codecraft 0.1.2

//! Dev mode: the F12 switch, its badge and menu, and the F9/F10/F11 keys.
//!
//! ```no_run
//! # use codecraft::AppState;
//! # fn demo(app: &mut AppState) {
//! if app.dev_mode() {
//!     // show the working
//! }
//! # }
//! ```
use bevy_ecs::prelude::*;
use yakui::widgets::{Layer, List, Pad, Reflow};
use yakui::{Alignment, CrossAxisAlignment, Dim2, Pivot, WidgetId};

use crate::ecs::{Application, IntoScheduleConfigs, Plugin};
use crate::input::{KeyCode, Keys};
use crate::ui::icons::path;
use crate::ui::{self, MouseInput, Outliner, PointerCapture, Profiler};

/// The key that turns it on and off.
pub const TOGGLE: KeyCode = KeyCode::F12;

/// The key that shows and hides the outliner, while dev mode is on.
pub const OUTLINER: KeyCode = KeyCode::F11;

/// The key that steps through the five faces the UI can be drawn in.
pub const FONT: KeyCode = KeyCode::F10;

/// The key that shows and hides the frame profiler, while dev mode is on.
pub const PROFILER: KeyCode = KeyCode::F9;

/// Whether dev mode is on.
#[derive(Resource, Clone, Copy, Debug, Default, PartialEq, Eq)]
pub struct DevMode(pub bool);

impl DevMode {
    pub fn is_on(self) -> bool {
        self.0
    }
}

/// The dev menu's state, and where its parts were drawn last frame.
#[derive(Resource, Default)]
pub struct DevMenu {
    pub open: bool,
    submenu: Option<usize>,
    pub(crate) badge: Option<WidgetId>,
    pub(crate) tops: Vec<WidgetId>,
    pub(crate) entries: Vec<WidgetId>,
}

impl DevMenu {
    pub fn is_open(&self) -> bool {
        self.open
    }
}

/// Flips dev mode on F12.
pub fn dev_mode_system(keys: Res<Keys>, mut commands: Commands) {
    if keys.just_pressed(TOGGLE) {
        commands.queue(|world: &mut World| {
            let on = !world.resource::<DevMode>().is_on();
            set(world, on);
        });
    }
}

/// Turns dev mode on or off; going off closes the menu and the outliner.
pub fn set(world: &mut World, on: bool) {
    let was = std::mem::replace(&mut world.resource_mut::<DevMode>().0, on);
    if was != on {
        log::info!("dev mode {}", if on { "on" } else { "off" });
    }
    if !on {
        let mut menu = world.resource_mut::<DevMenu>();
        menu.open = false;
        menu.submenu = None;
        world.resource_mut::<Outliner>().open = false;
    }
}

/// Shows and hides the outliner on [`OUTLINER`], while dev mode is on.
pub fn outliner_key_system(keys: Res<Keys>, dev: Res<DevMode>, mut outliner: ResMut<Outliner>) {
    if !dev.is_on() || !keys.just_pressed(OUTLINER) {
        return;
    }
    outliner.toggle();
    log::info!(
        "outliner {}",
        match outliner.is_open() {
            true => "up",
            false => "down",
        },
    );
}

/// Shows and hides the frame profiler on [`PROFILER`], while dev mode is on.
pub fn profiler_key_system(keys: Res<Keys>, dev: Res<DevMode>, mut profiler: ResMut<Profiler>) {
    if dev.is_on() && keys.just_pressed(PROFILER) {
        profiler.on = !profiler.on;
        log::info!(
            "profiler {}",
            match profiler.on {
                true => "on",
                false => "off",
            }
        );
    }
}

/// Steps through the five Monaspace faces on [`FONT`], while dev mode is on.
pub fn font_key_system(keys: Res<Keys>, dev: Res<DevMode>, mut font: ResMut<ui::Font>) {
    if dev.is_on() && keys.just_pressed(FONT) {
        font.cycle();
    }
}

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
enum Action {
    Nothing,
    Outliner,
    Exit,
}

struct Top {
    label: &'static str,
    entries: &'static [(&'static str, Action)],
}

// No Create menu yet: it would build itself from a registry this renderer lacks.
const MENU: &[Top] = &[
    Top {
        label: "APP",
        entries: &[
            ("PLAY", Action::Nothing),
            ("EDIT", Action::Nothing),
            ("CONNECTIONS", Action::Nothing),
            ("SETTINGS", Action::Nothing),
            ("ABOUT", Action::Nothing),
            ("EXIT", Action::Exit),
        ],
    },
    Top {
        label: "FILE",
        entries: &[
            ("IMPORT MODEL", Action::Nothing),
            ("OPEN SCENE", Action::Nothing),
            ("SAVE SCENE AS", Action::Nothing),
        ],
    },
    Top {
        label: "VIEW",
        entries: &[
            ("OUTLINER", Action::Outliner),
            ("INSTANCES", Action::Nothing),
            ("PROPERTIES", Action::Nothing),
            ("TIMELINE", Action::Nothing),
            ("ACTIONS", Action::Nothing),
            ("SCREENSHOT", Action::Nothing),
            ("RECENTER VIEW", Action::Nothing),
        ],
    },
];

