#!/usr/bin/env python
"""
snogen is a script to generate SNOMAN command files.

Example:

    # simulate 100 1 GeV muons
    $ snogen -n 100 -e 1000 -p mu_minus | /path/to/snoman.exe

The output filename can be specified on the command line:

    $ snogen -o [output filename]

By default it will be [particle name]_[energy]_[number of events].zdab.
"""
from __future__ import print_function, division
import string

class MyTemplate(string.Template):
    delimiter = '@'

if __name__ == '__main__':
    import argparse

    parser = argparse.ArgumentParser("generate a SNOMAN command file")
    parser.add_argument("-p", "--particle-id", default="e_minus",
                        help="particle id")
    parser.add_argument("-e", "--mc-energy", default=500.0, type=float,
                        help="total energy")
    parser.add_argument("-n", "--num-events", default=100, type=int,
                        help="number of events")
    parser.add_argument("-o", "--output", default=None,
                        help="output file name")
    args = parser.parse_args()

    if args.output is None:
        output = "%s_%.0f_%i.zdab" % (args.particle_id,args.mc_energy,args.num_events)
    else:
        output = args.output

    with open("mc_run_10000_macro.cmd") as f:
        s = f.read()

    template = MyTemplate(s)
    print(template.safe_substitute(particle_id=args.particle_id,mc_energy=args.mc_energy,num_events=args.num_events,output=output))