//! This example illustrates how to load and play an audio file, and control where the sounds seems to come from.
use bevy::prelude::*;

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

fn setup(
    mut commands: Commands,
    asset_server: Res<AssetServer>,
    audio: Res<Audio>,
    audio_sinks: Res<Assets<SpatialAudioSink>>,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    // Space between the two ears
    let gap = 4.0;

    let music = asset_server.load("sounds/Windless Slopes.ogg");
    let handle = audio_sinks.get_handle(audio.play_spatial_with_settings(
        music,
        PlaybackSettings::LOOP,
        Transform::IDENTITY,
        gap,
        Vec3::ZERO,
    ));
    commands.insert_resource(AudioController(handle));

    // left ear
    commands.spawn(PbrBundle {
        mesh: meshes.add(Mesh::from(shape::Cube { size: 0.2 })),
        material: materials.add(Color::RED.into()),
        transform: Transform::from_xyz(-gap / 2.0, 0.0, 0.0),
        ..default()
    });

    // right ear
    commands.spawn(PbrBundle {
        mesh: meshes.add(Mesh::from(shape::Cube { size: 0.2 })),
        material: materials.add(Color::GREEN.into()),
        transform: Transform::from_xyz(gap / 2.0, 0.0, 0.0),
        ..default()
    });

    // sound emitter
    commands.spawn((
        PbrBundle {
            mesh: meshes.add(Mesh::from(shape::UVSphere {
                radius: 0.2,
                ..default()
            })),
            material: materials.add(Color::BLUE.into()),
            transform: Transform::from_xyz(0.0, 0.0, 0.0),
            ..default()
        },
        Emitter,
    ));

    // light
    commands.spawn(PointLightBundle {
        point_light: PointLight {
            intensity: 1500.0,
            shadows_enabled: true,
            ..default()
        },
        transform: Transform::from_xyz(4.0, 8.0, 4.0),
        ..default()
    });
    // camera
    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(0.0, 5.0, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
        ..default()
    });
}

#[derive(Component)]
struct Emitter;

#[derive(Resource)]
struct AudioController(Handle<SpatialAudioSink>);

fn update_positions(
    audio_sinks: Res<Assets<SpatialAudioSink>>,
    music_controller: Res<AudioController>,
    time: Res<Time>,
    mut emitter: Query<&mut Transform, With<Emitter>>,
) {
    if let Some(sink) = audio_sinks.get(&music_controller.0) {
        let mut emitter_transform = emitter.single_mut();
        emitter_transform.translation.x = time.elapsed_seconds().sin() * 3.0;
        emitter_transform.translation.z = time.elapsed_seconds().cos() * 3.0;
        sink.set_emitter_position(emitter_transform.translation);
    }
}