from .module import Module
from .utils import _pair, _quadruple, _ntuple
from .. import functional as F

from torch import Tensor
from ..common_types import _size_2_t, _size_4_t, _size_6_t
from typing import Sequence, Tuple


# TODO: grad_output size asserts in THNN

__all__ = ['CircularPad1d', 'CircularPad2d', 'CircularPad3d', 'ConstantPad1d', 'ConstantPad2d',
           'ConstantPad3d', 'ReflectionPad1d', 'ReflectionPad2d', 'ReflectionPad3d',
           'ReplicationPad1d', 'ReplicationPad2d', 'ReplicationPad3d', 'ZeroPad1d', 'ZeroPad2d', 'ZeroPad3d']


class _CircularPadNd(Module):
    __constants__ = ['padding']
    padding: Sequence[int]

    def _check_input_dim(self, input):
        raise NotImplementedError

    def forward(self, input: Tensor) -> Tensor:
        self._check_input_dim(input)
        return F.pad(input, self.padding, 'circular')

    def extra_repr(self) -> str:
        return f'{self.padding}'


class CircularPad1d(_CircularPadNd):
    r"""Pads the input tensor using circular padding of the input boundary.

    Tensor values at the beginning of the dimension are used to pad the end,
    and values at the end are used to pad the beginning. If negative padding is
    applied then the ends of the tensor get removed.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 2-`tuple`, uses
            (:math:`\text{padding\_left}`, :math:`\text{padding\_right}`)

    Shape:
        - Input: :math:`(C, W_{in})` or :math:`(N, C, W_{in})`.
        - Output: :math:`(C, W_{out})` or :math:`(N, C, W_{out})`, where

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> # xdoctest: +IGNORE_WANT("not sure why xdoctest is choking on this")
        >>> m = nn.CircularPad1d(2)
        >>> input = torch.arange(8, dtype=torch.float).reshape(1, 2, 4)
        >>> input
        tensor([[[0., 1., 2., 3.],
                 [4., 5., 6., 7.]]])
        >>> m(input)
        tensor([[[2., 3., 0., 1., 2., 3., 0., 1.],
                 [6., 7., 4., 5., 6., 7., 4., 5.]]])
        >>> # using different paddings for different sides
        >>> m = nn.CircularPad1d((3, 1))
        >>> m(input)
        tensor([[[1., 2., 3., 0., 1., 2., 3., 0.],
                 [5., 6., 7., 4., 5., 6., 7., 4.]]])

    """
    padding: Tuple[int, int]

    def __init__(self, padding: _size_2_t) -> None:
        super().__init__()
        self.padding = _pair(padding)

    def _check_input_dim(self, input):
        if input.dim() != 2 and input.dim() != 3:
            raise ValueError(
                f"expected 2D or 3D input (got {input.dim()}D input)"
            )


class CircularPad2d(_CircularPadNd):
    r"""Pads the input tensor using circular padding of the input boundary.

    Tensor values at the beginning of the dimension are used to pad the end,
    and values at the end are used to pad the beginning. If negative padding is
    applied then the ends of the tensor get removed.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 4-`tuple`, uses (:math:`\text{padding\_left}`,
            :math:`\text{padding\_right}`, :math:`\text{padding\_top}`, :math:`\text{padding\_bottom}`)

    Shape:
        - Input: :math:`(N, C, H_{in}, W_{in})` or :math:`(C, H_{in}, W_{in})`.
        - Output: :math:`(N, C, H_{out}, W_{out})` or :math:`(C, H_{out}, W_{out})`, where

