use crate::{keys::KeySpawn, tb_entities::EnemySpawn};
use bevy::prelude::*;

#[derive(Event, Reflect)]
pub struct Hit {
    pub damage: u32,
}

#[derive(Component, Reflect)]
struct Hp(i32);

pub fn plugin(app: &mut App) {
    app.add_systems(Update, init);
}

fn init(mut commands: Commands, query: Query<Entity, (With<EnemySpawn>, Without<Hp>)>) {
    for e in query.iter() {
        commands.entity(e).insert(Hp(100)).observe(on_hit);
    }
}

fn on_hit(
    trigger: Trigger<Hit>,
    mut commands: Commands,
    mut query: Query<(&mut Hp, &Transform, &EnemySpawn)>,
) {
    let Hit { damage } = trigger.event();

    let Ok((mut hp, transform, enemy)) = query.get_mut(trigger.entity()) else {
        return;
    };

    hp.0 = hp.0.saturating_sub(*damage as i32);

    info!("npc hp changed: {} [{}]", hp.0, trigger.entity());

    if hp.0 <= 0 {
        commands.entity(trigger.entity()).despawn_recursive();

        if !enemy.key.is_empty() {
            commands.trigger(KeySpawn(transform.translation, enemy.key.clone()));
        }
    }
}