#!/usr/bin/env python

# This example shows basic a basic aanet event loop and the many
# options there are for printing event information. 
#
#

"""
 Usage user_info.py -f input_file -o output_file.root

 The Evt, Trk and Hit classes of aanet derive from a small base
 class AAObject, which provides simple functionality to add user
 data to the event. This is usefull if you want to add a small bit
 of information to each Event/Track/Hit, and don't care too much
 about speed. 

 options:
 -f : input file default=/sps/km3net/users/heijboer/example_files/JGandalf_aanet_muon-CC_3-100GeV_1.root
 -o : output file                                    default=info.root
 -n : process this many events,                      default=10
 -p : print 1-line event summaries,                  default=True
 -h : this help message and exit                     default=False       
 -i : Python interative mode (prompt when done)      default=True 
"""

import sys, aa
from ROOT import *
# aa.py contains helper to deal with cmd line options
options = aa.Options( __doc__, sys.argv[1:] ) 

outfile = options.o

f = EventFile( options.f )
f.set_output( outfile )    # this opend an aanet output file
f.autosave = true          # true = default, but just illustrate

for evt in f : 

    evt.setusr("my_parameter",  42 )

    for t in evt.mc_trks : 
        t.setusr("trackpar", 42*42 )

    # You can also just use the usr member

    for h in evt.hits :
        
        h.usr.resize(3);
        h.usr[0] = 1;
        h.usr[1] = 2;
        h.usr[2] = 3;
        
    if f.index > options.n : break;

del f

#================================================================
print ("-- now reading the file with user info --")

f2 = EventFile( outfile )

for evt in f2 :
    print evt.getusr("my_parameter")
    print evt.mc_trks[0].getusr("trackpar")

    for i in range (evt.hits.size()):
        print i,evt.hits[i].usr[2]
    print 

# If you know the index-numbers, you can use them in TTree::Draw
# and TTree::Scan. (Unfortunatelly, you can not refer to the usr
# variables by name when doing this).

E.Draw("hits[].usr[2]") # lots of entries at 3