          :math:`H_{out} = H_{in} + \text{padding\_top} + \text{padding\_bottom}`

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> m = nn.CircularPad2d(2)
        >>> input = torch.arange(9, dtype=torch.float).reshape(1, 1, 3, 3)
        >>> input
        tensor([[[[0., 1., 2.],
                  [3., 4., 5.],
                  [6., 7., 8.]]]])
        >>> m(input)
        tensor([[[[4., 5., 3., 4., 5., 3., 4.],
                  [7., 8., 6., 7., 8., 6., 7.],
                  [1., 2., 0., 1., 2., 0., 1.],
                  [4., 5., 3., 4., 5., 3., 4.],
                  [7., 8., 6., 7., 8., 6., 7.],
                  [1., 2., 0., 1., 2., 0., 1.],
                  [4., 5., 3., 4., 5., 3., 4.]]]])
        >>> # using different paddings for different sides
        >>> m = nn.CircularPad2d((1, 1, 2, 0))
        >>> m(input)
        tensor([[[[5., 3., 4., 5., 3.],
                  [8., 6., 7., 8., 6.],
                  [2., 0., 1., 2., 0.],
                  [5., 3., 4., 5., 3.],
                  [8., 6., 7., 8., 6.]]]])

    """
    padding: Tuple[int, int, int, int]

    def __init__(self, padding: _size_4_t) -> None:
        super().__init__()
        self.padding = _quadruple(padding)

    def _check_input_dim(self, input):
        if input.dim() != 3 and input.dim() != 4:
            raise ValueError(
                f"expected 3D or 4D input (got {input.dim()}D input)"
            )


class CircularPad3d(_CircularPadNd):
    r"""Pads the input tensor using circular padding of the input boundary.

    Tensor values at the beginning of the dimension are used to pad the end,
    and values at the end are used to pad the beginning. If negative padding is
    applied then the ends of the tensor get removed.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 6-`tuple`, uses
            (:math:`\text{padding\_left}`, :math:`\text{padding\_right}`,
            :math:`\text{padding\_top}`, :math:`\text{padding\_bottom}`,
            :math:`\text{padding\_front}`, :math:`\text{padding\_back}`)

    Shape:
        - Input: :math:`(N, C, D_{in}, H_{in}, W_{in})` or :math:`(C, D_{in}, H_{in}, W_{in})`.
        - Output: :math:`(N, C, D_{out}, H_{out}, W_{out})` or :math:`(C, D_{out}, H_{out}, W_{out})`,
          where

          :math:`D_{out} = D_{in} + \text{padding\_front} + \text{padding\_back}`

          :math:`H_{out} = H_{in} + \text{padding\_top} + \text{padding\_bottom}`

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> # xdoctest: +IGNORE_WANT("non-deterministic")
        >>> m = nn.CircularPad3d(3)
        >>> input = torch.randn(16, 3, 8, 320, 480)
        >>> output = m(input)
        >>> # using different paddings for different sides
        >>> m = nn.CircularPad3d((3, 3, 6, 6, 1, 1))
        >>> output = m(input)

    """
    padding: Tuple[int, int, int, int, int, int]

    def __init__(self, padding: _size_6_t) -> None:
        super().__init__()
        self.padding = _ntuple(6)(padding)

    def _check_input_dim(self, input):
        if input.dim() != 4 and input.dim() != 5:
            raise ValueError(
                f"expected 4D or 5D input (got {input.dim()}D input)"
            )


class _ConstantPadNd(Module):
    __constants__ = ['padding', 'value']
    value: float
    padding: Sequence[int]

    def __init__(self, value: float) -> None:
        super().__init__()
        self.value = value

    def forward(self, input: Tensor) -> Tensor:
        return F.pad(input, self.padding, 'constant', self.value)

    def extra_repr(self) -> str:
        return f'padding={self.padding}, value={self.value}'


class ConstantPad1d(_ConstantPadNd):
    r"""Pads the input tensor boundaries with a constant value.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in both boundaries. If a 2-`tuple`, uses
            (:math:`\text{padding\_left}`, :math:`\text{padding\_right}`)

    Shape:
        - Input: :math:`(C, W_{in})` or :math:`(N, C, W_{in})`.
        - Output: :math:`(C, W_{out})` or :math:`(N, C, W_{out})`, where

