package org.honours.greenstone;

import java.io.File;

import org.apache.log4j.Logger;

import org.greenstone.gsdl3.util.GSXML;
import org.greenstone.gsdl3.util.XMLConverter;
import org.honours.Main;
import org.w3c.dom.*;

/**
 * This class is used to obtain elements from
 * a collection's corresponding collectionConfig.xml
 * file.
 * @author - Korii
 */
public class CollectionConfigReader {

	static Logger logger = Logger.getLogger(org.honours.greenstone.CollectionConfigReader.class.getName());
	
	private XMLConverter _xmlConverter;
	private Document _document;
	
	private String _collectionConfigFile;
	
	public CollectionConfigReader(String collectionName){
		
		_xmlConverter = new XMLConverter();
		_collectionConfigFile = Main.GSDL_COLLECT_PATH + collectionName + File.separator + "etc" + 
		File.separator + "collectionConfig.xml";
		_document = _xmlConverter.getDOM(new File(_collectionConfigFile));
	}
	
	/**
	 * Method available to retrieve a collection's description.
	 * @return
	 */
	public String retrieveDescription(){
	
		return obtainElementTextFromDisplayItemList("description");
	}
	
	/**
	 * Method available to retrieve a collection's full name.
	 * @return
	 */
	public String retrieveFullCollectionName(){
		return obtainElementTextFromDisplayItemList("name");
	}
	
	/**
	 * Retrieves text from an element in the displayItemList 
	 * section of the collectionConfig.xml file.
	 * @return - the collection's description text
	 */
	public String obtainElementTextFromDisplayItemList(String name){
		
		NodeList nl = _document.getDocumentElement().getElementsByTagName("displayItemList");
		Element displayItemList = (Element)nl.item(0);
		
		nl = displayItemList.getChildNodes();
		int i = 0;
		
		while(i <= nl.getLength()){
			
			Node node = nl.item(i);
			if(node != null){
				
				if(node.getNodeType() == Node.ELEMENT_NODE){
					
					Element e = (Element)node;
					
					if(e.getTagName().equals("displayItem") &&
							e.getAttribute("name").equals(name)){
						return GSXML.getNodeText(e);
					}
				}
			}
			
			i++;
		}
		
		return null;
	}
	
}