use std::cell::RefCell;
use std::rc::Rc;

use gpui::{
    Context, IntoElement, Modifiers, MouseButton, ParentElement as _, Render, Styled as _,
    TestAppContext, VisualTestContext, Window, div, point, px,
};
use gpui_native_core::button::{Button, ButtonVariant};
use gpui_native_core::dialog::Dialog;
use gpui_native_theme::Theme;

struct Harness {
    open: bool,
    alert: bool,
    changes: Rc<RefCell<Vec<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();
        let on_change_view = view.clone();
        let close_changes = self.changes.clone();
        let close_view = view.clone();
        div().size_full().child(
            Dialog::new("test-dialog")
                .open(self.open)
                .alert(self.alert)
                .title("Delete file?")
                .on_change(move |next, _, cx| {
                    eprintln!("HARNESS on_change: {next}");
                    changes.borrow_mut().push(next);
                    on_change_view.update(cx, |harness, cx| {
                        harness.open = next;
                        cx.notify();
                    });
                })
                .content(|_, _| {
                    div()
                        .w(px(300.))
                        .h(px(80.))
                        .child("This cannot be undone.")
                        .into_any_element()
                })
                .actions(move |_, _| {
                    vec![
                        Button::new("dialog-cancel")
                            .label("Cancel")
                            .variant(ButtonVariant::Secondary)
                            .on_click({
                                let close_changes = close_changes.clone();
                                let close_view = close_view.clone();
                                move |_, _, cx| {
                                    close_changes.borrow_mut().push(false);
                                    close_view.update(cx, |harness, cx| {
                                        harness.open = false;
                                        cx.notify();
                                    });
                                }
                            })
                            .into_any_element(),
                        Button::new("dialog-delete")
                            .label("Delete")
                            .variant(ButtonVariant::Destructive)
                            .on_click({
                                let close_changes = close_changes.clone();
                                let close_view = close_view.clone();
                                move |_, _, cx| {
                                    close_changes.borrow_mut().push(false);
                                    close_view.update(cx, |harness, cx| {
                                        harness.open = false;
                                        cx.notify();
                                    });
                                }
                            })
                            .into_any_element(),
                    ]
                }),
        )
    }
}

/// An open 332px-wide dialog centered in the window: the panel spans
/// roughly `(794..1126, 448..640)`, so `(100, 100)` is on the scrim and
/// the window center is on the panel.
fn dialog_window(
    open: bool,
    alert: bool,
) -> (TestAppContext, VisualTestContext, 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 {
        open,
        alert,
        changes: harness_changes,
    });
    let mut visual = VisualTestContext::from_window(window.into(), &cx);
    visual.update(|window, cx| {
        window.draw(cx).clear(cx);
    });
    (cx, visual, changes)
}

fn draw(visual: &mut VisualTestContext) {
    visual.update(|window, cx| {
        eprintln!("DRAW");
        window.draw(cx).clear(cx);
    });
}

fn click(visual: &mut VisualTestContext, position: gpui::Point<gpui::Pixels>) {
    visual.simulate_mouse_down(position, MouseButton::Left, Modifiers::default());
    visual.simulate_mouse_up(position, MouseButton::Left, Modifiers::default());
}

#[test]
fn escape_closes_a_modal_dialog_and_stays_closed() {
    let (_cx, mut visual, changes) = dialog_window(true, false);

    visual.simulate_keystrokes("escape");
    assert_eq!(*changes.borrow(), vec![false]);
    draw(&mut visual);

    // Closed: escape on the inert remainder reports nothing further.
    visual.simulate_keystrokes("escape");
    assert_eq!(*changes.borrow(), vec![false]);
}

#[test]
fn escape_is_inert_on_an_alert() {
    let (_cx, mut visual, changes) = dialog_window(true, true);
    visual.simulate_keystrokes("escape");
    assert!(changes.borrow().is_empty());
}

#[test]
fn scrim_click_closes_a_modal_but_not_an_alert() {
    let (_cx, mut visual, changes) = dialog_window(true, false);
    click(&mut visual, point(px(100.), px(100.)));
    assert_eq!(*changes.borrow(), vec![false]);

    draw(&mut visual);
    click(&mut visual, point(px(100.), px(100.)));
    assert_eq!(*changes.borrow(), vec![false]);

    // The same click on an alert's scrim answers nothing.
    let (_cx, mut visual, changes) = dialog_window(true, true);
    click(&mut visual, point(px(100.), px(100.)));
    assert!(changes.borrow().is_empty());
}

#[test]
fn clicking_the_panel_does_not_dismiss() {
    // The window center is where the centered panel sits.
    let (_cx, mut visual, changes) = dialog_window(true, false);
    click(&mut visual, point(px(960.), px(540.)));
    assert!(changes.borrow().is_empty());
}

#[test]
fn a_closed_dialog_is_inert() {
    let (_cx, mut visual, changes) = dialog_window(false, false);
    visual.simulate_keystrokes("escape");
    click(&mut visual, point(px(100.), px(100.)));
    assert!(changes.borrow().is_empty());
}