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

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

struct Harness {
    clicks: Rc<RefCell<usize>>,
    disabled: bool,
    with_override: 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().gap_2().child({
            let mut link = Link::new("test-link-href")
                .label("Release notes")
                .href("https://example.com/release-notes");
            if self.with_override {
                link = link.on_click(move |_, _, _| {
                    *clicks.borrow_mut() += 1;
                });
            }
            link.disabled(self.disabled)
        })
    }
}

/// A maximized window with two link rows at the top-left; row 1 spans
/// roughly y 0..21, row 2 y 29..50.
fn link_window(
    with_override: bool,
    disabled: bool,
) -> (TestAppContext, AnyWindowHandle, Rc<RefCell<usize>>) {
    let mut cx = TestAppContext::single();
    cx.update(Theme::init);
    let clicks = Rc::new(RefCell::new(0usize));
    let harness_clicks = clicks.clone();
    let window = cx.add_window(move |_, _| Harness {
        clicks: harness_clicks,
        disabled,
        with_override,
    });
    let window = window.into();
    cx.update_window(window, |_, window, cx| {
        window.draw(cx).clear(cx);
    })
    .unwrap();
    (cx, window, clicks)
}

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

#[test]
fn clicking_a_link_with_href_opens_it_through_the_platform() {
    let (cx, window, clicks) = link_window(false, false);
    let mut visual = VisualTestContext::from_window(window, &cx);
    visual.simulate_click(point(px(20.), px(10.)), Modifiers::default());
    assert_eq!(
        visual.opened_url().as_deref(),
        Some("https://example.com/release-notes")
    );
    assert_eq!(*clicks.borrow(), 0);
}

#[test]
fn on_click_replaces_the_href_opening() {
    let (cx, window, clicks) = link_window(true, false);
    let mut visual = VisualTestContext::from_window(window, &cx);
    visual.simulate_click(point(px(20.), px(10.)), Modifiers::default());
    assert_eq!(*clicks.borrow(), 1);
    assert_eq!(visual.opened_url(), None, "the handler replaces the href");
}

#[test]
fn disabled_link_does_nothing() {
    let (cx, window, clicks) = link_window(false, true);
    let mut visual = VisualTestContext::from_window(window, &cx);
    visual.simulate_click(point(px(20.), px(10.)), Modifiers::default());
    assert_eq!(visual.opened_url(), None);
    assert_eq!(*clicks.borrow(), 0);
}

#[test]
fn enter_opens_the_href_while_focused() {
    let (mut cx, window, clicks) = link_window(false, false);
    let mut visual = VisualTestContext::from_window(window, &cx);
    visual.simulate_click(point(px(20.), px(10.)), Modifiers::default());
    assert_eq!(
        visual.opened_url().as_deref(),
        Some("https://example.com/release-notes"),
        "the pointer click itself opens"
    );

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

    cx.update_window(window, |_, window, cx| {
        window.dispatch_event(
            KeyDownEvent {
                keystroke: Keystroke::parse("enter").unwrap(),
                is_held: false,
                prefer_character_input: false,
            }
            .to_platform_input(),
            cx,
        );
        window.dispatch_event(
            KeyUpEvent {
                keystroke: Keystroke::parse("enter").unwrap(),
            }
            .to_platform_input(),
            cx,
        );
    })
    .unwrap();

    assert_eq!(*clicks.borrow(), 0, "Enter re-opens through the platform");
    assert_eq!(
        visual.opened_url().as_deref(),
        Some("https://example.com/release-notes")
    );
}