//! This example illustrates how have a mouse's clicks/wheel/movement etc fall through the spawned transparent window to a window below.
//! If you build this, and hit 'P' it should toggle on/off the mouse's passthrough.
//! Note: this example will not work on following platforms: iOS / Android / Web / X11. Window fall through is not supported there.

use bevy::{
    prelude::*,
    window::{CursorOptions, PrimaryWindow, WindowLevel},
};

fn main() {
    App::new()
        .insert_resource(ClearColor(Color::NONE)) // Use a transparent window, to make effects obvious.
        .add_plugins(DefaultPlugins)
        .add_observer(configure_window)
        .add_systems(Startup, setup)
        .add_systems(Update, toggle_mouse_passthrough) // This allows us to hit 'P' to toggle on/off the mouse's passthrough
        .run();
}

fn configure_window(trigger: On<Add, PrimaryWindow>, mut window: Query<&mut Window>) {
    let mut window = window.get_mut(trigger.target()).unwrap();
    window.transparent = true;
    window.decorations = true;
    window.window_level = WindowLevel::AlwaysOnTop;
}

fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
    // UI camera
    commands.spawn(Camera2d);
    // Text with one span
    commands.spawn((
        // Accepts a `String` or any type that converts into a `String`, such as `&str`
        Text::new("Hit 'P' then scroll/click around!"),
        TextFont {
            font: asset_server.load("fonts/FiraSans-Bold.ttf"),
            font_size: 83.0, // Nice and big so you can see it!
            ..default()
        },
        // Set the style of the TextBundle itself.
        Node {
            position_type: PositionType::Absolute,
            bottom: Val::Px(5.),
            right: Val::Px(10.),
            ..default()
        },
    ));
}
// A simple system to handle some keyboard input and toggle on/off the hit test.
fn toggle_mouse_passthrough(
    keyboard_input: Res<ButtonInput<KeyCode>>,
    mut cursor_options: Single<&mut CursorOptions>,
) {
    if keyboard_input.just_pressed(KeyCode::KeyP) {
        cursor_options.hit_test = !cursor_options.hit_test;
    }
}