package org.greenstone.gsdl3.action;

import org.greenstone.gsdl3.core.ModuleInterface;
import org.greenstone.gsdl3.util.*;
// XML classes
import org.w3c.dom.Node; 
import org.w3c.dom.Element; 
import org.w3c.dom.Document; 

// other java stuff
import java.io.File;

/** base class for Actions */
abstract public class Action {

    /** the interface setup variables */
    protected ConfigVars config_=null;
    /** container Document to create XML Nodes */
    protected Document doc_=null; 
    /** a converter class to parse XML and create Docs */
    protected XMLConverter converter_=null;
    /** cgi args converter */
    protected GSCGI cgi_ = null;
    /** a transformer class to transform xml using xslt */
    protected XMLTransformer transformer_=null;
    /** a reference to the message router that it must talk to to
     * get info. it may be a communicator acting as a proxy, but it 
     doesn't care about that */
    protected ModuleInterface mr_=null;

    public Action() {
	converter_ = new XMLConverter();
	transformer_ = new XMLTransformer();
	doc_ = converter_.newDOM();
    }
    /** gsdl_home_ must be set before configure called */
    public void setConfigVars(ConfigVars config) {
	config_ = config;
    }
    /** sets the message router */
    public void setMessageRouter(ModuleInterface m) {
       mr_ = m;
    }
    /** sets the GSCGI object - used to convert between short and long names
     * of params */
    public void setCGI(GSCGI cgi) {
	cgi_ = cgi;
	// add in any action specific params
	addCGIParams();
    }
    public void configure() {
	// does nothing yet
    }
    /** any action specific cgi params should be added to the GSCGI object-
     * overwrite this if a new action has its own params
     * using cgi_.addStaticParam(param-name) */
    protected void addCGIParams() {
	
    }
    /** process takes an xml representation of cgi args
     * and returns the page of results - may be in html/xml/other
     * depending on the output att of the request */
    public String process(String xml_in) {
       
	Element message = converter_.getDOM(xml_in).getDocumentElement();
	
	Element result = process(message);
	return converter_.getString(result);
    }
	
    /** the main process method - must be implemented in subclass */
    abstract public Element process(Element xml_in);

    protected Element getAndTransformFormat(Element format_response) {
	
	Element format_elem = (Element)GSXML.getChildByTagName(format_response, GSXML.FORMAT_ELEM);
	if (format_elem == null) {
	    return null;
	}
	System.out.println("old format="+converter_.getString(format_elem));
	// transform it to proper xsl
	String stylesheet_file = GSFile.stylesheetFile(config_, "config_format.xsl");
	Document stylesheet = converter_.getDOM(new File(stylesheet_file));
	Element new_format = (Element)transformer_.transform(stylesheet, format_elem);

	System.out.println("new format="+converter_.getString(new_format));
	return new_format;

    }

}