from dataclasses import field
from enum import Enum
from typing import Optional

from flet.controls.adaptive_control import AdaptiveControl
from flet.controls.alignment import Alignment
from flet.controls.base_control import control
from flet.controls.constrained_control import ConstrainedControl
from flet.controls.control import Control
from flet.controls.types import ClipBehavior

__all__ = ["Stack", "StackFit"]


class StackFit(Enum):
    LOOSE = "loose"
    EXPAND = "expand"
    PASS_THROUGH = "passThrough"


@control("Stack")
class Stack(ConstrainedControl, AdaptiveControl):
    """
    Positions its children on top of each other, following a LIFO (Last In First Out) order.

    This control is useful if you want to overlap several children in a simple way.
    For example having some text and an image, overlaid with a gradient and a button
    attached to the bottom.

    Stack is also useful if you want to implement implicit animations
    (https://flet.dev/docs/guides/python/animations/) that require knowing absolute
    position of a target value.
    """

    controls: list[Control] = field(default_factory=list)
    """
    A list of Controls to display.

    For the display order, it follows the order of the list,
    so the last control in the list will be displayed on top (LIFO - Last In First Out).
    """

    clip_behavior: ClipBehavior = ClipBehavior.HARD_EDGE
    """
    The content will be clipped (or not) according to this option.
    """

    alignment: Optional[Alignment] = None
    """
    Specifies the alignment for non-positioned (those without explicit
    alignment properties such as [`top`][flet.ConstrainedControl.top]
    or [`bottom`][flet.ConstrainedControl.bottom]) and
    partially-positioned [`controls`][flet.Stack.controls].
    """

    fit: StackFit = StackFit.LOOSE
    """
    How to size the non-positioned [`controls`][flet.Stack.controls].
    """