source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/service/AbstractSearch.java@ 32419

/*
 *    AbstractSearch.java
 *    Copyright (C) 2005 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 java.util.ArrayList;
import java.util.HashMap;

import org.apache.log4j.Logger;
import org.greenstone.gsdl3.util.AbstractBasicDocument;
import org.greenstone.gsdl3.util.BasicDocument;
import org.greenstone.gsdl3.util.GSPath;
import org.greenstone.gsdl3.util.GSXML;
import org.greenstone.gsdl3.util.XMLConverter;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

/**
 * Partially implements a generic search service
 * 
 */

public abstract class AbstractSearch extends ServiceRack
{

    static Logger logger = Logger.getLogger(org.greenstone.gsdl3.service.AbstractSearch.class.getName());

    // the search service
    protected String QUERY_SERVICE = null; // set by subclass 

    // compulsory params
    protected static final String INDEX_PARAM = "index";
    protected static final String QUERY_PARAM = "query";
    protected static final String RAW_PARAM = "rawquery";

    // optional standard params - some of these have to be implemented
    protected static final String MAXDOCS_PARAM = "maxDocs";
    protected static final String HITS_PER_PAGE_PARAM = "hitsPerPage";
    protected static final String START_PAGE_PARAM = "startPage";

    protected AbstractBasicDocument gs_doc = null;

    /** can more than one index be searched at the same time? */
    protected boolean does_multi_index_search = false;
    /** does this service support paging of results? */
    protected boolean does_paging = false;
    /** does this service support asking for a subset of results? */
    protected boolean does_chunking = false;
    /** does this service support faceting search results */
    protected boolean does_faceting = false;
    /** does this service support highlighting snippets results */
    protected boolean does_highlight_snippets = false;
    protected boolean does_full_field_highlighting = false;
    /**
     * the default document type - use if all documents are the same type
     */
    protected String default_document_type = null;
    /**
     * the default index, or comma separated list if more than one is the
     * default (with start and end commas, eg ,TI,SU,). Should be set by
     * configure()
     */
    protected String default_index = "";

  protected Element service_metadata_list = null;
  protected HashMap<String, String> paramDefaults = null;

    public AbstractSearch()
    {
      paramDefaults = new HashMap<String, String>();
    }

    /**
     * Sets up the short service info for service by QUERY_SERVICE (e.g.
     * TextQuery or AudioQuery) If other services will be provided, should be
     * added in the subclass configure also looks for search format info, and
     * document format info
     */
    public boolean configure(Element info, Element extra_info)
    {
        if (!super.configure(info, extra_info))
        {
            return false;
        }

        logger.info("Configuring AbstractSearch...");

        this.config_info = info;

        // set up short_service_info_ 
        // => for now just has id and type. the name (lang dependent)
        //    will be added in if the list is requested.

        Element tq_service = this.desc_doc.createElement(GSXML.SERVICE_ELEM);
        tq_service.setAttribute(GSXML.TYPE_ATT, GSXML.SERVICE_TYPE_QUERY);
        tq_service.setAttribute(GSXML.NAME_ATT, QUERY_SERVICE);
        this.short_service_info.appendChild(tq_service);

        // load up paging defaults
        if (does_chunking) {
          paramDefaults.put(MAXDOCS_PARAM, "100");
        }
        if (does_paging) {
          paramDefaults.put(HITS_PER_PAGE_PARAM, "20");
          paramDefaults.put(START_PAGE_PARAM, "1");
        }

        // load up any search param defaults
        Element search_elem = (Element) GSXML.getChildByTagName(extra_info, GSXML.SEARCH_ELEM);
        if (search_elem != null) {
          getSearchParamDefaults(search_elem);
        }
        // add some format info to service map if there is any 
        // => lookin extra info first look in buildConfig

        Element format = (Element) GSXML.getChildByTagName(info, GSXML.FORMAT_ELEM);

        if (format == null)
        {
          // try to find a format element inside <search> that contains a gsf:template. Note what if we have only xsl:templates??
            
