#!/usr/bin/python3
# -*- coding: utf-8 -*-
#
# Copyright 2004-2022 Univention GmbH
#
# https://www.univention.de/
#
# All rights reserved.
#
# The source code of this program is made available
# under the terms of the GNU Affero General Public License version 3
# (GNU AGPL V3) as published by the Free Software Foundation.
#
# Binary versions of this program provided by Univention to you as
# well as other copyrighted, protected or trademarked materials like
# Logos, graphics, fonts, specific documentations and configurations,
# cryptographic keys etc. are subject to a license agreement between
# you and Univention and not subject to the GNU AGPL V3.
#
# In the case you use this program under the terms of the GNU AGPL V3,
# the program is provided in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public
# License with the Debian GNU/Linux or Univention distribution in file
# /usr/share/common-licenses/AGPL-3; if not, see
# <https://www.gnu.org/licenses/>.

"""
A Python pre-processor
"""

from __future__ import print_function
import os
import sys
import getopt
import re
import py_compile

define = []
opts, args = getopt.getopt(sys.argv[1:], 'D:')
for opt, val in opts:
	if opt == '-D':
		define.append(val)

input, output = args

print('byte-compiling: %s' % input)
if os.path.exists(output):
	os.unlink(output)

if output.endswith('.pyo'):
	output_pp = open(output + '.pp', 'w')
else:
	output_pp = open(output, 'w')

ifdef_pattern = re.compile('^#ifdef (.*)')
endif_pattern = re.compile(r'^#endif *(/\*.*\*/)*')

hide_depth = 0
depth = 0
hide = 0

for line in open(input).readlines():
	line = line[0:-1]

	if ifdef_pattern.match(line):
		var = ifdef_pattern.findall(line)[0]
		depth += 1
		if not hide:
			hide = var not in define
			hide_depth = depth
	elif endif_pattern.match(line):
		if depth == hide_depth:
			hide = 0
		depth -= 1
	elif not hide:
		print(line, file=output_pp)
output_pp.close()

if output.endswith('.pyo'):
	e = py_compile.compile(output + '.pp', output, input)
	# os.unlink(output+'.pp')

if not os.path.exists(output):
	sys.exit(1)
