fix(entity): feeding a parrot a cookie poisons and kills it (#2564)

`ParrotEntity` had no interact handler, so a cookie used on a parrot did
nothing at all. Vanilla `Parrot.mobInteract` consumes the cookie, applies
poison for 900 ticks and then kills the parrot.

The branch is gated on the `parrot_poisonous_food` item tag rather than on
the cookie id, matching vanilla. Anything else falls through to the default
mob interaction, so leashing and name tags keep working.

pumpkin/src/entity/passive/parrot.rs

@@ -1,16 +1,25 @@
 use std::sync::{Arc, Weak};
 
+use pumpkin_data::damage::DamageType;
+use pumpkin_data::effect::StatusEffect;
 use pumpkin_data::entity::EntityType;
+use pumpkin_data::item_stack::ItemStack;
+use pumpkin_data::tag::{self, Taggable};
 
 use crate::entity::{
-    Entity, NBTStorage,
+    Entity, EntityBase, EntityBaseFuture, NBTStorage,
     ai::goal::{
         look_around::RandomLookAroundGoal, look_at_entity::LookAtEntityGoal, swim::SwimGoal,
         wander_around::WanderAroundGoal,
     },
     mob::{Mob, MobEntity},
+    player::Player,
 };
 
+/// Duration in ticks of the poison a parrot gets from eating a cookie, matching
+/// vanilla `Parrot.mobInteract`.
+const COOKIE_POISON_DURATION: i32 = 900;
+
 /// Represents a Parrot, a passive flying mob that can mimic nearby mob sounds.
 ///
 /// Wiki: <https://minecraft.wiki/w/Parrot>
@@ -42,6 +51,38 @@ impl ParrotEntity {
 
         mob_arc
     }
+
+    /// Feeds the parrot a cookie: it is poisoned and then killed, as in vanilla
+    /// `Parrot.mobInteract`.
+    async fn eat_cookie(&self, player: &Arc<Player>, item_stack: &mut ItemStack) {
+        item_stack.decrement_unless_creative(player.gamemode.load(), 1);
+
+        self.mob_entity
+            .living_entity
+            .add_effect(pumpkin_data::potion::Effect {
+                effect_type: &StatusEffect::POISON,
+                duration: COOKIE_POISON_DURATION,
+                amplifier: 0,
+                ambient: false,
+                show_particles: true,
+                show_icon: true,
+                blend: true,
+            })
+            .await;
+
+        // Vanilla guards this call with `player.isCreative() || !this.isInvulnerable()`,
+        // but `hurt` re-checks invulnerability itself and `player_attack` doesn't bypass
+        // it, so the guard only skips a call that would do nothing anyway.
+        self.damage_with_context(
+            self,
+            f32::MAX,
+            DamageType::PLAYER_ATTACK,
+            None,
+            Some(player.as_ref()),
+            Some(player.as_ref()),
+        )
+        .await;
+    }
 }
 
 impl NBTStorage for ParrotEntity {}
@@ -50,4 +91,52 @@ impl Mob for ParrotEntity {
     fn get_mob_entity(&self) -> &MobEntity {
         &self.mob_entity
     }
+
+    fn mob_interact<'a>(
+        &'a self,
+        player: &'a Arc<Player>,
+        item_stack: &'a mut ItemStack,
+    ) -> EntityBaseFuture<'a, bool> {
+        Box::pin(async move {
+            // Vanilla checks the poisonous food tag last, after taming, which isn't
+            // implemented yet. Nothing in `parrot_food` is also in
+            // `parrot_poisonous_food`, so the two branches can't be confused.
+            if !item_stack
+                .get_item()
+                .has_tag(&tag::Item::MINECRAFT_PARROT_POISONOUS_FOOD)
+            {
+                return self.mob_entity.mob_interact(player, item_stack).await;
+            }
+
+            self.eat_cookie(player, item_stack).await;
+            true
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::COOKIE_POISON_DURATION;
+    use pumpkin_data::item::Item;
+    use pumpkin_data::tag::{self, Taggable};
+
+    /// The interaction is gated on the vanilla `parrot_poisonous_food` tag rather than
+    /// on a hardcoded cookie id, so check the tag actually resolves the way the
+    /// interaction assumes.
+    #[test]
+    fn cookie_is_poisonous_parrot_food() {
+        assert!(Item::COOKIE.has_tag(&tag::Item::MINECRAFT_PARROT_POISONOUS_FOOD));
+    }
+
+    /// Seeds tame a parrot in vanilla and must not reach the poison branch.
+    #[test]
+    fn parrot_food_is_not_poisonous() {
+        assert!(!Item::WHEAT_SEEDS.has_tag(&tag::Item::MINECRAFT_PARROT_POISONOUS_FOOD));
+        assert!(!Item::COOKED_CHICKEN.has_tag(&tag::Item::MINECRAFT_PARROT_POISONOUS_FOOD));
+    }
+
+    #[test]
+    fn poison_lasts_45_seconds() {
+        assert_eq!(COOKIE_POISON_DURATION, 900);
+    }
 }