#!/usr/bin/env python
import os
import subprocess
import sys

# you may configure the paths below which modifications are allowed.
# should contain the full paths to job_working_directory and new_file_path.
# if set to None every file can be modified by the script.
# this can increase security in particular if write access to this
# script is removed by the admin.
#
# ALLOWED_PATHS = [ "job_working_directory", "new_file_path" ]
ALLOWED_PATHS = None


def validate_parameters():
    if len(sys.argv) < 4:
        sys.stderr.write("usage: %s path user_name gid\n" % sys.argv[0])
        exit(1)

    path = os.path.abspath(sys.argv[1])
    if ALLOWED_PATHS is None:
        allowed = True
    else:
        allowed = False
        for p in ALLOWED_PATHS:
            if path.startswith(p):
                allowed = True
                break
    if not allowed:
        sys.stderr.write("owner and group modifications in %s are not allowed\n" % path)
        sys.exit(1)

    galaxy_user_name = sys.argv[2]
    gid = sys.argv[3]

    return path, galaxy_user_name, gid


def main():
    path, galaxy_user_name, gid = validate_parameters()
    for cmd in [["chown", "-Rh", galaxy_user_name, path], ["chgrp", "-Rh", gid, path]]:
        p = subprocess.Popen(cmd, shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        (stdoutdata, stderrdata) = p.communicate()
        exitcode = p.returncode
        if exitcode != 0:
            sys.exit("external_chown_script: could not chown\ncmd was %s\n" % " ".join(cmd))


if __name__ == "__main__":
    main()