/// Draws the badge, the menu, the outliner and the profiler, and acts on what was clicked.
pub fn dev_ui_system(world: &mut World) {
    if !world.resource::<DevMode>().is_on() {
        return;
    }
    let mouse = *world.resource::<MouseInput>();
    let over_panel = world.resource::<PointerCapture>().over_panel;
    let mut menu = world.remove_resource::<DevMenu>().unwrap_or_default();
    if menu.open && mouse.just_pressed && !over_panel {
        menu.open = false;
    }

    let mut chosen: Option<Action> = None;
    let mut toggle_badge = false;
    let mut hovered_top: Option<usize> = None;
    let mut over_submenu = false;
    menu.tops.clear();
    menu.entries.clear();

    // Its own layer, so the dev UI takes the pointer before a game panel under it.
    Layer::new().show(|| {
        ui::screen(|| {
            ui::outliner::show(world);
            world.resource::<Profiler>().show();

            ui::place(1.0, 1.0, Pivot::BOTTOM_RIGHT, || {
                yakui::pad(Pad::all(ui::SCREEN_MARGIN), || {
                    // Badge first, menu hung off it: yakui widget identity is tree position, and a badge that moved would lose its click.
                    let mut stack = List::column();
                    stack.main_axis_size = yakui::MainAxisSize::Min;
                    stack.cross_axis_alignment = CrossAxisAlignment::End;
                    stack.show(|| {
                        let caret = match menu.open {
                            true => path::CARET_DOWN,
                            false => path::CARET_UP,
                        };
                        ui::rows(|| {
                            let badge = ui::menu_row("DEV", Some(path::WRENCH), Some(caret));
                            menu.badge = Some(badge.id);
                            toggle_badge = badge.clicked;
                        });

                        Reflow::new(Alignment::TOP_RIGHT, Pivot::BOTTOM_RIGHT, Dim2::ZERO).show(
                            || {
                                if !menu.open {
                                    return;
                                }
                                ui::rows(|| {
                                    for (index, top) in MENU.iter().enumerate() {
                                        let mut row = List::row();
                                        row.main_axis_size = yakui::MainAxisSize::Min;
                                        row.show(|| {
                                            let response = ui::menu_row(
                                                top.label,
                                                None,
                                                Some(path::CARET_LEFT),
                                            );
                                            menu.tops.push(response.id);
                                            if response.hovering {
                                                hovered_top = Some(index);
                                            }
                                            if menu.submenu == Some(index) {
                                                submenu(
                                                    top,
                                                    &mut menu,
                                                    &mut chosen,
                                                    &mut over_submenu,
                                                );
                                            }
                                        });
                                    }
                                });
                            },
                        );
                    });
                });
            });
        });
    });

    // Hovering a row wins; else the open submenu stays while the pointer is inside it, so it can travel from row to submenu.
    menu.submenu = hovered_top.or(match over_submenu {
        true => menu.submenu,
        false => None,
    });
    if toggle_badge {
        menu.open = !menu.open;
    }
    if let Some(action) = chosen {
        menu.open = false;
        menu.submenu = None;
        match action {
            Action::Nothing => {}
            Action::Outliner => world.resource_mut::<Outliner>().toggle(),
            Action::Exit => std::process::exit(0),
        }
    }
    if !menu.open {
        menu.submenu = None;
    }
    world.insert_resource(menu);
}

// The hover region sits inside the panel: the opaque panel would hide the pointer from anything wrapped round it.
fn submenu(top: &Top, menu: &mut DevMenu, chosen: &mut Option<Action>, over_submenu: &mut bool) {
    Reflow::new(
        Alignment::BOTTOM_LEFT,
        Pivot::BOTTOM_RIGHT,
        Dim2::pixels(-ui::PANEL_PADDING, 0.0),
    )
    .show(|| {
        Layer::new().show(|| {
            ui::panel(|| {
                let region = ui::clickable(None, || {
                    let mut column = List::column();
                    column.main_axis_size = yakui::MainAxisSize::Min;
                    column.show(|| {
                        for (label, action) in top.entries {
                            let entry = ui::menu_row(*label, None, None);
                            menu.entries.push(entry.id);
                            if entry.clicked {
                                *chosen = Some(*action);
                            }
                        }
                    });
                });
                *over_submenu |= region.hovering;
            });
        });
    });
}

