"""
Types shared across multiple submodules
"""
from typing import Sequence, Callable, MutableSequence
import numpy            # type: ignore


# Field types
# TODO: figure out a better way to set the docstrings without creating actual subclasses?
#   Probably not a big issue since they're only used for type hinting
class fdfield_t(numpy.ndarray):
    """
    Vector field with shape (3, X, Y, Z) (e.g. `[E_x, E_y, E_z]`)

    This is actually is just an unaltered `numpy.ndarray`
    """
    pass

class vfdfield_t(numpy.ndarray):
    """
    Linearized vector field (single vector of length 3*X*Y*Z)

    This is actually just an unaltered `numpy.ndarray`
    """
    pass


dx_lists_t = Sequence[Sequence[numpy.ndarray]]
'''
 'dxes' datastructure which contains grid cell width information in the following format:

     [[[dx_e[0], dx_e[1], ...], [dy_e[0], ...], [dz_e[0], ...]],
      [[dx_h[0], dx_h[1], ...], [dy_h[0], ...], [dz_h[0], ...]]]

   where `dx_e[0]` is the x-width of the `x=0` cells, as used when calculating dE/dx,
   and `dy_h[0]` is the y-width of the `y=0` cells, as used when calculating dH/dy, etc.
'''

dx_lists_mut = MutableSequence[MutableSequence[numpy.ndarray]]
'''
 Mutable version of `dx_lists_t`
'''


fdfield_updater_t = Callable[..., fdfield_t]
'''
 Convenience type for functions which take and return an fdfield_t
'''