1 files changed, 58 insertions, 0 deletions
diff --git a/azalea-entity/src/plugin/effect_events.rs b/azalea-entity/src/plugin/effect_events.rs
new file mode 100644
index 00000000..2d37c463
--- /dev/null
+++ b/azalea-entity/src/plugin/effect_events.rs
@@ -0,0 +1,58 @@
+use azalea_registry::builtin::MobEffect;
+use bevy_ecs::{entity::Entity, event::EntityEvent, observer::On, system::Query};
+use tracing::warn;
+
+use crate::{ActiveEffects, Attributes, MobEffectData, effects::attribute_modifier_for_effect};
+
+#[derive(EntityEvent)]
+pub struct AddEffectEvent {
+    pub entity: Entity,
+    pub id: MobEffect,
+    pub data: MobEffectData,
+}
+pub fn handle_add_effect(
+    add_effect: On<AddEffectEvent>,
+    mut query: Query<(&mut ActiveEffects, &mut Attributes)>,
+) {
+    let Ok((mut active_effects, mut attributes)) = query.get_mut(add_effect.entity) else {
+        warn!("got handle_add_effect for an entity without the required components");
+        return;
+    };
+
+    active_effects.insert(add_effect.id, add_effect.data.clone());
+
+    if let Some((attribute, modifier)) = attribute_modifier_for_effect(add_effect.id) {
+        let modifier = modifier.create(add_effect.data.amplifier);
+        if let Some(attribute) = attributes.get_mut(attribute) {
+            attribute.insert(modifier);
+        }
+    }
+}
+
+#[derive(EntityEvent)]
+pub struct RemoveEffectsEvent {
+    pub entity: Entity,
+    pub effects: Vec<MobEffect>,
+}
+pub fn handle_remove_effects(
+    remove_effects: On<RemoveEffectsEvent>,
+    mut query: Query<(&mut ActiveEffects, &mut Attributes)>,
+) {
+    let Ok((mut active_effects, mut attributes)) = query.get_mut(remove_effects.entity) else {
+        warn!("got handle_remove_effects for an entity without the required components");
+        return;
+    };
+
+    for &effect in &remove_effects.effects {
+        active_effects.remove(effect);
+
+        if let Some((attribute, modifier)) = attribute_modifier_for_effect(effect) {
+            // we're just trying to get the id of the modifier, so the amplifier passed here
+            // doesn't matter
+            let modifier = modifier.create(0);
+            if let Some(attribute) = attributes.get_mut(attribute) {
+                attribute.remove(&modifier.id);
+            }
+        }
+    }
+}