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> # xdoctest: +IGNORE_WANT("non-deterministic")
        >>> m = nn.ConstantPad1d(2, 3.5)
        >>> input = torch.randn(1, 2, 4)
        >>> input
        tensor([[[-1.0491, -0.7152, -0.0749,  0.8530],
                 [-1.3287,  1.8966,  0.1466, -0.2771]]])
        >>> m(input)
        tensor([[[ 3.5000,  3.5000, -1.0491, -0.7152, -0.0749,  0.8530,  3.5000,
                   3.5000],
                 [ 3.5000,  3.5000, -1.3287,  1.8966,  0.1466, -0.2771,  3.5000,
                   3.5000]]])
        >>> m = nn.ConstantPad1d(2, 3.5)
        >>> input = torch.randn(1, 2, 3)
        >>> input
        tensor([[[ 1.6616,  1.4523, -1.1255],
                 [-3.6372,  0.1182, -1.8652]]])
        >>> m(input)
        tensor([[[ 3.5000,  3.5000,  1.6616,  1.4523, -1.1255,  3.5000,  3.5000],
                 [ 3.5000,  3.5000, -3.6372,  0.1182, -1.8652,  3.5000,  3.5000]]])
        >>> # using different paddings for different sides
        >>> m = nn.ConstantPad1d((3, 1), 3.5)
        >>> m(input)
        tensor([[[ 3.5000,  3.5000,  3.5000,  1.6616,  1.4523, -1.1255,  3.5000],
                 [ 3.5000,  3.5000,  3.5000, -3.6372,  0.1182, -1.8652,  3.5000]]])

    """
    padding: Tuple[int, int]

    def __init__(self, padding: _size_2_t, value: float):
        super().__init__(value)
        self.padding = _pair(padding)


class ConstantPad2d(_ConstantPadNd):
    r"""Pads the input tensor boundaries with a constant value.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 4-`tuple`, uses (:math:`\text{padding\_left}`,
            :math:`\text{padding\_right}`, :math:`\text{padding\_top}`, :math:`\text{padding\_bottom}`)

    Shape:
        - Input: :math:`(N, C, H_{in}, W_{in})` or :math:`(C, H_{in}, W_{in})`.
        - Output: :math:`(N, C, H_{out}, W_{out})` or :math:`(C, H_{out}, W_{out})`, where

          :math:`H_{out} = H_{in} + \text{padding\_top} + \text{padding\_bottom}`

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> # xdoctest: +IGNORE_WANT("non-deterministic")
        >>> m = nn.ConstantPad2d(2, 3.5)
        >>> input = torch.randn(1, 2, 2)
        >>> input
        tensor([[[ 1.6585,  0.4320],
                 [-0.8701, -0.4649]]])
        >>> m(input)
        tensor([[[ 3.5000,  3.5000,  3.5000,  3.5000,  3.5000,  3.5000],
                 [ 3.5000,  3.5000,  3.5000,  3.5000,  3.5000,  3.5000],
                 [ 3.5000,  3.5000,  1.6585,  0.4320,  3.5000,  3.5000],
                 [ 3.5000,  3.5000, -0.8701, -0.4649,  3.5000,  3.5000],
                 [ 3.5000,  3.5000,  3.5000,  3.5000,  3.5000,  3.5000],
                 [ 3.5000,  3.5000,  3.5000,  3.5000,  3.5000,  3.5000]]])
        >>> # using different paddings for different sides
        >>> m = nn.ConstantPad2d((3, 0, 2, 1), 3.5)
        >>> m(input)
        tensor([[[ 3.5000,  3.5000,  3.5000,  3.5000,  3.5000],
                 [ 3.5000,  3.5000,  3.5000,  3.5000,  3.5000],
                 [ 3.5000,  3.5000,  3.5000,  1.6585,  0.4320],
                 [ 3.5000,  3.5000,  3.5000, -0.8701, -0.4649],
                 [ 3.5000,  3.5000,  3.5000,  3.5000,  3.5000]]])

