# Copyright 2020 Huawei Technologies Co., Ltd
#
# 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.
# ============================================================================

"""Some utils."""
import hashlib
import logging
import os
import inspect
from functools import wraps
from dataclasses import dataclass


def cal_sha256(file_path):
    """
    Calculate sha256 value of input file.

    Args:
        file_path (str): file path to calculate.

    Returns:
        str, returns sha256 value of input file or empty str if cal failed.
    """
    buf_size = 64 * 1024  # once read 64kb
    sha256 = hashlib.sha256()
    file_real_path = os.path.realpath(file_path)
    if not os.path.isfile(file_real_path) or not os.access(file_real_path, os.R_OK):
        return ""
    _, extension = os.path.splitext(file_path)
    try:
        if extension == '.ptx':
            with open(file_real_path, 'r') as kf:
                while True:
                    data = kf.read(buf_size)
                    if not data:
                        break
                    sha256.update(data.encode("utf-8"))
        else:
            with open(file_real_path, 'rb') as kf:
                while True:
                    data = kf.read(buf_size)
                    if not data:
                        break
                    sha256.update(data)
    except IOError:
        logging.error("Open file %s failed.", file_path)
        return ""
    return sha256.hexdigest()


def cell_attr_register(fn=None, attrs=None):
    """
    Cell init attributes register.

    Registering the decorator of the built-in operator cell __init__
    function will add save all the parameters of __init__ as operator attributes.

    Args:
        fn (function): __init__ function of cell.
        attrs (list(string) | string): attr list.

    Returns:
        function, original function.
    """
    def wrap_cell(fn):
        @wraps(fn)
        def deco(self, *args, **kwargs):
            arguments = []
            if attrs is None:
                bound_args = inspect.signature(fn).bind(self, *args, **kwargs)
                arguments = bound_args.arguments
                del arguments['self']
                arguments = arguments.values()
            fn(self, *args, **kwargs)
            if attrs is not None:
                if isinstance(attrs, list):
                    for item in attrs:
                        if not isinstance(item, str):
                            raise ValueError(f"attr must be a string")
                        if hasattr(self, item):
                            arguments.append(getattr(self, item))
                elif isinstance(attrs, str):
                    if hasattr(self, attrs):
                        arguments = getattr(self, attrs)
                else:
                    raise ValueError(f"attrs must be list or string")
            self.cell_init_args = type(self).__name__ + str(arguments)
        return deco
    if fn is not None:
        return wrap_cell(fn)
    return wrap_cell


@dataclass
class Slice:
    """
    Slice class
    """
    start: int
    end: int
    step: int


@dataclass
class Ellipsis_:
    """
    Ellipsis class
    """