/*
 * Copyright 2002-2013 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.cloud.deployer.admin.server.local.security;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.directory.server.core.DefaultDirectoryService;
import org.apache.directory.server.core.authn.AuthenticationInterceptor;
import org.apache.directory.server.core.entry.ServerEntry;
import org.apache.directory.server.core.exception.ExceptionInterceptor;
import org.apache.directory.server.core.interceptor.Interceptor;
import org.apache.directory.server.core.normalization.NormalizationInterceptor;
import org.apache.directory.server.core.operational.OperationalAttributeInterceptor;
import org.apache.directory.server.core.partition.impl.btree.jdbm.JdbmPartition;
import org.apache.directory.server.core.referral.ReferralInterceptor;
import org.apache.directory.server.core.subtree.SubentryInterceptor;
import org.apache.directory.server.ldap.LdapServer;
import org.apache.directory.server.protocol.shared.store.LdifFileLoader;
import org.apache.directory.server.protocol.shared.transport.TcpTransport;
import org.apache.directory.shared.ldap.exception.LdapNameNotFoundException;
import org.apache.directory.shared.ldap.name.LdapDN;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.Lifecycle;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.security.ldap.server.ApacheDSContainer;
import org.springframework.util.Assert;

/**
 * This class has been copied from {@link ApacheDSContainer}. Once the relevant Spring Security issue has
 * been addressed, we can remove this class. See also:
 *
 * https://github.com/spring-projects/spring-security/issues/4096
 *
 * Provides lifecycle services for the embedded apacheDS server defined by the supplied
 * configuration. Used by {code LdapServerBeanDefinitionParser}. An instance will be
 * stored in the application context for each embedded server instance. It will start the
 * server when the context is initialized and shut it down when it is closed. It is
 * intended for temporary embedded use and will not retain changes across start/stop
 * boundaries. The working directory is deleted on shutdown.
 *
 * <p>
 * If used repeatedly in a single JVM process with the same configuration (for example,
 * when repeatedly loading an application context during testing), it's important that the
 * application context is closed to allow the bean to be disposed of and the server
 * shutdown prior to attempting to start it again.
 * <p>
 * This class is intended for testing and internal security namespace use and is not
 * considered part of framework public API.
 *
 * @author Luke Taylor
 * @author Rob Winch
 */
public class ApacheDSContainerWithSecurity implements InitializingBean, DisposableBean, Lifecycle,
		ApplicationContextAware {
	private final Log logger = LogFactory.getLog(getClass());

	final DefaultDirectoryService service;
	LdapServer server;

	private ApplicationContext ctxt;
	private File workingDir;

	private boolean running;
	private final String ldifResources;
	private final JdbmPartition partition;
	private final String root;
	private int port = 53389;

	private boolean enabledLdapOverSsl;
	private File keyStoreFile;
	private String keyStorePassword;

	public ApacheDSContainerWithSecurity(String root, String ldifs) throws Exception {
		this.ldifResources = ldifs;
		service = new DefaultDirectoryService();
		List<Interceptor> list = new ArrayList<Interceptor>();

		list.add(new NormalizationInterceptor());
		list.add(new AuthenticationInterceptor());
		list.add(new ReferralInterceptor());
		// list.add( new AciAuthorizationInterceptor() );
		// list.add( new DefaultAuthorizationInterceptor() );
		list.add(new ExceptionInterceptor());
		// list.add( new ChangeLogInterceptor() );
		list.add(new OperationalAttributeInterceptor());
		// list.add( new SchemaInterceptor() );
		list.add(new SubentryInterceptor());
		// list.add( new CollectiveAttributeInterceptor() );
		// list.add( new EventInterceptor() );
		// list.add( new TriggerInterceptor() );
		// list.add( new JournalInterceptor() );

		service.setInterceptors(list);
		partition = new JdbmPartition();
		partition.setId("rootPartition");
		partition.setSuffix(root);
		this.root = root;
		service.addPartition(partition);
		service.setExitVmOnShutdown(false);
		service.setShutdownHookEnabled(false);
		service.getChangeLog().setEnabled(false);
		service.setDenormalizeOpAttrsEnabled(true);
	}

	public void afterPropertiesSet() throws Exception {

		if (this.enabledLdapOverSsl && this.keyStoreFile == null) {
			throw new IllegalArgumentException("When LdapOverSsl is enabled, the keyStoreFile property must be set.");
		}

		if (workingDir == null) {
			String apacheWorkDir = System.getProperty("apacheDSWorkDir");

			if (apacheWorkDir == null) {
				apacheWorkDir = createTempDirectory("apacheds-spring-security-");
			}

			setWorkingDirectory(new File(apacheWorkDir));
		}

		server = new LdapServer();

