# -*- coding: utf-8 -*-
from __future__ import (
    print_function,
    division,
    unicode_literals,
    absolute_import
)

# Std. lib imports.
import sys

# Local imports.
from natsort.compat.py23 import (
    PY_VERSION,
    cmp_to_key,
    py23_unichr,
)

# This string should be sorted after any other byte string because
# it contains the max unicode character repeated 20 times.
# You would need some odd data to come after that.
null_string = ''
null_string_max = py23_unichr(sys.maxunicode) * 20

# Make the strxfrm function from strcoll on Python2
# It can be buggy (especially on BSD-based systems),
# so prefer icu if available.
try:
    import icu
    from locale import getlocale

    null_string_locale = b''

    # This string should in theory be sorted after any other byte
    # string because it contains the max byte char repeated many times.
    # You would need some odd data to come after that.
    null_string_locale_max = b'x7f' * 50

    def dumb_sort():
        return False

    # If using icu, get the locale from the current global locale,
    def get_icu_locale():
        try:
            return icu.Locale('.'.join(getlocale()))
        except TypeError:  # pragma: no cover
            return icu.Locale()

    def get_strxfrm():
        return icu.Collator.createInstance(get_icu_locale()).getSortKey

    def get_thousands_sep():
        sep = icu.DecimalFormatSymbols.kGroupingSeparatorSymbol
        return icu.DecimalFormatSymbols(get_icu_locale()).getSymbol(sep)

    def get_decimal_point():
        sep = icu.DecimalFormatSymbols.kDecimalSeparatorSymbol
        return icu.DecimalFormatSymbols(get_icu_locale()).getSymbol(sep)

except ImportError:
    import locale
    if PY_VERSION < 3:
        from locale import strcoll
        sentinel = object()

        def custom_strcoll(a, b, last=sentinel):
            """strcoll that can handle a sentinel that is always last."""
            if a is last:
                return 0 if a is b else 1
            elif b is last:  # a cannot also be sentinel b/c above logic
                return -1
            else:  # neither are sentinel
                return strcoll(a, b)

        strxfrm = cmp_to_key(custom_strcoll)
        null_string_locale = strxfrm('')
        null_string_locale_max = strxfrm(sentinel)
    else:
        from locale import strxfrm
        null_string_locale = ''

        # This string should be sorted after any other byte string because
        # it contains the max unicode character repeated 20 times.
        # You would need some odd data to come after that.
        null_string_locale_max = py23_unichr(sys.maxunicode) * 20

    # On some systems, locale is broken and does not sort in the expected
    # order. We will try to detect this and compensate.
    def dumb_sort():
        return strxfrm('A') < strxfrm('a')

    def get_strxfrm():
        return strxfrm

    def get_thousands_sep():
        sep = locale.localeconv()['thousands_sep']
        # If this locale library is broken, some of the thousands separator
        # characters are incorrectly blank. Here is a lookup table of the
        # corrections I am aware of.
        if dumb_sort():
            try:
                loc = '.'.join(locale.getlocale())
            except TypeError:  # No locale loaded, default to ','
                return ','
            return {'de_DE.ISO8859-15': '.',
                    'es_ES.ISO8859-1': '.',
                    'de_AT.ISO8859-1': '.',
                    'de_at': '\xa0',
                    'nl_NL.UTF-8': '.',
                    'es_es': '.',
                    'fr_CH.ISO8859-15': '\xa0',
                    'fr_CA.ISO8859-1': '\xa0',
                    'de_CH.ISO8859-1': '.',
                    'fr_FR.ISO8859-15': '\xa0',
                    'nl_NL.ISO8859-1': '.',
                    'ca_ES.UTF-8': '.',
                    'nl_NL.ISO8859-15': '.',
                    'de_ch': "'",
                    'ca_es': '.',
                    'de_AT.ISO8859-15': '.',
                    'ca_ES.ISO8859-1': '.',
                    'de_AT.UTF-8': '.',
                    'es_ES.UTF-8': '.',
                    'fr_fr': '\xa0',
                    'es_ES.ISO8859-15': '.',
                    'de_DE.ISO8859-1': '.',
                    'nl_nl': '.',
                    'fr_ch': '\xa0',
                    'fr_ca': '\xa0',
                    'de_DE.UTF-8': '.',
                    'ca_ES.ISO8859-15': '.',
                    'de_CH.ISO8859-15': '.',
                    'fr_FR.ISO8859-1': '\xa0',
                    'fr_CH.ISO8859-1': '\xa0',
                    'de_de': '.',
                    'fr_FR.UTF-8': '\xa0',
                    'fr_CA.ISO8859-15': '\xa0',
                    }.get(loc, sep)
        else:
            return sep

    def get_decimal_point():
        return locale.localeconv()['decimal_point']