    """
    __constants__ = ['padding', 'value']
    padding: Tuple[int, int, int, int]

    def __init__(self, padding: _size_4_t, value: float) -> None:
        super().__init__(value)
        self.padding = _quadruple(padding)


class ConstantPad3d(_ConstantPadNd):
    r"""Pads the input tensor boundaries with a constant value.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 6-`tuple`, uses
            (:math:`\text{padding\_left}`, :math:`\text{padding\_right}`,
            :math:`\text{padding\_top}`, :math:`\text{padding\_bottom}`,
            :math:`\text{padding\_front}`, :math:`\text{padding\_back}`)

    Shape:
        - Input: :math:`(N, C, D_{in}, H_{in}, W_{in})` or :math:`(C, D_{in}, H_{in}, W_{in})`.
        - Output: :math:`(N, C, D_{out}, H_{out}, W_{out})` or
          :math:`(C, D_{out}, H_{out}, W_{out})`, where

          :math:`D_{out} = D_{in} + \text{padding\_front} + \text{padding\_back}`

          :math:`H_{out} = H_{in} + \text{padding\_top} + \text{padding\_bottom}`

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> m = nn.ConstantPad3d(3, 3.5)
        >>> input = torch.randn(16, 3, 10, 20, 30)
        >>> output = m(input)
        >>> # using different paddings for different sides
        >>> m = nn.ConstantPad3d((3, 3, 6, 6, 0, 1), 3.5)
        >>> output = m(input)

    """
    padding: Tuple[int, int, int, int, int, int]

    def __init__(self, padding: _size_6_t, value: float) -> None:
        super().__init__(value)
        self.padding = _ntuple(6)(padding)


class _ReflectionPadNd(Module):
    __constants__ = ['padding']
    padding: Sequence[int]

    def forward(self, input: Tensor) -> Tensor:
        return F.pad(input, self.padding, 'reflect')

    def extra_repr(self) -> str:
        return f'{self.padding}'


class ReflectionPad1d(_ReflectionPadNd):
    r"""Pads the input tensor using the reflection of the input boundary.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 2-`tuple`, uses
            (:math:`\text{padding\_left}`, :math:`\text{padding\_right}`)

    Shape:
        - Input: :math:`(C, W_{in})` or :math:`(N, C, W_{in})`.
        - Output: :math:`(C, W_{out})` or :math:`(N, C, W_{out})`, where

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> m = nn.ReflectionPad1d(2)
        >>> # xdoctest: +IGNORE_WANT("other tests seem to modify printing styles")
        >>> input = torch.arange(8, dtype=torch.float).reshape(1, 2, 4)
        >>> input
        tensor([[[0., 1., 2., 3.],
                 [4., 5., 6., 7.]]])
        >>> m(input)
        tensor([[[2., 1., 0., 1., 2., 3., 2., 1.],
                 [6., 5., 4., 5., 6., 7., 6., 5.]]])
        >>> # using different paddings for different sides
        >>> m = nn.ReflectionPad1d((3, 1))
        >>> m(input)
        tensor([[[3., 2., 1., 0., 1., 2., 3., 2.],
                 [7., 6., 5., 4., 5., 6., 7., 6.]]])

    """
    padding: Tuple[int, int]

    def __init__(self, padding: _size_2_t) -> None:
        super().__init__()
        self.padding = _pair(padding)


class ReflectionPad2d(_ReflectionPadNd):
    r"""Pads the input tensor using the reflection of the input boundary.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 4-`tuple`, uses (:math:`\text{padding\_left}`,
            :math:`\text{padding\_right}`, :math:`\text{padding\_top}`, :math:`\text{padding\_bottom}`)

    Shape:
        - Input: :math:`(N, C, H_{in}, W_{in})` or :math:`(C, H_{in}, W_{in})`.
        - Output: :math:`(N, C, H_{out}, W_{out})` or :math:`(C, H_{out}, W_{out})` where

