from ._utils import set_module as _set_module

__all__ = ["ComplexWarning", "TooHardError", "AxisError"]


@_set_module('numpy')
class ComplexWarning(RuntimeWarning):
    """
    The warning raised when casting a complex dtype to a real dtype.

    As implemented, casting a complex number to a real discards its imaginary
    part, but this behavior may not be what the user actually wants.

    """
    pass



# Exception used in shares_memory()
@_set_module('numpy')
class TooHardError(RuntimeError):
    """max_work was exceeded.

    This is raised whenever the maximum number of candidate solutions
    to consider specified by the ``max_work`` parameter is exceeded.
    Assigning a finite number to max_work may have caused the operation
    to fail.

    """

    pass


@_set_module('numpy')
class AxisError(ValueError, IndexError):
    """Axis supplied was invalid.

    This is raised whenever an ``axis`` parameter is specified that is larger
    than the number of array dimensions.
    For compatibility with code written against older numpy versions, which
    raised a mixture of `ValueError` and `IndexError` for this situation, this
    exception subclasses both to ensure that ``except ValueError`` and
    ``except IndexError`` statements continue to catch `AxisError`.

    .. versionadded:: 1.13

    Parameters
    ----------
    axis : int or str
        The out of bounds axis or a custom exception message.
        If an axis is provided, then `ndim` should be specified as well.
    ndim : int, optional
        The number of array dimensions.
    msg_prefix : str, optional
        A prefix for the exception message.

    Attributes
    ----------
    axis : int, optional
        The out of bounds axis or ``None`` if a custom exception
        message was provided. This should be the axis as passed by
        the user, before any normalization to resolve negative indices.

        .. versionadded:: 1.22
    ndim : int, optional
        The number of array dimensions or ``None`` if a custom exception
        message was provided.

        .. versionadded:: 1.22


    Examples
    --------
    >>> array_1d = np.arange(10)
    >>> np.cumsum(array_1d, axis=1)
    Traceback (most recent call last):
      ...
    numpy.AxisError: axis 1 is out of bounds for array of dimension 1

    Negative axes are preserved:

    >>> np.cumsum(array_1d, axis=-2)
    Traceback (most recent call last):
      ...
    numpy.AxisError: axis -2 is out of bounds for array of dimension 1

    The class constructor generally takes the axis and arrays'
    dimensionality as arguments:

    >>> print(np.AxisError(2, 1, msg_prefix='error'))
    error: axis 2 is out of bounds for array of dimension 1

    Alternatively, a custom exception message can be passed:

    >>> print(np.AxisError('Custom error message'))
    Custom error message

    """

    __slots__ = ("axis", "ndim", "_msg")

    def __init__(self, axis, ndim=None, msg_prefix=None):
        if ndim is msg_prefix is None:
            # single-argument form: directly set the error message
            self._msg = axis
            self.axis = None
            self.ndim = None
        else:
            self._msg = msg_prefix
            self.axis = axis
            self.ndim = ndim

    def __str__(self):
        axis = self.axis
        ndim = self.ndim

        if axis is ndim is None:
            return self._msg
        else:
            msg = f"axis {axis} is out of bounds for array of dimension {ndim}"
            if self._msg is not None:
                msg = f"{self._msg}: {msg}"
            return msg