/*
    * 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.maintenance.backup.vfs;
  
  import java.io.ByteArrayOutputStream;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.commons.exec.CommandLine;
  import org.apache.commons.exec.DefaultExecutor;
  import org.apache.commons.exec.ExecuteException;
  import org.apache.commons.exec.ExecuteStreamHandler;
  import org.apache.commons.exec.Executor;
  import org.apache.commons.exec.PumpStreamHandler;
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.commons.vfs2.FileContent;
  import org.apache.commons.vfs2.FileObject;
  import org.argeo.maintenance.MaintenanceException;
  
  /**
   * Runs an OS command and save its standard output as a file. Typically used for
   * MySQL or OpenLDAP dumps.
   */
  public class OsCallBackup extends AbstractAtomicBackup {
  	private final static Log log = LogFactory.getLog(OsCallBackup.class);
  
  	private String command;
  	private Map<String, String> variables = new HashMap<String, String>();
  	private Executor executor = new DefaultExecutor();
  
  	private Map<String, String> environment = new HashMap<String, String>();
  
  	/** Name of the sudo user, root if "", not sudo if null */
  	private String sudo = null;
  
  	public OsCallBackup() {
  	}
  
  	public OsCallBackup(String name) {
  		super(name);
  	}
  
  	public OsCallBackup(String name, String command) {
  		super(name);
  		this.command = command;
  	}
  
  	@Override
  	public void writeBackup(FileObject targetFo) {
  		String commandToUse = command;
  
  		// sudo
  		if (sudo != null) {
  			if (sudo.equals(""))
  				commandToUse = "sudo " + commandToUse;
  			else
  				commandToUse = "sudo -u " + sudo + " " + commandToUse;
  		}
  
  		CommandLine commandLine = CommandLine.parse(commandToUse, variables);
  		ByteArrayOutputStream errBos = new ByteArrayOutputStream();
  		if (log.isTraceEnabled())
  			log.trace(commandLine.toString());
  
  		try {
  			// stdout
  			FileContent targetContent = targetFo.getContent();
  			// stderr
  			ExecuteStreamHandler streamHandler = new PumpStreamHandler(targetContent.getOutputStream(), errBos);
  			executor.setStreamHandler(streamHandler);
  			executor.execute(commandLine, environment);
  		} catch (ExecuteException e) {
  			byte[] err = errBos.toByteArray();
  			String errStr = new String(err);
  			throw new MaintenanceException("Process " + commandLine + " failed (" + e.getExitValue() + "): " + errStr, e);
  		} catch (Exception e) {
  			byte[] err = errBos.toByteArray();
  			String errStr = new String(err);
  			throw new MaintenanceException("Process " + commandLine + " failed: " + errStr, e);
  		} finally {
  			IOUtils.closeQuietly(errBos);
  		}
  	}
  
 	public void setCommand(String command) {
 		this.command = command;
 	}
 
 	protected String getCommand() {
 		return command;
 	}
 
 	/**
 	 * A reference to the environment variables that will be passed to the
 	 * process. Empty by default.
 	 */
 	protected Map<String, String> getEnvironment() {
 		return environment;
 	}
 
 	protected Map<String, String> getVariables() {
 		return variables;
 	}
 
 	public void setVariables(Map<String, String> variables) {
 		this.variables = variables;
 	}
 
 	public void setExecutor(Executor executor) {
 		this.executor = executor;
 	}
 
 	public void setSudo(String sudo) {
 		this.sudo = sudo;
 	}
 
 }