#!/usr/bin/env python2.4

import os, sys
import getopt
import Image, ImageFile

jhead = "/usr/bin/jhead"

assert os.access(jhead, os.X_OK), "Can't find jhead executable."

def scale(factor, qual, orig, tmp, small, big):
    # scale orig -> tmp
    img = Image.open(orig)
    format = img.format
    newsize = tuple([int(round(x*factor)) for x in img.size])
    img = img.resize(newsize, Image.ANTIALIAS)

    # save & preserve EXIF
    img.save(tmp, format, quality=qual)
    os.system('%s -te "%s" "%s" 2>/dev/null 1>/dev/null' % (jhead, orig, tmp))

    # rename to big, small
    os.rename(orig, big)
    os.rename(tmp, small)
    
    return newsize

def main(argv):
    factor = 0.5
    jpegqual = 85
    opts, args = getopt.getopt(argv, "f:q:")
    
    for o, a in opts:
        if o=='-f':
            factor = float(a)
        elif o=='-q':
            jpegqual = int(a)
    
    for orig in args:
        base, ext = orig.rsplit(".", 1)
        tmp = base + "--tmp." + ext

        if base.endswith("--big"):
            base = base[:-5]
            big = orig
            small = base + "." + ext
        else:
            big = base + "--big." + ext
            small = orig
            if os.access(big, os.F_OK):
                print "File already exists: " + big
                continue
        
        #print orig, big
        newsize = scale(factor, jpegqual, orig, tmp, small, big)
        print "%s to %ix%i" % (orig, newsize[0], newsize[1])



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