from typing import Optional

from flet.controls.base_control import control
from flet.controls.control import Control
from flet.controls.types import ColorValue, Number

__all__ = ["VerticalDivider"]


@control("VerticalDivider")
class VerticalDivider(Control):
    """
    A thin vertical line, with padding on either side.

    In the material design language, this represents a divider.
    """

    width: Optional[Number] = None
    """
    The divider's width. The divider itself is always drawn as a vertical line
    that is centered within the width specified by this value.
    
    If `None`, [`DividerTheme.space`][flet.DividerTheme.space] is used.
    If that's is also `None`, defaults to `16.0`.
    """

    thickness: Optional[Number] = None
    """
    The thickness of this divider.

    Note:
        A divider with a thickness of `0.0` is always drawn as a line with a width of
        exactly one device pixel.

    If `None`, [`DividerTheme.thickness`][flet.DividerTheme.thickness] is used.
    If that's is also `None`, defaults to `0.0`.
    """

    color: Optional[ColorValue] = None
    """
    The color to use when painting the
    line.
    
    If `None`, [`DividerTheme.color`][flet.DividerTheme.color] is used.
    If that's is also `None`, defaults to [`Theme.divider_color`][flet.Theme.divider_color].
    """

    leading_indent: Optional[Number] = None
    """
    The amount of empty space to the leading edge of the divider.
    
    If `None`, [`DividerTheme.leading_indent`][flet.DividerTheme.leading_indent] is used.
    If that's is also `None`, defaults to `0.0`.
    """

    trailing_indent: Optional[Number] = None
    """
    The amount of empty space to the trailing edge of the divider.
    
    If `None`, [`DividerTheme.trailing_indent`][flet.DividerTheme.trailing_indent] is used.
    If that's is also `None`, defaults to `0.0`.
    """

    def before_update(self):
        super().before_update()
        assert self.width is None or self.width >= 0, (
            "width must be greater than or equal to 0"
        )
        assert self.thickness is None or self.thickness >= 0, (
            "thickness must be greater than or equal to 0"
        )
        assert self.leading_indent is None or self.leading_indent >= 0, (
            "leading_indent must be greater than or equal to 0"
        )
        assert self.trailing_indent is None or self.trailing_indent >= 0, (
            "trailing_indent must be greater than or equal to 0"
        )