source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/action/BrowseAction.java@ 25635

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

import java.util.HashMap;
import java.util.HashSet;
import java.util.Vector;
import java.io.File;
import java.io.Serializable;

import org.apache.log4j.*;

//NOTE: this class not used at present!!!!!
/** action for classifier browsing */
public class BrowseAction extends Action {

    static Logger logger = Logger.getLogger(org.greenstone.gsdl3.action.BrowseAction.class.getName());

    public static final String CLASSIFIER_ARG = "cl";
    public static final String SIBLING_ARG = "sib";

    /** process the request */
    public Node process (Node message_node) {

    Element message = this.converter.nodeToElement(message_node);

    // get the request - assume only one
    Element request = (Element)GSXML.getChildByTagName(message, GSXML.REQUEST_ELEM);

    // the result
    Element result = this.doc.createElement(GSXML.MESSAGE_ELEM);
    Element response = classifierBrowse(request);
    result.appendChild(response);
    return result;
    }
    

    protected Element classifierBrowse(Element request) {

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

    // extract the params from the cgi-request, and check that we have a coll specified
    Element cgi_paramList = (Element)GSXML.getChildByTagName(request, GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
    HashMap<String, Serializable> params = GSXML.extractParams(cgi_paramList, false);

    String service_name = (String)params.get(GSParams.SERVICE);
    String collection = (String)params.get(GSParams.COLLECTION);
    if (collection == null || collection.equals("")) {
        logger.error("classifierBrowse, need to specify a collection!");
        return page_response;
       
    }
    
    //whether to retrieve siblings or not
    boolean get_siblings = false;
    String sibs = (String) params.get(SIBLING_ARG);
    if (sibs != null && sibs.equals("1")) {
        get_siblings = true;
    }

    UserContext userContext = new UserContext(request); 
    String to = GSPath.appendLink(collection, service_name);
    
    // the first part of the response is the service description 
    // for now get this again from the service. 
    // this should be cached somehow later on. 
    
    Element info_message = this.doc.createElement(GSXML.MESSAGE_ELEM);
    Element info_request = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_DESCRIBE, to, userContext); 
    info_message.appendChild(info_request);
    
    // also get the format stuff now if there is some
    Element format_request = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_FORMAT, to, userContext);
    info_message.appendChild(format_request);
    // process the requests

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

    // the two responses
    NodeList responses = info_response.getElementsByTagName(GSXML.RESPONSE_ELEM);
    Element service_response = (Element)responses.item(0);
    Element format_response = (Element)responses.item(1);

    Element service_description = (Element)GSXML.getChildByTagName(service_response, GSXML.SERVICE_ELEM);
    page_response.appendChild(this.doc.importNode(service_description, true));
    
    //append site metadata
    addSiteMetadata(page_response, userContext);
    addInterfaceOptions(page_response);

    // if rt=d, then we are just displaying the service
    String request_type = (String)params.get(GSParams.REQUEST_TYPE);
    if (request_type.equals("d")) {
        //return the page that we have so far
        return page_response;
    }
    
    // get the node that the user has clicked on
    String classifier_node = (String)params.get(CLASSIFIER_ARG);
    
    // if the node is not defined, return the page that we have so far
    if (classifier_node ==null || classifier_node.equals("")) {
        return page_response;
    }
    
    // the id of the classifier is the top id of the selected node
    String top_id = OID.getTop(classifier_node);
    
    HashSet<String> metadata_names = new HashSet<String>();

    // add the format info into the response
    Element format_elem = (Element)GSXML.getChildByTagName(format_response, GSXML.FORMAT_ELEM);
    if (format_elem != null) {
        // find the one for the classifier we are in
        Element this_format = GSXML.getNamedElement(format_elem, GSXML.CLASSIFIER_ELEM, GSXML.NAME_ATT, top_id);
        if (this_format == null) {
        this_format = (Element)GSXML.getChildByTagName(format_elem, GSXML.DEFAULT_ELEM);
        }
        if (this_format != null) {
        Element new_format = GSXML.duplicateWithNewName(this.doc, this_format, GSXML.FORMAT_ELEM, false);
        // set teh format type
        new_format.setAttribute(GSXML.TYPE_ATT, "browse");

        page_response.appendChild(new_format);
        getRequiredMetadataNames(new_format, metadata_names);
        }
    }
    
    logger.info("extracted meta names, "+metadata_names.toString());
    // get the browse structure for the selected node
    Element classify_message = this.doc.createElement(GSXML.MESSAGE_ELEM);
    Element classify_request = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_PROCESS, to, userContext);
    classify_message.appendChild(classify_request);
        
