/*
    * EL4J, the Extension Library for the J2EE, adds incremental enhancements to
    * the spring framework, http://el4j.sf.net
    * Copyright (C) 2006 by ELCA Informatique SA, Av. de la Harpe 22-24,
    * 1000 Lausanne, Switzerland, http://www.elca.ch
    *
    * EL4J is published under the GNU Lesser General Public License (LGPL)
    * Version 2.1. See http://www.gnu.org/licenses/
    *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU Lesser General Public License for more details.
   *
   * For alternative licensing, please contact info@elca.ch
   */
  
  // Checkstyle: MagicNumber off
  
  package ch.elca.el4j.services.xmlmerge.anttask;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Properties;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.DirectoryScanner;
  import org.apache.tools.ant.Task;
  import org.apache.tools.ant.types.FileSet;
  
  import ch.elca.el4j.services.monitoring.notification.CoreNotificationHelper;
  import ch.elca.el4j.services.xmlmerge.AbstractXmlMergeException;
  import ch.elca.el4j.services.xmlmerge.ConfigurationException;
  import ch.elca.el4j.services.xmlmerge.XmlMerge;
  import ch.elca.el4j.services.xmlmerge.config.ConfigurableXmlMerge;
  import ch.elca.el4j.services.xmlmerge.config.PropertyXPathConfigurer;
  
  /**
   * Task for merging XML files in Ant.
   *
   * <p>Attributes:
   * <ul>
   * <li><b>dest</b> Output merged file. <i>Required</i>
   * <li><b>conf</b> Configuration file. <i>Required</i>
   * </ul>
   *
   * <p>Content:
   * <ul><li><b>FileSet</b> Selects the files to merge.</li></ul>
   *
   * Usage example:
   *
   * <pre>
   *   &lt;target name="test-task">
   *       &lt;taskdef name="xmlmerge" classname="ch.elca.el4j.xmlmerge.anttask.XmlMergeTask"
   *           classpath="module-xml_merge.jar;jdom.jar;jaxen.jar;saxpath.jar "/>
   *
   *       &lt;xmlmerge dest="out.xml" conf="test.properties">
   *           &lt;fileset dir="test">
   *             &lt;include name="source*.xml"/>
   *          &lt;/fileset>
   *       &lt;/xmlmerge>
   *   &lt;/target>
   * </pre>
   *
   * @svnLink $Revision: 3884 $;$Date: 2009-08-04 15:48:31 +0200 (Di, 04. Aug 2009) $;$Author: swismer $;$URL: https://el4j.svn.sourceforge.net/svnroot/el4j/branches/el4j_3_1/el4j/framework/modules/xml_merge/common/src/main/java/ch/elca/el4j/services/xmlmerge/anttask/XmlMergeTask.java $
   *
   * @author Laurent Bovet (LBO)
   * @author Alex Mathey (AMA)
   */
  public class XmlMergeTask extends Task {
  
  	/**
  	 * Configuration file name.
  	 */
  	String m_confFilename = null;
  
  	/**
  	 * Output merged file name.
  	 */
  	String m_destFilename = null;
  
  	/**
  	 * List of file sets.
  	 */
  	List m_filesets = new ArrayList();
  
  	/**
  	 * Sets the configuration file name.
  	 * @param confFilename The configuration file name to set.
  	 */
  	public void setConf(String confFilename) {
  		m_confFilename = confFilename;
 	}
 
 	/**
 	 * Sets the destination file name.
 	 * @param destFilename The destination file name to set.
 	 */
 	public void setDest(String destFilename) {
 		m_destFilename = destFilename;
 	}
 
 	/**
 	 * Adds a file set.
 	 * @param fileset The file set to add
 	 */
 	public void addFileSet(FileSet fileset) {
 		m_filesets.add(fileset);
 	}
 
 	/**
 	 * Validates the configuration and destination files and the file sets.
 	 */
 	public void validate() {
 		if (m_confFilename == null) {
 			throw new BuildException("conf file not set");
 		}
 		if (m_destFilename == null) {
 			throw new BuildException("dest file not set");
 		}
 		if (m_filesets.isEmpty()) {
 			throw new BuildException("no source fileset specified");
 		}
 	}
 
 	/**
 	 * {@inheritDoc}
 	 */
 	@Override
 	public void execute() {
 		validate();
 
 		// Get the files to merge
 		List streamsToMerge = new ArrayList();
 
 		for (Iterator it = m_filesets.iterator(); it.hasNext();) {
 			FileSet fs = (FileSet) it.next();
 			DirectoryScanner ds = fs.getDirectoryScanner(getProject());
 			String[] includedFiles = ds.getIncludedFiles();
 			for (int i = 0; i < includedFiles.length; i++) {
 				try {
 					streamsToMerge.add(new FileInputStream(new File(ds
 						.getBasedir(), includedFiles[i])));
 				} catch (IOException e) {
 					throw new BuildException(e);
 				}
 			}
 		}
 
 		// Create the stream to write
 		OutputStream out;
 		File destFile = new File(m_destFilename);
 
 		if (!destFile.isAbsolute()) {
 			destFile = new File(getProject().getBaseDir(), m_destFilename);
 		}
 
 		try {
 			out = new FileOutputStream(destFile);
 		} catch (IOException e) {
 			throw new BuildException(e);
 		}
 
 		// Create conf properties
 		Properties confProps = new Properties();
 		File confFile = new File(m_confFilename);
 
 		if (!confFile.isAbsolute()) {
 			confFile = new File(getProject().getBaseDir(), m_confFilename);
 		}
 
 		InputStream configIn = null;
 		try {
 			configIn = new FileInputStream(confFile);
 			confProps.load(configIn);
 		} catch (IOException e) {
 			throw new BuildException(e);
 		} finally {
 			if (configIn != null) {
 				try {
 					configIn.close();
 				} catch (IOException e) {
 					CoreNotificationHelper.notifyMisconfiguration(
 						"The file '" + confFile
 						+ "' could not be close.", e);
 				}
 			}
 		}
 
 		// Create the XmlMerge instance and execute the merge
 
 		XmlMerge xmlMerge;
 		try {
 			xmlMerge = new ConfigurableXmlMerge(new PropertyXPathConfigurer(
 				confProps));
 		} catch (ConfigurationException e) {
 			throw new BuildException(e);
 		}
 
 		InputStream in;
 
 		try {
 			in = xmlMerge.merge((InputStream[]) streamsToMerge
 				.toArray(new InputStream[streamsToMerge.size()]));
 		} catch (AbstractXmlMergeException e) {
 			throw new BuildException(e);
 		}
 
 		writeFromTo(in, out);
 
 		try {
 			in.close();
 		} catch (IOException e) {
 			throw new BuildException(e);
 		}
 
 		try {
 			out.close();
 		} catch (IOException e) {
 			throw new BuildException(e);
 		}
 	}
 
 	/**
 	 * Writes from an InputStream to an OutputStream.
 	 * @param in The stream to read from
 	 * @param out The stream to write to
 	 * @throws BuildException If an error occurred during the write process
 	 */
 	private void writeFromTo(InputStream in, OutputStream out)
 		throws BuildException {
 		int len = 0;
 		byte[] buffer = new byte[1024];
 
 		try {
 			while ((len = in.read(buffer)) != -1) {
 				out.write(buffer, 0, len);
 			}
 		} catch (IOException ioe) {
 			throw new BuildException(ioe);
 		}
 	}
 }
 
 //Checkstyle: MagicNumber on