'''
datetime.tzinfo timezone definitions generated from the
Olson timezone database:

    ftp://elsie.nci.nih.gov/pub/tz*.tar.gz

See the datetime section of the Python Library Reference for information
on how to use these modules.
'''

import sys
import datetime
import os.path

from pytz.exceptions import AmbiguousTimeError
from pytz.exceptions import InvalidTimeError
from pytz.exceptions import NonExistentTimeError
from pytz.exceptions import UnknownTimeZoneError
from pytz.lazy import LazyDict, LazyList, LazySet  # noqa
from pytz.tzinfo import unpickler, BaseTzInfo
from pytz.tzfile import build_tzinfo


# The IANA (nee Olson) database is updated several times a year.
OLSON_VERSION = '2019c'
VERSION = '2019.3'  # pip compatible version number.
__version__ = VERSION

OLSEN_VERSION = OLSON_VERSION  # Old releases had this misspelling

__all__ = [
    'timezone', 'utc', 'country_timezones', 'country_names',
    'AmbiguousTimeError', 'InvalidTimeError',
    'NonExistentTimeError', 'UnknownTimeZoneError',
    'all_timezones', 'all_timezones_set',
    'common_timezones', 'common_timezones_set',
    'BaseTzInfo',
]


if sys.version_info[0] > 2:  # Python 3.x

    # Python 3.x doesn't have unicode(), making writing code
    # for Python 2.3 and Python 3.x a pain.
    unicode = str

    def ascii(s):
        r"""
        >>> ascii('Hello')
        'Hello'
        >>> ascii('\N{TRADE MARK SIGN}') #doctest: +IGNORE_EXCEPTION_DETAIL
        Traceback (most recent call last):
            ...
        UnicodeEncodeError: ...
        """
        if type(s) == bytes:
            s = s.decode('ASCII')
        else:
            s.encode('ASCII')  # Raise an exception if not ASCII
        return s  # But the string - not a byte string.

else:  # Python 2.x

    def ascii(s):
        r"""
        >>> ascii('Hello')
        'Hello'
        >>> ascii(u'Hello')
        'Hello'
        >>> ascii(u'\N{TRADE MARK SIGN}') #doctest: +IGNORE_EXCEPTION_DETAIL
        Traceback (most recent call last):
            ...
        UnicodeEncodeError: ...
        """
        return s.encode('ASCII')


def open_resource(name):
    """Open a resource from the zoneinfo subdir for reading.

    Uses the pkg_resources module if available and no standard file
    found at the calculated location.

    It is possible to specify different location for zoneinfo
    subdir by using the PYTZ_TZDATADIR environment variable.
    """
    name_parts = name.lstrip('/').split('/')
    for part in name_parts:
        if part == os.path.pardir or os.path.sep in part:
            raise ValueError('Bad path segment: %r' % part)
    zoneinfo_dir = os.environ.get('PYTZ_TZDATADIR', None)
    if zoneinfo_dir is not None:
        filename = os.path.join(zoneinfo_dir, *name_parts)
    else:
        filename = os.path.join(os.path.dirname(__file__),
                                'zoneinfo', *name_parts)
        if not os.path.exists(filename):
            # http://bugs.launchpad.net/bugs/383171 - we avoid using this
            # unless absolutely necessary to help when a broken version of
            # pkg_resources is installed.
            try:
                from pkg_resources import resource_stream
            except ImportError:
                resource_stream = None

            if resource_stream is not None:
                return resource_stream(__name__, 'zoneinfo/' + name)
    return open(filename, 'rb')


def resource_exists(name):
    """Return true if the given resource exists"""
    try:
        open_resource(name).close()
        return True
    except IOError:
        return False


_tzinfo_cache = {}


def timezone(zone):
    r''' Return a datetime.tzinfo implementation for the given timezone

    >>> from datetime import datetime, timedelta
    >>> utc = timezone('UTC')
    >>> eastern = timezone('US/Eastern')
    >>> eastern.zone
    'US/Eastern'
    >>> timezone(unicode('US/Eastern')) is eastern
    True
    >>> utc_dt = datetime(2002, 10, 27, 6, 0, 0, tzinfo=utc)
    >>> loc_dt = utc_dt.astimezone(eastern)
    >>> fmt = '%Y-%m-%d %H:%M:%S %Z (%z)'
    >>> loc_dt.strftime(fmt)
    '2002-10-27 01:00:00 EST (-0500)'
    >>> (loc_dt - timedelta(minutes=10)).strftime(fmt)
    '2002-10-27 00:50:00 EST (-0500)'
    >>> eastern.normalize(loc_dt - timedelta(minutes=10)).strftime(fmt)
    '2002-10-27 01:50:00 EDT (-0400)'
    >>> (loc_dt + timedelta(minutes=10)).strftime(fmt)
    '2002-10-27 01:10:00 EST (-0500)'

    Raises UnknownTimeZoneError if passed an unknown zone.

