#!/usr/bin/env python3
# -*- 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 os.path
from os import walk
import argparse
import regex
import pyperclip

def main():
	"""
	Main function
	"""
	# Parse arguments
	parser = argparse.ArgumentParser(description='Search and replace tool for UTF-8 files',
	                                 prog='SSnR', allow_abbrev=False)

	regex_group = parser.add_argument_group('Regular expression', "Search and replace regular expression")
	regex_group.add_argument('-ex', '--regex', help='Regex', required=True)
	regex_group.add_argument('-rex', '--replace', help='Replace', required=False)

	input_group = parser.add_argument_group('Input', "Input arguments, if none set use stdin")
	input_group.add_argument('-if', '--input_file', help='Input file', required=False, nargs='+')
	input_group.add_argument('-iex', '--input_regex', help='Regex input file', required=False)
	input_group.add_argument('-str', '--input_string', help='Input string', required=False)
	input_group.add_argument('-ic', '--input_clipboard', help='Use the clipboard as input',
	                         required=False, action='store_true')

	output_group = parser.add_argument_group('Output', "In replace mode, ouput arguments, if none set use stdout")
	output_group.add_argument('-oex', '--output_regex', help='Regex output file', required=False)
	output_group.add_argument('-of', '--output_file', help='Output file', required=False)
	output_group.add_argument('-oc', '--output_clipboard', help='Use the clipboard as output',
	                          required=False, action='store_true')

	option_group = parser.add_argument_group('Options', "Some options")
	option_group.add_argument('-pm', '--print_nb_match', help='Print the number of match in replace',
	                          required=False, action='store_true')
	option_group.add_argument('-igc', '--ignore_case', help='Ignore the case',
	                          required=False, action='store_true')
	option_group.add_argument('-r', '--recursive', help='Use the regex input recursivly in the folders',
	                          required=False, action='store_true')

	args = vars(parser.parse_args())


	# Compile regex
	try:
		ex = compile_regex(args["regex"], args["ignore_case"])
	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

	# Get input
	input_filenames = []
	if args["input_regex"] is not None:
		try:
			input_ex = compile_regex(args["input_regex"], False)
		except SyntaxError as exception:
			print("Error when compiling input regex: " + str(exception))
			return -1
		except regex.error as exception:
			print("Error when compiling input regex: " + exception.msg)
			return -1
		for (dirpath, dirnames, dir_filenames) in walk("."):
			for filename in dir_filenames:
				if input_ex.fullmatch(filename):
					input_filenames.append(os.path.join(dirpath, filename))
					is_file = True
			if not args["recursive"]:
				break
		if not input_filenames:
			print("Error: no input file")
			return -1
	elif args["input_file"] is not None:
		for input_file in args["input_file"]:
			if os.path.isfile(input_file):
				is_file = True
				input_filenames.append(input_file)
			else:
				print("Error: file not found: " + str(args["input"]))
		if not input_filenames:
			print("Error: no input file")
			return -1
	elif args["input_string"] is not None:
		string = args["input_string"]
		is_file = False
	elif args["input_clipboard"]:
		string = pyperclip.paste()
		is_file = False
	else:
		string = sys.stdin.read()
		is_file = False

	# Get output
	output_filenames = []
	if args["output_regex"] is not None:
		if input_ex is None:
			print("Error: You need a regex input file to use a regex output file")
			return -1
		for input_filename in input_filenames:
			output_filenames.append(input_ex.subn(args["output_regex"], input_filename)[0])
		use_output_file = True
	elif args["output_file"] is not None:
		output_filenames.append(args["output_file"])
		use_output_file = True
	elif args["output_clipboard"]:
		use_output_file = False
		use_output_clipboard = True
	else:
		use_output_file = False
		use_output_clipboard = False

	# Search or replace
	file_index = 0
	if is_file:
		for filename in input_filenames:
			try:
				with open(filename, "r", encoding="utf8") as file:
					string = file.read()
			except OSError as exception:
				print("Error: file \"" + filename + "\" not found: " + str(exception))
				continue
			except UnicodeDecodeError as exception:
				print("Error: the file \"" + filename + "\" is not UTF-8 encoded: " + str(exception))
				continue

			if args["replace"] is not None:
				replace_string, nb_replace = replace(ex, string, args["replace"])
				if use_output_file:
					try:
						output_file = open(output_filenames[file_index], "w", encoding="utf8")
					except OSError as exception:
						print("Error: file not found: " + str(exception))
						return -1
					output_file.write(replace_string)
					print("File: " + filename)
					print(" - Number of replace: " + str(nb_replace))
					if len(output_filenames) > 1:
						file_index += 1
				elif use_output_clipboard:
					pyperclip.copy(replace_string)
				else:
					print(replace_string)
					if args["print_nb_match"]:
						print("File: " + filename)
						print(" - Number of replace: " + str(nb_replace))
			else:
				nb_match, str_found = search(ex, string, is_file)
				if nb_match > 0:
					print("File: " + filename)
					print(" - Number of match: " + str(nb_match))
					print(str_found)
	else:
		if args["replace"] is not None:
			replace_string, nb_replace = replace(ex, string, args["replace"])
			if use_output_file:
				print("Number of replace: " + str(nb_replace))
				try:
					output_file = open(output_filenames[file_index], "w", encoding="utf8")
				except OSError as exception:
					print("Error: file not found: " + str(exception))
					return -1
				output_file.write(replace_string)
			elif use_output_clipboard:
				pyperclip.copy(replace_string)
			else:
				print(replace_string)
				if args["print_nb_match"]:
					print("Number of replace: " + str(nb_replace))
		else:
			nb_match, str_found = search(ex, string, is_file)
			print("Number of match: " + str(nb_match))
			print(str_found)
	return 0

def compile_regex(ex, ignore_case):
	"""
	Compile regex
		:param ex: Regular expression
	"""
	if ignore_case:
		regex_compile = regex.compile(ex, regex.MULTILINE | regex.IGNORECASE)
	else:
		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, is_file):
	"""
	Search in a string
		:param ex: Regular expression
		:param string: A string
	"""
	if is_file:
		new_lines = get_line_pos(string)

	ite = ex.finditer(string)
	nb_match = 0
	str_found = ""
	for match in ite:
		nb_match += 1
		if is_file:
			num_line, begin_pos, end_pos = find_line(match.start(0), match.end(0), new_lines)
			str_found += " - Found \"%s\" at line %d [%d:%d]\n" % (match.group(0), num_line, begin_pos, end_pos)
		else:
			str_found += " - Found \"%s\" at [%d:%d]\n" % (match.group(0), match.start(0), match.end(0))
	return nb_match, str_found


def replace(ex, string, replace_string):
	"""
	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)
	return res[0], res[1]

def get_line_pos(string):
	"""
	Get new lines postion in a string
		:param string: a string
	"""
	ex =	regex.compile("^", regex.MULTILINE)
	ite = ex.finditer(string)
	new_lines = []
	for match in ite:
		new_lines.append(match.start(0))
	return new_lines

def find_line(begin_pos, end_pos, new_lines):
	"""
	Find the line number and the position in the line
		:param pos: the position to find the line
		:param new_lines: then new lines
	"""
	num_line = 0
	old_pos_line = 0
	for pos_line in new_lines:
		if pos_line > begin_pos:
			return num_line, begin_pos - old_pos_line + 1, end_pos - old_pos_line
		num_line += 1
		old_pos_line = pos_line
	return num_line, begin_pos - old_pos_line + 1, end_pos - old_pos_line


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