use bevy::input::keyboard::KeyboardInput;
use bevy::input::ButtonState;
use bevy::prelude::*;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, init)
        .add_systems(Update, update)
        .run();
}

fn init(mut commands: Commands) {
    // UI Camera
    commands.spawn((
        Camera2dBundle { ..default() },
        UiCameraConfig { show_ui: true },
    ));

    // Text Box
    commands.spawn(TextBundle::from_section(
        "Start typing! (Escape to clear)\n",
        TextStyle {
            color: Color::WHITE,
            ..default()
        },
    ));
}

fn update(mut query: Query<&mut Text>, mut events: EventReader<KeyboardInput>) {
    for KeyboardInput {
        key_code,
        scan_code,
        state,
        ..
    } in events.iter()
    {
        if *state == ButtonState::Pressed {
            let mut text = query.single_mut();
            if *key_code == Some(KeyCode::Escape) {
                text.sections.drain(1..);
            } else {
                let style = TextStyle {
                    color: Color::WHITE,
                    ..default()
                };
                let added = format!(
                    "Pressed: KeyCode: {:?} / ScanCode {:?}\n",
                    key_code, scan_code
                );
                text.sections.push(TextSection::new(added, style));
            }
        }
    }
}