source: trunk/gsdl3/src/java/org/greenstone/gsdl3/action/QueryAction.java@ 3441

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.Text; 
import org.w3c.dom.Document; 
import org.w3c.dom.Element; 

import java.util.HashMap;
import java.util.Map;
//import java.util.Map;
import java.util.Iterator;

public class QueryAction extends Action {
    

    public String process (Element message) {


    // create the return page tree
    Element page = doc_.createElement("page");
    page.setAttribute("lang", message.getAttribute("lang"));
    // add the lang stuff from message
    page.appendChild(doc_.importNode(GSXML.getChildByTagName(message, "translate"), true));
    // add the system stuff from message
    page.appendChild(doc_.importNode(GSXML.getChildByTagName(message, "config"), true));

    Element request = (Element)message.getElementsByTagName("request").item(0);
    String info = request.getAttribute("info");
    // remove the q/ bit
    info = GSPath.removeFirstLink(info);
    String query_type = GSPath.getFirstLink(info);
    
    if (query_type.equals("")) {
        query_type = "text";
    }

    if (query_type.equals("text")) {
        return textQuery(page, request);
    }
    if (query_type.equals("field")) {
        return fieldQuery(page, request);
    }
    return unknownQuery(page, request);

    
    }
    
    // we may be able to generalize this for all query types?
    protected String textQuery(Element page, Element request) {

    // chack that the stylesheet is present - cant output a page without one. we may adapt this to use unknownquery stylesheet? - or ask for one from the MR
    String stylesheet = GSFile.stylesheetFile(config_, "textquery.xsl");
    if (stylesheet==null) {
        return GSHTML.errorPage("textquery stylesheet not found!");
    }

    // extract the params from the cgi-request, and check that we have a coll specified
    // first convert short to long names
    Element cgi_paramList = (Element)GSXML.getChildByTagName(request, "paramList");
    cgi_.toLong(cgi_paramList);
    HashMap params = GSXML.extractParams(cgi_paramList);

    String collection = (String)params.get("c");
    if (collection == null || collection.equals("")) {
        return GSHTML.errorPage("textquery, need to specify a colleciton!");
    }

    // the first part of the data for the page is the cgi-params
    Element cgi_request = (Element)doc_.importNode(request, true);
    page.appendChild(cgi_request);

    // get the service info from the MR - this will probably need to be cached somehow later on. and add as a description node to the cgi-request - this doesn't work. change to add the specified value as a current attribute to the param - need to do somthing different for query

    Element mr_info_message = doc_.createElement("message");
    Element mr_info_request = doc_.createElement("request");
    mr_info_message.appendChild(mr_info_request);
    mr_info_request.setAttribute("type", "describe");

    String to = collection;
    to = GSPath.appendLink(to, "TextQuery");
    mr_info_request.setAttribute("to", to);

    Element mr_info_response = (Element) mr_.process(mr_info_message);
    System.err.println("describe response for service");
    System.err.println(converter_.getString(mr_info_response));
    Element description = doc_.createElement("description");
    // just param list for now - may need content info too
    Node pl = GSXML.getNodeByPath(mr_info_response, "response/service/paramList");
    if (pl ==null) {
        System.out.println("pl is null");
    }
    else {
        System.out.println("pl name is "+pl.getNodeName());
    }
    Element imported_paramList = (Element)doc_.importNode(pl, true);
    // convert the name to short
    cgi_.addShortNames(imported_paramList);

    description.appendChild(imported_paramList);
    
    // for each param in page_request, set the current value if present
    //actually, prob dont need to know the default value, just which one to display - overwrite the default att?
    
    Element param = (Element)imported_paramList.getFirstChild();
    while (param !=null) {
        if (param.getNodeName().equals("param")) { // just in case
        String name = param.getAttribute("name");
        String current = (String)params.get(name);
        if (current !=null && !current.equals("")) {
            param.setAttribute("default", current);
        }
        }
        param = (Element)param.getNextSibling();
    }
    
    cgi_request.appendChild(description);
    
    // check the query string
    String query = (String)params.get("q");

    if (query==null|| query.equals("")) {
        // if there is no q set, just output the search form
        return transformer_.transform(stylesheet, page);       
    }
    
    // else do the request, output search box and results
    Element mr_query_message = doc_.createElement("message");
    Element mr_query_request = doc_.createElement("request");
    mr_query_message.appendChild(mr_query_request);

    mr_query_request.setAttribute("type", "query");
    mr_query_request.setAttribute("to", to);

    // paramList
    Element paramList = doc_.createElement("paramList");
    mr_query_request.appendChild(paramList);

    Iterator i = params.entrySet().iterator();
    while (i.hasNext()) {
        Map.Entry e = (Map.Entry)i.next();
        String name = cgi_.toLong((String)e.getKey());
        if (!name.equals("")) {
        String value = (String)e.getValue();
        // if (!name.equals("c")) {
        Element p = doc_.createElement("param");
        p.setAttribute("name", name);
        p.setAttribute("value", value);
        paramList.appendChild(p);
        // }
        }
    }

    // content - contains the query string
    Element query_content = doc_.createElement("content");
    Text query_text = doc_.createTextNode(query);
    query_content.appendChild(query_text);
    mr_query_request.appendChild(query_content);
    
    Element mr_query_response = (Element)mr_.process(mr_query_message);

    // this result is the list of docs.
    // now take that list, and get the Titles
    // for now, just create a whole new request

    // check that there are some resources - for now check the list, but later should use a numdocs metadata elem
    Element resource_list = (Element)GSXML.getNodeByPath(mr_query_response, "response/content/resourceList"); // resourceList not present if no docs found
    if (resource_list == null) {

        Element result_response = (Element)GSXML.getChildByTagName(mr_query_response, "response");
        
        page.appendChild(doc_.importNode(result_response, true));
        return transformer_.transform(stylesheet, page);
    }

    // we have a doc list, so get the metadata - for now, get title.
    // can we dynamically decide what metadata to get?
    // get the Title metadata
    Element mr_metadata_message = doc_.createElement("message");
    Element mr_metadata_request = doc_.createElement("request");
    mr_metadata_message.appendChild(mr_metadata_request);

    mr_metadata_request.setAttribute("type", "query");
    to = GSPath.appendLink(collection, "MetadataRetrieve");
    mr_metadata_request.setAttribute("to", to);
    
    Element meta_content = doc_.createElement("content");
    mr_metadata_request.appendChild(meta_content);

    // the first part of the content is the doc list
    meta_content.appendChild(doc_.importNode(resource_list, true));

    // the second part of the content is the metadata list
    Element metadata_list = doc_.createElement("metadataList");
    Element title = doc_.createElement("element");
    title.setAttribute("name", "Title");
    metadata_list.appendChild(title);
    meta_content.appendChild(metadata_list);

    Element mr_metadata_response = (Element)mr_.process(mr_metadata_message);
    
    Element result_response = (Element)GSXML.getChildByTagName(mr_metadata_response, "response");
    
    page.appendChild(doc_.importNode(result_response, true));
    
    return transformer_.transform(stylesheet, page);
    
    }

    protected String fieldQuery(Element page, Element request) {
    return GSHTML.errorPage("field query not implemented");


    }
    protected String unknownQuery(Element page, Element request) {

    return GSHTML.errorPage("unknown query subtype - unknown query not implemented");
    }
}