package org.lcsim.util.heprep;
   
   import hep.graphics.heprep.HepRepFactory;
   import hep.graphics.heprep.HepRepInstance;
   import hep.graphics.heprep.HepRepInstanceTree;
   import hep.graphics.heprep.HepRepType;
   import hep.graphics.heprep.HepRepTypeTree;
   import hep.physics.vec.Hep3Vector;
   
  import java.awt.Color;
  import java.util.Collection;
  import java.util.List;
  
  import org.lcsim.detector.DetectorElementStore;
  import org.lcsim.detector.IDetectorElement;
  import org.lcsim.detector.ITransform3D;
  import org.lcsim.detector.identifier.IExpandedIdentifier;
  import org.lcsim.detector.identifier.IIdentifier;
  import org.lcsim.detector.identifier.IIdentifierDictionary;
  import org.lcsim.detector.solids.LineSegment3D;
  import org.lcsim.detector.tracker.silicon.SiSensor;
  import org.lcsim.detector.tracker.silicon.SiSensorElectrodes;
  import org.lcsim.detector.tracker.silicon.SiStrips;
  import org.lcsim.event.EventHeader;
  import org.lcsim.event.EventHeader.LCMetaData;
  import org.lcsim.event.RawTrackerHit;
  
  /**
   * Convert RawTrackerHit objects into HepRep line segments.
   * @author Jeremy McCormick <jeremym@slac.stanford.edu>
   * @version $Id: RawTrackerHitConverter.java,v 1.2 2012/06/14 00:02:39 jeremy Exp $
   */
  class RawTrackerHitConverter implements HepRepCollectionConverter
  {
     public boolean canHandle(Class k) {
        return RawTrackerHit.class.isAssignableFrom(k);
     }
     
     public void convert(EventHeader event, List collection, HepRepFactory factory, HepRepTypeTree typeTree, HepRepInstanceTree instanceTree) {      
        LCMetaData meta = event.getMetaData(collection);
        String name = meta.getName();           
  
        HepRepType typeX = factory.createHepRepType(typeTree, name);
        typeX.addAttValue("layer", LCSimHepRepConverter.HITS_LAYER);
        typeX.addAttValue("drawAs", "Line");
        typeX.addAttValue("color", Color.GREEN);
        
        try {      
            // Setup links to SiSensor objects in detector geometry.
            setSensors(meta, (List<RawTrackerHit>)collection);
              
            // Loop over hits and draw them as lines.
            for (RawTrackerHit hit : (List<RawTrackerHit>)collection) {
                try {
                    SiSensor sensor = (SiSensor)hit.getDetectorElement();
                    Collection<SiSensorElectrodes> trodes = sensor.getReadoutElectrodes();
                    SiStrips strips = (SiStrips)trodes.toArray()[0];
                    LineSegment3D line = strips.getStrip(hit.getIdentifierFieldValue("strip"));
                    ITransform3D transform = strips.getLocalToGlobal();
                    Hep3Vector startPoint = transform.transformed(line.getStartPoint());
                    Hep3Vector endPoint = transform.transformed(line.getEndPoint());
                    HepRepInstance instance = factory.createHepRepInstance(instanceTree, typeX);
                    factory.createHepRepPoint(instance, startPoint.x(), startPoint.y(), startPoint.z());
                    factory.createHepRepPoint(instance, endPoint.x(), endPoint.y(), endPoint.z());
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
        catch (Exception e) {
            e.printStackTrace();
        }
     }
     
     private void setSensors(LCMetaData meta, List<RawTrackerHit> hits) {
  
         // Get the ID dictionary and field information.
         IIdentifierDictionary dict = meta.getIDDecoder().getSubdetector().getDetectorElement().getIdentifierHelper().getIdentifierDictionary();
         int fieldIdx = dict.getFieldIndex("side");
         int sideIdx = dict.getFieldIndex("strip");
         
         for (RawTrackerHit hit : hits) {
                
             // The "side" and "strip" fields needs to be stripped from the ID for sensor lookup.
             IExpandedIdentifier expId = dict.unpack(hit.getIdentifier());
             expId.setValue(fieldIdx, 0);
             expId.setValue(sideIdx, 0);
             IIdentifier strippedId = dict.pack(expId);
         
             // Find the sensor DetectorElement.
             List<IDetectorElement> des = DetectorElementStore.getInstance().find(strippedId);
             if (des == null || des.size() == 0) {
                 throw new RuntimeException("Failed to find any DetectorElements with stripped ID <0x" + Long.toHexString(strippedId.getValue()) + ">.");
             }
             else if (des.size() == 1) {
                 hit.setDetectorElement((SiSensor)des.get(0));
             }
             else {
                 // Use first sensor found, which should work unless there are sensors with duplicate IDs.
                for (IDetectorElement de : des) {
                    if (de instanceof SiSensor) {
                        hit.setDetectorElement((SiSensor)de);
                        break;
                    }
                }
            }   
            
            // No sensor was found.
            if (hit.getDetectorElement() == null) {
                throw new RuntimeException("No sensor was found for hit with stripped ID <0x" + Long.toHexString(strippedId.getValue()) + ">.");
            }
        }
    }
 }