# Copyright (c) 2010-2012 OpenStack, LLC.
#
# 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.
"""Miscellaneous utility functions for use with Swift."""
import hashlib
import hmac
import json
import logging
import six
import time
import traceback

TRUE_VALUES = set(('true', '1', 'yes', 'on', 't', 'y'))
EMPTY_ETAG = 'd41d8cd98f00b204e9800998ecf8427e'


def config_true_value(value):
    """
    Returns True if the value is either True or a string in TRUE_VALUES.
    Returns False otherwise.
    This function comes from swift.common.utils.config_true_value()
    """
    return value is True or \
        (isinstance(value, six.string_types) and value.lower() in TRUE_VALUES)


def prt_bytes(bytes, human_flag):
    """
    convert a number > 1024 to printable format, either in 4 char -h format as
    with ls -lh or return as 12 char right justified string
    """

    if human_flag:
        suffix = ''
        mods = list('KMGTPEZY')
        temp = float(bytes)
        if temp > 0:
            while temp > 1023:
                try:
                    suffix = mods.pop(0)
                except IndexError:
                    break
                temp /= 1024.0
            if suffix != '':
                if temp >= 10:
                    bytes = '%3d%s' % (temp, suffix)
                else:
                    bytes = '%.1f%s' % (temp, suffix)
        if suffix == '':    # must be < 1024
            bytes = '%4s' % bytes
    else:
        bytes = '%12s' % bytes

    return bytes


def generate_temp_url(path, seconds, key, method, absolute=False):
    """Generates a temporary URL that gives unauthenticated access to the
    Swift object.

    :param path: The full path to the Swift object. Example:
    /v1/AUTH_account/c/o.
    :param seconds: The amount of time in seconds the temporary URL will
    be valid for.
    :param key: The secret temporary URL key set on the Swift cluster.
    To set a key, run 'swift post -m
    "Temp-URL-Key:b3968d0207b54ece87cccc06515a89d4"'
    :param method: A HTTP method, typically either GET or PUT, to allow for
    this temporary URL.
    :raises: ValueError if seconds is not a positive integer
    :raises: TypeError if seconds is not an integer
    :return: the path portion of a temporary URL
    """
    if seconds < 0:
        raise ValueError('seconds must be a positive integer')
    try:
        if not absolute:
            expiration = int(time.time() + seconds)
        else:
            expiration = int(seconds)
    except TypeError:
        raise TypeError('seconds must be an integer')