/* This file is part of the project "Hilbert II" - http://www.qedeq.org" target="alexandria_uri">http://www.qedeq.org
    *
    * Copyright 2000-2014,  Michael Meyling <mime@qedeq.org>.
    *
    * "Hilbert II" is free software; you can redistribute
    * it and/or modify it under the terms of the GNU General Public
    * License as published by the Free Software Foundation; either
    * version 2 of the License, or (at your option) any later version.
    *
   * 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 General Public License for more details.
   */
  package org.qedeq.kernel.xml.tracker;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.Locale;
  
  import javax.xml.parsers.ParserConfigurationException;
  
  import org.qedeq.base.io.SourceArea;
  import org.qedeq.base.utility.StringUtility;
  import org.qedeq.kernel.bo.KernelContext;
  import org.xml.sax.SAXException;
  
  
  /**
   * Find position of simple XPath expressions within an XML file.
   *
   * @author  Michael Meyling
   */
  public final class XPathLocationFinder {
  
      /**
       * Constructor.
       */
      private XPathLocationFinder() {
          // nothing to do
      }
  
      /**
       * Main method.
       *
       * @param   args    Various parameters. See implementation of
       *                  {@link #printProgramInformation()}.
       * @throws  ParserConfigurationException    Severe parser configuration problem.
       * @throws  SAXException                    XML problem.
       * @throws  IOException                     IO problem.
       */
      public static final void main(final String[] args) throws ParserConfigurationException,
              SAXException, IOException {
          String from = null;
          String xpath = null;
  
          if (args.length == 0) {
              printProgramInformation();
              return;
          }
  
          for (int i = 0; i < args.length; i++) {
              if (args[i].startsWith("-")) {  // option
                  final String option = args[i].substring(1).toLowerCase(Locale.US);
                  if (option.equals("help") || option.equals("h")
                          || option.equals("?")) {
                      printProgramInformation();
                      return;
                  }
                  if (option.equals("xpath") || option.equals("xp")) {
                      if (i + 1 >= args.length) {
                          printProgramInformation();
                          System.err.println("\"-xpath\" must be followed by a xpath.");
                          return;
                      }
                      xpath = args[i + 1];
                      i++;
                  } else {                    // unknown option
                      printProgramInformation();
                      System.err.println("Unknown option: " + option);
                      return;
                  }
              } else {                        // no option, must be file name
                  from = args[i];
              }
          }
          if (from == null) {
              printProgramInformation();
              System.err.println("XML file must be specified.");
              return;
          }
          if (xpath == null) {
              printProgramInformation();
              System.err.println("XPath must be specified.");
              return;
          }
          System.out.println(StringUtility.getClassName(XPathLocationFinder.class) + ", running on: "
              + KernelContext.getInstance().getDescriptiveKernelVersion());
          try {
             final SimpleXPath sXPath = new SimpleXPath(xpath);
             SourceArea result = XPathLocationParser.findSourceArea(new File(from), new SimpleXPath(xpath));
             System.out.println(result);
         } catch (RuntimeException e) {
             System.err.println(e);
         }
     }
 
     /**
      * Writes calling convention to <code>System.err</code>.
      */
     public static final void printProgramInformation() {
         System.err.println("Name");
         System.err.println("----");
         System.err.println(StringUtility.getClassName(XPathLocationFinder.class)
             + " - find simple XML paths");
         System.err.println();
         System.err.println("Synopsis");
         System.err.println("-------------------");
         System.err.println("[-h] -xp[ath] <simpleXPath> <xmlFile>");
         System.err.println();
         System.err.println("Description");
         System.err.println("-----------");
         System.err.println(
             "This program finds the location of a given simple XPath in an XML file.");
         System.err.println();
         System.err.println("Options and Parameters");
         System.err.println("---------------------");
         System.err.println("-h             writes this text and returns");
         System.err.println("-xpath         set the language filter (default: \"en\")");
         System.err.println(
             "<simpleXPath>  simple XML XPath, a subset of the abbreviation XPath notation");
         System.err.println(
             "                \"/element1/element2[3]@attribute\" is an example for such a");
         System.err.println(
             "                notation. This selects from the first occurrence of \"element1\"");
         System.err.println(
             "                and from the third occurrence of subnode \"element2\" the attribute");
         System.err.println(
             "                \"attribute\". The attribute is optional. It is always exactly one");
         System.err.println("                node or the attribute of one node specified.");
         System.err.println("                General syntax:");
         System.err.println("                {<element>\"[\"<index>\"]}+[\"@\"<attribute>]");
         System.err.println("<xmlFile>      XML file");
         System.err.println();
         System.err.println("Parameter Examples");
         System.err.println("------------------");
         System.err.println(
             "-xp QEDEQ/CHAPTER/SECTION/NODE[2]/PRECEDING/AXIOM/FORMULA/FORALL/VAR@id");
         System.err.println("sample/qedeq_basic_concept.xml");
         System.err.println();
         System.err.println("Further information");
         System.err.println("-------------------");
         System.err.println("For more information about *Hilbert II* look at:");
         System.err.println("\thttp://www.qedeq.org/");
         System.err.println();
     }
 
 }