#!/usr/bin/env python

import sys, os
sys.path.append('/home/fac/gacs/lib/python')
from Util import *

from stat import *

import re


def usage(progname):
    usage_str = \
    "  Usage: " + progname + """ --course <course> --file <filename>
[--subdir <subdirectory> --students <student1>,<student2> ... ]
  (students separeted by commas, no space).
  Remove a file from (a subdirectory of) the homework submission directory
of each student.  The subdirectory name can contain slashes.
  If the argument --students is present, the removing happens only in the
directories of these students.
"""
    sys.stderr.write(usage_str)
    sys.exit(1)


def rm_from_dir(subm_dir, subdir, filename):
    if not os.path.isdir(subm_dir):
        sys.stderr.write(subm_dir + " is not a directory.\n")
        return
    if subdir:
        target = os.path.join(subm_dir, subdir)
    else:
        target = subm_dir

    if not os.path.isdir(target):
        target = subm_dir
    target = os.path.join(target, os.path.basename(filename))
    try:
        if os.path.exists(target):
            os.remove(target)
    except (OSError, IOError), detail:
        die("Removing "+target+" failed.", detail)


# --------------------- Main ----------------------

progname = sys.argv[0]
long_optlist = ["course=", "file=", "subdir=", "students="]
options, args = getopt_map("x", long_optlist)

if not (options.has_key('--course') and options.has_key('--file')):
    usage(progname)

course, filename = options['--course'], options['--file']
if not os.path.exists(filename):
    sys.stderr.write("File " + filename + " does not exist.\n")
    sys.exit(1)

if options.has_key('--subdir'): subdir = options['--subdir']
else: subdir = ""

spool = os.path.join(os.sep, "cs", "course", course,
                     "current", "homework", "spool")

if options.has_key("--students"):
    students = options['--students'].split(",")
else:
    students = os.listdir(spool)

for student in students:
    rm_from_dir(os.path.join(spool, student), subdir, filename)