# Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
#
# 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.

import six
import math

__all__ = []

int_type = int
long_type = int


# str and bytes related functions
def to_text(obj, encoding='utf-8', inplace=False):
 """
 All string in PaddlePaddle should be represented as a literal string.

 This function will convert object to a literal string without any encoding.
 Especially, if the object type is a list or set container, we will iterate
 all items in the object and convert them to literal string.

 In Python3:
 Decode the bytes type object to str type with specific encoding

 In Python2:
 Decode the str type object to unicode type with specific encoding

 Args:
 obj(unicode|str|bytes|list|set) : The object to be decoded.
 encoding(str) : The encoding format to decode a string
 inplace(bool) : If we change the original object or we create a new one

 Returns:
 Decoded result of obj

 Examples:

 .. code-block:: python

 import paddle

 data = "paddlepaddle"
 data = paddle.compat.to_text(data)
 # paddlepaddle

 """
 if obj is None:
 return obj

 if isinstance(obj, list):
 if inplace:
 for i in six.moves.xrange(len(obj)):
 obj[i] = _to_text(obj[i], encoding)
 return obj
 else:
 return [_to_text(item, encoding) for item in obj]
 elif isinstance(obj, set):
 if inplace:
 for item in obj:
 obj.remove(item)
 obj.add(_to_text(item, encoding))
 return obj
 else:
 return set([_to_text(item, encoding) for item in obj])
 elif isinstance(obj, dict):
 if inplace:
 new_obj = {}
 for key, value in six.iteritems(obj):
 new_obj[_to_text(key, encoding)] = _to_text(value, encoding)
 obj.update(new_obj)
 return obj
 else:
 new_obj = {}
 for key, value in six.iteritems(obj):
 new_obj[_to_text(key, encoding)] = _to_text(value, encoding)
 return new_obj
 else:
 return _to_text(obj, encoding)


def _to_text(obj, encoding):
 """
 In Python3:
 Decode the bytes type object to str type with specific encoding

 In Python2:
 Decode the str type object to unicode type with specific encoding,
 or we just return the unicode string of object

 Args:
 obj(unicode|str|bytes) : The object to be decoded.
 encoding(str) : The encoding format

 Returns:
 decoded result of obj
 """
 if obj is None:
 return obj

 if isinstance(obj, six.binary_type):
 return obj.decode(encoding)
 elif isinstance(obj, six.text_type):
 return obj
 elif isinstance(obj, (bool, float)):
 return obj
 else:
 return six.u(obj)


def to_bytes(obj, encoding='utf-8', inplace=False):
 """
 All string in PaddlePaddle should be represented as a literal string.

 This function will convert object to a bytes with specific encoding.
 Especially, if the object type is a list or set container, we will iterate
 all items in the object and convert them to bytes.

 In Python3:
 Encode the str type object to bytes type with specific encoding

 In Python2:
 Encode the unicode type object to str type with specific encoding,
 or we just return the 8-bit string of object

 Args:
 obj(unicode|str|bytes|list|set) : The object to be encoded.
 encoding(str) : The encoding format to encode a string
 inplace(bool) : If we change the original object or we create a new one

 Returns:
 Decoded result of obj

 Examples:

 .. code-block:: python

 import paddle

 data = "paddlepaddle"
 data = paddle.compat.to_bytes(data)
 # b'paddlepaddle'

 """
 if obj is None:
 return obj

 if isinstance(obj, list):
 if inplace:
 for i in six.moves.xrange(len(obj)):
 obj[i] = _to_bytes(obj[i], encoding)
 return obj
 else:
 return [_to_bytes(item, encoding) for item in obj]
 elif isinstance(obj, set):
 if inplace:
 for item in obj:
 obj.remove(item)
 obj.add(_to_bytes(item, encoding))
 return obj
 else:
 return set([_to_bytes(item, encoding) for item in obj])
 else:
 return _to_bytes(obj, encoding)


def _to_bytes(obj, encoding):
 """
 In Python3:
 Encode the str type object to bytes type with specific encoding

 In Python2:
 Encode the unicode type object to str type with specific encoding,
 or we just return the 8-bit string of object

 Args:
 obj(unicode|str|bytes) : The object to be encoded.
 encoding(str) : The encoding format

 Returns:
 encoded result of obj
 """
 if obj is None:
 return obj

 assert encoding is not None
 if isinstance(obj, six.text_type):
 return obj.encode(encoding)
 elif isinstance(obj, six.binary_type):
 return obj
 else:
 return six.b(obj)


# math related functions
def round(x, d=0):
 """
 Compatible round which act the same behaviour in Python3.

 Args:
 x(float) : The number to round halfway.

 Returns:
 round result of x
 """
 if six.PY3:
 # The official walkaround of round in Python3 is incorrect
 # we implement according this answer: https://www.techforgeek.info/round_python.html
 if x > 0.0:
 p = 10**d
 return float(math.floor((x * p) + math.copysign(0.5, x))) / p
 elif x < 0.0:
 p = 10**d
 return float(math.ceil((x * p) + math.copysign(0.5, x))) / p
 else:
 return math.copysign(0.0, x)
 else:
 import __builtin__
 return __builtin__.round(x, d)


def floor_division(x, y):
 """
 Compatible division which act the same behaviour in Python3 and Python2,
 whose result will be a int value of floor(x / y) in Python3 and value of
 (x / y) in Python2.

 Args:
 x(int|float) : The number to divide.
 y(int|float) : The number to be divided

 Returns:
 division result of x // y
 """
 return x // y


# exception related functions
def get_exception_message(exc):
 """
 Get the error message of a specific exception

 Args:
 exec(Exception) : The exception to get error message.

 Returns:
 the error message of exec
 """
 assert exc is not None

 return str(exc)