[] { label, nameCallback,
					passwordCallback });
		} catch (Exception e) {
			throw new RuntimeException("Unexpected exception when handling", e);
		}

		// Set user name and password
		String username = nameCallback.getName();
		String password = "";
		if (passwordCallback.getPassword() != null) {
			password = String.valueOf(passwordCallback.getPassword());
		}

		// String url = urlCallback.getName();
		// TODO: set it via system properties
		String workspace = null;

		SiteAuthenticationToken credentials = new SiteAuthenticationToken(
				username, password, null, workspace);

		// try {
		Authentication authentication = authenticationManager
				.authenticate(credentials);
		registerAuthentication(authentication);
		boolean res = super.login();
		return res;
		// } catch (BadCredentialsException bce) {
		// throw bce;
		// } catch (LoginException e) {
		// // LoginException loginException = new LoginException(
		// // "Bad credentials");
		// // loginException.initCause(e);
		// throw e;
		// }
	}

	@Override
	public boolean logout() throws LoginException {
		subject.getPrincipals().clear();
		return super.logout();
	}

	/**
	 * Register an {@link Authentication} in the security context.
	 * 
	 * @param authentication
	 *            has to implement {@link Authentication}.
	 */
	protected void registerAuthentication(Object authentication) {
		SecurityContextHolder.getContext().setAuthentication(
				(Authentication) authentication);
	}

	public void setAuthenticationManager(
			AuthenticationManager authenticationManager) {
		this.authenticationManager = authenticationManager;
	}
}