/**
 *#########################################################################
 *
 * A component of the Gatherer application, part of the Greenstone digital
 * library suite from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * <BR><BR>
 *
 * Author: John Thompson, Greenstone Digital Library, University of Waikato
 *
 * <BR><BR>
 *
 * Copyright (C) 1999 New Zealand Digital Library Project
 *
 * <BR><BR>
 *
 * 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.
 *
 * <BR><BR>
 *
 * 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.
 *
 * <BR><BR>
 *
 * 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.gatherer;

import java.awt.*;
import java.io.*;
import java.lang.ref.*;
import java.net.*;
import java.util.*;
import javax.swing.*;
import javax.swing.plaf.*;
import org.greenstone.gatherer.util.ArrayTools;
import org.greenstone.gatherer.util.StaticStrings;
import org.greenstone.gatherer.util.Utility;
import org.greenstone.gatherer.util.XMLTools;
import org.w3c.dom.*;

/** This class stores the mapping between sites and servlets available for them. The info is read in from the web.xml file.
 * @author Katherine Don, New Zealand Digital Library, University of Waikato
 * @version 
 */
public class ServletConfiguration {
    
    static public String ADD_COMMAND = "?a=s&sa=a&st=collection&sn=";
    static public String DEACTIVATE_COMMAND = "?a=s&sa=d&st=collection&sn=";
    private String gsdl3_path = "";
    private ArrayList sites = null;
    private HashMap mappings = null;

    public ServletConfiguration(String gsdl3_path) {
	
	this.gsdl3_path = gsdl3_path;
	
	//String web_xml_path = gsdl3_path + File.separator + "web" + File.separator + "WEB-INF"+ File.separator + "web.xml";
	File web_xml = new File(gsdl3_path + "WEB-INF"+ File.separator + "web.xml");

	if (!web_xml.exists()) {
	    DebugStream.println("Error: no web.xml found at "+web_xml.toString());
	    return;
	}

	this.sites = new ArrayList();
	// find the sites
	File start = new File(Utility.getSitesDir(gsdl3_path));
	File possible_sites[] = start.listFiles();
	ArrayTools.sort(possible_sites);
	for (int i=0; possible_sites != null && i < possible_sites.length; i++) {
	    File site_config = new File(possible_sites[i], "siteConfig.xml");
	    if (site_config.exists()) {
		this.sites.add(possible_sites[i].getName());
	    }
	}
	
	this.mappings = new HashMap();
	Document web_config = XMLTools.parseXMLFile(web_xml.getAbsolutePath(), false);
       
	NodeList servlet_mappings = web_config.getElementsByTagName("servlet-mapping");
	// make a little map class
	HashMap url_mappings = new HashMap();
	for (int i=0; i<servlet_mappings.getLength(); i++) {
	    Element map = (Element)servlet_mappings.item(i);
	    String name = XMLTools.getValue(XMLTools.getNodeFromNamed(map, "servlet-name"));
	    String pattern = XMLTools.getValue(XMLTools.getNodeFromNamed(map, "url-pattern"));
	    url_mappings.put(name, pattern);

	}

	NodeList servlets = web_config.getElementsByTagName("servlet");
	for (int i=0; i<servlets.getLength(); i++) {
	    Element servlet = (Element)servlets.item(i);
	    String name = XMLTools.getValue(XMLTools.getNodeFromNamed(servlet, "servlet-name"));
	    String description = XMLTools.getValue(XMLTools.getNodeFromNamed(servlet, "description"));
	    String site = getServletSite(servlet);
	       
	    if (site != null) {
		ArrayList this_site = (ArrayList)mappings.get(site);
		if (this_site == null) {
		    this_site = new ArrayList();
		}
		String url = (String)url_mappings.get(name);
		this_site.add(url);
		mappings.put(site, this_site);
	    }
	    
	}

	web_config = null;
	url_mappings = null;
    }
    
    public ArrayList getSites() {
	return this.sites;
    }

    public ArrayList getServletsForSite(String site) {
	return (ArrayList)this.mappings.get(site);
    }
    public String getServletPath(String site) {
	
	// for now, get the first one
	ArrayList servlets = (ArrayList)mappings.get(site);
	if(servlets == null) {
	    return null;
	}
	return (String)servlets.get(0);
    }

    private String getServletSite(Element servlet) {
	
	NodeList params = servlet.getElementsByTagName("init-param");
	if ( params == null || params.getLength() == 0) {
	    return null;
	}
	String site = null;
	for (int i=0; i<params.getLength()&& site == null; i++) {
	    String p_name = XMLTools.getValue(XMLTools.getNodeFromNamed(params.item(i), "param-name"));
	    if (p_name.equals("site_name")) {
		site = XMLTools.getValue(XMLTools.getNodeFromNamed(params.item(i), "param-value"));
	    }
	}
	return site;
    }
}