/*
    * Copyright (C) 2007-2012 Argeo GmbH
    *
    * 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.argeo.slc.jcr.execution;
  
  import java.net.InetAddress;
  import java.net.UnknownHostException;
  import java.util.UUID;
  
  import javax.jcr.Node;
  import javax.jcr.Repository;
  import javax.jcr.RepositoryException;
  import javax.jcr.Session;
  import javax.jcr.security.Privilege;
  
  import org.argeo.jcr.JcrUtils;
  import org.argeo.slc.SlcConstants;
  import org.argeo.slc.SlcException;
  import org.argeo.slc.SlcNames;
  import org.argeo.slc.SlcTypes;
  import org.argeo.slc.core.execution.DefaultAgent;
  import org.argeo.slc.core.execution.ProcessThread;
  import org.argeo.slc.execution.ExecutionModulesManager;
  import org.argeo.slc.execution.ExecutionProcess;
  import org.argeo.slc.jcr.SlcJcrConstants;
  
  /** SLC VM agent synchronizing with a JCR repository. */
  public class JcrAgent extends DefaultAgent implements SlcNames {
  	// final static String ROLE_REMOTE = "ROLE_REMOTE";
  	final static String NODE_REPO_URI = "argeo.node.repo.uri";
  
  	private Repository repository;
  
  	private String agentNodeName = "default";
  
  	/*
  	 * LIFECYCLE
  	 */
  	protected String initAgentUuid() {
  		Session session = null;
  		try {
  			session = repository.login();
  
  			String agentFactoryPath = getAgentFactoryPath();
  			Node vmAgentFactoryNode = JcrUtils.mkdirsSafe(session, agentFactoryPath, SlcTypes.SLC_AGENT_FACTORY);
  			JcrUtils.addPrivilege(session, SlcJcrConstants.SLC_BASE_PATH, SlcConstants.ROLE_SLC, Privilege.JCR_ALL);
  			if (!vmAgentFactoryNode.hasNode(agentNodeName)) {
  				String uuid = UUID.randomUUID().toString();
  				Node agentNode = vmAgentFactoryNode.addNode(agentNodeName, SlcTypes.SLC_AGENT);
  				agentNode.setProperty(SLC_UUID, uuid);
  			}
  			session.save();
  			return vmAgentFactoryNode.getNode(agentNodeName).getProperty(SLC_UUID).getString();
  		} catch (RepositoryException e) {
  			JcrUtils.discardQuietly(session);
  			throw new SlcException("Cannot find JCR agent UUID", e);
  		} finally {
  			JcrUtils.logoutQuietly(session);
  		}
  	}
  
  	@Override
  	public void destroy() {
  		super.destroy();
  	}
  
  	/*
  	 * SLC AGENT
  	 */
  	@Override
  	protected ProcessThread createProcessThread(ThreadGroup processesThreadGroup,
  			ExecutionModulesManager modulesManager, ExecutionProcess process) {
  		if (process instanceof JcrExecutionProcess)
  			return new JcrProcessThread(processesThreadGroup, modulesManager, (JcrExecutionProcess) process);
  		else
  			return super.createProcessThread(processesThreadGroup, modulesManager, process);
  	}
  
  	/*
  	 * UTILITIES
  	 */
  	public String getNodePath() {
  		return getAgentFactoryPath() + '/' + getAgentNodeName();
  	}
  
  	public String getAgentFactoryPath() {
  		try {
 			Boolean isRemote = System.getProperty(NODE_REPO_URI) != null;
 			String agentFactoryPath;
 			if (isRemote) {
 				InetAddress localhost = InetAddress.getLocalHost();
 				agentFactoryPath = SlcJcrConstants.AGENTS_BASE_PATH + "/" + localhost.getCanonicalHostName();
 
 				if (agentFactoryPath.equals(SlcJcrConstants.VM_AGENT_FACTORY_PATH))
 					throw new SlcException("Unsupported hostname " + localhost.getCanonicalHostName());
 			} else {// local
 				agentFactoryPath = SlcJcrConstants.VM_AGENT_FACTORY_PATH;
 			}
 			return agentFactoryPath;
 		} catch (UnknownHostException e) {
 			throw new SlcException("Cannot find agent factory base path", e);
 		}
 	}
 
 	/*
 	 * BEAN
 	 */
 	public String getAgentNodeName() {
 		return agentNodeName;
 	}
 
 	public void setRepository(Repository repository) {
 		this.repository = repository;
 	}
 
 	public void setAgentNodeName(String agentNodeName) {
 		this.agentNodeName = agentNodeName;
 	}
 }