/*
 *  eXist Open Source Native XML Database: Extension module
 *  Copyright (C) 2008 Josef Willenborg
 *  jwillenborg@mpiwg-berlin.mpg.de
 *  http://www.mpiwg-berlin.mpg.de
 *  
 *  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 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 Lesser General Public License for more details.
 *  
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *  
 *  $Id: TextModule.java $
 */
package org.exist.xquery.modules.mpdltext;

import org.exist.memtree.NodeImpl;
import org.exist.dom.NodeSet;
import org.exist.dom.QName;
import org.exist.memtree.DocumentImpl;
import org.exist.memtree.MemTreeBuilder;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.Item;
import org.exist.xquery.value.MemoryNodeSet;
import org.exist.xquery.value.NodeValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * @author Josef Willenborg (jwillenborg@mpiwg-berlin.mpg.de)
 */
public class ToCLevelGenerator extends BasicFunction {

	public final static FunctionSignature signature =
		new FunctionSignature(
			new QName("generate-toc-levels", MPDLTextModule.NAMESPACE_URI, MPDLTextModule.PREFIX),
			"A function which generates toc levels of the given toc entries " +
			"and the starting levels",
			new SequenceType[] { new SequenceType(Type.ITEM, Cardinality.ZERO_OR_MORE) },
			new SequenceType(Type.NODE, Cardinality.ZERO_OR_MORE));

	public ToCLevelGenerator(XQueryContext context) {
		super(context, signature);
	}

  public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
    Sequence tocEntriesSeq = args[0];
    if (tocEntriesSeq.isEmpty())
      return Sequence.EMPTY_SEQUENCE;
    boolean tocEntriesIsPersistent = tocEntriesSeq.isPersistentSet();  // Workaround: when entries are persistent (not in memory) 
    if (tocEntriesIsPersistent)
      return evalAsPersistentSeq(args, contextSequence);
    int level = 0;
    int level1 = 0;
    int level2 = 0;
    int level3 = 0;
    int level4 = 0;
    int level5 = 0;
    int level6 = 0;
    int level7 = 0;
    DocumentImpl doc = null;
    MemTreeBuilder builder = context.getDocumentBuilder();
    builder.startElement("", "toc-entries", "toc-entries", null);
    for (int i=0; i<tocEntriesSeq.getItemCount(); i++) {
      MemoryNodeSet nodeToNodeSet = tocEntriesSeq.toMemNodeSet();
      Node node = nodeToNodeSet.get(i);
      NodeList childNodeList = node.getChildNodes();
      int childsLength = childNodeList.getLength();
      if (childsLength > 0) {
        builder.startElement("", "toc-entry", "toc-entry", null);
        for (int j=0; j<childsLength; j++) {
          NodeImpl childNode = (NodeImpl)childNodeList.item(j);
          String childNodeName = childNode.getLocalName();
          String childNodeValue = childNode.getStringValue(); 
          builder.startElement("", childNodeName, childNodeName, null);
          if (childNodeValue != null)
            builder.characters(childNodeValue);
          builder.endElement();
          if (childNodeName.equals("level")) {
            int nodeLevel = 1;  // default is a level one node
            try {
              nodeLevel = new Integer(childNodeValue).intValue();
            } catch (NumberFormatException e) {
              // nothing 
            }
            if (level > nodeLevel) {
              if (nodeLevel == 1) {
                level2 = 0; level3 = 0; level4 = 0; level5 = 0; level6 = 0; level7 = 0;
              } else if (nodeLevel == 2) {
                level3 = 0; level4 = 0; level5 = 0; level6 = 0; level7 = 0;
              } else if (nodeLevel == 3) {
                level4 = 0; level5 = 0; level6 = 0; level7 = 0;
              } else if (nodeLevel == 4) {
                level5 = 0; level6 = 0; level7 = 0;
              } else if (nodeLevel == 5) {
                level6 = 0; level7 = 0;
              } else if (nodeLevel == 6) {
                level7 = 0;
              }
            }
            level = nodeLevel; 
            if (level == 1)
              level1++;
            else if (level == 2)
              level2++;
            else if (level == 3)
              level3++;
            else if (level == 4)
              level4++;
            else if (level == 5)
              level5++;
            else if (level == 6)
              level6++;
            else if (level == 7)
              level7++;
          }
        }
        String levelString =  "";
        if (level1 != 0)
          levelString += level1 + ".";
        if (level2 != 0)
          levelString += level2 + ".";
        if (level3 != 0)
          levelString += level3 + ".";
        if (level4 != 0)
          levelString += level4 + ".";
        if (level5 != 0)
          levelString += level5 + ".";
        if (level6 != 0)
          levelString += level6 + ".";
        if (level7 != 0)
          levelString += level7 + ".";
        
        builder.startElement("", "level-string", "level-string", null);
        builder.characters(levelString);
        builder.endElement();