		// AbstractLdapIntegrationTests assume IPv4, so we specify the same here
		TcpTransport transport = new TcpTransport(port);

		if (enabledLdapOverSsl) {
			transport.setEnableSSL(true);
			server.setKeystoreFile(this.keyStoreFile.getAbsolutePath());
			server.setCertificatePassword(this.keyStorePassword);
		}

		server.setTransports(transport);
		server.setDirectoryService(service);
		start();
	}

	public void destroy() throws Exception {
		stop();
	}

	public void setApplicationContext(ApplicationContext applicationContext)
			throws BeansException {
		ctxt = applicationContext;
	}

	public void setWorkingDirectory(File workingDir) {
		Assert.notNull(workingDir);

		logger.info("Setting working directory for LDAP_PROVIDER: "
				+ workingDir.getAbsolutePath());

		if (workingDir.exists()) {
			throw new IllegalArgumentException(
					"The specified working directory '"
							+ workingDir.getAbsolutePath()
							+ "' already exists. Another directory service instance may be using it or it may be from a "
							+ " previous unclean shutdown. Please confirm and delete it or configure a different "
							+ "working directory");
		}

		this.workingDir = workingDir;

		service.setWorkingDirectory(workingDir);
	}

	public void setPort(int port) {
		this.port = port;
	}

	public void setKeyStoreFile(File keyStoreFile) {
		Assert.isTrue(keyStoreFile.exists(), "The keyStoreFile does not exist.");
		Assert.isTrue(keyStoreFile.isFile(), "The keyStoreFile must be a file.");
		this.keyStoreFile = keyStoreFile;
	}

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

	public void setEnabledLdapOverSsl(boolean enabledLdapOverSsl) {
		this.enabledLdapOverSsl = enabledLdapOverSsl;
	}

	public DefaultDirectoryService getService() {
		return service;
	}

	public void start() {
		if (isRunning()) {
			return;
		}

		if (service.isStarted()) {
			throw new IllegalStateException("DirectoryService is already running.");
		}

		logger.info("Starting directory server...");
		try {
			service.startup();
			server.start();
		}
		catch (Exception e) {
			throw new RuntimeException("Server startup failed", e);
		}

		try {
			service.getAdminSession().lookup(partition.getSuffixDn());
		}
		catch (LdapNameNotFoundException e) {
			try {
				LdapDN dn = new LdapDN(root);
				Assert.isTrue(root.startsWith("dc="));
				String dc = root.substring(3, root.indexOf(','));
				ServerEntry entry = service.newEntry(dn);
				entry.add("objectClass", "top", "domain", "extensibleObject");
				entry.add("dc", dc);
				service.getAdminSession().add(entry);
			}
			catch (Exception e1) {
				logger.error("Failed to create dc entry", e1);
			}
		}
		catch (Exception e) {
			logger.error("Lookup failed", e);
		}

		running = true;

		try {
			importLdifs();
		}
		catch (Exception e) {
			throw new RuntimeException("Failed to import LDIF file(s)", e);
		}
	}

	public void stop() {
		if (!isRunning()) {
			return;
		}

		logger.info("Shutting down directory server ...");
		try {
			server.stop();
			service.shutdown();
		}
		catch (Exception e) {
			logger.error("Shutdown failed", e);
			return;
		}

		running = false;

		if (workingDir.exists()) {
			logger.info("Deleting working directory " + workingDir.getAbsolutePath());
			deleteDir(workingDir);
		}
	}

	private void importLdifs() throws Exception {
		// Import any ldif files
		Resource[] ldifs;

		if (ctxt == null) {
			// Not running within an app context
			ldifs = new PathMatchingResourcePatternResolver().getResources(ldifResources);
		}
		else {
			ldifs = ctxt.getResources(ldifResources);
		}

		// Note that we can't just import using the ServerContext returned
		// from starting Apache DS, apparently because of the long-running issue
		// DIRSERVER-169.
		// We need a standard context.
		// DirContext dirContext = contextSource.getReadWriteContext();

		if (ldifs == null || ldifs.length == 0) {
			return;
		}

		if (ldifs.length == 1) {
			String ldifFile;

			try {
				ldifFile = ldifs[0].getFile().getAbsolutePath();
			}
			catch (IOException e) {
				ldifFile = ldifs[0].getURI().toString();
			}
			logger.info("Loading LDIF file: " + ldifFile);
			LdifFileLoader loader = new LdifFileLoader(service.getAdminSession(),
					new File(ldifFile), null, getClass().getClassLoader());
			loader.execute();
		}
		else {
			throw new IllegalArgumentException(
					"More than one LDIF resource found with the supplied pattern:"
							+ ldifResources + " Got " + Arrays.toString(ldifs));
		}
	}

	private String createTempDirectory(String prefix) throws IOException {
		String parentTempDir = System.getProperty("java.io.tmpdir");
		String fileNamePrefix = prefix + System.nanoTime();
		String fileName = fileNamePrefix;

		for (int i = 0; i < 1000; i++) {
			File tempDir = new File(parentTempDir, fileName);
			if (!tempDir.exists()) {
				return tempDir.getAbsolutePath();
			}
			fileName = fileNamePrefix + "~" + i;
		}

		throw new IOException("Failed to create a temporary directory for file at "
				+ new File(parentTempDir, fileNamePrefix));
	}

	private boolean deleteDir(File dir) {
		if (dir.isDirectory()) {
			String[] children = dir.list();
			for (String child : children) {
				boolean success = deleteDir(new File(dir, child));
				if (!success) {
					return false;
				}
			}
		}

		return dir.delete();
	}

	public boolean isRunning() {
		return running;
	}
}