/*
    *  Copyright (C) 2003-2005 SINTEF
    *  Author:  Fredrik Vraalsen (fredrik dot vraalsen at sintef dot no)
    *  Webpage: http://coras.sourceforge.net/
    *
    *  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 2.1
    *  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., 59 Temple Place, Suite 330, Boston, MA
   *  02111-1307 USA
   */
  package coras.internalmodel;
  
  import java.net.URL;
  import java.rmi.RemoteException;
  import java.util.Collection;
  import java.util.Iterator;
  
  import javax.xml.bind.JAXBContext;
  import javax.xml.bind.JAXBException;
  import javax.xml.bind.Unmarshaller;
  import javax.xml.transform.Transformer;
  import javax.xml.transform.dom.DOMResult;
  import javax.xml.transform.dom.DOMSource;
  
  import no.sintef.assetrepository.interfaces.AssetRepresentationPK;
  import no.sintef.assetrepository.interfaces.AssetRepresentationValue;
  import no.sintef.assetrepository.interfaces.AssetServices;
  import no.sintef.assetrepository.interfaces.AssetServicesUtil;
  import no.sintef.assetrepository.interfaces.AssetVersionValue;
  import no.sintef.assetrepository.interfaces.VersionedAssetPK;
  import no.sintef.assetrepository.interfaces.VersionedAssetValue;
  import no.sintef.xml.XmlHelper;
  
  import org.apache.log4j.Logger;
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  import org.w3c.dom.Node;
  
  import coras.repository.session.CorasServicesEJBImpl;
  import coras.representations.RepresentationTypeEnum;
  import coras.table.jaxb.TableType;
  
  public class TableFiller {
  
  	private static final Logger LOGGER = Logger.getLogger(TableFiller.class);
  
  	private static final String NAMESPACE_URI = "http://coras.sourceforge.net/schemas/coras-internal-xml-1_0.xsd";
      private static final String PREFIX = "ci";
      private static final String ROOT_ELEM = "tableFiller";
  	
      private static TableFiller theFiller = null;
      private ClassLoader cl = null;
      private Unmarshaller unmarshaller = null;
      
      private TableFiller() throws JAXBException {
          cl = getClass().getClassLoader();
          JAXBContext jc = JAXBContext.newInstance("coras.table.jaxb");
          unmarshaller = jc.createUnmarshaller();
      }
      
      public static synchronized TableFiller getTableFiller() {
      	if (theFiller == null) {
      		try {
  				theFiller = new TableFiller();
  			} catch (JAXBException e) {
                  LOGGER.error("Could not create TableFiller: " + e);
  				e.printStackTrace();
  				theFiller = null;
  			}
      	}
      	return theFiller;
      }
      
  	public TableType fillTable(VersionedAssetPK resultPk) throws Exception {
          AssetServices services = AssetServicesUtil.getHome().create();
          VersionedAssetValue result = services.getVersionedAsset(resultPk);
          AssetVersionValue resultVersion = services.getAssetVersion(result.getBaseVersion());
          
          String subtype = (String) resultVersion.getProperties().get("subtype");
          String name = "coras/internalmodel/tablefiller/" + subtype.replaceAll(" ", "_") + ".xsl";
          URL tableFillerUrl = cl.getResource(name);
          if (tableFillerUrl == null) {
          	return null;
          }
          Transformer tableFillerTransformer = XmlHelper.getTransformer(tableFillerUrl, LOGGER);
          
          Node content = getTableContent(resultVersion, services);
          if (content == null) {
          	return null;
         }
         Element internalRepr = CorasServicesEJBImpl.getInternalRepresentation(resultVersion.getParent(), services); //imf.getInternalRepresentation(resultVersions);
         Document elementDoc = getElementDoc(content, internalRepr);
         DOMSource elementDocSource = new DOMSource(elementDoc);
         DOMResult newContentResult = new DOMResult();
         tableFillerTransformer.transform(elementDocSource, newContentResult);
         Node newResult = newContentResult.getNode();
         return (TableType) unmarshaller.unmarshal(newResult);
 	}
 
 	private Node getTableContent(AssetVersionValue resultVersion, AssetServices services) throws RemoteException {
 		Collection representations = resultVersion.getRepresentations();
 		for (Iterator i = representations.iterator(); i.hasNext();) {
 			AssetRepresentationPK representationPk = (AssetRepresentationPK) i.next();
 			AssetRepresentationValue representation = services.getAssetRepresentation(representationPk);
 			if (RepresentationTypeEnum.TABLE == RepresentationTypeEnum.forName(representation.getType())) {
 				return (Node) representation.getContent();
 			}
 		}
 		return null;
 	}
 
 	private Document getElementDoc(Node resultContent, Node internalRepr) {
 	    if (resultContent == null || internalRepr == null)
 	        return null;
 	    
 	    try {
 	        Document doc = XmlHelper.createDocument(NAMESPACE_URI, PREFIX, ROOT_ELEM, null);
 	        Element rootElem = doc.getDocumentElement();
 	        
 	        /*
 	        String type = resultVersion.getType();
 	        IRepresentation repr = resultVersion.getRepresentationByType(type);
 	        if (repr instanceof XmlRepresentation) {
 	            Node n = (Node)repr.getContent();
 	            if (n != null) {
 	                n = doc.importNode(n, true);
 	                n = XmlHelper.getRootElement(n);
 	                if (n != null)
 	                    rootElem.appendChild(n);
 	            }
 	        }
 	        */
 	        resultContent = XmlHelper.getRootElement(resultContent);
 	        if (resultContent != null) {
 	            resultContent = doc.importNode(resultContent, true);
 	            resultContent = XmlHelper.getRootElement(resultContent);
 	            if (resultContent != null)
 	                rootElem.appendChild(resultContent);
 	        }
 	        
 	        internalRepr = doc.importNode(internalRepr, true);
 	        if (internalRepr != null)
 	            rootElem.appendChild(internalRepr);
 	        return doc;
 	    } catch (Exception e) {
 	        e.printStackTrace();
 	        return null;
 	    }
 	}
 	
 }