target ui indicating health too (#17)

src/npc.rs

@@ -1,4 +1,9 @@
-use crate::{keys::KeySpawn, sounds::PlaySound, tb_entities::EnemySpawn};
+use std::{collections::HashMap, usize};
+
+use crate::{
+    heads_ui::HEAD_COUNT, keys::KeySpawn, player::head_id_to_str, sounds::PlaySound,
+    tb_entities::EnemySpawn,
+};
 use bevy::prelude::*;
 
 #[derive(Event, Reflect)]
@@ -7,22 +12,47 @@ pub struct Hit {
 }
 
 #[derive(Component, Reflect)]
-struct Hp(i32);
+pub struct Hitpoints {
+    max: i32,
+    current: i32,
+}
+
+impl Hitpoints {
+    fn new(v: i32) -> Self {
+        Self { max: v, current: v }
+    }
+
+    pub fn health(&self) -> f32 {
+        self.current as f32 / self.max as f32
+    }
+}
+
+#[derive(Component)]
+pub struct NpcHead(pub usize);
 
 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);
+// TODO: use game state to initialize only once
+fn init(mut commands: Commands, query: Query<(Entity, &EnemySpawn), Without<Hitpoints>>) {
+    let mut names: HashMap<String, usize> = HashMap::default();
+    for i in 0..HEAD_COUNT {
+        names.insert(head_id_to_str(i).to_string(), i);
+    }
+    for (e, spawn) in query.iter() {
+        let id = names[&spawn.head];
+        commands
+            .entity(e)
+            .insert((Hitpoints::new(100), NpcHead(id)))
+            .observe(on_hit);
     }
 }
 
 fn on_hit(
     trigger: Trigger<Hit>,
     mut commands: Commands,
-    mut query: Query<(&mut Hp, &Transform, &EnemySpawn)>,
+    mut query: Query<(&mut Hitpoints, &Transform, &EnemySpawn)>,
 ) {
     let Hit { damage } = trigger.event();
 
@@ -32,11 +62,11 @@ fn on_hit(
 
     commands.trigger(PlaySound::Hit);
 
-    hp.0 = hp.0.saturating_sub(*damage as i32);
+    hp.current = hp.current.saturating_sub(*damage as i32);
 
-    info!("npc hp changed: {} [{}]", hp.0, trigger.entity());
+    info!("npc hp changed: {} [{}]", hp.current, trigger.entity());
 
-    if hp.0 <= 0 {
+    if hp.current <= 0 {
         commands.entity(trigger.entity()).despawn_recursive();
 
         if !enemy.key.is_empty() {