/*
    * #%L
    * JRst :: Api
    * %%
    * Copyright (C) 2004 - 2012 CodeLutin
    * %%
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU Lesser General Public License as 
    * published by the Free Software Foundation, either version 3 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 Lesser Public License for more details.
   * 
   * You should have received a copy of the GNU General Lesser Public 
   * License along with this program.  If not, see
   * <http://www.gnu.org/licenses/lgpl-3.0.html>.
   * #L%
   */
  package org.nuiton.jrst;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.codehaus.plexus.component.annotations.Component;
  import org.dom4j.Document;
  import org.dom4j.DocumentException;
  import org.dom4j.DocumentHelper;
  import org.nuiton.jrst.legacy.JRSTReader;
  import org.python.util.PythonInterpreter;
  
  import java.io.ByteArrayOutputStream;
  import java.io.File;
  import java.net.URL;
  
  /**
   * Old mecanism to transform rst file to xml format using {@link JRSTReader}.
   *
   * @author tchemit <chemit@codelutin.com>
   * @since 2.0.1
   */
  @Component(role = JRSTToXmlStrategy.class, hint = "docutils",
             description = "Transform a RST model (using jython + docutils), " +
                           "to a xml format.")
  
  public class JRSTToXmlStrategyDocutils implements JRSTToXmlStrategy {
  
      private static final String DOCUTILS_LAUNCHER = "__run__.py";
  
      private static final String IMPORT_SCRIPT = "import __run__";
  
      private static final String WINDOWS_NAME = "win";
  
      private static final String OS_NAME = "os.name";
  
      private static final String BANG = "!";
  
      private static final String FILE_URI_PREFIX = "file:";
  
      /** Logger. */
      private static final Log log =
              LogFactory.getLog(JRSTToXmlStrategyDocutils.class);
  
      @Override
      public Document generateRstToXml(File in, String encoding) throws Exception {
          ByteArrayOutputStream out = null;
  
          try {
              // Transformation to XML
              out = new ByteArrayOutputStream();
  
              // Transformation of the __run__ URL into a path that python will use
              // For example the URL is :
              // jar:file:/home/user/.m2/repository/org/nuiton/jrst/docutils/1.6-SNAPSHOT/docutils-1.6-SNAPSHOT.jar!/__run__.py
              // and it becomes :
              // /home/user/.m2/repository/org/nuiton/jrst/docutils/1.6-SNAPSHOT/docutils-1.6-SNAPSHOT.jar/
              URL resource = JRST.class.getResource("/" + DOCUTILS_LAUNCHER);
              String docutilsPath = resource.getPath()
                      .replaceAll(DOCUTILS_LAUNCHER, "");
  
              docutilsPath = docutilsPath.replaceAll(BANG, "");
              docutilsPath = docutilsPath.replaceAll(FILE_URI_PREFIX, "");
  
              // Import of the main script to use docutils ( __run__ )
              PythonInterpreter interp = new PythonInterpreter();
              String commandImport = IMPORT_SCRIPT;
              interp.exec(commandImport);
  
              // If the OS is windows, escapes the backslashs in the filepath
              String filePath = in.getAbsolutePath();
              String property = System.getProperty(OS_NAME).toLowerCase();
              if (property.contains(WINDOWS_NAME)) {
                  filePath = filePath.replaceAll("\\\\", "\\\\\\\\");
              }
  
              // Sets an output stream in the python interpreter and executes the code
              interp.setOut(out);
  
             // Execution of the docutils script to transform rst to xml
             String commandExec = String.format("__run__.exec_docutils('%s', '%s', '%s')",
                                                docutilsPath, JRST.TYPE_XML, filePath);
             interp.exec(commandExec);
 
             // Cleans the python interpreter to avoid problems if they are multiple execution of this method
             interp.cleanup();
 
             // Transforms the output stream to a document
             String xmlString = new String(out.toByteArray(), encoding);
 
             Document doc = null;
             try {
                 doc = DocumentHelper.parseText(xmlString);
             } catch (DocumentException e) {
                 log.error("Error during the creation of the document", e);
             }
             out.close();
 
             return doc;
         } finally {
             if (out != null) {
                 out.close();
             }
         }
     }
 }