/*
 * Copyright 2005-2014 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.ws.soap.security.xwss.callback.jaas;

import java.security.Principal;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
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.login.LoginException;
import javax.security.auth.spi.LoginModule;

public class PlainTextLoginModule implements LoginModule {

	private Subject subject;

	private CallbackHandler callbackHandler;

	private boolean success;

	private List<Principal> principals = new ArrayList<Principal>();

	@Override
	public boolean abort() {
		success = false;
		logout();
		return true;
	}

	@Override
	public boolean commit() throws LoginException {
		if (success) {
			if (subject.isReadOnly()) {
				throw new LoginException("Subject is read-only");
			}
			try {
				subject.getPrincipals().addAll(principals);
				principals.clear();
				return true;
			}
			catch (Exception e) {
				throw new LoginException(e.getMessage());
			}
		}
		else {
			principals.clear();
		}
		return true;
	}

	@Override
	public void initialize(Subject subject,
						   CallbackHandler callbackHandler,
						   Map<String,?> sharedState,
						   Map<String,?> options) {
		this.subject = subject;
		this.callbackHandler = callbackHandler;
	}

	@Override
	public boolean login() throws LoginException {
		if (callbackHandler == null) {
			return false;
		}
		try {
			NameCallback nameCallback = new NameCallback("Username: ");
			PasswordCallback passwordCallback = new PasswordCallback("Password: ", false);
			Callback[] callbacks = new Callback[]{nameCallback, passwordCallback};

			callbackHandler.handle(callbacks);

			String username = nameCallback.getName();
			String password = new String(passwordCallback.getPassword());

			((PasswordCallback) callbacks[1]).clearPassword();

			success = validate(username, password);

			callbacks[0] = null;
			callbacks[1] = null;

			if (!success) {
				throw new LoginException("Authentication failed: Password does not match");
			}

			return true;
		}
		catch (LoginException ex) {
			throw ex;
		}
		catch (Exception ex) {
			success = false;
			throw new LoginException(ex.getMessage());
		}
	}

	private boolean validate(String username, String password) {
		if ("Bert".equals(username) && "Ernie".equals(password)) {
			this.principals.add(new SimplePrincipal(username));
			return true;
		}
		else {
			return false;
		}
	}

	@Override
	public boolean logout() {
		principals.clear();

		Iterator<SimplePrincipal> iterator = subject.getPrincipals(SimplePrincipal.class).iterator();
		while (iterator.hasNext()) {
			SimplePrincipal principal = iterator.next();
			subject.getPrincipals().remove(principal);
		}

		return true;
	}


}