use crate::{
    GameState, billboards::Billboard, global_observer, loading_assets::GameAssets,
    physics_layers::GameLayer, player::Player, sounds::PlaySound,
    squish_animation::SquishAnimation,
};
use avian3d::prelude::*;
use bevy::prelude::*;
use std::f32::consts::PI;

#[derive(Event, Reflect)]
pub struct HeadDrops(pub Vec3, pub usize);

#[derive(Component, Reflect)]
#[reflect(Component)]
struct HeadDrop(pub usize);

#[derive(Event, Reflect)]
pub struct HeadCollected(pub usize);

pub fn plugin(app: &mut App) {
    app.add_systems(Update, collect_head.run_if(in_state(GameState::Playing)));

    global_observer!(app, on_head_drop);
}

fn on_head_drop(trigger: Trigger<HeadDrops>, mut commands: Commands, assets: Res<GameAssets>) {
    let HeadDrops(position, id) = trigger.event();

    let angle = rand::random::<f32>() * PI * 2.;
    let spawn_dir = Quat::from_rotation_y(angle) * Vec3::new(0.5, 0.6, 0.).normalize();

    commands.trigger(PlaySound::HeadDrop);

    commands
        .spawn((
            Name::new("headdrop"),
            HeadDrop(*id),
            Transform::from_translation(*position),
            Visibility::default(),
            Collider::sphere(1.5),
            ExternalImpulse::new(spawn_dir * 180.).with_persistence(false),
            LockedAxes::ROTATION_LOCKED,
            RigidBody::Dynamic,
            CollisionLayers::new(LayerMask(GameLayer::Collectibles.to_bits()), LayerMask::ALL),
            CollisionEventsEnabled,
            Restitution::new(0.6),
        ))
        .with_child((
            Billboard,
            SquishAnimation(2.6),
            SceneRoot(assets.mesh_head_drop.clone()),
        ));
}

fn collect_head(
    mut commands: Commands,
    mut collision_event_reader: EventReader<CollisionStarted>,
    query_player: Query<&Player>,
    query_collectable: Query<&HeadDrop>,
) {
    for CollisionStarted(e1, e2) in collision_event_reader.read() {
        let collectable = if query_player.contains(*e1) && query_collectable.contains(*e2) {
            *e2
        } else if query_player.contains(*e2) && query_collectable.contains(*e1) {
            *e1
        } else {
            continue;
        };

        let key = query_collectable.get(collectable).unwrap();

        commands.trigger(PlaySound::HeadCollect);
        commands.trigger(HeadCollected(key.0));
        commands.entity(collectable).despawn();
    }
}