#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
#  SSnR.py
#
#  Copyright 2017 Rémi BERTHO <remi.bertho@dalan.fr>
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 3 of the License, or
#  (at your option) any later version.
#
#  This program is distributed 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 General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.
#
#

import sys
import argparse
import regex

def main():
	"""
	Main function
	"""
	parser = argparse.ArgumentParser(description='Search and replace tool', prog='SSnR')
	parser.add_argument('-e', '--regex', help='Regex', required=True)
	parser.add_argument('-s', '--string', help='String', required=True)
	parser.add_argument('-r', '--replace', help='Replace', required=False)
	parser.add_argument('-m', '--print_nb_match', help='Print the number of match in replace',
	                    required=False, action='store_true')
	args = vars(parser.parse_args())

	# Compile regex
	try:
		ex = compile_regex(args["regex"])
	except SyntaxError as exception:
		print("Error when compiling regex: " + str(exception))
		return -1
	except regex.error as exception:
		print("Error when compiling regex: " + exception.msg)
		return -1

	if args["replace"] is not None:
		replace(ex, args["string"], args["replace"], args["print_nb_match"])
	else:
		search(ex, args["string"])
	return 0

def compile_regex(ex):
	"""
	Compile regex
		:param ex: Regular expression
	"""
	regex_compile = regex.compile(ex, regex.MULTILINE)
	if regex_compile is None:
		raise SyntaxError('Error in the regex')
	else:
		return regex_compile

def search(ex, string):
	"""
	Search in a string
		:param ex: Regular expression
		:param string: A string
	"""
	ite = ex.finditer(string)
	nb_match = 0
	for match in ite:
		nb_match += 1
		print(" - Found \"" + match.group(0) + "\" at [" + str(match.start(0)) +
		      ":" + str(match.end(0)) + "]")
	print("Number of match: " + str(nb_match))


def replace(ex, string, replace_string, print_nb):
	"""
	Replace in a string
		:param ex: Regular expression
		:param string: A string
		:param print_nb: Print the number of match
	"""
	res = ex.subn(replace_string, string)
	print(res[0])
	if print_nb:
		print("Number of match: " + str(res[1]))

if __name__ == '__main__':
	sys.exit(main())