source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/action/PageAction.java@ 29521

package org.greenstone.gsdl3.action;

import java.io.Serializable;
import java.util.HashMap;

import org.apache.log4j.Logger;
import org.greenstone.gsdl3.util.GSParams;
import org.greenstone.gsdl3.util.GSPath;
import org.greenstone.gsdl3.util.GSXML;
import org.greenstone.gsdl3.util.UserContext;
import org.greenstone.gsdl3.util.XMLConverter;
import org.greenstone.util.GlobalProperties;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class PageAction extends Action
{
    static Logger logger = Logger.getLogger(org.greenstone.gsdl3.action.PageAction.class.getName());

    public static final String HOME_PAGE = "home";
    public static final String ABOUT_PAGE = "about";
    public static final String PREFS_PAGE = "pref";
    public static final String GLI4GS3_PAGE = "gli4gs3";

    public Node process(Node message_node)
    {
        Element message = GSXML.nodeToElement(message_node);
        Document doc = XMLConverter.newDOM();
        
        Element request = (Element) GSXML.getChildByTagName(message, GSXML.REQUEST_ELEM);
        Element paramList = (Element) GSXML.getChildByTagName(request, GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
        String collection = "";
        if (paramList != null)
        {
            HashMap<String, Serializable> params = GSXML.extractParams(paramList, false);
            if (params != null && params.get(GSParams.COLLECTION) != null)
            {
                collection = (String) params.get(GSParams.COLLECTION);
            }
        }

        // the page name is the subaction
        String page_name = request.getAttribute(GSXML.SUBACTION_ATT);
        if (page_name.equals(""))
        { // if no page specified, assume home page
            page_name = HOME_PAGE;
        }
        Element result = doc.createElement(GSXML.MESSAGE_ELEM);
        Element response;
        if (page_name.equals(HOME_PAGE))
        {
          response = homePage(request);
            //} else if (page_name.equals(ABOUT_PAGE)) {
        }
        else if (page_name.equals(ABOUT_PAGE) || page_name.equals(PREFS_PAGE))
        {
          response = aboutPage(request);
            //}else if (page_name.equals(PREFS_PAGE)) {
            //response = prefsPage(request);
        }
        else if (page_name.equals(GLI4GS3_PAGE))
        {
          response = gli4gs3Page(request);
        }
        else
        { // unknown page
          response = unknownPage(request);
        }

        Element formatMessage = doc.createElement(GSXML.MESSAGE_ELEM);
        Element formatRequest = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_FORMAT, collection, new UserContext(request));
        formatMessage.appendChild(formatRequest);
        Element formatResponseMessage = (Element) this.mr.process(formatMessage);
        Element formatResponse = (Element) GSXML.getChildByTagName(formatResponseMessage, GSXML.RESPONSE_ELEM);

        Element globalFormat = (Element) GSXML.getChildByTagName(formatResponse, GSXML.FORMAT_ELEM);
        if (globalFormat != null)
        {
          response.appendChild(response.getOwnerDocument().importNode(globalFormat, true));
        }

        result.appendChild(doc.importNode(response, true));
        logger.debug("page action result: " + this.converter.getPrettyString(result));

        return result;
    }

  protected Element homePage(Element request)
    {
      Document doc = XMLConverter.newDOM();
        
        UserContext userContext = new UserContext(request);
        // first, get the message router info
        Element info_message = doc.createElement(GSXML.MESSAGE_ELEM);
        Element coll_list_request = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_DESCRIBE, "", userContext);
        info_message.appendChild(coll_list_request);
        Element info_response_message = (Element) this.mr.process(info_message);
        if (info_response_message == null)
        {
            logger.error(" couldn't query the message router!");
            return null;
        }
        Element info_response = (Element) GSXML.getChildByTagName(info_response_message, GSXML.RESPONSE_ELEM);
        if (info_response == null)
        {
            logger.error("couldn't query the message router!");
            return null;
        }

        // second, get the metadata for each collection - we only want specific
        // elements but for now, we'll just get it all
        Element collection_list = (Element) GSXML.getChildByTagName(info_response, GSXML.COLLECTION_ELEM + GSXML.LIST_MODIFIER);
        logger.debug(GSXML.xmlNodeToString(collection_list));
        if (collection_list != null)
        {
            NodeList colls = GSXML.getChildrenByTagName(collection_list, GSXML.COLLECTION_ELEM);
            if (colls.getLength() > 0)
            {
                sendMultipleRequests(doc, colls, null, GSXML.REQUEST_TYPE_DESCRIBE, userContext);
            }
        }

