/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe 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 3 of the License, or
    * (at your option) any later version.
    *
   * MyCoRe 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.frontend.xeditor.tracker;
  
  import java.io.IOException;
  import java.io.StringReader;
  
  import org.jdom2.Attribute;
  import org.jdom2.Element;
  import org.jdom2.JDOMException;
  import org.jdom2.ProcessingInstruction;
  import org.jdom2.Text;
  import org.jdom2.input.SAXBuilder;
  import org.jdom2.output.Format;
  import org.jdom2.output.XMLOutputter;
  import org.mycore.common.MCRException;
  
  public class MCRChangeData {
  
      protected String type;
  
      protected int pos;
  
      protected Element context;
  
      protected String text;
  
      protected ProcessingInstruction pi;
  
      private static final XMLOutputter RAW_OUTPUTTER = new XMLOutputter(Format.getRawFormat().setEncoding("UTF-8"));
  
      public MCRChangeData(String type, String text, int pos, Element context) {
          this.type = type;
          this.text = text;
          this.pos = pos;
          this.context = context;
      }
  
      public MCRChangeData(String type, Attribute attribute) {
          this(type, attribute2text(attribute), 0, attribute.getParent());
      }
  
      public MCRChangeData(String type, Element data, int pos, Element context) {
          this(type, element2text(data), pos, context);
      }
  
      public ProcessingInstruction getProcessingInstruction() {
          if (pi == null) {
              String data = RAW_OUTPUTTER.outputString(new Text(text));
              this.pi = new ProcessingInstruction(type, data);
          }
          return pi;
      }
  
      public MCRChangeData(ProcessingInstruction pi, String prefix) {
          this.pi = pi;
          this.context = pi.getParentElement();
          this.pos = context.indexOf(pi);
          this.type = pi.getTarget().substring(prefix.length());
  
          String xml = "<x>" + pi.getData() + "</x>";
          this.text = text2element(xml).getText();
      }
  
      public String getType() {
          return type;
      }
  
      public Element getContext() {
          return context;
      }
  
      public int getPosition() {
          return pos;
      }
  
      public String getText() {
          return text;
      }
  
      public Element getElement() {
          return text2element(text);
      }
 
     public Attribute getAttribute() {
         return text2attribute(text);
     }
 
     private static String element2text(Element element) {
         return RAW_OUTPUTTER.outputString(element);
     }
 
     private Element text2element(String text) {
         try {
             return new SAXBuilder().build(new StringReader(text)).detachRootElement();
         } catch (JDOMException | IOException ex) {
             throw new MCRException("Exception in text2element: " + text, ex);
         }
     }
 
     private static String attribute2text(Attribute attribute) {
         Element x = new Element("x").setAttribute(attribute.clone());
         String text = element2text(x);
         return text.substring(3, text.length() - 2).trim();
     }
 
     public Attribute text2attribute(String text) {
         String xtext = "<x " + text + " />";
         return text2element(xtext).getAttributes().get(0).detach();
     }
 }