source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/collection/OAICollection.java@ 32828

/*
 *    OAICollection.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.collection;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;

import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;
import org.greenstone.gsdl3.core.ModuleInterface;
import org.greenstone.gsdl3.service.ServiceRack;
import org.greenstone.gsdl3.service.OAIPMH;
import org.greenstone.gsdl3.util.GSFile;
import org.greenstone.gsdl3.util.GSXML;
import org.greenstone.gsdl3.util.GSXSLT;
import org.greenstone.gsdl3.util.OAIXML;
import org.greenstone.gsdl3.util.SimpleMacroResolver;
import org.greenstone.gsdl3.util.UserContext;
import org.greenstone.gsdl3.util.XMLConverter;
import org.greenstone.gsdl3.util.XMLTransformer;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

/**
 * Represents a collection for the OAI server. This is a cut down version of Collection, as we
 * only want to load the OAIPMH service rack, not any of the others
 * 
 */
public class OAICollection extends Collection
{

    static Logger logger = Logger.getLogger(org.greenstone.gsdl3.collection.OAICollection.class.getName());

    /** does this collection provide the OAI service */
    protected boolean has_oai = false;

    /** earliest datestamp of an OAI collection. Also used to work out the earliest datetimestamp of the entire OAI repository */
    protected long earliestOAIDatestamp = 0;

    /** a reference to the OAIPMH service rack */
    protected OAIPMH oai_service_rack = null;

    /**
     * Configures the collection.
     * 
     * site_home and cluster_name  must be set before configure is called.
     * 
     * collection metadata is obtained, and services loaded.
     * 
     * @return true/false on success/fail
     */
    public boolean configure()
    {
        if (this.site_home == null || this.cluster_name == null)
        {
            logger.error("Collection: site_home and collection_name must be set before configure called!");
            return false;
        }

        macro_resolver.addMacro("_httpcollection_", this.site_http_address + "/collect/" + this.cluster_name);

        Element coll_config_xml = loadCollConfigFile();
        if (coll_config_xml == null) {
          logger.error("Collection: couldn't configure collection: " + this.cluster_name + ", " + "Couldn't load collection config file");

          return false;
        }
        Element build_config_xml = loadBuildConfigFile();
        if (build_config_xml == null)
        {
          logger.error("Collection: couldn't configure collection: " + this.cluster_name + ", " + "Couldn't load build config file");

          return false;
        }
        GSXSLT.modifyCollectionConfigForDebug(coll_config_xml);

        // process the metadata and display items and default library params
        super.configureLocalData(coll_config_xml);
        super.configureLocalData(build_config_xml);
        // get extra collection specific stuff
        findAndLoadInfo(coll_config_xml, build_config_xml);

        // load up the OAIPMH serviceRack
        configureServiceRacks(coll_config_xml, build_config_xml);

        return true;

    }

    // NOTE:
    // Calling cleanUp() on OAIPMH object oai_service_rack will close any open dbs handles on module deactivation by MESSAGEROUTER (no deactivate yet called by OAIMESSAGEROUTER)
    // But the OAIPMH object's cleanUp() is already called by superclass ServiceCluster, which goes around calling cleanUp() on all services/ServiceRacks.

    /**
     * whether this collection has OAIPMH services
     */
    public boolean hasOAI()
    {
        return has_oai;
    }

    /**
     * The earliesttimestamp entry in the oai-inf.db representing when the collection was created.
     * Used by the OAIReceptionist
    */   
    public long getEarliestOAIDatestamp()
    {
        return earliestOAIDatestamp;
    }
    
  /** add any extra info for collection from OAIConfig.xml */
  public boolean configureOAI(Element oai_config) {
    // just pass the element to each service - should only be one
    return this.oai_service_rack.configureOAI(oai_config);
  }

  /** override this to only load up OAIPMH serviceRack  - don't need all the rest of them for oai*/
    protected boolean configureServiceRackList(Element service_rack_list, Element extra_info)
    {

      // find the OAIPMH service
      Element oai_service_xml = GSXML.getNamedElement(service_rack_list, GSXML.SERVICE_CLASS_ELEM, GSXML.NAME_ATT, "OAIPMH");
      if (oai_service_xml == null) {
        return false;
      }
      
      // the xml request to send to the serviceRack to query what services it provides
      Document doc = XMLConverter.newDOM();
      Element message = doc.createElement(GSXML.MESSAGE_ELEM);
      Element request = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_DESCRIBE, "", new UserContext());
      message.appendChild(request);

      if(this.oai_service_rack == null) {
        this.oai_service_rack = new OAIPMH();
      }
      this.oai_service_rack.setSiteHome(this.site_home);
      this.oai_service_rack.setSiteAddress(this.site_http_address);
      this.oai_service_rack.setClusterName(this.cluster_name);
      this.oai_service_rack.setServiceCluster(this);
      this.oai_service_rack.setMessageRouter(this.router);
      // pass the xml node to the service for configuration
      if (this.oai_service_rack.configure(oai_service_xml, extra_info)) {

          // once we've configured the OAIPMH service, we can use the OAIPMH service to
          // retrieve the earliest timestamp of this OAI collection from the oai-inf db
          long earliestTimestamp = this.oai_service_rack.getEarliestTimestamp();
          if(earliestTimestamp == -1) {
          this.earliestOAIDatestamp = -1;
          logger.warn("No OAI timestamp for collection " + this.cluster_name);
          } else {
          this.earliestOAIDatestamp = earliestTimestamp; // milliseconds
          }
          
        
        // find out the supported service types for this service module
        Node types = this.oai_service_rack.process(message);
        NodeList typenodes = ((Element) types).getElementsByTagName(GSXML.SERVICE_ELEM);
        
        for (int j = 0; j < typenodes.getLength(); j++)
          {
        String service = ((Element) typenodes.item(j)).getAttribute(GSXML.NAME_ATT);
        
        if (service_map.get(service) != null)
          {
            char extra = '0';
            String new_service = service + extra;
            
            while (service_map.get(new_service) != null)
              {
            extra++;
            new_service = service + extra;
              }
            this.service_name_map.put(new_service, service);
            service = new_service;
            ((Element) typenodes.item(j)).setAttribute(GSXML.NAME_ATT, service);
          }
        this.service_map.put(service, this.oai_service_rack);
        // also add info to the ServiceInfo XML element
        this.service_list.appendChild(this.desc_doc.importNode(typenodes.item(j), true));
          }
        has_oai = true;
        return true;
      }
      

      return false;
    }

}