use {
    bevy::{
        prelude::{
            App, Assets, Commands, Deref, Handle, Input, KeyCode, PostStartup, Res, ResMut,
            Resource, Startup, Update,
        },
        DefaultPlugins,
    },
    bevy_oddio::{
        builtins::sine::{self, Sine},
        output::AudioSink,
        Audio, AudioPlugin,
    },
    oddio::Sample,
};

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_plugins(AudioPlugin::new())
        .add_systems(Startup, init_assets)
        .add_systems(PostStartup, play_sine)
        .add_systems(Update, get_input)
        .run();
}

#[derive(Resource, Deref)]
struct SineHandle(Handle<Sine>);
#[derive(Resource)]
struct SineSink(Handle<AudioSink<Sine>>);

fn init_assets(mut commands: Commands, mut assets: ResMut<Assets<Sine>>) {
    let handle = assets.add(Sine);
    commands.insert_resource(SineHandle(handle));
}

fn play_sine(
    mut commands: Commands,
    mut audio: ResMut<Audio<Sample, Sine>>,
    sine: Res<SineHandle>,
) {
    // Note is in A4.
    let handle = audio.play(sine.clone(), sine::Settings::new(0.0, 440.0));
    commands.insert_resource(SineSink(handle));
}

fn get_input(
    keys: Res<Input<KeyCode>>,
    sink: Res<SineSink>,
    mut sinks: ResMut<Assets<AudioSink<Sine>>>,
) {
    let Some(sink) = sinks.get_mut(&sink.0) else {
        return;
    };

    let control = sink.control::<oddio::Stop<_>, _>();

    if keys.just_pressed(KeyCode::Space) {
        if control.is_paused() {
            control.resume();
        } else {
            control.pause();
        }
    }
}