    //Create a parameter list to specify the required structure information
    // for now, always get ancestors and children
    Element param_list = this.doc.createElement(GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
    classify_request.appendChild(param_list);
    Element param = this.doc.createElement(GSXML.PARAM_ELEM);
    param_list.appendChild(param);
    param.setAttribute(GSXML.NAME_ATT, "structure");
    param.setAttribute(GSXML.VALUE_ATT, "ancestors");
    param = this.doc.createElement(GSXML.PARAM_ELEM);
    param_list.appendChild(param);
    param.setAttribute(GSXML.NAME_ATT, "structure");
    param.setAttribute(GSXML.VALUE_ATT, "children");
    if (get_siblings) {
        param = this.doc.createElement(GSXML.PARAM_ELEM);
        param_list.appendChild(param);
        param.setAttribute(GSXML.NAME_ATT, "structure");
        param.setAttribute(GSXML.VALUE_ATT, "siblings");
    }

    // put the classifier node into a classifier node list
    Element classifier_list = this.doc.createElement(GSXML.CLASS_NODE_ELEM+GSXML.LIST_MODIFIER);
    Element classifier = this.doc.createElement(GSXML.CLASS_NODE_ELEM);
    classifier.setAttribute(GSXML.NODE_ID_ATT, classifier_node);
    classifier_list.appendChild(classifier);
    classify_request.appendChild(classifier_list);
        
    // process the request
    Element classify_response = (Element)this.mr.process(classify_message);
    // get the structure element
    String path = GSPath.appendLink(GSXML.RESPONSE_ELEM, GSXML.CLASS_NODE_ELEM+GSXML.LIST_MODIFIER);
    path = GSPath.appendLink(path, GSXML.CLASS_NODE_ELEM);
    path = GSPath.appendLink(path, GSXML.NODE_STRUCTURE_ELEM);
    // assume that we always get back the top level CL1 node - this becomes the page_classifier node
    path = GSPath.appendLink(path, GSXML.CLASS_NODE_ELEM);
    Element cl_structure = (Element)GSXML.getNodeByPath(classify_response,
                                path);
    if (cl_structure ==null) {
        logger.error("classifier structure request returned no structure");
        return page_response;
    }   
    
    // add the classifier node as the page classifier 
    Element page_classifier = GSXML.duplicateWithNewName(this.doc, cl_structure,  GSXML.CLASSIFIER_ELEM, true);
    page_response.appendChild(page_classifier);
    page_classifier.setAttribute(GSXML.NAME_ATT, top_id);
    
    // get the metadata for each classifier node, 
    // then for each document node

    Element metadata_message = this.doc.createElement(GSXML.MESSAGE_ELEM);

    boolean did_classifier = false;
    boolean did_documents = false;
    
    
    // if there are classifier nodes 
    // create a metadata request for the classifier, and add it to 
    // the the message
    NodeList cl_nodes = page_classifier.getElementsByTagName(GSXML.CLASS_NODE_ELEM);
    
    if (cl_nodes.getLength() > 0) {
        did_classifier = true;
        Element cl_meta_request = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_PROCESS, to+"MetadataRetrieve", userContext);
        metadata_message.appendChild(cl_meta_request);
        
        Element new_cl_nodes_list = this.doc.createElement(GSXML.CLASS_NODE_ELEM+GSXML.LIST_MODIFIER);
        cl_meta_request.appendChild(new_cl_nodes_list);
        
        for (int c=0; c<cl_nodes.getLength(); c++) {

        Element cl = this.doc.createElement(GSXML.CLASS_NODE_ELEM);
        cl.setAttribute(GSXML.NODE_ID_ATT, ((Element)cl_nodes.item(c)).getAttribute(GSXML.NODE_ID_ATT));
        new_cl_nodes_list.appendChild(cl);
        }