pub struct DevPlugin;

impl Plugin for DevPlugin {
    fn build(&self, app: &mut Application) {
        app.init_resource::<DevMode>();
        app.init_resource::<DevMenu>();
        app.init_resource::<Outliner>();
        app.init_resource::<ui::Font>();
        app.init_resource::<Profiler>();
        app.add_update_systems(dev_mode_system);
        app.add_update_systems(outliner_key_system);
        app.add_update_systems(font_key_system);
        app.add_update_systems(profiler_key_system);
        // It reads this frame's click, so it goes before the edge is spent.
        app.add_update_systems(dev_ui_system.before(ui::clear_input_edge_system));
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::ui::{CursorPosition, ScreenSize, Ui, UiPlugin};
    use yakui::geometry::Vec2;

    fn app() -> Application {
        let mut app = Application::new();
        app.add_plugin(UiPlugin);
        app.insert_resource(Keys::default());
        app.add_plugin(DevPlugin);
        app.world.insert_resource(ScreenSize {
            width: 1280.0,
            height: 800.0,
        });
        app
    }

    fn frame(app: &mut Application) {
        Ui::begin_frame(&mut app.world);
        app.update();
        Ui::end_frame(&mut app.world);
    }

    fn press(app: &mut Application, key: KeyCode) {
        app.world.resource_mut::<Keys>().press(key, false);
        frame(app);
        let mut keys = app.world.resource_mut::<Keys>();
        keys.end_frame();
        keys.release(key);
    }

    fn press_f12(app: &mut Application) {
        press(app, TOGGLE);
    }

    fn outliner_open(app: &Application) -> bool {
        app.world.resource::<Outliner>().is_open()
    }

    fn menu_open(app: &Application) -> bool {
        app.world.resource::<DevMenu>().is_open()
    }

    fn rect_of(app: &Application, id: WidgetId) -> yakui::geometry::Rect {
        app.world
            .non_send::<Ui>()
            .rect_of(id)
            .expect("it was drawn last frame")
    }

    fn badge(app: &Application) -> yakui::geometry::Rect {
        let id = app.world.resource::<DevMenu>().badge.expect("a badge");
        rect_of(app, id)
    }

    fn hover(app: &mut Application, at: Vec2) {
        app.world
            .insert_resource(CursorPosition { x: at.x, y: at.y });
        frame(app);
    }

    fn click(app: &mut Application, at: Vec2) {
        app.world
            .insert_resource(CursorPosition { x: at.x, y: at.y });
        app.world.insert_resource(MouseInput {
            left_down: true,
            just_pressed: true,
            ..MouseInput::default()
        });
        frame(app);
        app.world.insert_resource(MouseInput {
            just_released: true,
            ..MouseInput::default()
        });
        frame(app);
    }

    fn center(rect: yakui::geometry::Rect) -> Vec2 {
        rect.pos() + rect.size() * 0.5
    }

    #[test]
    fn f12_turns_it_on_and_off_again() {
        let mut app = app();
        assert!(
            !app.world.resource::<DevMode>().is_on(),
            "off to start with"
        );

        press_f12(&mut app);
        assert!(app.world.resource::<DevMode>().is_on());

        press_f12(&mut app);
        assert!(!app.world.resource::<DevMode>().is_on());
    }

    #[test]
    fn the_badge_is_drawn_only_while_it_is_on() {
        let mut app = app();
        frame(&mut app);
        assert!(app.world.resource::<DevMenu>().badge.is_none());

        press_f12(&mut app);
        frame(&mut app);
        let badge = badge(&app);
        assert!(
            badge.pos().x > 1000.0 && badge.pos().y > 700.0,
            "in the bottom-right corner: {badge:?}"
        );
    }

    #[test]
    fn the_badge_opens_the_menu_and_closes_it_again() {
        let mut app = app();
        press_f12(&mut app);
        frame(&mut app);

        assert!(!menu_open(&app));
        let at = center(badge(&app));
        click(&mut app, at);
        assert!(menu_open(&app), "one click opens");

        let at = center(badge(&app));
        click(&mut app, at);
        assert!(!menu_open(&app), "and the next one closes");
    }

    #[test]
    fn clicking_away_from_the_menu_closes_it() {
        let mut app = app();
        press_f12(&mut app);
        frame(&mut app);
        let at = center(badge(&app));
        click(&mut app, at);
        assert!(menu_open(&app));

        click(&mut app, Vec2::new(20.0, 20.0));
        assert!(
            !menu_open(&app),
            "a click on the game is not a click on the menu"
        );
    }

