source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/service/AbstractGS2DocumentRetrieve.java@ 26090

/*
 *    AbstractGS2DocumentRetrieve.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.gsdl3.core.GSException;
import org.greenstone.gsdl3.util.BasicDocumentDatabase;
import org.greenstone.gsdl3.util.GSXML;
import org.greenstone.gsdl3.util.GSFile;
import org.greenstone.gsdl3.util.OID;
import org.greenstone.gsdl3.util.MacroResolver;
import org.greenstone.gsdl3.util.GS2MacroResolver;
import org.greenstone.gsdl3.util.GSConstants;
import org.greenstone.gsdl3.util.SimpleCollectionDatabase;
import org.greenstone.gsdl3.util.DBInfo;
// XML classes
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

// General Java classes
import java.io.File;
import java.util.StringTokenizer;
import java.util.Vector;
import java.util.Set;
import java.util.Iterator;
import java.util.ArrayList;

import org.apache.log4j.*;

// Apache Commons
import org.apache.commons.lang3.*;

/**
 * Implements the generic retrieval and classifier services for GS2 collections.
 * 
 * @author Katherine Don
 * @author Michael Dewsnip
 */

public abstract class AbstractGS2DocumentRetrieve extends AbstractDocumentRetrieve
{

    static Logger logger = Logger.getLogger(org.greenstone.gsdl3.service.AbstractGS2DocumentRetrieve.class.getName());

    //    protected static final String EXTLINK_PARAM = "ext"; here or in base??    
    protected String index_stem = null;

    protected SimpleCollectionDatabase coll_db = null;
  BasicDocumentDatabase gs_doc_db = null;
    /** constructor */
    protected AbstractGS2DocumentRetrieve()
    {
        this.macro_resolver = new GS2MacroResolver();
    }

    public void cleanUp()
    {
        super.cleanUp();
        this.coll_db.closeDatabase();
        this.gs_doc_db.cleanUp();
    }

    /** configure this service */
    public boolean configure(Element info, Element extra_info)
    {
        if (!super.configure(info, extra_info))
        {
            return false;
        }

        logger.info("Configuring AbstractGS2DocumentRetrieve...");
        //this.config_info = info;

        // the index stem is either specified in the config file or is  the collection name
        Element index_stem_elem = (Element) GSXML.getChildByTagName(info, GSXML.INDEX_STEM_ELEM);
        if (index_stem_elem != null)
        {
            this.index_stem = index_stem_elem.getAttribute(GSXML.NAME_ATT);
        }
        if (this.index_stem == null || this.index_stem.equals(""))
        {
            logger.error("AbstractGS2DocumentRetrieve.configure(): indexStem element not found, stem will default to collection name");
            this.index_stem = this.cluster_name;
        }

        // find out what kind of database we have
        Element database_type_elem = (Element) GSXML.getChildByTagName(info, GSXML.DATABASE_TYPE_ELEM);
        String database_type = null;
        if (database_type_elem != null)
        {
            database_type = database_type_elem.getAttribute(GSXML.NAME_ATT);
        }
        if (database_type == null || database_type.equals(""))
        {
            database_type = "gdbm"; // the default
        }
        coll_db = new SimpleCollectionDatabase(database_type);
        if (!coll_db.databaseOK())
        {
            logger.error("Couldn't create the collection database of type " + database_type);
            return false;
        }

        // Open database for querying
        String coll_db_file = GSFile.collectionDatabaseFile(this.site_home, this.cluster_name, this.index_stem, database_type);
        if (!this.coll_db.openDatabase(coll_db_file, SimpleCollectionDatabase.READ))
        {
            logger.error("Could not open collection database!");
            return false;
        }

        gs_doc_db = new BasicDocumentDatabase(this.doc, database_type, this.site_home, this.cluster_name, this.index_stem);
        if (!gs_doc_db.isValid())
        {
            logger.error("Failed to open Document Database.");
            return false;
        }
        this.gs_doc = gs_doc_db;

        // we need to set the database for our GS2 macro resolver
        GS2MacroResolver gs2_macro_resolver = (GS2MacroResolver) this.macro_resolver;
        gs2_macro_resolver.setDB(this.coll_db);

        return true;
    }

    /** if id ends in .fc, .pc etc, then translate it to the correct id */
    protected String translateId(String node_id)
    {
        return OID.translateOID(this.coll_db, node_id); //return this.coll_db.translateOID(node_id);
    }

    /**
     * if an id is not a greenstone id (an external id) then translate it to a
     * greenstone one
     */
    protected String translateExternalId(String node_id)
    {
        return this.coll_db.externalId2OID(node_id);
    }

    /**
     * returns the id of the root node of the document containing node node_id.
     * . may be the same as node_id
     */
    protected String getRootId(String node_id)
    {
      return this.gs_doc.getRootId(node_id);
    }



    /**
     * get the metadata for the classifier node node_id returns a metadataList
     * element: <metadataList><metadata
     * name="xxx">value</metadata></metadataList>
     */
    protected Element getMetadataList(String node_id, boolean all_metadata, ArrayList<String> metadata_names) throws GSException
    {
        Element metadata_list = this.doc.createElement(GSXML.METADATA_ELEM + GSXML.LIST_MODIFIER);
        DBInfo info = this.coll_db.getInfo(node_id);
        if (info == null)
        {
            return null;
        }
        String lang = "en"; // why do we need this??
        if (all_metadata) // this will get all metadata for current node
        {
            // return everything out of the database
            Set<String> keys = info.getKeys();
            Iterator<String> it = keys.iterator();
            while (it.hasNext())
            {
                String key = it.next();
                //String value = info.getInfo(key);
                Vector<String> values = info.getMultiInfo(key);
                for (int i = 0; i < values.size(); i++)
                {
                    GSXML.addMetadata(this.doc, metadata_list, key, this.macro_resolver.resolve(values.elementAt(i), lang, MacroResolver.SCOPE_META, node_id));
                }
            }

        }
        // now we go through the list of names. If we have specified 
        // all_metadata, then here we only get the ones like 
        // parent_Title, that are not the current node.
        for (int i = 0; i < metadata_names.size(); i++)
          {
            String meta_name = metadata_names.get(i);
            
            if (!all_metadata || meta_name.indexOf(GSConstants.META_RELATION_SEP)!=-1) {
            Vector <String> values = getMetadata(node_id, info, meta_name, lang);
            if (values != null) {
              for (int j = 0; j < values.size(); j++)
            {
              // some of these may be parent/ancestor. does resolve need a different id???
              GSXML.addMetadata(this.doc, metadata_list, meta_name,  this.macro_resolver.resolve(values.elementAt(j), lang, MacroResolver.SCOPE_META, node_id));
            }
            }
            }
          }
        
        return metadata_list;
    }

  protected Vector<String> getMetadata(String node_id, DBInfo info, String metadata, String lang) {

    DBInfo current_info = info;
    
    int index = metadata.indexOf(GSConstants.META_RELATION_SEP);
    if (index == -1) {
      // metadata is for this node
      Vector<String> values = info.getMultiInfo(metadata);
      return values;
    }
    // we need to get metadata for one or more different nodes
    String relation = metadata.substring(0, index);
    String relation_id="";
    metadata = metadata.substring(index + 1);
    if (relation.equals("parent") || relation.equals("ancestors")) {
      relation_id = OID.getParent(node_id);
      if (relation_id.equals(node_id)) {
    return null;
      }
    } else if (relation.equals("root")) {
      relation_id = OID.getTop(node_id);
    }

    DBInfo relation_info;
    if (relation_id.equals(node_id)) {
      relation_info = info;
    } else {
      relation_info = this.coll_db.getInfo(relation_id);
    }
    if (relation_info == null)
      {
    return null;
      }

    Vector<String> values = relation_info.getMultiInfo(metadata);
    // do resolving
    if (!relation.equals("ancestors")){
      return values;
    }

    // ancestors: go up the chain

    String current_id = relation_id;
    relation_id = OID.getParent(current_id);
    while (!relation_id.equals(current_id))
      {
    relation_info = this.coll_db.getInfo(relation_id);
    if (relation_info == null)
      return values;
    
    Vector<String> more_values = relation_info.getMultiInfo(metadata);
    if (more_values != null)
      {
        values.addAll(0, more_values);
      }
    
            
    current_id = relation_id;
    relation_id = OID.getParent(current_id);
      }
    return values; // for now
  }

    protected int getNumChildren(String node_id)
    {
      return this.gs_doc.getNumChildren(node_id);
    }


    /**
     * returns the content of a node should return a nodeContent element:
     * <nodeContent>text content or other elements</nodeContent>
     */
    abstract protected Element getNodeContent(String doc_id, String lang) throws GSException;


    /**
     * needs to get info from collection database - if the calling code gets it
     * already it may pay to pass it in instead
     */
    protected String resolveTextMacros(String doc_content, String doc_id, String lang)
    {
        // resolve any collection specific macros
        doc_content = macro_resolver.resolve(doc_content, lang, MacroResolver.SCOPE_TEXT, doc_id);
        return doc_content;
    }



}