/*
 *    GSDL2ClassifierService.java
 *    Copyright (C) 2002 New Zealand Digital Library, http://www.nzdl.org
 *
 *    This program 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.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package org.greenstone.gsdl3.service;

import org.greenstone.gdbm.*;
import org.greenstone.gsdl3.util.*;

import org.w3c.dom.Document; 
import org.w3c.dom.Node; 
import org.w3c.dom.Text; 
import org.w3c.dom.Element; 
import org.w3c.dom.NodeList; 
/**
 * A Service class for GSDL2-style Classifiers
 *
 * @author <a href="mailto:kjdon@cs.waikato.ac.nz">Katherine Don</a>
 * @version $Revision: 3453 $
 */
public class GSDL2ClassifierService 
    extends ServiceModule {

    /** gdbm wrapper */
    private GDBMWrapper gdbm_src_=null;

    public GSDL2ClassifierService() {
	gdbm_src_ = new GDBMWrapper();

    }
 
    /** processes the request */
    protected Element processService(String name, Element request) {

	if (!name.equals("ClassifierBrowse")) {
	    System.err.println("GSDL2ClassifierService:should never get here. service type wrong:"+name);
	return null;
	}
	// the response element
	Element result = doc_.createElement("response");
	String from = GSPath.appendLink(collection_name_, "ClassifierBrowse");
	result.setAttribute("from", from);
	result.setAttribute("type", "query");
	Element result_content = doc_.createElement("content");
	result.appendChild(result_content);

	// get the classifier name out of request content - assume only one for now
	Element elem = (Element)GSXML.getNodeByPath(request, "content/resourceList/resource");
	String elem_name = elem.getAttribute("name");
	System.out.println("elem name="+elem_name);

	if (OID.needsTranslating(elem_name)) {
	    System.out.println("translating oid");
	    elem_name = gdbm_src_.translateOID(elem_name);
	}
	// get the info from gdbm db
	DBInfo info = gdbm_src_.getInfo(elem_name);

	// build up the XML
	Element classifier = doc_.createElement("classifier");
	
	String classifier_name = OID.getTop(elem_name);
	classifier.setAttribute("name", classifier_name);
	result_content.appendChild(classifier);
	DBInfo top_info;

	if (elem_name.equals(classifier_name)) { 
	    top_info = info;
	} else {
	    top_info = gdbm_src_.getInfo(classifier_name);
	}

	// a substitute template - should be read from config file
	//String extra = "<stylesheet xmlns:xsl='http://www.w3.org/1999/XSL/Transform'><xsl:template match='resource' priority='3'><xsl:param name='collName'>coll-name</xsl:param><xsl:variable name='library' select='ancestor::page/config/library_name'/><td><a href='{$library}?a=r&amp;c={$collName}&amp;r={@name}'><img src='interfaces/default/images/book.gif' width='18' height='11' border='0'/></a></td><td>***</td><td><xsl:value-of select='metadataList/metadata[@name=\"Title\"]'/></td></xsl:template></stylesheet>";
	//Element extra_doc = converter_.getDOM(extra).getDocumentElement();
	//result.appendChild(doc_.importNode(extra_doc, true));
	
	// get the classifier attributes
	String type = top_info.getInfo("childtype");
	if (type.equals("VList")) {
	    
	    classifier.setAttribute("type", "vertical");
	    classifier.setAttribute("interleave", "true");
	    classifier.setAttribute("link", "icon");
	}
	else if (type.equals("HList")){
	    classifier.setAttribute("type", "horizontal");
	    classifier.setAttribute("interleave", "false");
	    classifier.setAttribute("link", "name");
	} else {
	    System.out.println("unknown type!!! check this");
	    classifier.setAttribute("type", "vertical");
	    classifier.setAttribute("interleave", "true");
	    classifier.setAttribute("link", "icon");
	}

	Element this_node;
	if (elem_name.equals(classifier_name)) {
	    this_node = classifier;
	} else { // have to build up the parents 
	    // the current node
	    this_node = doc_.createElement("node");
	    this_node.setAttribute("name", elem_name);
	    type = info.getInfo("childtype");
	    if (type.equals("VList")) {
		this_node.setAttribute("type", "vertical");
	    } else {
		this_node.setAttribute("type", "horzizontal");
	    }
	    String title = info.getInfo("Title");
	    Element meta_list = doc_.createElement("metadataList");
	    GSXML.addMetadata(doc_, meta_list, "Title", title);
	    this_node.appendChild(meta_list);

	    System.out.println("classifier_name="+classifier_name);
	    System.out.println("this name="+elem_name);
	    // the parents
	    String middle_name = OID.getParent(elem_name);
	    Element middle_node = this_node;
	    while (!middle_name.equals(classifier_name)) {
		System.out.println("middle_name="+middle_name);
		// add in a new node
		Element temp_node = doc_.createElement("node");
		temp_node.setAttribute("name", middle_name);
		
		DBInfo i = gdbm_src_.getInfo(middle_name);
		type = i.getInfo("childtype");
		if (type.equals("VList")) {
		    temp_node.setAttribute("type", "vertical");
		} else {
		    temp_node.setAttribute("type", "horzizontal");
		}
		title = i.getInfo("Title");
		meta_list = doc_.createElement("metadataList");
		GSXML.addMetadata(doc_, meta_list, "Title", title);
		temp_node.appendChild(meta_list);

		// link into the tree
		temp_node.appendChild(middle_node);
		middle_node = temp_node;
		middle_name = OID.getParent(middle_name);
	    }
	    classifier.appendChild(middle_node);
	}
	// get the child nodes
	String contains = info.getInfo("contains");
	// replace the " with parent name
	contains = OID.translateParent(contains, elem_name);
	String [] children = contains.split(";");
	for (int i=0; i<children.length; i++) {
	    String child = children[i];
	    DBInfo child_info = gdbm_src_.getInfo(child);
	    String title = child_info.getInfo("Title");
	    Element node;
	    if (child.startsWith("HASH")) {
		// a resource
		node = doc_.createElement("resource");
	    } else { // a node in the classification
		node = doc_.createElement("node");
		
	    }
	    
	    node.setAttribute("name", child);
	    Element meta_list = doc_.createElement("metadataList");
	    GSXML.addMetadata(doc_, meta_list, "Title", title);
	    node.appendChild(meta_list);
	    this_node.appendChild(node);
	    
	}
	
	System.out.println("classifier result:");
	System.out.println(converter_.getString(result));
	return result;
	
    }
    

    /** configure this service */
    public boolean configure(Element info) {

	System.out.println("configuring GSDL2ClassifierService");

	Element e = null;
	// these entries should reflect the build config file - some services may not be available depending on how the colleciton was built.
	// set up short_service_info_ - for now just has name and type
	e = doc_.createElement("service");
	e.setAttribute("type", "query");
	e.setAttribute("name", "ClassifierBrowse");
	short_service_info_.appendChild(e);

	// set up service_info_map_ - for now, just has the same elements as above
	// should have full details about each service incl params lists etc.
	e = doc_.createElement("service");
	e.setAttribute("type", "query");
	e.setAttribute("name", "ClassifierBrowse");

	// get the classifier list out of the service info
	Node classList = GSXML.getChildByTagName(info, "classifierList");
	e.appendChild(doc_.importNode(classList, true));

	service_info_map_.put("ClassifierBrowse", e);
	
	if (gdbm_src_.openDatabase(GSFile.GDBMDatabaseFile(site_home_, collection_name_), GDBMWrapper.READER)) {
	    return true;
	}
	else {
	    System.err.println("couldn't open gdbm database!");
	    return false;
	}
	
    }


}