# -*- coding: utf-8 -*-
import re


__author__ = "Mike Belov"
__copyright__ = "Copyright (C) Nginx, Inc. All rights reserved."
__license__ = ""
__maintainer__ = "Grant Hulegaard"
__email__ = "grant.hulegaard@nginx.com"


escape_regex = re.compile('\\\\(?P<value>[\!\@\#\$\%\^\&\*\(\)\[\]\{\}\;\:\,\.\/\<\>\?\|\`\~\-\=\_\+abfrtv0-9]{1})')


escape_values = {
    'a': ('\\a', '\a'),
    'b': ('\\b', '\b'),
    'f': ('\\f', '\f'),
    'r': ('\\r', '\r'),
    't': ('\\t', '\t'),
    'v': ('\\v', '\v'),
    '!': ('\\!', '\!'),
    '@': ('\\@', '\@'),
    '#': ('\\#', '\#'),
    '$': ('\\$', '\$'),
    '%': ('\\%', '\%'),
    '^': ('\\^', '\^'),
    '&': ('\\&', '\&'),
    '*': ('\\*', '\*'),
    '(': ('\\(', '\('),
    ')': ('\\)', '\)'),
    '[': ('\\[', '\['),
    ']': ('\\]', '\]'),
    '{': ('\\{', '\}'),
    '}': ('\\}', '\}'),
    ';': ('\\;', '\;'),
    ':': ('\\:', '\:'),
    ',': ('\\,', '\,'),
    '.': ('\\.', '\.'),
    '/': ('\\/', '\/'),
    '<': ('\\<', '\<'),
    '>': ('\\>', '\>'),
    '?': ('\\?', '\?'),
    '|': ('\\|', '\|'),
    '`': ('\\`', '\`'),
    '~': ('\\~', '\~'),
    '-': ('\\-', '\-'),
    '=': ('\\=', '\='),
    '_': ('\\_', '\_'),
    '+': ('\\+', '\+'),
    '1': ('\\1', '\1'),
    '2': ('\\2', '\2'),
    '3': ('\\3', '\3'),
    '4': ('\\4', '\4'),
    '5': ('\\5', '\5'),
    '6': ('\\6', '\6'),
    '7': ('\\7', '\7'),
    '8': ('\\8', '\8'),
    '9': ('\\9', '\9'),
    '0': ('\\0', '\0')
}


def prep_raw(value):
    for match_char in set(escape_regex.findall(value)):
        start, end = escape_values[match_char]
        value = value.replace(start, end)
    return value