source: trunk/gsdl3/src/java/org/greenstone/gsdl3/service/GS2Search.java@ 3822

/*
 *    GS2Search.java
 *    Copyright (C) 2002 New Zealand Digital Library, http://www.nzdl.org
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package org.greenstone.gsdl3.service;


// Greenstone classes
import org.greenstone.gdbm.*;
import org.greenstone.gsdl3.util.*;

// XML classes
import org.w3c.dom.Element; 


/**
 *
 * @author <a href="mailto:[email protected]">Katherine Don</a>
 * @version $Revision: 3822 $
 */

public abstract class GS2Search 
    extends ServiceRack {

    // the services on offer
    // these strings must match what is found in the properties file
    protected static final String TEXT_QUERY_SERVICE = "TextQuery";

    // Parameters used
    protected static final String CASE_PARAM = "case";
    protected static final String STEM_PARAM = "stem";
    protected static final String MATCH_PARAM = "matchMode";
    protected static final String MATCH_PARAM_ALL = "all";
    protected static final String MATCH_PARAM_SOME = "some";
    protected static final String MAXDOCS_PARAM = "maxDocs";
    protected static final String BOOLEAN_PARAM_ON = "1";
    protected static final String BOOLEAN_PARAM_OFF = "0";
    protected static final String QUERY_PARAM = "query";

    protected static final String EQUIV_TERM_ELEM = "equivTerm";

    protected static final String STEM_ATT = "stem";
    protected static final String NUM_DOCS_MATCH_ATT = "numDocsMatch";
    protected static final String FREQ_ATT = "freq";

    protected GDBMWrapper gdbm_src_ = null;

    protected Element config_info_ = null;


    /** constructor */
    public GS2Search()
    {
    gdbm_src_ = new GDBMWrapper();
    }


    /** configure this service */
    public boolean configure(Element info)
    {
    System.out.println("Configuring GS2Search...");
    config_info_ = info;

    // these entries should reflect the build config file - some services may not be available depending on how the colleciton was built.
    // set up short_service_info_ - for now just has name and type
    Element tq_service = doc_.createElement(GSXML.SERVICE_ELEM);
    tq_service.setAttribute(GSXML.TYPE_ATT, GSXML.SERVICE_TYPE_QUERY);
    tq_service.setAttribute(GSXML.NAME_ATT, TEXT_QUERY_SERVICE);
    short_service_info_.appendChild(tq_service);

    // set up service_info_map_ - for now, just has the same elements as above
    // should have full details about each service incl params lists etc.
    Element tq_service_full = (Element) tq_service.cloneNode(true);
    Element param_list = doc_.createElement(GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
    createTextQueryParamList(param_list, false, null);
    tq_service_full.appendChild(param_list);
    service_info_map_.put(TEXT_QUERY_SERVICE, tq_service_full);

    // Open GDBM database for querying
    String gdbm_db_file = GSFile.GDBMDatabaseFile(site_home_, cluster_name_);
    if (!gdbm_src_.openDatabase(gdbm_db_file, GDBMWrapper.READER)) {
        System.err.println("Error: Could not open GDBM database!");
        return false;
    }

    return true;
    }


    /** creates a new param element and adds it to the param list */
    protected void createParameter(String name, Element param_list, boolean display,
                   String lang)
    {
    Element param=null;

    if (name.equals(CASE_PARAM)) {
        if (display) {
        String[] bool_ops = {"0", "1"};
        String[] bool_texts = {getTextString("param.boolean.off", lang),getTextString("param.boolean.on", lang)}; 
        param = GSXML.createParameterDisplay(doc_, CASE_PARAM, getTextString("param."+CASE_PARAM, lang),  bool_ops, bool_texts);
        } else {
        param = GSXML.createParameter(doc_, CASE_PARAM, GSXML.PARAM_TYPE_BOOLEAN, BOOLEAN_PARAM_ON, null);
        }
    }
    else if (name.equals(STEM_PARAM)) {
        if (display) {
        String[] bool_ops = {"0", "1"};
        String[] bool_texts = {getTextString("param.boolean.off", lang),getTextString("param.boolean.on", lang)}; 
        param = GSXML.createParameterDisplay(doc_, STEM_PARAM, getTextString("param."+STEM_PARAM, lang),  bool_ops, bool_texts);
        } else {
        param = GSXML.createParameter(doc_, STEM_PARAM, GSXML.PARAM_TYPE_BOOLEAN, BOOLEAN_PARAM_ON, null);
        }
    }
    else if (name.equals(MATCH_PARAM)) {
        String[] vals = {MATCH_PARAM_ALL, MATCH_PARAM_SOME};
        if (display) {
        String[] val_texts = {getTextString("param."+MATCH_PARAM+"."+MATCH_PARAM_ALL, lang),getTextString("param."+MATCH_PARAM+"."+MATCH_PARAM_SOME, lang)}; 