        // get metadata for any services
        Element service_list = (Element) GSXML.getChildByTagName(info_response, GSXML.SERVICE_ELEM + GSXML.LIST_MODIFIER);
        if (service_list != null)
        {
            NodeList services = GSXML.getChildrenByTagName(service_list, GSXML.SERVICE_ELEM);
            if (services.getLength() > 0)
            {
                sendMultipleRequests(doc, services, null, GSXML.REQUEST_TYPE_DESCRIBE, userContext);
            }
        }

        // get metadata for service clusters
        Element cluster_list = (Element) GSXML.getChildByTagName(info_response, GSXML.CLUSTER_ELEM + GSXML.LIST_MODIFIER);
        if (cluster_list != null)
        {
            NodeList clusters = GSXML.getChildrenByTagName(cluster_list, GSXML.CLUSTER_ELEM);
            if (clusters.getLength() > 0)
            {
                sendMultipleRequests(doc, clusters, null, GSXML.REQUEST_TYPE_DESCRIBE, userContext);

            }
        }

        addSiteMetadata(info_response, userContext);
        addInterfaceOptions(info_response);
        // all the components have been merged into info_response
        return info_response;

    } // homePage

    protected Element aboutPage(Element request)
    {
      Document doc = XMLConverter.newDOM();
        
        UserContext userContext = new UserContext(request);
        // extract the params from the cgi-request, 
        Element cgi_paramList = (Element) GSXML.getChildByTagName(request, GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
        HashMap<String, Serializable> params = GSXML.extractParams(cgi_paramList, false);

        String coll_name = (String) params.get(GSParams.COLLECTION);
        if (coll_name == null || coll_name.equals(""))
        {
            logger.error("about page requested with no collection or cluster specified!");
            // return an empty response
            Element response = doc.createElement(GSXML.RESPONSE_ELEM);
            addSiteMetadata(response, userContext);
            addInterfaceOptions(response);
            return response;
        }

        // get the collection or cluster description
        Element coll_about_message = doc.createElement(GSXML.MESSAGE_ELEM);

        Element coll_about_request = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_DESCRIBE, coll_name, userContext);
        coll_about_message.appendChild(coll_about_request);
        Element coll_about_response = (Element) this.mr.process(coll_about_message);

        // add collection type attribute to paramList
        String col_type = "";
        NodeList collect_elem = coll_about_response.getElementsByTagName(GSXML.COLLECTION_ELEM);
        if (collect_elem.getLength() != 0)
        {
            for (int i = 0; i < collect_elem.getLength(); i++)
            {
                Element e = (Element) collect_elem.item(i);
                col_type = e.getAttribute(GSXML.TYPE_ATT);
            }
        }
        else
        {
            logger.error(GSXML.COLLECTION_ELEM + " element is null");
        }

        NodeList paramList = request.getElementsByTagName(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
        if (paramList.getLength() != 0)
        {
            for (int i = 0; i < paramList.getLength(); i++)
            {
                Element e = (Element) paramList.item(i);
                Element ct = GSXML.createParameter(request.getOwnerDocument(), GSParams.COLLECTION_TYPE, col_type.equalsIgnoreCase("mg") ? "0" : "1");
                e.appendChild(ct);
            }
        }
        else
        {
            logger.info("paramList is null!!");
        }

        if (coll_about_response == null)
        {
            return null;
        }

        // second, get the info for each service - we only want display items 
        // but for now, we'll just get it all
        NodeList services = coll_about_response.getElementsByTagName(GSXML.SERVICE_ELEM);
        if (services.getLength() > 0)
        {
            sendMultipleRequests(doc, services, coll_name, GSXML.REQUEST_TYPE_DESCRIBE, userContext);
        }

        Element response = (Element) GSXML.getChildByTagName(coll_about_response, GSXML.RESPONSE_ELEM);
        //add the site metadata
        addSiteMetadata(response, userContext);
        addInterfaceOptions(response);
        return response;
    }

    //protected Element prefsPage(Element request) {

    //  return null;
    //}

    /** if we dont know the page type, use this method */
    protected Element unknownPage(Element request)
    {
      Document doc = XMLConverter.newDOM();
        
