#!/usr/bin/env python3

# -*- coding: utf-8 -*-

######################################################

#

# Y(4S) -> BBbar event generation

#

# This tutorial demonstrates how to generate

#

# e+e- -> Y(4S) -> BBbar

#

# events with EvtGen in BASF2, where the decay of Y(4S)

# is specified by the given .dec file.

#

# The generated events are saved to the output ROOT file.

# In each event the generated particles (MCParticle objects)

# are stored in the StoreArray<MCParticle>.

#

# Contributors: A. Zupanc (June 2014)

#

######################################################

from basf2 import *

from modularAnalysis import generateY4S

from modularAnalysis import loadGearbox

from modularAnalysis import printPrimaryMCParticles

from reconstruction import add_mdst_output

from modularAnalysis import analysis_main

from ROOT import Belle2

from beamparameters import add_beamparameters

defaultFilename = "evtgen.root"

defaultFoldername = "test"

filename = defaultFoldername + '/' + defaultFilename

for arg in sys.argv:

print(arg)

if len(sys.argv)==2:

filename = sys.argv[1]

if os.path.isfile(filename):

sys.exit('Required input file does exist. ')

add_beamparameters(analysis_main, 'Y4S')

# generation of 100 events according to the specified DECAY table

# Y(4S) -> Btag- Bsig+

# Btag- -> D0 pi-; D0 -> K- pi+

# Bsig+ -> mu+ nu_mu

#

# generateY4S function is defined in analysis/scripts/modularAnalysis.py

#generateY4S(1000, 'Y4SEventGeneration.dec')

generateY4S(5000, 'mydec-k-cpmix.dec')

# If the simulation and reconstruction is not performed in the sam job,

# then the Gearbox needs to be loaded with the loadGearbox() function.

loadGearbox()

# dump generated events in MDST format to the output ROOT file

#

# add_mdst_output function is defined in reconstruction/scripts/reconstruction.py

add_mdst_output(analysis_main, True, filename)

printPrimaryMCParticles()

# process all modules added to the analysis_main path

# (note: analysis_main is the default path created in the modularAnapys.py)

process(analysis_main)

# print out the summary

print(statistics)