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::checkbox::Checkbox;
use gpui_native_theme::Theme;

struct Harness {
    changes: Rc<RefCell<Vec<bool>>>,
    checked: bool,
    disabled: bool,
}

impl Render for Harness {
    fn render(&mut self, _window: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
        let changes = self.changes.clone();
        let view = cx.entity();
        div().size_full().flex().flex_col().child(
            Checkbox::new("test-checkbox")
                .label("Telemetry")
                .checked(self.checked)
                .disabled(self.disabled)
                .on_change(move |next, _, cx| {
                    changes.borrow_mut().push(next);
                    view.update(cx, |harness, cx| {
                        harness.checked = next;
                        cx.notify();
                    });
                }),
        )
    }
}

/// A maximized window whose checkbox sits in the top-left corner, so
/// `point(px(8.), px(10.))` lands on it.
fn checkbox_window(
    checked: bool,
    disabled: bool,
) -> (VisualTestContext, AnyWindowHandle, Rc<RefCell<Vec<bool>>>) {
    let mut cx = TestAppContext::single();
    cx.update(Theme::init);
    let changes = Rc::new(RefCell::new(Vec::new()));
    let harness_changes = changes.clone();
    let window = cx.add_window(move |_, _| Harness {
        changes: harness_changes,
        checked,
        disabled,
    });
    let window = window.into();
    cx.update_window(window, |_, window, cx| {
        window.draw(cx).clear(cx);
    })
    .unwrap();
    (VisualTestContext::from_window(window, &cx), window, changes)
}

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

#[test]
fn clicking_reports_the_next_value_through_the_controlled_loop() {
    let (mut cx, _window, changes) = checkbox_window(false, false);
    cx.simulate_click(point(px(8.), px(10.)), Modifiers::default());
    assert_eq!(*changes.borrow(), vec![true]);

    // The second click must report `false`: only if the owner applied the
    // first change does the checkbox know it is now checked.
    cx.simulate_click(point(px(8.), px(10.)), Modifiers::default());
    assert_eq!(*changes.borrow(), vec![true, false]);
}

#[test]
fn disabled_checkbox_does_not_report_changes() {
    let (mut cx, _window, changes) = checkbox_window(false, true);
    cx.simulate_click(point(px(8.), px(10.)), Modifiers::default());
    assert!(changes.borrow().is_empty());
}

#[test]
fn enter_and_space_report_the_next_value_while_focused() {
    let (mut cx, window, changes) = checkbox_window(false, false);
    cx.simulate_click(point(px(8.), px(10.)), Modifiers::default());
    assert_eq!(
        *changes.borrow(),
        vec![true],
        "the pointer click itself toggles"
    );

    // Repaint with the checkbox 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!(*changes.borrow(), vec![true, false, true]);
}