package org.argeo.cms.auth;

import java.io.IOException;
import java.util.Locale;
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.LanguageCallback;
import javax.security.auth.callback.NameCallback;
import javax.security.auth.callback.PasswordCallback;
import javax.security.auth.callback.UnsupportedCallbackException;
import javax.security.auth.login.CredentialNotFoundException;
import javax.security.auth.login.FailedLoginException;
import javax.security.auth.login.LoginException;
import javax.security.auth.spi.LoginModule;

import org.argeo.cms.CmsException;
import org.argeo.eclipse.ui.specific.UiContext;
import org.osgi.framework.BundleContext;
import org.osgi.framework.FrameworkUtil;
import org.osgi.service.useradmin.Authorization;
import org.osgi.service.useradmin.User;
import org.osgi.service.useradmin.UserAdmin;

public class UserAdminLoginModule implements LoginModule {
	private Subject subject;
	private CallbackHandler callbackHandler;
	private Map<String, Object> sharedState = null;

	// private boolean isAnonymous = false;

	// private state
	private BundleContext bc;
	private Authorization authorization;

	@SuppressWarnings("unchecked")
	@Override
	public void initialize(Subject subject, CallbackHandler callbackHandler, Map<String, ?> sharedState,
			Map<String, ?> options) {
		this.subject = subject;
		try {
			bc = FrameworkUtil.getBundle(UserAdminLoginModule.class).getBundleContext();
			assert bc != null;
			// this.subject = subject;
			this.callbackHandler = callbackHandler;
			this.sharedState = (Map<String, Object>) sharedState;
			// if (options.containsKey("anonymous"))
			// isAnonymous =
			// Boolean.parseBoolean(options.get("anonymous").toString());
		} catch (Exception e) {
			throw new CmsException("Cannot initialize login module", e);
		}
	}

	@Override
	public boolean login() throws LoginException {
		Authorization sharedAuth = (Authorization) sharedState.get(CmsAuthUtils.SHARED_STATE_AUTHORIZATION);
		if (sharedAuth != null) {
			if (callbackHandler == null && sharedAuth.getName() != null)
				throw new LoginException("Shared authorization should be anonymous");
			return false;
		}
		UserAdmin userAdmin = bc.getService(bc.getServiceReference(UserAdmin.class));
		if (callbackHandler == null) {// anonymous
			authorization = userAdmin.getAuthorization(null);
			sharedState.put(CmsAuthUtils.SHARED_STATE_AUTHORIZATION, authorization);
			return true;
		}

		final String username;
		final char[] password;
		if (sharedState.containsKey(CmsAuthUtils.SHARED_STATE_NAME)
				&& sharedState.containsKey(CmsAuthUtils.SHARED_STATE_PWD)) {
			username = (String) sharedState.get(CmsAuthUtils.SHARED_STATE_NAME);
			password = (char[]) sharedState.get(CmsAuthUtils.SHARED_STATE_NAME);
			// TODO locale?
		} else {

			// ask for username and password
			NameCallback nameCallback = new NameCallback("User");
			PasswordCallback passwordCallback = new PasswordCallback("Password", false);
			LanguageCallback langCallback = new LanguageCallback();
			try {
				callbackHandler.handle(new Callback[] { nameCallback, passwordCallback, langCallback });
			} catch (IOException e) {
				throw new LoginException("Cannot handle callback: " + e.getMessage());
				// } catch (ThreadDeath e) {
				// throw new ThreadDeathLoginException("Callbackhandler thread
				// died", e);
			} catch (UnsupportedCallbackException e) {
				return false;
			}

			// i18n
			Locale locale = langCallback.getLocale();
			if (locale == null)
				locale = Locale.getDefault();
			UiContext.setLocale(locale);

			// authorization = (Authorization)
			// sharedState.get(CmsAuthUtils.SHARED_STATE_AUTHORIZATION);
			//
			// if (authorization == null) {
			// create credentials
			username = nameCallback.getName();
			if (username == null || username.trim().equals("")) {
				// authorization = userAdmin.getAuthorization(null);
				throw new CredentialNotFoundException("No credentials provided");
			}
			// char[] password = {};
			if (passwordCallback.getPassword() != null)
				password = passwordCallback.getPassword();
			else
				throw new CredentialNotFoundException("No credentials provided");
		}

		// FIXME move Argeo specific convention from user admin to here
		User user = userAdmin.getUser(null, username);
		if (user == null)
			throw new FailedLoginException("Invalid credentials");
		if (!user.hasCredential(null, password))
			throw new FailedLoginException("Invalid credentials");
		// return false;

		// Log and monitor new login
		// if (log.isDebugEnabled())
		// log.debug("Logged in to CMS with username [" + username +
		// "]");

		authorization = userAdmin.getAuthorization(user);
		assert authorization != null;

		// }
		// if
		// (!sharedState.containsKey(CmsAuthUtils.SHARED_STATE_AUTHORIZATION))
		sharedState.put(CmsAuthUtils.SHARED_STATE_AUTHORIZATION, authorization);
		return authorization != null;
	}

	@Override
	public boolean commit() throws LoginException {
		// Set<KerberosPrincipal> kerberosPrincipals =
		// subject.getPrincipals(KerberosPrincipal.class);
		// if (kerberosPrincipals.size() != 0) {
		// KerberosPrincipal kerberosPrincipal =
		// kerberosPrincipals.iterator().next();
		// System.out.println(kerberosPrincipal);
		// UserAdmin userAdmin =
		// bc.getService(bc.getServiceReference(UserAdmin.class));
		// User user = userAdmin.getUser(null, kerberosPrincipal.getName());
		// Authorization authorization = userAdmin.getAuthorization(user);
		// sharedState.put(SHARED_STATE_AUTHORIZATION, authorization);
		// }
		if (authorization == null) {
			return false;
			// throw new LoginException("Authorization should not be null");
		} else {
			CmsAuthUtils.addAuthentication(subject, authorization);
			return true;
		}
	}

	@Override
	public boolean abort() throws LoginException {
		authorization = null;
		return true;
	}

	@Override
	public boolean logout() throws LoginException {
		CmsAuthUtils.cleanUp(subject);
		return true;
	}
}