        String[] splitStr = levelString.split("\\.");
        int realLevel = splitStr.length;
        builder.startElement("", "real-level", "real-level", null);
        builder.characters("" + realLevel);
        builder.endElement();
        builder.endElement();
      }
    }
    builder.endElement();
    doc = ((DocumentImpl)builder.getDocument());
    return doc;
  }

  public Sequence evalAsPersistentSeq(Sequence[] args, Sequence contextSequence) throws XPathException {
    Sequence tocEntriesSeq = args[0];
    if (tocEntriesSeq.isEmpty())
      return Sequence.EMPTY_SEQUENCE;
    int level = 0;
    int level1 = 0;
    int level2 = 0;
    int level3 = 0;
    int level4 = 0;
    int level5 = 0;
    int level6 = 0;
    int level7 = 0;
    DocumentImpl doc = null;
    MemTreeBuilder builder = context.getDocumentBuilder();
    builder.startElement("", "toc-entries", "toc-entries", null);
    for (int i=0; i<tocEntriesSeq.getItemCount(); i++) {
      Item item = tocEntriesSeq.itemAt(i);
      NodeValue nv = (NodeValue) item;
      NodeImpl nodeTmp = (NodeImpl) nv;
      NodeSet nodeToNodeSet = nodeTmp.toNodeSet();
      Node node = nodeToNodeSet.item(0);
      NodeList childNodeList = node.getChildNodes();
      int childsLength = childNodeList.getLength();
      if (childsLength > 0) {
        builder.startElement("", "toc-entry", "toc-entry", null);
        for (int j=0; j<childsLength; j++) {
          Node childNode = childNodeList.item(j);
          String childNodeName = childNode.getLocalName();
          String childNodeValue = childNode.getNodeValue();
          builder.startElement("", childNodeName, childNodeName, null);
          if (childNodeValue != null)
            builder.characters(childNodeValue);
          builder.endElement();
          if (childNodeName.equals("level")) {
            int nodeLevel = 1;  // default is a level one node
            try {
              nodeLevel = new Integer(childNodeValue).intValue();
            } catch (NumberFormatException e) {
              // nothing 
            }
            if (level > nodeLevel) {
              if (nodeLevel == 1) {
                level2 = 0; level3 = 0; level4 = 0; level5 = 0; level6 = 0; level7 = 0;
              } else if (nodeLevel == 2) {
                level3 = 0; level4 = 0; level5 = 0; level6 = 0; level7 = 0;
              } else if (nodeLevel == 3) {
                level4 = 0; level5 = 0; level6 = 0; level7 = 0;
              } else if (nodeLevel == 4) {
                level5 = 0; level6 = 0; level7 = 0;
              } else if (nodeLevel == 5) {
                level6 = 0; level7 = 0;
              } else if (nodeLevel == 6) {
                level7 = 0;
              }
            }
            level = nodeLevel; 
            if (level == 1)
              level1++;
            else if (level == 2)
              level2++;
            else if (level == 3)
              level3++;
            else if (level == 4)
              level4++;
            else if (level == 5)
              level5++;
            else if (level == 6)
              level6++;
            else if (level == 7)
              level7++;
          }
        }
        String levelString =  "";
        if (level1 != 0)
          levelString += level1 + ".";
        if (level2 != 0)
          levelString += level2 + ".";
        if (level3 != 0)
          levelString += level3 + ".";
        if (level4 != 0)
          levelString += level4 + ".";
        if (level5 != 0)
          levelString += level5 + ".";
        if (level6 != 0)
          levelString += level6 + ".";
        if (level7 != 0)
          levelString += level7 + ".";
        
        builder.startElement("", "level-string", "level-string", null);
        builder.characters(levelString);
        builder.endElement();

        String[] splitStr = levelString.split("\\.");
        int realLevel = splitStr.length;
        builder.startElement("", "real-level", "real-level", null);
        builder.characters("" + realLevel);
        builder.endElement();
        builder.endElement();
      }
    }
    builder.endElement();
    doc = ((DocumentImpl)builder.getDocument());
    return doc;
  }

}