package org.astrogrid.portal.resources;
   
   import org.apache.avalon.framework.parameters.Parameters;
   import org.apache.cocoon.acting.AbstractAction;
   import org.apache.cocoon.environment.Request;
   import org.apache.cocoon.environment.Session;
   import org.apache.cocoon.environment.Redirector;
   import org.apache.cocoon.environment.SourceResolver;
   import org.apache.cocoon.environment.ObjectModelHelper;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.Map;
  
  import org.apache.commons.logging.Log;
  import org.apache.axis.components.logger.LogFactory;
  import org.apache.axis.utils.XMLUtils;
  import org.astrogrid.util.DomHelper;
  
  import org.astrogrid.registry.client.admin.RegistryAdminDocumentHelper;
  import org.astrogrid.registry.client.RegistryDelegateFactory;
  import org.astrogrid.registry.client.query.RegistryService;
  import org.astrogrid.registry.RegistryException;
  
  import org.astrogrid.config.Config;
  
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  import org.w3c.dom.Node;
  import org.w3c.dom.NodeList;
  import org.xml.sax.SAXParseException;
  
  import org.astrogrid.util.DomHelper;
  import org.astrogrid.registry.common.WSDLBasicInformation;
  import org.astrogrid.store.Ivorn;
  
  
  /***
   * @author Phil Nicolson (pjn3@star.le.ac.uk) Jan 05
   * @version $Name:  $Revision: 1.2 $Date:
   */
  public class ResourceAction extends AbstractAction {
  
    /*** Compile-time switch used to turn tracing on/off. 
     * Set this to false to eliminate all trace statements within the byte code.*/
    private static final boolean TRACE_ENABLED = true;
  
    /*** Compile-time switch used to turn certain debugging statements on/off. 
     * Set this to false to eliminate these debugging statements within the byte code.*/
    private static final boolean DEBUG_ENABLED = true;
  
    private static Log log = LogFactory.getLog("ResourceAction");     
  
    public static final String 
        ACTION_PARAM_TAG = "action" ,
        ACTION_CATALOG_QUERY = "search for catalogs" ,
        ACTION_TASK_QUERY = "search for tasks" ,
        ACTION_FILESTORE_QUERY = "filestore_query" ,
  	  ERROR_MESSAGE_PARAMETER = "resource_error_message" ,
  	  ERROR_INFO_PARAMETER = "resource_info_message" ,
  	  PARAM_RESULT_COUNT = "resource_result_count" ;
  
    // General constraints
    public static final String
        PARAM_RESOURCE_NAME = "resourceNameField",
        PARAM_DESCRIPTION = "descriptionField",
        PARAM_PUBLISHER = "publisherField",
        PARAM_TITLE = "titleField",
        PARAM_CONSTRAINT_JOIN = "ConstraintAndOr",
        PARAM_CONSTRAINT_ALL = "finalAndOr",
    // Wavelength
        PARAM_WAVELENGTH = "wavelength" ,
        PARAM_WAVELENGTH_JOIN = "WavelengthAndOr",
    // Mission
        PARAM_MISSION = "mission" ,
        PARAM_MISSION_JOIN = "MissionAndOr",
    // Keyword
        PARAM_KEYWORD = "keyword",
        PARAM_KEYWORD_JOIN = "KeywordAndOr",
        
    // Task
        PARAM_AUTHORITY_FIELD = "taskNameField",
        PARAM_TASK_JOIN = "TaskAndOr";  
  
    public static Config conf = null;   
       
    static {
      if(conf == null) {
        conf = org.astrogrid.config.SimpleConfig.getSingleton();
      }      
    }
   
  
    /***
    * Our action method.
    *
    */
    public Map act ( Redirector redirector,
                     SourceResolver resolver,
                     Map objectModel,
                    String source,
                    Parameters params ) {                  
      if( TRACE_ENABLED ) trace( "ResourceAction.act() entry" );  
 
      ResourceActionImpl myAction = null;
      Map retMap = null;
 
      try {     
         myAction = new ResourceActionImpl( redirector,
                                            resolver,
                                            objectModel,
                                            source,
                                            params );
 
         retMap = myAction.act();                                            
      }
      catch ( Exception ex ) {
         ex.printStackTrace();
      }
      finally {
         if( TRACE_ENABLED ) trace( "ResourceAction.act() exit" );  
      }
 
      return retMap; 
  
