use crate::{Axis, AxisT, Len, Painter, SizeCtx};
use std::any::Any;

mod data;
mod handle;
mod like;
mod tag;
mod view;
mod widgets;

pub use data::*;
pub use handle::*;
pub use like::*;
pub use tag::*;
pub use view::*;
pub use widgets::*;

pub trait Widget: Any {
    fn draw(&mut self, painter: &mut Painter);
    fn desired_width(&mut self, ctx: &mut SizeCtx) -> Len;
    fn desired_height(&mut self, ctx: &mut SizeCtx) -> Len;
}

pub trait WidgetAxisFns {
    fn desired_len<A: AxisT>(&mut self, ctx: &mut SizeCtx) -> Len;
}

impl<W: Widget + ?Sized> WidgetAxisFns for W {
    fn desired_len<A: AxisT>(&mut self, ctx: &mut SizeCtx) -> Len {
        match A::get() {
            Axis::X => self.desired_width(ctx),
            Axis::Y => self.desired_height(ctx),
        }
    }
}

impl Widget for () {
    fn draw(&mut self, _: &mut Painter) {}
    fn desired_width(&mut self, _: &mut SizeCtx) -> Len {
        Len::ZERO
    }
    fn desired_height(&mut self, _: &mut SizeCtx) -> Len {
        Len::ZERO
    }
}

impl dyn Widget {
    pub fn as_any(&self) -> &dyn Any {
        self
    }

    pub fn as_any_mut(&mut self) -> &mut dyn Any {
        self
    }
}

/// A function that returns a widget given a UI.
/// Useful for defining trait functions on widgets that create a parent widget so that the children
/// don't need to be IDs yet
pub trait WidgetFn<State, W: Widget + ?Sized>: FnOnce(&mut State) -> W {}
impl<State, W: Widget + ?Sized, F: FnOnce(&mut State) -> W> WidgetFn<State, W> for F {}

pub struct WidgetArr<const LEN: usize> {
    pub arr: [StrongWidget; LEN],
}

impl<const LEN: usize> WidgetArr<LEN> {
    pub fn new(arr: [StrongWidget; LEN]) -> Self {
        Self { arr }
    }
}

pub trait WidgetOption<State> {
    fn get(self, state: &mut State) -> Option<StrongWidget>;
}

impl<State> WidgetOption<State> for () {
    fn get(self, _: &mut State) -> Option<StrongWidget> {
        None
    }
}

impl<State, F: FnOnce(&mut State) -> Option<StrongWidget>> WidgetOption<State> for F {
    fn get(self, state: &mut State) -> Option<StrongWidget> {
        self(state)
    }
}