use crate::prelude::*;
use std::time::{Duration, Instant};
use winit::dpi::{LogicalPosition, LogicalSize};

pub struct Selector;

impl<Rsc: HasEvents, W: Widget + 'static> WidgetAttr<Rsc, W> for Selector
where
    Rsc::State: HasDefaultUiState,
{
    type Input = WeakWidget<TextEdit>;

    fn run(rsc: &mut Rsc, container: WeakWidget<W>, id: Self::Input) {
        rsc.register_event(container, CursorSense::click_or_drag(), move |ctx, rsc| {
            let region = ctx.data.render.window_region(&id).unwrap();
            let id_pos = region.top_left;
            let container_pos = ctx.data.render.window_region(&container).unwrap().top_left;
            // The pointer arrives from the platform in floats; everything
            // it is compared against is on the grid.
            let pos = (PxVec2::from_f32(ctx.data.pos) + container_pos - id_pos).to_f32();
            let size = region.size().to_f32();
            select(
                rsc,
                ctx.data.render,
                ctx.state,
                id,
                pos,
                size,
                ctx.data.sense.is_dragging(),
            );
        });
    }
}

pub struct Selectable;

impl<Rsc: HasEvents> WidgetAttr<Rsc, TextEdit> for Selectable
where
    Rsc::State: HasDefaultUiState,
{
    type Input = ();

    fn run(rsc: &mut Rsc, id: WeakWidget<TextEdit>, _: Self::Input) {
        rsc.register_event(id, CursorSense::click_or_drag(), move |ctx, rsc| {
            select(
                rsc,
                ctx.data.render,
                ctx.state,
                id,
                ctx.data.pos,
                ctx.data.size,
                ctx.data.sense.is_dragging(),
            );
        });
    }
}

fn select(
    rsc: &mut impl UiRsc,
    render: &UiRenderState,
    state: &mut impl HasDefaultUiState,
    id: WeakWidget<TextEdit>,
    pos: Vec2,
    size: Vec2,
    dragging: bool,
) {
    let state = state.default_state_mut();
    let now = Instant::now();
    let recent = (now - state.last_click) < Duration::from_millis(300);
    state.last_click = now;
    id.edit(rsc).select(pos, size, dragging, recent);
    if let Some(region) = render.window_region(&id) {
        state.window.set_ime_allowed(true);
        state.window.set_ime_cursor_area(
            LogicalPosition::<f32>::from(region.top_left.to_f32().tuple()),
            LogicalSize::<f32>::from(region.size().to_f32().tuple()),
        );
    }
    state.focus = Some(id);
}