#!/usr/bin/env python
""" Make a ds9 region file from a SExtractor catalogue."""
from barak.io import readsex, sex_to_DS9reg

usage = """\
Usage: sex2DS9reg sextractor_catalogue_filename [DS9region_filename]

Create a DS9 region file from a SExtractor output catalogue. It must
contain either X_IMAGE and Y_IMAGE, or XWIN_IMAGE and YWIN_IMAGE. If
A, B and THETA columns are also present, then ellipse regions are
drawn, otherwise just points.
"""

def main(args):

    if len(args) not in (1,2):
        print usage
        sys.exit()

    catname = args[0] 
    if len(args) == 1:
        regname = catname.rsplit('.')[0] + '.reg'
    else:
        regname = args[1]

    print 'Reading', catname
    s = readsex(catname)
    print 'writing to', regname
    sex_to_DS9reg(regname, s)

if __name__ == '__main__':
    import sys
    main(sys.argv[1:])

