"""Configuration Helper for ParticleHandler"""
from g4units import MeV, mm

from DDSim.Helper.ConfigHelper import ConfigHelper

class ParticleHandler( ConfigHelper ):
  """Configuration for the Particle Handler/ MCTruth treatment"""
  def __init__( self ):
    super(ParticleHandler, self).__init__()
    self._saveProcesses = ['Decay']
    self._minimalKineticEnergy = 1*MeV
    self._keepAllParticles = False
    self._printEndTracking = False
    self._printStartTracking = False
    self._minDistToParentVertex = 2.2e-14*mm
    self._enableDetailedHitsAndParticleInfo = False
    self._userParticleHandler = "Geant4TCUserParticleHandler"

  @property
  def enableDetailedHitsAndParticleInfo(self):
    """Enable lots of printout on simulated hits and MC-truth information"""
    return self._enableDetailedHitsAndParticleInfo

  @enableDetailedHitsAndParticleInfo.setter
  def enableDetailedHitsAndParticleInfo( self, val ):
    self._enableDetailedHitsAndParticleInfo = val

  @property
  def userParticleHandler( self ):
    """Optionally enable an extended Particle Handler"""
    return self._userParticleHandler
  @userParticleHandler.setter
  def userParticleHandler( self, val ):
    self._userParticleHandler = val

  @property
  def minDistToParentVertex( self ):
    """Minimal distance between particle vertex and endpoint of parent after
    which the vertexIsNotEndpointOfParent flag is set
    """
    return self._minDistToParentVertex
  @minDistToParentVertex.setter
  def minDistToParentVertex( self, val ):
    self._minDistToParentVertex = val

  @property
  def saveProcesses(self):
    """List of processes to save, on command line give as whitespace separated string in quotation marks"""
    return self._saveProcesses
  @saveProcesses.setter
  def saveProcesses(self, stringVal):
    self._saveProcesses = ConfigHelper.makeList( stringVal )

  @property
  def minimalKineticEnergy(self):
    """MinimalKineticEnergy to store particles created in the tracking region"""
    return self._minimalKineticEnergy
  @minimalKineticEnergy.setter
  def minimalKineticEnergy( self, val ):
    self._minimalKineticEnergy = val

  @property
  def keepAllParticles( self ):
    """ Keep all created particles """
    return self._keepAllParticles
  @keepAllParticles.setter
  def keepAllParticles( self, val ):
    self._keepAllParticles = val

  @property
  def printStartTracking( self ):
    """ Printout at Start of Tracking """
    return self._printStartTracking
  @printStartTracking.setter
  def printStartTracking( self, val ):
    self._printEndTracking = val

  @property
  def printEndTracking( self ):
    """ Printout at End of Tracking """
    return self._printEndTracking
  @printEndTracking.setter
  def printEndTracking( self, val ):
    self._printEndTracking = val

  def setDumpDetailedParticleInfo( self, kernel, DDG4 ):
    #---- debug code from Markus for detailed dumps of hits and MC-truth assignement ------
    # Add the particle dumper to associate the MC truth
    evt = DDG4.EventAction(kernel,"Geant4ParticleDumpAction/ParticleDump")
    kernel.eventAction().adopt(evt)
    evt.enableUI()
    # Add the hit dumper BEFORE any hit truth is fixed
    evt = DDG4.EventAction(kernel,"Geant4HitDumpAction/RawDump")
    kernel.eventAction().adopt(evt)
    evt.enableUI()
    # Add the hit dumper to the event action sequence
    evt = DDG4.EventAction(kernel,"Geant4HitTruthHandler/HitTruth")
    kernel.eventAction().adopt(evt)
    evt.enableUI()
    # Add the hit dumper AFTER any hit truth is fixed. We should see the reduced track references
    evt = DDG4.EventAction(kernel,"Geant4HitDumpAction/HitDump")
    kernel.eventAction().adopt(evt)
    evt.enableUI()

  def setupUserParticleHandler(self, part, kernel, DDG4):
    """Create the UserParticleHandler and configure it.

    FIXME: this is not extensible at the moment
    """
    if not self.userParticleHandler:
      return

    if self.userParticleHandler == "Geant4TCUserParticleHandler":
      user = DDG4.Action(kernel,"%s/UserParticleHandler" % self.userParticleHandler)
      try:
        user.TrackingVolume_Zmax = DDG4.tracker_region_zmax
        user.TrackingVolume_Rmax = DDG4.tracker_region_rmax
        print " *** definition of tracker region *** "
        print "    tracker_region_zmax = " , user.TrackingVolume_Zmax
        print "    tracker_region_rmax = " , user.TrackingVolume_Rmax
        print " ************************************ "
      except AttributeError as e:
        print "ERROR - attribute of tracker region missing in detector model   ", str(e)
        print "   make sure to specify the global constants tracker_region_zmax and tracker_region_rmax "
        print "   this is needed for the MC-truth link of created sim-hits  !  "
        print " Or Disable the User Particle Handler with --part.userParticleHandler=''"
        exit(1)
      part.adopt(user)

    print "ERROR: unknown UserParticleHandler: %r" % self.userParticleHandler
    exit(1)