use std::{cell::RefCell, rc::Rc};

use gpui::{
    AnyWindowHandle, AppContext as _, Context, IntoElement, KeyDownEvent, KeyUpEvent, Keystroke,
    Modifiers, ParentElement as _, Render, Styled as _, TestAppContext, VisualTestContext, Window,
    div, point, px,
};
use gpui_native_core::button::Button;
use gpui_native_theme::Theme;

struct Harness {
    clicks: Rc<RefCell<usize>>,
    disabled: bool,
}

impl Render for Harness {
    fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
        let clicks = self.clicks.clone();
        div().size_full().flex().flex_col().child(
            Button::new("test-button")
                .label("Save")
                .disabled(self.disabled)
                .on_click(move |_, _, _| *clicks.borrow_mut() += 1),
        )
    }
}

/// A maximized window whose button stretches across the top 28px, so
/// `point(px(60.), px(14.))` always lands on it.
fn button_window(disabled: bool) -> (VisualTestContext, AnyWindowHandle, Rc<RefCell<usize>>) {
    let mut cx = TestAppContext::single();
    cx.update(Theme::init);
    let clicks = Rc::new(RefCell::new(0));
    let harness_clicks = clicks.clone();
    let window = cx.add_window(move |_, _| Harness {
        clicks: harness_clicks,
        disabled,
    });
    let window = window.into();
    cx.update_window(window, |_, window, cx| {
        window.draw(cx).clear(cx);
    })
    .unwrap();
    (VisualTestContext::from_window(window, &cx), window, clicks)
}

fn draw(cx: &mut VisualTestContext, window: AnyWindowHandle) {
    cx.update_window(window, |_, window, cx| {
        window.draw(cx).clear(cx);
    })
    .unwrap();
}

#[test]
fn pointer_click_fires_on_click() {
    let (mut cx, _window, clicks) = button_window(false);
    cx.simulate_click(point(px(60.), px(14.)), Modifiers::default());
    assert_eq!(*clicks.borrow(), 1);
}

#[test]
fn disabled_button_ignores_clicks() {
    let (mut cx, _window, clicks) = button_window(true);
    cx.simulate_click(point(px(60.), px(14.)), Modifiers::default());
    assert_eq!(*clicks.borrow(), 0);
}

#[test]
fn enter_and_space_fire_on_click_while_focused() {
    let (mut cx, window, clicks) = button_window(false);
    cx.simulate_click(point(px(60.), px(14.)), Modifiers::default());
    assert_eq!(*clicks.borrow(), 1, "the pointer click itself activates");

    // Repaint with the button focused so its Enter/Space handlers register.
    draw(&mut cx, window);

    for key in ["enter", "space"] {
        cx.simulate_event(KeyDownEvent {
            keystroke: Keystroke::parse(key).unwrap(),
            is_held: false,
            prefer_character_input: false,
        });
        cx.simulate_event(KeyUpEvent {
            keystroke: Keystroke::parse(key).unwrap(),
        });
    }

    assert_eq!(*clicks.borrow(), 3, "Enter and Space each fire on_click");
}