          :math:`H_{out} = H_{in} + \text{padding\_top} + \text{padding\_bottom}`

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> # xdoctest: +IGNORE_WANT("not sure why xdoctest is choking on this")
        >>> m = nn.ReflectionPad2d(2)
        >>> input = torch.arange(9, dtype=torch.float).reshape(1, 1, 3, 3)
        >>> input
        tensor([[[[0., 1., 2.],
                  [3., 4., 5.],
                  [6., 7., 8.]]]])
        >>> m(input)
        tensor([[[[8., 7., 6., 7., 8., 7., 6.],
                  [5., 4., 3., 4., 5., 4., 3.],
                  [2., 1., 0., 1., 2., 1., 0.],
                  [5., 4., 3., 4., 5., 4., 3.],
                  [8., 7., 6., 7., 8., 7., 6.],
                  [5., 4., 3., 4., 5., 4., 3.],
                  [2., 1., 0., 1., 2., 1., 0.]]]])
        >>> # using different paddings for different sides
        >>> m = nn.ReflectionPad2d((1, 1, 2, 0))
        >>> m(input)
        tensor([[[[7., 6., 7., 8., 7.],
                  [4., 3., 4., 5., 4.],
                  [1., 0., 1., 2., 1.],
                  [4., 3., 4., 5., 4.],
                  [7., 6., 7., 8., 7.]]]])

    """
    padding: Tuple[int, int, int, int]

    def __init__(self, padding: _size_4_t) -> None:
        super().__init__()
        self.padding = _quadruple(padding)


class ReflectionPad3d(_ReflectionPadNd):
    r"""Pads the input tensor using the reflection of the input boundary.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 6-`tuple`, uses
            (:math:`\text{padding\_left}`, :math:`\text{padding\_right}`,
            :math:`\text{padding\_top}`, :math:`\text{padding\_bottom}`,
            :math:`\text{padding\_front}`, :math:`\text{padding\_back}`)

    Shape:
        - Input: :math:`(N, C, D_{in}, H_{in}, W_{in})` or :math:`(C, D_{in}, H_{in}, W_{in})`.
        - Output: :math:`(N, C, D_{out}, H_{out}, W_{out})` or :math:`(C, D_{out}, H_{out}, W_{out})`,
          where

          :math:`D_{out} = D_{in} + \text{padding\_front} + \text{padding\_back}`

          :math:`H_{out} = H_{in} + \text{padding\_top} + \text{padding\_bottom}`

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> # xdoctest: +IGNORE_WANT("not sure why xdoctest is choking on this")
        >>> m = nn.ReflectionPad3d(1)
        >>> input = torch.arange(8, dtype=torch.float).reshape(1, 1, 2, 2, 2)
        >>> m(input)
        tensor([[[[[7., 6., 7., 6.],
                   [5., 4., 5., 4.],
                   [7., 6., 7., 6.],
                   [5., 4., 5., 4.]],
                  [[3., 2., 3., 2.],
                   [1., 0., 1., 0.],
                   [3., 2., 3., 2.],
                   [1., 0., 1., 0.]],
                  [[7., 6., 7., 6.],
                   [5., 4., 5., 4.],
                   [7., 6., 7., 6.],
                   [5., 4., 5., 4.]],
                  [[3., 2., 3., 2.],
                   [1., 0., 1., 0.],
                   [3., 2., 3., 2.],
                   [1., 0., 1., 0.]]]]])
    """
    padding: Tuple[int, int, int, int, int, int]

    def __init__(self, padding: _size_6_t) -> None:
        super().__init__()
        self.padding = _ntuple(6)(padding)


class _ReplicationPadNd(Module):
    __constants__ = ['padding']
    padding: Sequence[int]

    def forward(self, input: Tensor) -> Tensor:
        return F.pad(input, self.padding, 'replicate')

    def extra_repr(self) -> str:
        return f'{self.padding}'


class ReplicationPad1d(_ReplicationPadNd):
    r"""Pads the input tensor using replication of the input boundary.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 2-`tuple`, uses
            (:math:`\text{padding\_left}`, :math:`\text{padding\_right}`)