        param = GSXML.createParameterDisplay(doc_, MATCH_PARAM, getTextString("param."+MATCH_PARAM, lang), vals, val_texts);
        } else {
        param = GSXML.createParameter(doc_, MATCH_PARAM, GSXML.PARAM_TYPE_ENUM_SINGLE, MATCH_PARAM_ALL, vals);
        }   
    }
    else if (name.equals(MAXDOCS_PARAM)) {
        if (display) {
        param = GSXML.createParameterDisplay(doc_, MAXDOCS_PARAM, getTextString("param."+MAXDOCS_PARAM, lang), null, null);
        } else {
        param = GSXML.createParameter(doc_, MAXDOCS_PARAM, GSXML.PARAM_TYPE_INTEGER, "10", null);
        }
    }
    else if (name.equals(QUERY_PARAM)) {
        if (display) {
        param = GSXML.createParameterDisplay(doc_, QUERY_PARAM, getTextString("param."+QUERY_PARAM, lang), null, null);
        } else {
        param = GSXML.createParameter(doc_, QUERY_PARAM, GSXML.PARAM_TYPE_STRING, null, null);
        }
    }

    // add the param to the list
    if (param != null) {
        param_list.appendChild(param);
    }
    }


    /** this creates all the params and appends them to param_list.
     * if display=true it creates the text strings version
     * otherwise it creates the description version
     */
    protected boolean createTextQueryParamList(Element param_list, boolean display,
                           String lang)
    {
    // the order they are specified here is the order they appear on 
    // the query form
    createParameter(CASE_PARAM, param_list, display, lang);
    createParameter(STEM_PARAM, param_list, display, lang);
    createParameter(MATCH_PARAM, param_list, display, lang);
    createParameter(MAXDOCS_PARAM, param_list, display, lang);
    createParameter(QUERY_PARAM, param_list, display, lang);
    return true;
    }


    /** creates a display element containing all the text strings needed to display
    the service page, in the language specified */
    protected Element createServiceDisplay(String service, String lang)
    {
    // Create a service display for the basic text query service
    Element display = doc_.createElement(GSXML.DISPLAY_ELEM);
    display.appendChild(GSXML.createTextElement(doc_, GSXML.DISPLAY_NAME_ELEM,
                            getTextString(service+".name", lang)));
    display.appendChild(GSXML.createTextElement(doc_, GSXML.DISPLAY_SUBMIT_ELEM,
                            getTextString(service+".submit", lang)));

    // now need to add in the params
    if (service.equals(TEXT_QUERY_SERVICE)) {
        createTextQueryParamList(display, true, lang);
    }

    return display;
    }


    /** Creates a new documentNode element containing ID and type */
    protected Element createDocumentNodeElement(String doc_id)
    {
    Element doc_node = doc_.createElement(GSXML.DOC_NODE_ELEM);
    doc_node.setAttribute(GSXML.DOC_NODE_ID_ATT, doc_id);
    if (OID.isTop(doc_id))
        doc_node.setAttribute(GSXML.DOC_NODE_TYPE_ATT, GSXML.NODE_TYPE_ROOT);
    else if (isLeafNode(doc_id))
        doc_node.setAttribute(GSXML.DOC_NODE_TYPE_ATT, GSXML.NODE_TYPE_LEAF);
    else
        doc_node.setAttribute(GSXML.DOC_NODE_TYPE_ATT, GSXML.NODE_TYPE_INTERIOR);
    return doc_node;
    }


    /** Returns true if the OID specifies a leaf node, false otherwise
    Note: this makes a request to the GDBM database so it may not be cheap */
    protected boolean isLeafNode(String oid)
    {
    DBInfo info = gdbm_src_.getInfo(oid);
    String children = info.getInfo("contains");
    return (children == "");
    }


    /** Process a text query - implemented by concrete subclasses */
    protected abstract Element processTextQuery(Element request);
}