use bevy::{app::{App, Plugin, Startup, Update}, ecs::{component::Component, system::{Commands, Query}}, math::{Quat, Vec3}, transform::components::Transform};
use kira::{AudioManager, AudioManagerSettings, DefaultBackend, Tween, listener::ListenerHandle};

use crate::source::FelixAudioSource;

pub const SAMPLE_RATE: usize = 48_000;
pub const BUFFER_SIZE: usize = 512;

const MONO_20MS: usize = SAMPLE_RATE * 20 / 1000;

pub mod source;
pub mod utils;
pub mod voice;

// TODO: Make this use HRTF at some point
//       Maybe revisit steam audio?
//       Or just find some other library that does HRTFs.

fn update_audio_system(
  mut audio_system: Query<&mut FelixAudioComponent>,
  listener: Query<(&FelixAudioListener, &Transform)>,
  sources: Query<(&mut FelixAudioSource, &Transform)>,
){
  let mut audio_system = audio_system.single_mut().expect("Cannot find FelixAudioComponent, has audio system been initialised?");
  let ( _, listener_transform ) = listener.single().expect("Cannot find FelixAudioListener.");

  audio_system.main_listener.set_position(listener_transform.translation, Tween::default());
  audio_system.main_listener.set_orientation(listener_transform.rotation, Tween::default());

  for ( mut source, transform ) in sources{
    if source.needs_init(){
      source.init(&mut audio_system);
    } else {
      source.update(transform);
    }
  }
}

#[derive(Component)]
pub struct FelixAudioListener;

#[derive(Component)]
pub struct FelixAudioComponent{
  manager: AudioManager<DefaultBackend>,
  main_listener: ListenerHandle
}

pub struct FelixAudio;

impl Plugin for FelixAudio{
  fn build(&self, app: &mut App) {
    app.add_systems(Startup, move | mut commands: Commands | {
      let mut manager = AudioManager::<DefaultBackend>::new(AudioManagerSettings::default()).unwrap();
      let main_listener = manager.add_listener(Vec3::default(), Quat::default()).unwrap();

      let handle = FelixAudioComponent { manager, main_listener };

      commands.spawn(handle);
    });

    app.add_systems(Update, update_audio_system);
  }
}