/* ====================================================================
    * The Apache Software License, Version 1.1
    *
    * Copyright (c) 2003 The Apache Software Foundation.  All rights
    * reserved.
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions
    * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. The end-user documentation included with the redistribution,
   *    if any, must include the following acknowledgment:
   *       "This product includes software developed by the
   *        Apache Software Foundation (http://www.apache.org )."
   *    Alternately, this acknowledgment may appear in the software itself,
   *    if and wherever such third-party acknowledgments normally appear.
   *
   * 4. The names "Apache" and "Apache Software Foundation" and
   *    "Apache Maven" must not be used to endorse or promote products
   *    derived from this software without prior written permission. For
   *    written permission, please contact apache@apache.org.
   *
   * 5. Products derived from this software may not be called "Apache",
   *    "Apache Maven", nor may "Apache" appear in their name, without
   *    prior written permission of the Apache Software Foundation.
   *
   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * ====================================================================
   *
   * This software consists of voluntary contributions made by many
   * individuals on behalf of the Apache Software Foundation.  For more
   * information on the Apache Software Foundation, please see
   * <http://www.apache.org >.
   *
   * ====================================================================
   */
  
  package org.apache.maven.sitevalidator;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.UnsupportedEncodingException;
  import java.net.UnknownHostException;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.DirectoryScanner;
  import org.apache.tools.ant.Project;
  import org.apache.tools.ant.Task;
  import org.apache.tools.ant.types.DTDLocation;
  import org.apache.tools.ant.types.FileSet;
  import org.apache.tools.ant.types.XMLCatalog;
  import org.dom4j.Element;
  import org.dom4j.io.OutputFormat;
  import org.dom4j.io.XMLWriter;
  import org.dom4j.tree.DefaultElement;
  import org.xml.sax.InputSource;
  import org.xml.sax.SAXException;
  import org.xml.sax.SAXNotRecognizedException;
  import org.xml.sax.SAXNotSupportedException;
  import org.xml.sax.XMLReader;
  import org.xml.sax.helpers.XMLReaderFactory;
  
  /***
   * Validator task.
   * This task is a modified version of the standard ant validator task, specialized for checking
   * xhtml files and logging errors (without beaking the build)
   * @author fgiust
   * @version $Revision: 1.4 $ ($Author: fgiust $)
   */
  public class Validator extends Task
  {
      /***
       * validation feature
       */
     private static final String VALIDATION_FEATURE = "http://xml.org/sax/features/validation";
 
     /***
      * encoding - defaults to ISO-8859-1
      */
     private String encoding = "ISO-8859-1";
 
     /***
      * output file
      */
     private File outputFile = null;
 
     /***
      * XmlWriter used to write to outputFile
      */
     private XMLWriter out;
 
     /***
      * sets of file to be validated
      */
     private List filesets = new ArrayList();
 
     /***
      * XMLReader used to validation process
      */
     private XMLReader xmlReader = null;
 
     /***
      * Validator handler: implements both ErrorHandler and DTDHandler
      */
     private ValidatorHandler validatorHandler = new ValidatorHandler();
 
     /***
      * XMLCatalog containing references to local dtds and entities
      */
     private XMLCatalog xmlCatalog = new XMLCatalog();
 
     /***
      * sets the input/output files encoding
      * @param value encoding
      */
     public void setEncoding(String value)
     {
         encoding = value;
     }
 
     /***
      * sets the output file
      * @param file output file
      */
     public void setOUtput(File file)
     {
         outputFile = file;
     }
 
     /***
      * add an XMLCatalog as a nested element.
      * @param catalog XMLCatalog
      */
     public void addConfiguredXMLCatalog(XMLCatalog catalog)
     {
         xmlCatalog.addConfiguredXMLCatalog(catalog);
     }
 
     /***
      * specify a set of file to be checked
      * @param set Fileset
      */
     public void addFileset(FileSet set)
     {
         filesets.add(set);
     }
 
     /***
      * initialize task
      */
     public void init()
     {
         super.init();
         xmlCatalog.setProject(project);
     }
 
     /***
      * Create a DTD location record.
      * This stores the location of a DTD. The DTD is identified by its public Id
      * @return DTDLocation
      */
     public DTDLocation createDTD()
     {
         DTDLocation dtdLocation = new DTDLocation();
         xmlCatalog.addDTD(dtdLocation);
         return dtdLocation;
     }
 
     /***
      * Init the parser. Load the parser class and enable validation
      */
     private void initValidator()
     {
 
         // turn validation on
         try
         {
             xmlReader = XMLReaderFactory.createXMLReader();
             xmlReader.setFeature(VALIDATION_FEATURE, true);
 
