# -*- coding: utf-8 -*-

# MinIO Python Library for Amazon S3 Compatible Cloud Storage, (C)

# 2020 MinIO, Inc.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

"""Time formatter for S3 APIs."""

from __future__ import absolute_import

import locale

from contextlib import contextmanager

from datetime import datetime, timezone

from . import __LOCALE_LOCK__

_HTTP_HEADER_FORMAT = "%a, %d %b %Y %H:%M:%S GMT"

@contextmanager

def _set_locale(name):

"""Thread-safe wrapper to locale.setlocale()."""

with __LOCALE_LOCK__:

saved = locale.setlocale(locale.LC_ALL)

try:

yield locale.setlocale(locale.LC_ALL, name)

finally:

locale.setlocale(locale.LC_ALL, saved)

def _to_utc(value):

"""Convert to UTC time if value is not naive."""

return (

value.astimezone(timezone.utc).replace(tzinfo=None)

if value.tzinfo else value

)

def from_iso8601utc(value):

"""Parse UTC ISO-8601 formatted string to datetime."""

if value is None:

return None

try:

time = datetime.strptime(value, "%Y-%m-%dT%H:%M:%S.%fZ")

except ValueError:

time = datetime.strptime(value, "%Y-%m-%dT%H:%M:%SZ")

return time.replace(tzinfo=timezone.utc)

def to_iso8601utc(value):

"""Format datetime into UTC ISO-8601 formatted string."""

if value is None:

return None

value = _to_utc(value)

return (

value.strftime("%Y-%m-%dT%H:%M:%S.") + value.strftime("%f")[:3] + "Z"

)

def from_http_header(value):

"""Parse HTTP header date formatted string to datetime."""

with _set_locale("C"):

return datetime.strptime(

value, _HTTP_HEADER_FORMAT,

).replace(tzinfo=timezone.utc)

def to_http_header(value):

"""Format datatime into HTTP header date formatted string."""

with _set_locale("C"):

return _to_utc(value).strftime(_HTTP_HEADER_FORMAT)

def to_amz_date(value):

"""Format datetime into AMZ date formatted string."""

return _to_utc(value).strftime("%Y%m%dT%H%M%SZ")

def utcnow():

"""Timezone-aware wrapper to datetime.utcnow()."""

return datetime.utcnow().replace(tzinfo=timezone.utc)

def to_signer_date(value):

"""Format datetime into SignatureV4 date formatted string."""

return _to_utc(value).strftime("%Y%m%d")