            NodeList format_elems = null;
            if (search_elem != null)
            {
                format_elems = search_elem.getElementsByTagName(GSXML.FORMAT_ELEM);
            }
            for (int i = 0; i < format_elems.getLength(); i++)
            {
                format = (Element) format_elems.item(i);
                if (format.getElementsByTagName("gsf:template").getLength() != 0)
                {
                    break;
                }
            }
        }//end of if(format==null)
            //
        if (format != null)
        {
            this.format_info_map.put(QUERY_SERVICE, this.desc_doc.importNode(format, true));
        }

        // look for document display format - for documentType
        String path = GSPath.appendLink(GSXML.DISPLAY_ELEM, GSXML.FORMAT_ELEM);
        Element display_format = (Element) GSXML.getNodeByPath(extra_info, path);
        if (display_format != null)
        {
            // check for docType option.
            Element doc_type_opt = GSXML.getNamedElement(display_format, "gsf:option", GSXML.NAME_ATT, "documentType");
            if (doc_type_opt != null)
            {
                String value = doc_type_opt.getAttribute(GSXML.VALUE_ATT);
                if (!value.equals(""))
                {
                    this.default_document_type = value;
                }
            }
        }

        // Base line for document (might be overriden by sub-classes)
        gs_doc = new BasicDocument(this.default_document_type);

        return true;
    }

  protected void getSearchParamDefaults(Element search_elem) {

    NodeList param_defaults_list = GSXML.getChildrenByTagName(search_elem, GSXML.PARAM_DEFAULT_ELEM);
    for (int i=0; i<param_defaults_list.getLength(); i++) {
      Element paramdef = (Element)param_defaults_list.item(i);
      String name = paramdef.getAttribute(GSXML.NAME_ATT);
      String val = paramdef.getAttribute(GSXML.VALUE_ATT);
      if (!name.equals("") && !val.equals("")) {
    paramDefaults.put(name, val);
      }
    }
  }
    /**
     * returns a basic description for QUERY_SERVICE. If a subclass provides
     * other services they need to provide their own descriptions
     */
  protected Element getServiceDescription(Document doc, String service, String lang, String subset)
    {
        if (!service.equals(QUERY_SERVICE))
        {
            return null;
        }

        Element tq_service = doc.createElement(GSXML.SERVICE_ELEM);
        tq_service.setAttribute(GSXML.TYPE_ATT, GSXML.SERVICE_TYPE_QUERY);
        tq_service.setAttribute(GSXML.NAME_ATT, QUERY_SERVICE);
        if (subset == null || subset.equals(GSXML.DISPLAY_TEXT_ELEM + GSXML.LIST_MODIFIER))
        {
            tq_service.appendChild(GSXML.createDisplayTextElement(doc, GSXML.DISPLAY_TEXT_NAME, getServiceName(QUERY_SERVICE, lang)));
            tq_service.appendChild(GSXML.createDisplayTextElement(doc, GSXML.DISPLAY_TEXT_SUBMIT, getServiceSubmit(QUERY_SERVICE, lang)));
            tq_service.appendChild(GSXML.createDisplayTextElement(doc, GSXML.DISPLAY_TEXT_DESCRIPTION, getServiceDescription(QUERY_SERVICE, lang)));
        }
        if (subset == null || subset.equals(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER))
        {
            Element param_list = doc.createElement(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
            addCustomQueryParams(param_list, lang);
            addStandardQueryParams(param_list, lang);
            tq_service.appendChild(param_list);
        }
        if (subset == null || subset.equals(GSXML.METADATA_ELEM + GSXML.LIST_MODIFIER)) {

          if (service_metadata_list == null) {
            Document ml_doc = XMLConverter.newDOM();
            service_metadata_list = ml_doc.createElement(GSXML.METADATA_ELEM+GSXML.LIST_MODIFIER);
            if (does_paging) {
              service_metadata_list.appendChild(GSXML.createMetadataElement(ml_doc, "does_paging", "true"));
            }
          }
          tq_service.appendChild(doc.importNode(service_metadata_list, true));
        }
        return tq_service;

    }

    // perhaps these should be changed to search down the class hierarchy for 
    // values - do can just put the info in the resource bundle to use it
    /** returns the default name for the TextQuery service */
    protected String getServiceName(String service_id, String lang)
    {
        return getTextString(service_id + ".name", lang);
    }

    /** returns the default description for the TextQuery service */
    protected String getServiceDescription(String service_id, String lang)
    {
        return getTextString(service_id + ".description", lang);
    }

    /** returns the default submit button text for the TextQuery service */
    protected String getServiceSubmit(String service_id, String lang)
    {
        return getTextString(service_id + ".submit", lang);

    }

    /** adds the standard query params into the service description */
    protected void addStandardQueryParams(Element param_list, String lang)
    {
        // this test is not so good. here we are using absence of default index
        // to determine whether we have indexes or not. But in other places,
        // absence of default index just means to use the first one as default.
        if (!default_index.equals(""))
        {
            createParameter(INDEX_PARAM, param_list, lang);
        }
        if (does_chunking)
        {
            createParameter(MAXDOCS_PARAM, param_list, lang);
        }
        if (does_paging)
        {
            createParameter(HITS_PER_PAGE_PARAM, param_list, lang);
            createParameter(START_PAGE_PARAM, param_list, lang);
        }
        createParameter(QUERY_PARAM, param_list, lang);
    }

    /**
     * adds any service specific query params into the service default
     * implementation: add nothing. subclasses may need to override this to add
     * in their specific parameters
     */
    protected void addCustomQueryParams(Element param_list, String lang)
    {
        // default behaviour, do nothing
    }

    protected void createParameter(String name, Element param_list, String lang)
    {
        createParameter(name, param_list, lang, null);
    }

    protected void createParameter(String name, Element param_list, String lang, String default_value)
    {
        // at this level, not interested in boolean return type
        createParameterChain(name, param_list, lang, default_value);
    }

    /**
     * default implementations for the standard parameters plus some other
     * common ones index, maxDocs, hitsPerPage, startPage
     */

    protected boolean createParameterChain(String name, Element param_list, String lang, String default_value)
    {
      Document doc = param_list.getOwnerDocument();
        Element param = null;
        String param_default = default_value;
        if (default_value == null) {
          // have we got a stored up default? will be null if not there
          param_default = paramDefaults.get(name);
        }
        if (name.equals(QUERY_PARAM) || name.equals(RAW_PARAM))
        {
            param = GSXML.createParameterDescription(doc, name, getTextString("param." + name, lang), GSXML.PARAM_TYPE_STRING, param_default, null, null);
            param_list.appendChild(param);
            return true;
        }
        else if (name.equals(INDEX_PARAM))
        {
            // should we make these class fields?
            ArrayList<String> index_ids = new ArrayList<String>();
            ArrayList<String> index_names = new ArrayList<String>();
            getIndexData(index_ids, index_names, lang);
            String param_type = GSXML.PARAM_TYPE_ENUM_SINGLE;
            if (does_multi_index_search)
            {
                param_type = GSXML.PARAM_TYPE_ENUM_MULTI;
            }
            if (param_default == null)
            {
                param_default = this.default_index;
            }
            param = GSXML.createParameterDescription2(doc, INDEX_PARAM, getTextString("param." + INDEX_PARAM, lang), param_type, param_default, index_ids, index_names);
            param_list.appendChild(param);
            return true;
        }
        else if (name.equals(MAXDOCS_PARAM))
        {
            param = GSXML.createParameterDescription(doc, name, getTextString("param." + name, lang), GSXML.PARAM_TYPE_INTEGER, param_default, null, null);
            param_list.appendChild(param);
            return true;
        }
        else if (name.equals(HITS_PER_PAGE_PARAM))
        {
            param = GSXML.createParameterDescription(doc, name, getTextString("param." + name, lang), GSXML.PARAM_TYPE_INTEGER, param_default, null, null);
            param_list.appendChild(param);
            return true;
        }
        else if (name.equals(START_PAGE_PARAM))
        {
            // start page - set to 1 for the search page
            param = GSXML.createParameterDescription(doc, START_PAGE_PARAM, "", GSXML.PARAM_TYPE_INVISIBLE, param_default, null, null);
            param_list.appendChild(param);
            return true;
        }

        // Get to there then none of the above params matched
        // => return false so the chain can continue
        return false;
    }

    /**
     * create an element to go into the search results list. A node element has
     * the form <docNode nodeId='xxx' nodeType='leaf' docType='hierarchy'
     * rank='0.23'/>
     */
  protected Element createDocNode(Document doc, String node_id, String rank)
    {
      return this.gs_doc.createDocNode(doc, node_id, rank);
    }

    /**
     * returns the document type of the doc that the specified node belongs to.
     * should be one of GSXML.DOC_TYPE_SIMPLE, GSXML.DOC_TYPE_PAGED,
     * GSXML.DOC_TYPE_HIERARCHY
     */
    protected String getDocType(String node_id)
    {
        return this.gs_doc.getDocType(node_id);
    }

    /**
     * returns the node type of the specified node. should be one of
     * GSXML.NODE_TYPE_LEAF, GSXML.NODE_TYPE_INTERNAL, GSXML.NODE_TYPE_ROOT
     */
    protected String getNodeType(String node_id, String doc_type)
    {
        return this.gs_doc.getNodeType(node_id, doc_type);
    }

    /** returns true if the node has child nodes */
    protected boolean hasChildren(String node_id)
    {
        return this.gs_doc.hasChildren(node_id);
    }

    /** returns true if the node has a parent */
    protected boolean hasParent(String node_id)
    {
        return this.gs_doc.hasParent(node_id);
    }

    /**
     * get the details about the indexes available must be implemented by
     * subclass there must be at least one index
     */
    abstract protected void getIndexData(ArrayList<String> index_ids, ArrayList<String> index_names, String lang);

}