   } // end of act()
   
   private class ResourceActionImpl {
         
     private Redirector redirector;
     private SourceResolver resolver;
     private Map objectModel, results;
     private String source;
     private Parameters params;
     private Request request;
     private Session session;    
     private String action;     
         
     public ResourceActionImpl( Redirector redirector,
                                SourceResolver resolver,
                                Map objectModel,
                                String source,
                                Parameters params ) {                                   
       if( TRACE_ENABLED ) trace( "ResourceActionImpl() entry" ); 
             
       try {          
         this.redirector = redirector;
         this.resolver = resolver;
         this.objectModel = objectModel;
         this.source = source;
         this.params = params;         
         this.results = new HashMap();
             
         // Get current request and session.
         this.request = ObjectModelHelper.getRequest( objectModel );
         this.session = request.getSession();
             
         this.action = request.getParameter( ACTION_PARAM_TAG );              
                     
       }
       catch (Exception ex) {
         ex.printStackTrace();
       }
           
       finally {
         if( TRACE_ENABLED ) trace( "ResourceActionImpl() exit" ); 
       }
               
     } // end of ResourceActionImpl()
         
         
     public Map act() {
       if( TRACE_ENABLED ) trace( "ResourceActionImpl.act() entry" );      
         
       try {
 
         debug( "action is: " + action );
                     
         if( action == null )
         {
           // first time into resource browser - need to set attributes to empty string to prevent front end displaying them as null
 		  session.setAttribute( ERROR_MESSAGE_PARAMETER, "" ) ;
 		  session.setAttribute( ERROR_INFO_PARAMETER, "" ) ;
 		  session.setAttribute( PARAM_RESULT_COUNT, "" );           
         }      
               
         else if ( ACTION_CATALOG_QUERY.equals(action) )  {
           this.catalogQuery();
         }
         else if ( ACTION_TASK_QUERY.equals(action) )  { 
           this.taskQuery();                   
         }
         else if ( ACTION_FILESTORE_QUERY.equals(action) )  {
           this.filestoreQuery(); 
         }
         else {
           results = null;
           debug( "unsupported action"); 
           throw new UnsupportedOperationException(
                  action + " no longer supported" );
         }
             }
       catch( ConsistencyException cex ) {
         results = null;
         debug( "ConsistencyException occurred");
       }
       //PJN Note: these should only be here during testing...
       catch( Exception ex) {
         results = null;
         debug( "Exception: ex" );
         ex.printStackTrace();
       }
       //PJN Note: these should only be here during testing...
       catch( Throwable th ) {
         results = null;
         debug( "Throwable th" );
         th.printStackTrace();
       }
       finally {
         if( TRACE_ENABLED ) trace( "ResourceActionImpl.act() exit" );  
       }
     
       return results;
             
     } // end of ResourceActionImpl.act()
 
 
    /***
      * Generate xml string to pass to Registry 
      */
     private void catalogQuery() throws ConsistencyException {
       if( TRACE_ENABLED ) trace( "ResourceActionImpl.catalogQuery() entry" );
               
               
       String resource = "";
       String description = "";
       String publisher = "";
       String title = "";
       String constraintjoin = "";
       String wavelength[] = {""};
       String wavelengthjoin = "";
       String mission[] = {""};
       String missionjoin = "";
       String keyword[] = {""};
       String keywordjoin = "";
       String categoryjoin = "";
       String query = "";
       String andor = "";
       boolean andreqd = false; // used to add 'and' between e.g. (constraints) and (wavelength)
                     
       try { 
         // General constraints
         resource = request.getParameter( PARAM_RESOURCE_NAME ).trim();
         description = request.getParameter( PARAM_DESCRIPTION ).trim();
         publisher = request.getParameter( PARAM_PUBLISHER ).trim();
         title = request.getParameter( PARAM_TITLE ).trim();
         constraintjoin = request.getParameter( PARAM_CONSTRAINT_JOIN ).trim();         
 
         // Wavelength
         wavelength = request.getParameterValues( PARAM_WAVELENGTH );
         wavelengthjoin = request.getParameter( PARAM_WAVELENGTH_JOIN ).trim();
 
         // Mission
         mission = request.getParameterValues( PARAM_MISSION );       
         missionjoin = request.getParameter( PARAM_MISSION_JOIN ).trim();                
         