    Shape:
        - Input: :math:`(C, W_{in})` or :math:`(N, C, W_{in})`.
        - Output: :math:`(C, W_{out})` or :math:`(N, C, W_{out})`, where

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> # xdoctest: +IGNORE_WANT("not sure why xdoctest is choking on this")
        >>> m = nn.ReplicationPad1d(2)
        >>> input = torch.arange(8, dtype=torch.float).reshape(1, 2, 4)
        >>> input
        tensor([[[0., 1., 2., 3.],
                 [4., 5., 6., 7.]]])
        >>> m(input)
        tensor([[[0., 0., 0., 1., 2., 3., 3., 3.],
                 [4., 4., 4., 5., 6., 7., 7., 7.]]])
        >>> # using different paddings for different sides
        >>> m = nn.ReplicationPad1d((3, 1))
        >>> m(input)
        tensor([[[0., 0., 0., 0., 1., 2., 3., 3.],
                 [4., 4., 4., 4., 5., 6., 7., 7.]]])

    """
    padding: Tuple[int, int]

    def __init__(self, padding: _size_2_t) -> None:
        super().__init__()
        self.padding = _pair(padding)


class ReplicationPad2d(_ReplicationPadNd):
    r"""Pads the input tensor using replication of the input boundary.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 4-`tuple`, uses (:math:`\text{padding\_left}`,
            :math:`\text{padding\_right}`, :math:`\text{padding\_top}`, :math:`\text{padding\_bottom}`)

    Shape:
        - Input: :math:`(N, C, H_{in}, W_{in})` or :math:`(C, H_{in}, W_{in})`.
        - Output: :math:`(N, C, H_{out}, W_{out})` or :math:`(C, H_{out}, W_{out})`, where

          :math:`H_{out} = H_{in} + \text{padding\_top} + \text{padding\_bottom}`

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> m = nn.ReplicationPad2d(2)
        >>> # xdoctest: +IGNORE_WANT("non-deterministic")
        >>> input = torch.arange(9, dtype=torch.float).reshape(1, 1, 3, 3)
        >>> input
        tensor([[[[0., 1., 2.],
                  [3., 4., 5.],
                  [6., 7., 8.]]]])
        >>> m(input)
        tensor([[[[0., 0., 0., 1., 2., 2., 2.],
                  [0., 0., 0., 1., 2., 2., 2.],
                  [0., 0., 0., 1., 2., 2., 2.],
                  [3., 3., 3., 4., 5., 5., 5.],
                  [6., 6., 6., 7., 8., 8., 8.],
                  [6., 6., 6., 7., 8., 8., 8.],
                  [6., 6., 6., 7., 8., 8., 8.]]]])
        >>> # using different paddings for different sides
        >>> m = nn.ReplicationPad2d((1, 1, 2, 0))
        >>> m(input)
        tensor([[[[0., 0., 1., 2., 2.],
                  [0., 0., 1., 2., 2.],
                  [0., 0., 1., 2., 2.],
                  [3., 3., 4., 5., 5.],
                  [6., 6., 7., 8., 8.]]]])