        UserContext userContext = new UserContext(request);
        String page_name = request.getAttribute(GSXML.SUBACTION_ATT);

        // extract the params from the cgi-request, 
        Element cgi_paramList = (Element) GSXML.getChildByTagName(request, GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
        HashMap<String, Serializable> params = GSXML.extractParams(cgi_paramList, false);

        String coll_name = (String) params.get(GSParams.COLLECTION);
        if (coll_name == null || coll_name.equals(""))
        {
            // just return an empty response
            Element response = doc.createElement(GSXML.RESPONSE_ELEM);
            addSiteMetadata(response, userContext);
            addInterfaceOptions(response);
            return response;
        }

        // else get the coll description - actually this is the same as for the about page - should we merge these two methods??

        // if there is a service specified should we get the service description instead??
        // get the collection or cluster description
        Element coll_about_message = doc.createElement(GSXML.MESSAGE_ELEM);

        Element coll_about_request = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_DESCRIBE, coll_name, userContext);
        coll_about_message.appendChild(coll_about_request);

        Element coll_about_response = (Element) this.mr.process(coll_about_message);

        Element response = (Element) GSXML.getChildByTagName(coll_about_response, GSXML.RESPONSE_ELEM);

        //add the site metadata
        addSiteMetadata(response, userContext);
        addInterfaceOptions(response);

        return response;

    }

    protected boolean sendMultipleRequests(Document doc, NodeList items, String path_prefix, String request_type, UserContext userContext)
    {
        // we will send all the requests in a single message
        Element message = doc.createElement(GSXML.MESSAGE_ELEM);
        for (int i = 0; i < items.getLength(); i++)
        {
            Element c = (Element) items.item(i);
            String path = c.getAttribute(GSXML.NAME_ATT);
            if (path_prefix != null)
            {
                path = GSPath.appendLink(path_prefix, path);
            }
            Element request = GSXML.createBasicRequest(doc, request_type, path, userContext);
            message.appendChild(request);
        }

        Element response_message = (Element) this.mr.process(message);

        NodeList responses = response_message.getElementsByTagName(GSXML.RESPONSE_ELEM);
        // check that have same number of responses as requests
        if (items.getLength() != responses.getLength())
        {
            logger.error("didn't get a response for each request - somethings gone wrong!");
            return false;
        }

        for (int i = 0; i < items.getLength(); i++)
        {
            Element c1 = (Element) items.item(i);
            Element c2 = (Element) GSXML.getChildByTagName((Element) responses.item(i), c1.getTagName());
            if (c1 != null && c2 != null && c1.getAttribute(GSXML.NAME_ATT).endsWith(c2.getAttribute(GSXML.NAME_ATT)))
            {
                //add the new data into the original element
                GSXML.mergeElements(c1, c2);
            }
            else
            {
                logger.debug(" response does not correspond to request!");
            }

        }

        return true;

    }

    protected Element gli4gs3Page(Element request)
    {
      Document doc = XMLConverter.newDOM();
        
        String lang = request.getAttribute(GSXML.LANG_ATT);
        String uid = request.getAttribute(GSXML.USER_ID_ATT);

        Element page_response = doc.createElement(GSXML.RESPONSE_ELEM);

        Element applet_elem = doc.createElement("Applet");
        page_response.appendChild(applet_elem);
        applet_elem.setAttribute("ARCHIVE", "SignedGatherer.jar");
        applet_elem.setAttribute("CODE", "org.greenstone.gatherer.GathererApplet");
        applet_elem.setAttribute("CODEBASE", "applet");
        applet_elem.setAttribute("HEIGHT", "50");
        applet_elem.setAttribute("WIDTH", "380");
        Element gwcgi_param_elem = doc.createElement("PARAM");
        gwcgi_param_elem.setAttribute("name", "gwcgi");
        String library_name = GlobalProperties.getGSDL3WebAddress();
        gwcgi_param_elem.setAttribute("value", library_name);
        applet_elem.appendChild(gwcgi_param_elem);

        Element gsdl3_param_elem = doc.createElement("PARAM");
        gsdl3_param_elem.setAttribute("name", "gsdl3");
        gsdl3_param_elem.setAttribute("value", "true");
        applet_elem.appendChild(gsdl3_param_elem);

        return page_response;
    }
}