    >>> try:
    ...     timezone('Asia/Shangri-La')
    ... except UnknownTimeZoneError:
    ...     print('Unknown')
    Unknown

    >>> try:
    ...     timezone(unicode('\N{TRADE MARK SIGN}'))
    ... except UnknownTimeZoneError:
    ...     print('Unknown')
    Unknown

    '''
    if zone is None:
        raise UnknownTimeZoneError(None)

    if zone.upper() == 'UTC':
        return utc

    try:
        zone = ascii(zone)
    except UnicodeEncodeError:
        # All valid timezones are ASCII
        raise UnknownTimeZoneError(zone)

    zone = _case_insensitive_zone_lookup(_unmunge_zone(zone))
    if zone not in _tzinfo_cache:
        if zone in all_timezones_set:  # noqa
            fp = open_resource(zone)
            try:
                _tzinfo_cache[zone] = build_tzinfo(zone, fp)
            finally:
                fp.close()
        else:
            raise UnknownTimeZoneError(zone)

    return _tzinfo_cache[zone]


def _unmunge_zone(zone):
    """Undo the time zone name munging done by older versions of pytz."""
    return zone.replace('_plus_', '+').replace('_minus_', '-')


_all_timezones_lower_to_standard = None


def _case_insensitive_zone_lookup(zone):
    """case-insensitively matching timezone, else return zone unchanged"""
    global _all_timezones_lower_to_standard
    if _all_timezones_lower_to_standard is None:
        _all_timezones_lower_to_standard = dict((tz.lower(), tz) for tz in all_timezones)  # noqa
    return _all_timezones_lower_to_standard.get(zone.lower()) or zone  # noqa


ZERO = datetime.timedelta(0)
HOUR = datetime.timedelta(hours=1)


class UTC(BaseTzInfo):
    """UTC

    Optimized UTC implementation. It unpickles using the single module global
    instance defined beneath this class declaration.
    """
    zone = "UTC"

    _utcoffset = ZERO
    _dst = ZERO
    _tzname = zone

    def fromutc(self, dt):
        if dt.tzinfo is None:
            return self.localize(dt)
        return super(utc.__class__, self).fromutc(dt)

    def utcoffset(self, dt):
        return ZERO

    def tzname(self, dt):
        return "UTC"

    def dst(self, dt):
        return ZERO

    def __reduce__(self):
        return _UTC, ()

    def localize(self, dt, is_dst=False):
        '''Convert naive time to local time'''
        if dt.tzinfo is not None:
            raise ValueError('Not naive datetime (tzinfo is already set)')
        return dt.replace(tzinfo=self)

    def normalize(self, dt, is_dst=False):
        '''Correct the timezone information on the given datetime'''
        if dt.tzinfo is self:
            return dt
        if dt.tzinfo is None:
            raise ValueError('Naive time - no tzinfo set')
        return dt.astimezone(self)

    def __repr__(self):
        return "<UTC>"

    def __str__(self):
        return "UTC"


UTC = utc = UTC()  # UTC is a singleton


def _UTC():
    """Factory function for utc unpickling.

    Makes sure that unpickling a utc instance always returns the same
    module global.

    These examples belong in the UTC class above, but it is obscured; or in
    the README.txt, but we are not depending on Python 2.4 so integrating
    the README.txt examples with the unit tests is not trivial.

    >>> import datetime, pickle
    >>> dt = datetime.datetime(2005, 3, 1, 14, 13, 21, tzinfo=utc)
    >>> naive = dt.replace(tzinfo=None)
    >>> p = pickle.dumps(dt, 1)
    >>> naive_p = pickle.dumps(naive, 1)
    >>> len(p) - len(naive_p)
    17
    >>> new = pickle.loads(p)
    >>> new == dt
    True
    >>> new is dt
    False
    >>> new.tzinfo is dt.tzinfo
    True
    >>> utc is UTC is timezone('UTC')
    True
    >>> utc is timezone('GMT')
    False
    """
    return utc


_UTC.__safe_for_unpickling__ = True


def _p(*args):
    """Factory function for unpickling pytz tzinfo instances.

    Just a wrapper around tzinfo.unpickler to save a few bytes in each pickle
    by shortening the path.
    """
    return unpickler(*args)


_p.__safe_for_unpickling__ = True


class _CountryTimezoneDict(LazyDict):
    """Map ISO 3166 country code to a list of timezone names commonly used
    in that country.

    iso3166_code is the two letter code used to identify the country.

    >>> def print_list(list_of_strings):
    ...     'We use a helper so doctests work under Python 2.3 -> 3.x'
    ...     for s in list_of_strings:
    ...         print(s)

    >>> print_list(country_timezones['nz'])
    Pacific/Auckland
    Pacific/Chatham
    >>> print_list(country_timezones['ch'])
    Europe/Zurich
    >>> print_list(country_timezones['CH'])
    Europe/Zurich
    >>> print_list(country_timezones[unicode('ch')])
    Europe/Zurich
    >>> print_list(country_timezones['XXX'])
    Traceback (most recent call last):
    ...
    KeyError: 'XXX'

    Previously, this information was exposed as a function rather than a
    dictionary. This is still supported::

    >>> print_list(country_timezones('nz'))
    Pacific/Auckland
    Pacific/Chatham
    """
    def __call__(self, iso3166_code):
        """Backwards compatibility."""
        return self[iso3166_code]

    def _fill(self):
        data = {}
        zone_tab = open_resource('zone.tab')
        try: