source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/service/GS2LuceneRetrieve.java@ 32428

/*
 *    GS2LuceneRetrieve.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 org.greenstone.gsdl3.core.GSException;
import org.greenstone.gsdl3.util.GSFile;
import org.greenstone.gsdl3.util.GSXML;
import org.greenstone.gsdl3.util.DBInfo;
import org.greenstone.gsdl3.util.GSHTML;
import org.greenstone.gsdl3.util.OID;
// XML classes
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Text;

// General Java classes
import java.io.File;

import org.apache.log4j.Logger;

/**
 * Retrieve documents from a gs2 lucene collection. Note that this doesn't
 * actually use lucene, as the documents are stored in XML files
 */
public class GS2LuceneRetrieve extends AbstractGS2DocumentRetrieve
{

    static Logger logger = Logger.getLogger(org.greenstone.gsdl3.service.GS2LuceneRetrieve.class.getName());

    protected static final String DOC_LEVEL = "Doc";
    protected static final String SEC_LEVEL = "Sec";
    protected static final String ID_ATT = "gs2:docOID";

    // Parameters used
    private static final String LEVEL_PARAM = "level";

    // Elements used in the config file that are specific to this class
    private static final String DEFAULT_LEVEL_ELEM = "defaultLevel";

    private String default_level = null;
    private String text_dir = null;

    private boolean text_available = true;
    protected Element lastXMLDocumentElement = null;
    protected File lastXMLDocumentFile = null;


    public GS2LuceneRetrieve()
    {
    }

    public void cleanUp()
    {
        super.cleanUp();
    }

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

        // Do specific configuration
        logger.info("Configuring GS2LuceneRetrieve...");

        text_dir = GSFile.collectionIndexDir(this.site_home, this.cluster_name) + File.separatorChar + "text" + File.separatorChar;
        if (!(new File(text_dir).isDirectory()))
        {
            logger.error("Text directory " + text_dir + " does not exist, will be unable to retrieve text for " + cluster_name);
            text_available = false;
            return true; // return true so that we still get the other services for the collection
        }
        // Get the default level out of <defaultLevel> (buildConfig.xml)
        Element def = (Element) GSXML.getChildByTagName(info, DEFAULT_LEVEL_ELEM);
        if (def != null)
        {
            this.default_level = def.getAttribute(GSXML.SHORTNAME_ATT);
        }
        if (this.default_level == null || this.default_level.equals(""))
        {
            logger.error("Default level not specified for " + this.cluster_name + ", assuming " + DOC_LEVEL);
            this.default_level = DOC_LEVEL;
        }

        return true;

    }

    /**
     * returns the content of a node should return a nodeContent element:
     * <nodeContent>text content or other elements</nodeContent>
     */
  protected Element getNodeContent(Document doc, String doc_id, String lang) throws GSException
    {
        String[] args = new String[1];
        args[0] = doc_id;
        String doc_content = getTextString("TextRetrievalError", lang, args);
        try
        {
            if (!text_available)
            {
                throw new Exception("No text directory available");
            }

            DBInfo info = this.coll_db.getInfo(OID.getTop(doc_id));
            if (info == null)
            {
                throw new Exception("Couldn't get database entry for " + OID.getTop(doc_id));
            }

            String archivedir = info.getInfo("archivedir");
            File doc_xml_file = new File(text_dir + archivedir + File.separatorChar + "doc.xml");
            if (!doc_xml_file.isFile())
            {
                throw new Exception("Doc XML file " + doc_xml_file.getPath() + " does not exist");
            }
            Element full_document = null;
            if (lastXMLDocumentFile != null && lastXMLDocumentFile.equals(doc_xml_file)) {
                full_document = lastXMLDocumentElement;
            } else {
                Document doc_xml_doc = this.converter.getDOM(doc_xml_file, "utf-8");
                if (doc_xml_doc == null)
                {
                    throw new Exception("Couldn't parse file " + doc_xml_file.getPath());
                }
                full_document = doc_xml_doc.getDocumentElement();
                if (full_document == null)
                {
                    throw new Exception("Couldn't parse file " + doc_xml_file.getPath());
                }
            }
            lastXMLDocumentElement = full_document;
            lastXMLDocumentFile = doc_xml_file;
            
            Element current_section = null;
            if (default_level.equals(DOC_LEVEL))
            {
                current_section = full_document;
            }
            else
            {
                current_section = GSXML.getNamedElement(full_document, SEC_LEVEL, ID_ATT, doc_id);
            }
            if (current_section == null)
            {
                throw new Exception("Couldn't find section " + doc_id + " in file " + doc_xml_file.getPath());
            }
            doc_content = GSXML.getNodeText(current_section);
            if (doc_content == null)
            {
                doc_content = "";
            }
            else
            {
                doc_content = resolveTextMacros(doc_content, doc_id, lang);
            }
        }
        catch (Exception e)
        {
            
            logger.error("Error trying to get document text for " + doc_id + " in collection " + this.cluster_name + ": " + e);
            throw new GSException("Error trying to get document text for " + doc_id + " in collection " + this.cluster_name + ": " + e);
        }

        Element content_node = doc.createElement(GSXML.NODE_CONTENT_ELEM);
        Text t = doc.createTextNode(doc_content);
        content_node.appendChild(t);
        return content_node;
    }
}