    """
    padding: Tuple[int, int, int, int]

    def __init__(self, padding: _size_4_t) -> None:
        super().__init__()
        self.padding = _quadruple(padding)


class ReplicationPad3d(_ReplicationPadNd):
    r"""Pads the input tensor using replication of the input boundary.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 6-`tuple`, uses
            (:math:`\text{padding\_left}`, :math:`\text{padding\_right}`,
            :math:`\text{padding\_top}`, :math:`\text{padding\_bottom}`,
            :math:`\text{padding\_front}`, :math:`\text{padding\_back}`)

    Shape:
        - Input: :math:`(N, C, D_{in}, H_{in}, W_{in})` or :math:`(C, D_{in}, H_{in}, W_{in})`.
        - Output: :math:`(N, C, D_{out}, H_{out}, W_{out})` or :math:`(C, D_{out}, H_{out}, W_{out})`,
          where

          :math:`D_{out} = D_{in} + \text{padding\_front} + \text{padding\_back}`

          :math:`H_{out} = H_{in} + \text{padding\_top} + \text{padding\_bottom}`

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> # xdoctest: +IGNORE_WANT("non-deterministic")
        >>> m = nn.ReplicationPad3d(3)
        >>> input = torch.randn(16, 3, 8, 320, 480)
        >>> output = m(input)
        >>> # using different paddings for different sides
        >>> m = nn.ReplicationPad3d((3, 3, 6, 6, 1, 1))
        >>> output = m(input)

    """
    padding: Tuple[int, int, int, int, int, int]

    def __init__(self, padding: _size_6_t) -> None:
        super().__init__()
        self.padding = _ntuple(6)(padding)


class ZeroPad1d(ConstantPad1d):
    r"""Pads the input tensor boundaries with zero.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in both boundaries. If a 2-`tuple`, uses
            (:math:`\text{padding\_left}`, :math:`\text{padding\_right}`)

    Shape:
        - Input: :math:`(C, W_{in})` or :math:`(N, C, W_{in})`.
        - Output: :math:`(C, W_{out})` or :math:`(N, C, W_{out})`, where

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> # xdoctest: +IGNORE_WANT("non-deterministic")
        >>> m = nn.ZeroPad1d(2)
        >>> input = torch.randn(1, 2, 4)
        >>> input
        tensor([[[-1.0491, -0.7152, -0.0749,  0.8530],
                 [-1.3287,  1.8966,  0.1466, -0.2771]]])
        >>> m(input)
        tensor([[[ 0.0000,  0.0000, -1.0491, -0.7152, -0.0749,  0.8530,  0.0000,
                   0.0000],
                 [ 0.0000,  0.0000, -1.3287,  1.8966,  0.1466, -0.2771,  0.0000,
                   0.0000]]])
        >>> m = nn.ZeroPad1d(2)
        >>> input = torch.randn(1, 2, 3)
        >>> input
        tensor([[[ 1.6616,  1.4523, -1.1255],
                 [-3.6372,  0.1182, -1.8652]]])
        >>> m(input)
        tensor([[[ 0.0000,  0.0000,  1.6616,  1.4523, -1.1255,  0.0000,  0.0000],
                 [ 0.0000,  0.0000, -3.6372,  0.1182, -1.8652,  0.0000,  0.0000]]])
        >>> # using different paddings for different sides
        >>> m = nn.ZeroPad1d((3, 1))
        >>> m(input)
        tensor([[[ 0.0000,  0.0000,  0.0000,  1.6616,  1.4523, -1.1255,  0.0000],
                 [ 0.0000,  0.0000,  0.0000, -3.6372,  0.1182, -1.8652,  0.0000]]])

    """
    padding: Tuple[int, int]

    def __init__(self, padding: _size_2_t) -> None:
        super().__init__(padding, 0.)

    def extra_repr(self) -> str:
        return f'{self.padding}'

class ZeroPad2d(ConstantPad2d):
    r"""Pads the input tensor boundaries with zero.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 4-`tuple`, uses (:math:`\text{padding\_left}`,
            :math:`\text{padding\_right}`, :math:`\text{padding\_top}`, :math:`\text{padding\_bottom}`)

    Shape:
        - Input: :math:`(N, C, H_{in}, W_{in})` or :math:`(C, H_{in}, W_{in})`.
        - Output: :math:`(N, C, H_{out}, W_{out})` or :math:`(C, H_{out}, W_{out})`, where

