#! /usr/bin/env python3

"""(Ostensibly) fix copyright notices in files.

Actually, this script will simply replace a block of text in a file from one
string to another. It will only do this once though, i.e. not globally
throughout the file. It writes a backup file and then does an os.rename()
dance for atomicity.

Usage: fixnotices.py [options] [filenames]
Options:
 -h / --help
 Print this message and exit

 --oldnotice=file
 Use the notice in the file as the old (to be replaced) string, instead
 of the hard coded value in the script.

 --newnotice=file
 Use the notice in the file as the new (replacement) string, instead of
 the hard coded value in the script.

 --dry-run
 Don't actually make the changes, but print out the list of files that
 would change. When used with -v, a status will be printed for every
 file.

 -v / --verbose
 Print a message for every file looked at, indicating whether the file
 is changed or not.
"""

OLD_NOTICE = """/***********************************************************
Copyright (c) 2000, BeOpen.com.
Copyright (c) 1995-2000, Corporation for National Research Initiatives.
Copyright (c) 1990-1995, Stichting Mathematisch Centrum.
All rights reserved.

See the file "Misc/COPYRIGHT" for information on usage and
redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
******************************************************************/
"""
import os
import sys
import getopt

NEW_NOTICE = ""
DRYRUN = 0
VERBOSE = 0


def usage(code, msg=''):
 print(__doc__ % globals())
 if msg:
 print(msg)
 sys.exit(code)


def main():
 global DRYRUN, OLD_NOTICE, NEW_NOTICE, VERBOSE
 try:
 opts, args = getopt.getopt(sys.argv[1:], 'hv',
 ['help', 'oldnotice=', 'newnotice=',
 'dry-run', 'verbose'])
 except getopt.error as msg:
 usage(1, msg)

 for opt, arg in opts:
 if opt in ('-h', '--help'):
 usage(0)
 elif opt in ('-v', '--verbose'):
 VERBOSE = 1
 elif opt == '--dry-run':
 DRYRUN = 1
 elif opt == '--oldnotice':
 fp = open(arg)
 OLD_NOTICE = fp.read()
 fp.close()
 elif opt == '--newnotice':
 fp = open(arg)
 NEW_NOTICE = fp.read()
 fp.close()

 for arg in args:
 process(arg)


def process(file):
 f = open(file)
 data = f.read()
 f.close()
 i = data.find(OLD_NOTICE)
 if i < 0:
 if VERBOSE:
 print('no change:', file)
 return
 elif DRYRUN or VERBOSE:
 print(' change:', file)
 if DRYRUN:
 # Don't actually change the file
 return
 data = data[:i] + NEW_NOTICE + data[i+len(OLD_NOTICE):]
 new = file + ".new"
 backup = file + ".bak"
 f = open(new, "w")
 f.write(data)
 f.close()
 os.rename(file, backup)
 os.rename(new, file)


if __name__ == '__main__':
 main()