         // Keyword         
         keyword = request.getParameterValues( PARAM_KEYWORD );
         keywordjoin = request.getParameter( PARAM_KEYWORD_JOIN ).trim(); 
         
         categoryjoin = request.getParameter( PARAM_CONSTRAINT_ALL ).trim();
                              
         // Lets build up the XML for a query.
         query = "<query>\n"
          + "<selectionSequence>\n" // start of main sequence
          + "<selection item='searchElements' itemOp='EQ' value='Resource'/>\n"
          + "<selectionOp op='$and$'/>\n"
          + "<selection item='vr:Type' itemOp='EQ' value='Catalog'/>\n" ;
 		 
 
          // is this an empty search?
 		 if ( resource.length() > 0 || description.length() > 0 || 
 		      publisher.length() >0 || title.length() > 0 ||
 		      ( wavelength != null && wavelength.length > 0 ) || 
 		      ( mission != null && mission.length > 0 )  ||
 		      ( keyword != null && keyword.length > 0 ) ) 
 		  {
             query += "\n<selectionOp op='AND'/>";
 			query +=  "\n<selectionSequence>\n"; // start of inner sequence
         
             // GENERAL CONSTRAINTS
             if ( resource.length() > 0 || description.length() > 0 ||
                  publisher.length() >0 || title.length() > 0 ) {        
                  
 			  query +=  "\n<selectionSequence>\n"; // start of constraints sequence
 			         
               if ( resource.length() > 0 ) 
               {
                 query +=  "\n<selectionSequence>\n";          	
                 query += "<selection item='vr:Identifier/vr:AuthorityID' itemOp='CONTAINS' value='" + resource + "'/>";
   			    query += "<selectionOp op='OR'/>";
 			    query += "<selection item='vr:Identifier/vr:ResourceKey' itemOp='CONTAINS' value='" + resource + "'/>";
                 query +=  "\n</selectionSequence>\n";
                 andreqd = true;
               }
               if ( description.length() > 0 ) 
               {
                 if (andreqd) 
                   query += "\n<selectionOp op='"+constraintjoin+"'/>";
                 query += "<selection item='vr:Summary/vr:Description' itemOp='CONTAINS' value='" + description + "'/>";
                 andreqd = true;
               }
               if ( publisher.length() > 0 ) 
               {
                 if (andreqd)
                   query += "\n<selectionOp op='"+constraintjoin+"'/>";
                 query += "<selection item='vr:Curation/vr:Publisher/vr:Title' itemOp='CONTAINS' value='" + publisher + "'/>";
                 andreqd = true;
               }
               if ( title.length() > 0 ) 
               {
                 if (andreqd)
                   query += "\n<selectionOp op='"+constraintjoin+"'/>";
                 query += "<selection item='vr:Title' itemOp='CONTAINS' value='" + title + "'/>";
                 andreqd = true;
               }
               query +=  "\n</selectionSequence>\n"; // end of constraints sequence
             } // end of GENERAL CONSTRAINTS
 
             // WAVELENGTH
             if ( wavelength != null && wavelength.length > 0 ) 
             {
 			  if (andreqd)
                 query +=  "\n<selectionOp op='" + categoryjoin + "'/>" ;
 			  query += "<selectionSequence>"; // start of wavelength sequence
               for ( int i=0; i< wavelength.length; i++ ) {
                 if ( i > 0 ) 
                 {
                   query += "\n<selectionOp op='" + wavelengthjoin + "'/>";
                 }
                 query += "<selection item='vs:Coverage/vs:Spectral/vs:Waveband'"
                       + " itemOp='EQ' value='" + wavelength[i].trim() + "'/>";          
               }
 			  andreqd = true;
               query +=  "\n</selectionSequence>"; // end of wavelength sequence
             } // end of WAVELENGTH
 
             // MISSION
             if ( mission != null && mission.length > 0 ) 
             {
 			  if (andreqd)
                 query +=  "\n<selectionOp op='" + categoryjoin + "'/>";
               query += "\n<selectionSequence>"; // start of mission sequence
               for ( int i=0; i< mission.length; i++ ) {
                 if ( i > 0 ) 
                 {
                   query += "\n<selectionOp op='" + missionjoin + "'/>";
                 }
                 query += "<selection item='vr:Facility'"
                       + " itemOp='EQ' value='" + mission[i].trim() + "'/>";          
               }
 			  andreqd = true;
               query +=  "\n</selectionSequence>"; // end of main mission
             } // end of MISSION
 
