# Copyright 2025 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.
# ============================================================================
"""Activations."""
__all__ = ["get_act_func"]

import inspect

from mindspore import nn, mint


class SiLU(nn.Cell):
    r"""
    A self-defined SwiGlu.

    Inputs:
        - **x** (Tensor) - Tensor of shape :math:`(B, S, H)`.

    Outputs:
        - **output** (Tensor) - Output tensor of shape :math:`(B, S, H)`.

    Supported Platforms:
        ``Ascend``
    """

    def __init__(self):
        super().__init__()
        self.silu = mint.nn.SiLU()

    def construct(self, x):
        output = self.silu(x)
        return output


ACTIVATION_MAP = {
    "silu": SiLU
}


def get_act_func(activation_type, *args, **kwargs):
    r"""
    Get activation function by name and parameters.

    Args:
        activation_type (str): The name of the activation function.
        *args: Variable length argument list for the activation function.
        **kwargs: Arbitrary keyword arguments for the activation function.

    Returns:
        callable, the activation function.
    """
    if activation_type.lower() not in ACTIVATION_MAP:
        raise NotImplementedError(
            f"Invalid activation function: {activation_type}.\
                Supported activation functions are: {ACTIVATION_MAP.keys()}"
        )
    activation_func = ACTIVATION_MAP[activation_type.lower()]
    if inspect.isclass(activation_func):
        return activation_func(*args, **kwargs)
    return activation_func