          :math:`H_{out} = H_{in} + \text{padding\_top} + \text{padding\_bottom}`

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> # xdoctest: +IGNORE_WANT("non-deterministic")
        >>> m = nn.ZeroPad2d(2)
        >>> input = torch.randn(1, 1, 3, 3)
        >>> input
        tensor([[[[-0.1678, -0.4418,  1.9466],
                  [ 0.9604, -0.4219, -0.5241],
                  [-0.9162, -0.5436, -0.6446]]]])
        >>> m(input)
        tensor([[[[ 0.0000,  0.0000,  0.0000,  0.0000,  0.0000,  0.0000,  0.0000],
                  [ 0.0000,  0.0000,  0.0000,  0.0000,  0.0000,  0.0000,  0.0000],
                  [ 0.0000,  0.0000, -0.1678, -0.4418,  1.9466,  0.0000,  0.0000],
                  [ 0.0000,  0.0000,  0.9604, -0.4219, -0.5241,  0.0000,  0.0000],
                  [ 0.0000,  0.0000, -0.9162, -0.5436, -0.6446,  0.0000,  0.0000],
                  [ 0.0000,  0.0000,  0.0000,  0.0000,  0.0000,  0.0000,  0.0000],
                  [ 0.0000,  0.0000,  0.0000,  0.0000,  0.0000,  0.0000,  0.0000]]]])
        >>> # using different paddings for different sides
        >>> m = nn.ZeroPad2d((1, 1, 2, 0))
        >>> m(input)
        tensor([[[[ 0.0000,  0.0000,  0.0000,  0.0000,  0.0000],
                  [ 0.0000,  0.0000,  0.0000,  0.0000,  0.0000],
                  [ 0.0000, -0.1678, -0.4418,  1.9466,  0.0000],
                  [ 0.0000,  0.9604, -0.4219, -0.5241,  0.0000],
                  [ 0.0000, -0.9162, -0.5436, -0.6446,  0.0000]]]])

    """
    padding: Tuple[int, int, int, int]

    def __init__(self, padding: _size_4_t) -> None:
        super().__init__(padding, 0.)

    def extra_repr(self) -> str:
        return f'{self.padding}'

class ZeroPad3d(ConstantPad3d):
    r"""Pads the input tensor boundaries with zero.

    For `N`-dimensional padding, use :func:`torch.nn.functional.pad()`.

    Args:
        padding (int, tuple): the size of the padding. If is `int`, uses the same
            padding in all boundaries. If a 6-`tuple`, uses
            (:math:`\text{padding\_left}`, :math:`\text{padding\_right}`,
            :math:`\text{padding\_top}`, :math:`\text{padding\_bottom}`,
            :math:`\text{padding\_front}`, :math:`\text{padding\_back}`)

    Shape:
        - Input: :math:`(N, C, D_{in}, H_{in}, W_{in})` or :math:`(C, D_{in}, H_{in}, W_{in})`.
        - Output: :math:`(N, C, D_{out}, H_{out}, W_{out})` or
          :math:`(C, D_{out}, H_{out}, W_{out})`, where

          :math:`D_{out} = D_{in} + \text{padding\_front} + \text{padding\_back}`

          :math:`H_{out} = H_{in} + \text{padding\_top} + \text{padding\_bottom}`

          :math:`W_{out} = W_{in} + \text{padding\_left} + \text{padding\_right}`

    Examples::

        >>> m = nn.ZeroPad3d(3)
        >>> input = torch.randn(16, 3, 10, 20, 30)
        >>> output = m(input)
        >>> # using different paddings for different sides
        >>> m = nn.ZeroPad3d((3, 3, 6, 6, 0, 1))
        >>> output = m(input)

    """

    padding: Tuple[int, int, int, int, int, int]

    def __init__(self, padding: _size_6_t) -> None:
        super().__init__(padding, 0.)

    def extra_repr(self) -> str:
        return f'{self.padding}'