    #[test]
    fn a_submenu_opens_on_hover_to_the_left_and_stays_while_the_pointer_is_in_it() {
        let mut app = app();
        press_f12(&mut app);
        frame(&mut app);
        let at = center(badge(&app));
        click(&mut app, at);
        frame(&mut app);

        let tops = app.world.resource::<DevMenu>().tops.clone();
        assert_eq!(tops.len(), MENU.len(), "a row per top-level entry");
        assert!(
            app.world.resource::<DevMenu>().entries.is_empty(),
            "closed until the pointer arrives"
        );

        let row = rect_of(&app, tops[2]);
        let at = center(row);
        hover(&mut app, at);
        frame(&mut app);
        let entries = app.world.resource::<DevMenu>().entries.clone();
        assert_eq!(
            entries.len(),
            MENU[2].entries.len(),
            "hovering the row opens it"
        );
        let first = rect_of(&app, entries[0]);
        assert!(
            first.pos().x + first.size().x <= row.pos().x + 1.0,
            "a menu in the right-hand corner opens its submenus to the left: \
             entry at {first:?} against a row at {row:?}",
        );

        let at = center(rect_of(&app, entries[3]));
        hover(&mut app, at);
        frame(&mut app);
        assert!(
            !app.world.resource::<DevMenu>().entries.is_empty(),
            "and stays open once the pointer is in it"
        );

        hover(&mut app, Vec2::new(10.0, 10.0));
        frame(&mut app);
        assert!(
            app.world.resource::<DevMenu>().entries.is_empty(),
            "and closes once the pointer leaves both"
        );
        assert!(menu_open(&app), "hovering away is not a click away");
    }

    #[test]
    fn choosing_an_entry_acts_on_it_and_closes_the_menu() {
        let mut app = app();
        press_f12(&mut app);
        frame(&mut app);
        let at = center(badge(&app));
        click(&mut app, at);
        frame(&mut app);

        let view = app.world.resource::<DevMenu>().tops[2];
        let at = center(rect_of(&app, view));
        hover(&mut app, at);
        frame(&mut app);
        let outliner = app.world.resource::<DevMenu>().entries[0];
        let at = center(rect_of(&app, outliner));
        click(&mut app, at);

        assert!(outliner_open(&app), "VIEW > OUTLINER puts it up");
        assert!(!menu_open(&app), "picking from a menu puts it away");
    }

    #[test]
    fn f11_shows_the_outliner_and_hides_it_again() {
        let mut app = app();
        press_f12(&mut app);
        assert!(!outliner_open(&app), "down to start with");

        press(&mut app, OUTLINER);
        assert!(outliner_open(&app), "one press puts it up");

        press(&mut app, OUTLINER);
        assert!(!outliner_open(&app), "and the next takes it down");
    }

    #[test]
    fn f11_does_nothing_outside_dev_mode() {
        let mut app = app();
        press(&mut app, OUTLINER);
        assert!(!outliner_open(&app), "no outliner without the working");
    }

    #[test]
    fn leaving_dev_mode_takes_the_menu_and_the_outliner_with_it() {
        let mut app = app();
        press_f12(&mut app);
        press(&mut app, OUTLINER);
        frame(&mut app);
        let at = center(badge(&app));
        click(&mut app, at);
        assert!(menu_open(&app) && outliner_open(&app));

        press_f12(&mut app);
        assert!(!menu_open(&app), "the menu cannot outlive the mode");
        assert!(!outliner_open(&app), "nor can the outliner");
    }

    #[test]
    fn f10_steps_through_the_faces() {
        use crate::ui::{Family, Font};

        let mut app = app();
        press_f12(&mut app);
        assert_eq!(app.world.resource::<Font>().family(), Family::Neon);

        press(&mut app, FONT);
        assert_eq!(app.world.resource::<Font>().family(), Family::Neon.next());

        for _ in 1..Family::ALL.len() {
            press(&mut app, FONT);
        }
        assert_eq!(app.world.resource::<Font>().family(), Family::Neon);
    }

    #[test]
    fn f10_does_nothing_outside_dev_mode() {
        use crate::ui::{Family, Font};

        let mut app = app();
        press(&mut app, FONT);
        assert_eq!(app.world.resource::<Font>().family(), Family::Neon);
    }

    #[test]
    fn f9_puts_the_profiler_up_while_it_is_on() {
        let mut app = app();
        press(&mut app, PROFILER);
        assert!(!app.world.resource::<Profiler>().on, "not outside dev mode");

        press_f12(&mut app);
        press(&mut app, PROFILER);
        assert!(app.world.resource::<Profiler>().on);
        frame(&mut app);
    }

    #[test]
    fn nothing_happens_on_the_frames_between() {
        let mut app = app();
        press_f12(&mut app);

        frame(&mut app);
        frame(&mut app);
        assert!(app.world.resource::<DevMode>().is_on());
    }
}