         }
         catch (SAXNotRecognizedException e)
         {
             throw new BuildException("Could not start validation: " + xmlReader + " doesn't provide validation");
         }
         catch (SAXNotSupportedException e)
         {
             throw new BuildException("Could not start validation: " + xmlReader + " doesn't provide validation");
         }
         catch (SAXException e)
         {
             throw new BuildException("Could not start validation: " + xmlReader + " not found");
         }
 
         log(xmlReader.getClass().getName(), Project.MSG_DEBUG);
 
         // set entity resolver
         xmlReader.setEntityResolver(xmlCatalog);
 
         // set handler for validation messages
         xmlReader.setErrorHandler(validatorHandler);
         xmlReader.setEntityResolver(validatorHandler);
 
     }
 
     /***
      * execute the task
      * @throws BuildException if unable to build a validating SAX2 parser
      */
     public void execute() throws BuildException
     {
 
         // check output dir
         File dir = outputFile.getParentFile();
 
         // create output dir if missing
         if (dir != null)
         {
             dir.mkdirs();
         }
 
         // set output format
         OutputFormat format = OutputFormat.createPrettyPrint();
         format.setEncoding(encoding);
 
         // create the XMLWriter
         try
         {
             out = new XMLWriter(new FileOutputStream(outputFile), format);
         }
         catch (UnsupportedEncodingException e)
         {
             throw new BuildException("Unsopported encoding: [" + encoding + "]");
         }
         catch (FileNotFoundException e)
         {
             throw new BuildException("Unable to write to [" + outputFile.getAbsolutePath() + "]");
         }
 
         // init validator
         initValidator();
 
         // pass out to validator handler
         validatorHandler.setOut(out);
 
         // create the root element
         Element validation = new DefaultElement("validation");
         try
         {
             // start xml document and open the root element
             out.startDocument();
             out.writeOpen(validation);
 
             // create the root element
 
             // iterates on filesets
             Iterator fileIterator = filesets.iterator();
 
             while (fileIterator.hasNext())
             {
                 // next fileset
                 FileSet fs = (FileSet) fileIterator.next();
 
                 // scan for files
                 DirectoryScanner ds = fs.getDirectoryScanner(project);
 
                 // get all the file names
                 String[] files = ds.getIncludedFiles();
 
                 // iterates on files
                 for (int j = 0; j < files.length; j++)
                 {
                     // new file element
                     Element xmlfile = new DefaultElement("file");
 
                     // create a new File
                     File srcFile = new File(fs.getDir(project), files[j]);
 
                     // add file name to element
                     xmlfile.addAttribute("name", files[j]);
 
                     // open file element
                     out.writeOpen(xmlfile);
 
                     // perform validation
                     doValidate(srcFile);
 
                     // close file element
                     out.writeClose(xmlfile);
                 }
             }
 
             // close the root element
             out.writeClose(validation);
 
             // end document
             out.endDocument();
         }
 
         catch (SAXException e)
         {
             log(e.getClass() + " " + e.getMessage(), Project.MSG_WARN);
             throw new BuildException(e.getMessage());
         }
         catch (IOException e)
         {
             log(e.getClass() + " " + e.getMessage(), Project.MSG_WARN);
             throw new BuildException(e.getMessage());
         }
 
         finally
         {
             try
             {
                 // be sure out is closed
                 if (out != null)
                 {
                     out.close();
                 }
             }
             catch (IOException e)
             {
                 e.printStackTrace();
             }
         }
     }
 
     /***
      * parse the file
      * @param afile File to validate
      */
     private void doValidate(File afile)
     {
         log("Validating " + afile.getName() + "... ", Project.MSG_INFO);
 
         // init validation handler
         validatorHandler.init(afile);
 
         try
         {
 
             InputSource is = new InputSource(new FileInputStream(afile));
             String uri = "file:" + afile.getAbsolutePath().replace('//', '/');
             for (int index = uri.indexOf('#'); index != -1; index = uri.indexOf('#'))
             {
                 uri = uri.substring(0, index) + "%23" + uri.substring(index + 1);
             }
             is.setSystemId(uri);
             is.setEncoding(encoding);
 
             xmlReader.parse(is);
         }
         catch (SAXException e)
         {
             Element error = new DefaultElement("fatalerror");
             error.addText(e.getMessage());
             writeToLog(error);
 
         }
         catch (UnknownHostException e)
         {
             Element error = new DefaultElement("fatalerror");
 
             error.addText(
                 "Could not validate document " + afile + "; dtd missing from repository and unable to connect");
             writeToLog(error);
         }
         catch (IOException e)
         {
             Element error = new DefaultElement("fatalerror");
             error.addText(e.getMessage());
             writeToLog(error);
 
         }
 
         if (validatorHandler.getErrors() > 0)
         {
             log(afile + ", errors=" + validatorHandler.getErrors(), Project.MSG_INFO);
         }
 
     }
 
     /***
      * write an element to the xml log file
      * @param element Element to write
      */
     private void writeToLog(Element element)
     {
         try
         {
             out.write(element);
         }
         catch (IOException e)
         {
             e.printStackTrace();
         }
     }
 
 }