/*
    * $Id: VoResourceSupport.java,v 1.10 2005/03/29 19:53:40 mch Exp $
    *
    * (C) Copyright Astrogrid...
    */
   
   package org.astrogrid.dataservice.metadata.v0_10;
   
   import java.io.IOException;
  import java.text.SimpleDateFormat;
  import java.util.Calendar;
  import java.util.Date;
  import java.util.GregorianCalendar;
  import java.util.Locale;
  import java.util.TimeZone;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.astrogrid.cfg.ConfigReader;
  import org.astrogrid.cfg.ConfigFactory;
  import org.astrogrid.dataservice.metadata.MetadataException;
  import org.astrogrid.dataservice.service.DataServer;
  import org.astrogrid.xml.DomHelper;
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  import org.w3c.dom.NodeList;
  import org.xml.sax.SAXException;
  
  /***
   * Helper methods for constructing basic VoResource documents
   *
   * <p>See package documentation.
   * <p>
   * @author M Hill
   */
  
  public class VoResourceSupport {
     protected static Log log = LogFactory.getLog(VoResourceSupport.class);
     
     public static final String AUTHID_KEY = "datacenter.authorityId";
     public static final String RESKEY_KEY = "datacenter.resourceKey";
     
     /*** used to format dates so that the registry can process them. eg 2005-11-04T15:34:22Z -
      * the date must be GMT */
     public final static SimpleDateFormat REGISTRY_DATEFORMAT = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
  
     public static final String VORESOURCE_ELEMENT = "Resource";
     
     /*** Constructs a miniumum set of core elements for a VOresource from the given
      * strings */
     public String makeCore(String title, String id, String publisher, String contactName, String contactEmail, String description, String refUrl, String type) {
     
        String core =
           "<title>"+title+"</title>"+
           "<identifier>"+id+"</identifier>"+
           "<curation>"+
             "<publisher>"+publisher+"</publisher>"+
             "<contact>"+
               "<name>"+contactName+"</name>"+
               "<email>"+contactEmail+"</email>"+
             "</contact>"+
           "</curation>"+
           "<content>"+
             "<description>"+description+"</description>"+
             "<referenceURL>"+refUrl+"</referenceURL>"+
             "<type>"+type+"</type>"+
           "</content>";
           
        return core;
     }
  
     /*** Constructs  a VoResource opening tag with the given resource type */
     public String makeVoResourceElement(String vorType, String namespaces) {
        return "<"+VORESOURCE_ELEMENT+
           " xmlns:vor='http://www.ivoa.net/xml/VOResource/v0.10' "+
           " xmlns='http://www.ivoa.net/xml/VOResource/v0.10' "+
           namespaces+
           " status='active' updated='"+toRegistryForm(new Date())+"' xsi:type='"+vorType+"'"+
           ">";
     }
  
     /*** Constructs core VOResource elements with given string appended to the
      * identifier.  Looks at config file to see if a pre-prepared voresource core
      * file exists and uses that (incl validation) if so, and if not uses settings
      * in the configuration file to create it.
      */
     public String makeCore(String idEnd) throws IOException {
        String coreFile = ConfigFactory.getCommonConfig().getString("dataserver.metadata.core", null);
        if ( coreFile != null) {
           //use an on-disk resource file
           try {
              Document coreDoc = DomHelper.newDocument(ConfigReader.resolveFilename(coreFile));//validate & load
  
              //set ID
              NodeList idNodes = coreDoc.getElementsByTagName("identifier");
              if (idNodes.getLength() != 1) {
                 throw new MetadataException("Should be exactly one identifier node in core resource document at "+coreFile);
              }
              Element idNode = (Element) idNodes.item(0);
              DomHelper.setElementValue(idNode, DomHelper.getValueOf(idNode)+idEnd);
             
             return DomHelper.DocumentToString(coreDoc);
          }
          catch (SAXException e) {
             throw new MetadataException(e+" parsing Core Resource/Metadata document at "+coreFile,e);
          }
 
       }
       else {
          return makeConfigCore(idEnd);
       }
    }
 
    /*** Constructs core VOResource elements from settings in the configuration file */
    private String makeConfigCore(String idEnd) throws IOException {
       
          return makeCore(
             DataServer.getDatacenterName(),
             makeId(idEnd),
             ConfigFactory.getCommonConfig().getString("datacenter.publisher",null),
             ConfigFactory.getCommonConfig().getString("datacenter.contact.name", ""),
             ConfigFactory.getCommonConfig().getString("datacenter.contact.email", ""),
             //ConfigFactory.getCommonConfig().getString("datacenter.contact.date", ""));
             ConfigFactory.getCommonConfig().getString("data.description", ""),
             ConfigFactory.getCommonConfig().getString("datacenter.url", ""),
             "Catalog"
          );
    }
    
    /*** Constructs an IVORN ID from an authority key and a resource key and the given extension */
    public String makeId(String idEnd) {
       return "ivo://"+ConfigFactory.getCommonConfig().getString(AUTHID_KEY)+"/"+ConfigFactory.getCommonConfig().getString(RESKEY_KEY)+"/"+idEnd;
    }
    
    
    /*** Converts date to string suitable for registry */
    public String toRegistryForm(Date givenDate) {
       //deprecated methods
       //long minsOffset = aDate.getTimezoneOffset();
       //Date gmtDate = new Date( aDate.getTime() + aDate.getTimezoneOffset());
       //this also leaves us with a date that has it's original timezone, but a new value.  It's really a different time...
       
       //cludge to get timezone of given date; write it out and then parse it...
       SimpleDateFormat offsetGetter = new SimpleDateFormat("Z");
       String offsetName = offsetGetter.format(givenDate);
       TimeZone givenZone = TimeZone.getTimeZone(offsetName);
       int offset = givenZone.getOffset(givenDate.getTime());
 //      Date gmtDate = new Date(givenZone.getOffset();
       
       
       //convert to GMT
       Calendar localCalender = Calendar.getInstance();
       TimeZone localZone = localCalender.getTimeZone();
       Calendar ukcalender = new GregorianCalendar(Locale.ENGLISH);
       TimeZone gmtZone = TimeZone.getTimeZone("GMT");
 
       return "";
    }
   
 }