             // KEYWORD
             if ( keyword != null && keyword.length > 0 ) 
             {
 			  if (andreqd)
                 query +=  "\n<selectionOp op='" + categoryjoin + "'/>" ;
               query += "\n<selectionSequence>"; // start of keyword sequence
               for ( int i=0; i< keyword.length; i++ ) 
               {
                 if ( i > 0 ) 
                 {
                   query += "\n<selectionOp op='" + keywordjoin + "'/>";
                 }
               query += "<selection item='vr:Subject'"
                     + " itemOp='EQ' value='" + keyword[i].trim() + "'/>";          
               }
               query +=  "\n</selectionSequence>";  // end of keyword sequence
             } // end of KEYWORD
             
 		  query +=  "\n</selectionSequence>"; // end of inner sequence
             
 		  }
 		  
 	    query += "\n</selectionSequence>\n";  // end of main sequence  
         //  End of Query.
         query += "\n</query>";  
       }
       catch(Exception ex) {
 		session.setAttribute( ERROR_MESSAGE_PARAMETER, ex.getMessage() ) ;      	
 		debug("Error thrown whilst creating task query xml: "); 
 		debug( ex.getMessage() ) ;
         query = "";
       }        
 
       try {      
         debug( query ); 
         if ( query.length() > 0 ) 
           submitQuery( query );
       }
       catch(Exception ex) {
         ex.printStackTrace();
       }
       finally {
         if( TRACE_ENABLED ) trace( "ResourceActionImpl.catalogQuery() exit" );
       }                    
     } // end of catalogQuery()
 
       
     /***
       * Generate xml string to pass to Registry 
       */
     private void taskQuery() throws ConsistencyException {
       if( TRACE_ENABLED ) trace( "ResourceActionImpl.taskQuery() entry" );
 
       String authorityId = "";
       String taskTitle = "";
       String description = ""; 
       String taskJoin = "";          
       String query = "";
 	  boolean andreqd = false; // used to add 'and' between e.g. (constraints) and (wavelength)
   
       try {        
         authorityId = request.getParameter( PARAM_AUTHORITY_FIELD ).trim();				
         taskTitle = request.getParameter( PARAM_TITLE ).trim();
         description = request.getParameter( PARAM_DESCRIPTION ).trim();
 		taskJoin = request.getParameter( PARAM_TASK_JOIN ).trim();        
 
         // Lets build up the XML for a query.
         query = "<query>\n"
                 + "<selectionSequence>\n"
 				+ "<selectionSequence>\n"
                 + "<selection item='searchElements' itemOp='EQ'"
                 + " value='Resource'/>\n"
                 + "<selectionOp op='$and$'/>"
                 + "<selection item='@xsi:Type' itemOp='EQ'"
                 + " value='CeaHttpApplicationType'/>"
                 + "<selectionOp op='OR'/>"                
                 + "\n<selection item='@xsi:type' itemOp='EQ'"
                 + " value='CeaApplicationType'/>"
                 + "<selectionOp op='OR'/>"                
                 + "<selection item='@xsi:Type' itemOp='EQ'"
                 + " value='cea:CeaHttpApplicationType'/>"
                 + "<selectionOp op='OR'/>"                
                 + "\n<selection item='@xsi:type' itemOp='EQ'"
                 + " value='cea:CeaApplicationType'/>"
 				+  "\n</selectionSequence>\n";
 
 		// is this an empty search?
 		if ( authorityId.length() > 0 || taskTitle.length() > 0 || description.length() > 0 )
 		{					 
 		  query += "\n<selectionOp op='AND'/>"
 		        +  "\n<selectionSequence>\n"; // start of inner sequence
 
           if ( authorityId.length() > 0 ) 
           {
 			query +=  "\n<selectionSequence>\n";          	
 			query += "<selection item='vr:Identifier/vr:AuthorityID' itemOp='CONTAINS' value='" + authorityId + "'/>";
 		    query += "<selectionOp op='OR'/>";
 			query += "<selection item='vr:Identifier/vr:ResourceKey' itemOp='CONTAINS' value='" + authorityId + "'/>";
 			query +=  "\n</selectionSequence>\n";
 			andreqd = true;
           }
           if ( taskTitle.length() > 0 ) 
           {
 			if (andreqd) 
 			  query += "\n<selectionOp op='"+taskJoin+"'/>";          	
 			query += "<selection item='vr:Title' itemOp='CONTAINS' value='" + taskTitle + "'/>";
 			andreqd = true;
           }
           if ( description.length() > 0 ) 
           {
 		    if (andreqd) 
 			  query += "\n<selectionOp op='"+taskJoin+"'/>";          	          	
 			  query += "<selection item='vr:Summary/vr:Description' itemOp='CONTAINS' value='" + description + "'/>";
           }
 		
