source: greenstone3/trunk/src/java/org/greenstone/gsdl3/core/DefaultReceptionist.java@ 16874

package org.greenstone.gsdl3.core;

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

// other java classes
import java.io.File;
import java.util.HashMap;
import java.util.Enumeration;

import org.apache.log4j.*;

/** The default greenstone receptionist - needs some extra info for each page
 */
public class DefaultReceptionist extends TransformingReceptionist {

     static Logger logger = Logger.getLogger(org.greenstone.gsdl3.core.DefaultReceptionist.class.getName());
    
  /** add in the collection description to the page, then for each service, add in the service description */
    protected void addExtraInfo(Element page) {
      super.addExtraInfo(page);
    
    Element page_request = (Element)GSXML.getChildByTagName(page, GSXML.PAGE_REQUEST_ELEM);
    // if it is a system request, then we don't bother with this.
    String action = page_request.getAttribute(GSXML.ACTION_ATT);
    if (action.equals("s")) {
        logger.error("HACK: don't ask for coll info if system action");
        return;
    }
    logger.debug("add extra info, page request="+this.converter.getString(page_request));
    // is a collection defined?
    Element param_list = (Element)GSXML.getChildByTagName(page_request, GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
    if (param_list==null) { // must be the original home page
        logger.debug(" no param list, assuming home page");
        return;
    }
    Element coll_param = GSXML.getNamedElement(param_list, GSXML.PARAM_ELEM, GSXML.NAME_ATT, GSParams.COLLECTION);
    if (coll_param == null) {
        logger.debug(" coll param is null, returning");
        return;
    }

    // see if the collection/cluster element is already there
    String coll_name = coll_param.getAttribute(GSXML.VALUE_ATT);
    String lang = page_request.getAttribute(GSXML.LANG_ATT);
    String uid = page_request.getAttribute(GSXML.USER_ID_ATT);
    
    boolean get_service_description = false;
    Element page_response = (Element)GSXML.getChildByTagName(page, GSXML.PAGE_RESPONSE_ELEM);
    if (this.language_list != null) {
        page_response.appendChild(this.language_list);
    }
    Element coll_description = (Element)GSXML.getChildByTagName(page_response, GSXML.COLLECTION_ELEM);
    if (coll_description == null) {
        // try cluster
        coll_description = (Element)GSXML.getChildByTagName(page_response, GSXML.CLUSTER_ELEM);
    }
    if (coll_description == null) { 
        // we dont have one yet - get it
        Element coll_about_message = this.doc.createElement(GSXML.MESSAGE_ELEM);
        Element coll_about_request = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_DESCRIBE,  coll_name, lang, uid);
        coll_about_message.appendChild(coll_about_request);
        
        Node coll_about_response_message = this.mr.process(coll_about_message);
        Element coll_about_response = (Element)GSXML.getChildByTagName(coll_about_response_message, GSXML.RESPONSE_ELEM);
        if (coll_about_response == null) {
        return;
        }
        coll_description = (Element)GSXML.getChildByTagName(coll_about_response, GSXML.COLLECTION_ELEM);
        if (coll_description==null) { // may be a cluster
        coll_description = (Element)GSXML.getChildByTagName(coll_about_response, GSXML.CLUSTER_ELEM);
        }
        
        if (coll_description == null) {
        logger.error(" no collection description, returning");
        return;
        }
        // have found one, append it to the page response
        coll_description = (Element)this.doc.importNode(coll_description, true);
        page_response.appendChild(coll_description);
        get_service_description = true;
    }

    // have got a coll description
    
    // now get the dispay info for the services
    Element service_list = (Element)GSXML.getChildByTagName(coll_description, GSXML.SERVICE_ELEM+GSXML.LIST_MODIFIER);
    if (service_list == null) {
        logger.error(" no service list, returning");
        // something weird has gone wrong
        return;
    }

    NodeList services = service_list.getElementsByTagName(GSXML.SERVICE_ELEM);
    if (services.getLength()==0) {
        logger.error("DefaultReceoptionist: no services found for colllection/cluster "+ coll_name);
        return;
    }
    // check one service for display items
    if (!get_service_description) {
        // we dont know yet if we need to get these
        int i=1;
        Element test_s = (Element)services.item(0);
        while (i<services.getLength() && (test_s.getAttribute(GSXML.TYPE_ATT).equals(GSXML.SERVICE_TYPE_RETRIEVE) || test_s.getAttribute(GSXML.TYPE_ATT).equals(GSXML.SERVICE_TYPE_OAI))) {
        test_s = (Element)services.item(i); i++;
        }
        if (i==services.getLength()) {
        // we have only found retrieve or oai services, so dont need descripitons anyway
        return;
        }
        if (GSXML.getChildByTagName(test_s, GSXML.DISPLAY_TEXT_ELEM) !=null) {
        // have got descriptions already, 
        return;
        }
    }

    // if get here, we need to get the service descriptions
        
    // we will send all the requests in a single message
    Element info_message = this.doc.createElement(GSXML.MESSAGE_ELEM);
    for (int i=0; i<services.getLength(); i++) {
        Element c = (Element)services.item(i);
        String name = c.getAttribute(GSXML.NAME_ATT);
        String address = GSPath.appendLink(coll_name, name);
        Element info_request = GSXML.createBasicRequest(this.doc,  GSXML.REQUEST_TYPE_DESCRIBE, address, lang, uid);
        Element req_param_list = this.doc.createElement(GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
        req_param_list.appendChild(GSXML.createParameter(this.doc, GSXML.SUBSET_PARAM, GSXML.DISPLAY_TEXT_ELEM+GSXML.LIST_MODIFIER));
        info_request.appendChild(req_param_list);
        info_message.appendChild(info_request);
        
    }

    Element info_response = (Element)this.mr.process(info_message);

    NodeList service_responses = info_response.getElementsByTagName(GSXML.RESPONSE_ELEM);
    // check that have same number of responses as collections
    if (services.getLength() != service_responses.getLength()) {
        logger.error(" didn't get a response for each service - somethings gone wrong!");
        // for now, dont use the metadata
    } else {
        for (int i=0; i<services.getLength(); i++) {
        Element c1 = (Element)services.item(i);
        Element c2 = (Element)GSXML.getChildByTagName((Element)service_responses.item(i), GSXML.SERVICE_ELEM);
        if (c1 !=null && c2 !=null && c1.getAttribute(GSXML.NAME_ATT).equals(c2.getAttribute(GSXML.NAME_ATT))) {
            //add the service data into the original response
            GSXML.mergeElements(c1, c2);
        } else {
            logger.error(" response does not correspond to request!");
        } 
        
        }
    }
    
    }
}