package org.argeo.security.activemq;

import java.io.InputStream;
import java.net.URL;
import java.security.KeyStore;
import java.security.Principal;
import java.security.SecureRandom;

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.TrustManagerFactory;
import javax.security.auth.Subject;
import javax.security.auth.login.LoginContext;
import javax.security.auth.login.LoginException;

import org.apache.activemq.ActiveMQSslConnectionFactory;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.argeo.ArgeoException;
import org.argeo.security.core.UserPasswordDialog;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.core.io.Resource;
import org.springframework.jms.connection.CachingConnectionFactory;
import org.springframework.jms.connection.UserCredentialsConnectionFactoryAdapter;

public class SecuredActiveMqConnectionFactory implements ConnectionFactory,
		InitializingBean, DisposableBean {

	public final static String AUTHMODE_UI = "ui";
	public final static String AUTHMODE_OS = "os";
	public final static String AUTHMODE_DEFAULT = AUTHMODE_OS;
	private final static String LOGIN_CONFIG_PROPERTY = "java.security.auth.login.config";

	private final static Log log = LogFactory
			.getLog(SecuredActiveMqConnectionFactory.class);

	private String keyStorePassword;
	private Resource keyStore;
	private String keyStoreType = "JKS";// "PKCS12"
	private String brokerURL;

	private String authenticationMode;

	private CachingConnectionFactory cachingConnectionFactory;

	public Connection createConnection() throws JMSException {
		return cachingConnectionFactory.createConnection();
	}

	public Connection createConnection(String userName, String password)
			throws JMSException {
		throw new UnsupportedOperationException();
	}

	public void afterPropertiesSet() throws Exception {
		ActiveMQSslConnectionFactory activeMQSslConnectionFactory = new ActiveMQSslConnectionFactory();
		prepareActiveMqSslConnectionFactory(activeMQSslConnectionFactory);
		activeMQSslConnectionFactory.setBrokerURL(brokerURL);
		UserCredentialsConnectionFactoryAdapter uccfa = new UserCredentialsConnectionFactoryAdapter();
		uccfa.setTargetConnectionFactory(activeMQSslConnectionFactory);
		cachingConnectionFactory = new CachingConnectionFactory();
		cachingConnectionFactory.setTargetConnectionFactory(uccfa);

		initConnectionFactoryCredentials(uccfa);
		cachingConnectionFactory.initConnection();
		log.info("Connected to " + brokerURL);
		uccfa.setUsername(null);
		uccfa.setPassword(null);

	}

	protected void initConnectionFactoryCredentials(
			final UserCredentialsConnectionFactoryAdapter uccfa) {
		if (authenticationMode == null)
			authenticationMode = AUTHMODE_DEFAULT;

		if (AUTHMODE_OS.equals(authenticationMode)) {
			// Cache previous value of login conf location
			String oldLoginConfLocation = System
					.getProperty(LOGIN_CONFIG_PROPERTY);
			// Find OS family
			String osName = System.getProperty("os.name");
			final String auth;
			if (osName.startsWith("Windows"))
				auth = "Windows";
			else if (osName.startsWith("SunOS") || osName.startsWith("Solaris"))
				auth = "Solaris";
			else
				auth = "Unix";

			Subject subject;
			try {

				URL url = getClass().getResource(
						"/org/argeo/security/activemq/osLogin.conf");

				System.setProperty(LOGIN_CONFIG_PROPERTY, url.toString());
				LoginContext lc = new LoginContext(auth);
				lc.login();
				subject = lc.getSubject();
			} catch (LoginException le) {
				throw new ArgeoException("OS authentication failed", le);
			} finally {
				if (oldLoginConfLocation != null)
					System.setProperty(LOGIN_CONFIG_PROPERTY,
							oldLoginConfLocation);
			}

			// Extract user name
			String osUsername = null;
			for (Principal principal : subject.getPrincipals()) {
				String className = principal.getClass().getName();
				if ("Unix".equals(auth)
						&& "com.sun.security.auth.UnixPrincipal"
								.equals(className))
					osUsername = principal.getName();
				else if ("Windows".equals(auth)
						&& "com.sun.security.auth.NTUserPrincipal"
								.equals(className))
					osUsername = principal.getName();
				else if ("Solaris".equals(auth)
						&& "com.sun.security.auth.SolarisPrincipal"
								.equals(className))
					osUsername = principal.getName();
			}

			if (osUsername == null)
				throw new ArgeoException("Could not find OS user name");

			uccfa.setUsername(osUsername);
			uccfa.setPassword(null);

		} else if (AUTHMODE_UI.equals(authenticationMode)) {
			UserPasswordDialog dialog = new UserPasswordDialog() {
				private static final long serialVersionUID = -891646559691412088L;

				protected void useCredentials(String username, char[] password) {
					uccfa.setUsername(username);
					uccfa.setPassword(new String(password));
				}
			};
			dialog.setVisible(true);
		} else {
			throw new ArgeoException("Authentication mode '"
					+ authenticationMode + "' is not supported");
		}

	}

	protected void prepareActiveMqSslConnectionFactory(
			ActiveMQSslConnectionFactory connectionFactory) {
		try {
			KeyStore keyStoreKs = KeyStore.getInstance(keyStoreType);

			InputStream keyInput = keyStore.getInputStream();
			keyStoreKs.load(keyInput,
					keyStorePassword != null ? keyStorePassword.toCharArray()
							: null);
			keyInput.close();

			TrustManagerFactory tmf = TrustManagerFactory
					.getInstance(TrustManagerFactory.getDefaultAlgorithm());
			tmf.init(keyStoreKs);

			KeyManagerFactory keyManagerFactory = KeyManagerFactory
					.getInstance(KeyManagerFactory.getDefaultAlgorithm());
			keyManagerFactory.init(keyStoreKs, keyStorePassword.toCharArray());

			connectionFactory.setKeyAndTrustManagers(keyManagerFactory
					.getKeyManagers(), tmf.getTrustManagers(),
					new SecureRandom());
		} catch (Exception e) {
			throw new ArgeoException(
					"Cannot initailize JMS conneciton factory", e);
		}

	}

	public void destroy() throws Exception {
		if (cachingConnectionFactory != null)
			cachingConnectionFactory.destroy();
	}

	public void setKeyStorePassword(String keyStorePassword) {
		this.keyStorePassword = keyStorePassword;
	}

	public void setKeyStore(Resource keyStore) {
		this.keyStore = keyStore;
	}

	public void setKeyStoreType(String keyStoreType) {
		this.keyStoreType = keyStoreType;
	}

	public void setBrokerURL(String brokerUrl) {
		this.brokerURL = brokerUrl;
	}

}