 		  query +=  "\n</selectionSequence>"; // end of inner sequence
 		}
 		  
 		query += "\n</selectionSequence>\n";  // end of main sequence                  
         //  End of Query.
         query += "\n</query>";               
       }
       catch(Exception ex){
 		session.setAttribute( ERROR_MESSAGE_PARAMETER, ex.getMessage() ) ;      	
 		debug("Error thrown whilst creating task query xml: "); 
 		debug( ex.getMessage() ) ;
         query = "";
       }
       
       try {      
         debug( query ); 
         if ( query.length() > 0 )         
           submitQuery( query );                
       }
       catch(Exception ex) 
       {     	
 		ex.printStackTrace() ;
       }
       finally {
         if( TRACE_ENABLED ) trace( "ResourceActionImpl.taskQuery() exit" );
       }                    
     } // end of taskQuery()
 
 
     /***
       * This method does nothing at present! To follow...
       */
     private void filestoreQuery() throws ConsistencyException {
       if( TRACE_ENABLED ) trace( "ResourceActionImpl.filestoreQuery() entry" );
               
       try {          
       }
       catch(Exception ex){
       }
       finally {
         if( TRACE_ENABLED ) trace( "ResourceActionImpl.filestoreQuery() exit" );
       }                    
     } // end of filestoreQuery()
 
 
     /***
      * This method submits query to Registry
      * 
      * @param String query 	xml query string.     
      * @return void
      */
     private void submitQuery( String query ) throws ConsistencyException {
       if( TRACE_ENABLED ) trace( "ResourceActionImpl.submitQuery() entry" );
               
       try {
         ArrayList resultlist = null;
         String count = "";         
           // Now lets submit the query.
         RegistryService rs = RegistryDelegateFactory.createQuery( );
         debug( "Service = " + rs );
         if (query.length() > 0 )
         // if error thrown in building query string,
         // string will be empty so do not submit.
         {
            Document doc = rs.submitQuery( query );        
 
           //create the results and put it in the request.
            resultlist = createList( doc );
            count = "" + resultlist.size();
            
 		   debug( "Number of Result = " + count );
 		   session.setAttribute( PARAM_RESULT_COUNT, count );           
 
           // Not sure if this is req'd, but do we really want to retrieve everything from registry?
           if (resultlist.size() <= 100 ) {
             session.setAttribute("resultDoc", doc);			
           }
           else 
           {
 			session.setAttribute( ERROR_INFO_PARAMETER, "Your search will return more than 100 entries, please narrow it" ) ;
           }
         }                                                
       }
 
       catch( Exception ex ) 
       {     	
 		session.setAttribute( ERROR_MESSAGE_PARAMETER, ex.getMessage() ) ;      	
         debug("Error thrown whilst submitting query: "); 
         debug( ex.getMessage() ) ;        
       }
         
       finally {
         if( TRACE_ENABLED ) trace( "ResourceActionImpl.submitQuery() exit" );
       }                    
     } // end of submitQuery()
 
     /***
      * This method gets a list of key elements from the result document.
      * @param doc Query results in a DOM tree format.
      * @return ArrayList of relevant the String XML results.
      */
     private ArrayList createList( Document doc ) {
        NodeList nodes = doc.getDocumentElement().getChildNodes();
        return listNodes( nodes );
     }
     private ArrayList listNodes( NodeList nl ) {
       ArrayList al = new ArrayList();
       for(int i = 0; i < nl.getLength(); i++) {
         String element = null;
         Node node = nl.item(i);
         if( node instanceof org.w3c.dom.Element ) {
            element = XMLUtils.ElementToString( (Element) node );
            al.add( element );
         }                  
       }
       return al;
     }    
     
   } // end of inner class ResourceActionImpl
 
 
   private class ConsistencyException extends Exception {
   }
 
     private void trace( String traceString ) {
       // logger.debug( traceString );
       System.out.println( traceString );
   }
     
   private void debug( String logString ){
     // logger.debug( logString );
     System.out.println( logString );
   }     
 
 } // end of class ResourceAction