# Copyright (c) 2024, Huawei Technologies Co., Ltd.

# 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 os

import inspect

from functools import wraps





def get_class_absolute_path(cls):

    module = inspect.getmodule(cls)

    if module is not None:

        module_path = module.__name__

        class_name = cls.__name__

        return f"{module_path}.{class_name}"

    else:

        return None





def is_static_func(function_obj):

    return isinstance(function_obj, staticmethod)





def singleton(cls):

    """

    :param cls: any class

    :return: singleton handle



    When using the singleton function, you need to manually specify collection_path='dataSet_path'. Otherwise, the

    singleton function is initialized by class name.

    if cls has 'collection_path' property, _instance map will build by class_name and 'collection_path', the

    default value of collection path is class absolute path.



    _instance = {cls.name: {collection_path: instance}}

    """

    _instance = {}



    @wraps(cls)  # 使用 wraps 装饰器

    def _singleton(*args, **kw):

        # 适配多进程异步调用场景，确保不同子进程的单例类互相隔离

        pid = os.getpid()

        if pid not in _instance:

            _instance[pid] = {}



        collection_path = kw.get("collection_path")

        if not collection_path:

            collection_path = get_class_absolute_path(cls)

        if cls in _instance[pid] and collection_path in _instance[pid][cls]:

            return _instance[pid][cls].get(collection_path)

        if cls not in _instance[pid]:

            _instance[pid][cls] = {collection_path: cls(*args, **kw)}

        else:

            _instance[pid][cls][collection_path] = cls(*args, **kw)

        return _instance[pid][cls].get(collection_path)



    def reset_all_instances():

        """

        用于ut使用，清空单例类，防止ut不同测试用例间相互干扰

        """

        _instance.clear()



    # 保留原始类的属性和方法

    _singleton.__name__ = cls.__name__

    _singleton.__module__ = cls.__module__

    _singleton.__doc__ = cls.__doc__



    # 拷贝原始类的类方法和静态方法

    _singleton.__dict__.update(cls.__dict__)

    for base_class in inspect.getmro(cls)[::-1]:

        # 获取类的所有成员

        members = inspect.getmembers(base_class)



        # 过滤出函数对象

        function_objs = [member[1]

                         for member in members

                         if inspect.isfunction(member[1]) or inspect.ismethod(member[1])

                         ]

        for function_obj in function_objs:

            if inspect.isfunction(function_obj) and not is_static_func(function_obj):

                continue

            setattr(_singleton, function_obj.__name__, function_obj)



    _singleton.reset_all_instances = reset_all_instances

    singleton.reset_all_instances = reset_all_instances



    return _singleton