        // create and add in the param list - for now get all the metadata
        // should be based on info sent in from the recept, and the 
        // format stuff
        Element cl_param_list = null;
        if (metadata_names.isEmpty()) {
        cl_param_list  = this.doc.createElement(GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
        Element p = this.doc.createElement(GSXML.PARAM_ELEM);
        cl_param_list.appendChild(p);
        p.setAttribute(GSXML.NAME_ATT, "metadata");
        p.setAttribute(GSXML.VALUE_ATT, "Title");
        } else {
        cl_param_list  = createMetadataParamList(metadata_names);
        }

        cl_meta_request.appendChild(cl_param_list);
        
    }

    // if there are document nodes in the classification (happens 
    // sometimes), create a second request for document metadata and 
    // append to the message
    NodeList doc_nodes = page_classifier.getElementsByTagName(GSXML.DOC_NODE_ELEM);
    if (doc_nodes.getLength() > 0) {
        did_documents = true;
        Element doc_meta_request = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_PROCESS, GSPath.appendLink(collection, "DocumentMetadataRetrieve"), userContext);
        metadata_message.appendChild(doc_meta_request);
        
        Element doc_list = this.doc.createElement(GSXML.DOC_NODE_ELEM+GSXML.LIST_MODIFIER);
        doc_meta_request.appendChild(doc_list);
        
        for (int c=0; c<doc_nodes.getLength(); c++) {
        
        Element d = this.doc.createElement(GSXML.DOC_NODE_ELEM);
        d.setAttribute(GSXML.NODE_ID_ATT, ((Element)doc_nodes.item(c)).getAttribute(GSXML.NODE_ID_ATT));
        doc_list.appendChild(d);
        }

        // create and add in the param list - add all for now
        Element doc_param_list  = this.doc.createElement(GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
        Element p = this.doc.createElement(GSXML.PARAM_ELEM);
        doc_param_list.appendChild(p);
        p.setAttribute(GSXML.NAME_ATT, "metadata");
        p.setAttribute(GSXML.VALUE_ATT, "all");
        doc_meta_request.appendChild(doc_param_list);

    }
    
    // process the metadata requests
    Element metadata_response = (Element)this.mr.process(metadata_message);
    if (did_classifier) {
        // the classifier one will be the first response
        // add the metadata lists for each node back into the 
        // page_classifier nodes
        path = GSPath.appendLink(GSXML.RESPONSE_ELEM, 
                   GSXML.CLASS_NODE_ELEM+GSXML.LIST_MODIFIER);
        NodeList meta_response_cls = GSXML.getNodeByPath(metadata_response, path).getChildNodes();
        for (int i = 0; i < cl_nodes.getLength(); i++) {
        GSXML.mergeMetadataLists(cl_nodes.item(i), meta_response_cls.item(i));
        }
    }
    if (did_documents) {
        NodeList meta_response_docs = null;
        if (!did_classifier) {
        // its the first response
        path = GSPath.appendLink(GSXML.RESPONSE_ELEM, 
                     GSXML.DOC_NODE_ELEM+GSXML.LIST_MODIFIER);
        meta_response_docs = GSXML.getNodeByPath(metadata_response, path).getChildNodes();
        } else { // its the second response
        meta_response_docs = GSXML.getChildByTagName(metadata_response.getElementsByTagName(GSXML.RESPONSE_ELEM).item(1), GSXML.DOC_NODE_ELEM+GSXML.LIST_MODIFIER).getChildNodes();
        }
        
        for (int i = 0; i < doc_nodes.getLength(); i++) {
        GSXML.mergeMetadataLists(doc_nodes.item(i), meta_response_docs.item(i));
        }
    }
        

    logger.debug("(BrowseAction) Page:\n" + this.converter.getPrettyString(page_response));
    return page_response;
    }

    protected Element unknownBrowse(Element page, Element request, String browse_type) {
    logger.error("unknown browse subtype: "+browse_type);
    return null;
    }
}