Rewrite entity ai to be more flexible and follow game dev standards

src/main/kotlin/io/github/dockyardmc/entity/Entity.kt

@@ -72,6 +72,8 @@
     val stuckArrows: Bindable<Int> = bindablePool.provideBindable(0)
     var gravityTickCount = 0
 
+    val maxHealth get() = health.defaultValue
+
     val potionEffects: BindableMap<PotionEffect, AppliedPotionEffect> = bindablePool.provideBindableMap()
     val isInvisible: Bindable<Boolean> = bindablePool.provideBindable(false)
     val isGlowing: Bindable<Boolean> = bindablePool.provideBindable(false)
@@ -193,6 +195,11 @@
         teleport(newLoc)
     }
 
+    open fun lookAt(targetLocation: Location) {
+        val newLoc = this.location.setDirection(targetLocation.toVector3d() - (this.location).toVector3d())
+        teleport(newLoc)
+    }
+
     open fun lookAtClientside(target: Entity, player: Player) {
         lookAtClientside(target, listOf(player))
     }

src/main/kotlin/io/github/dockyardmc/entity/Warden.kt

@@ -12,7 +12,7 @@ import io.github.dockyardmc.protocol.packets.play.clientbound.EntityEvent
 import io.github.dockyardmc.registry.EntityTypes
 import io.github.dockyardmc.registry.registries.EntityType
 
-open class Warden(location: Location): Entity(location) {
+open class Warden(location: Location) : Entity(location) {
     override var type: EntityType = EntityTypes.WARDEN
     override val health: Bindable<Float> = Bindable(500f)
     override var inventorySize: Int = 0
@@ -27,7 +27,7 @@ open class Warden(location: Location): Entity(location) {
 
     fun playAnimation(animation: WardenAnimation) {
 
-        when(animation) {
+        when (animation) {
             WardenAnimation.EMERGE -> pose.value = EntityPose.EMERGING
             WardenAnimation.ROAR -> pose.value = EntityPose.ROARING
             WardenAnimation.SNIFF -> pose.value = EntityPose.SNIFFING

src/main/kotlin/io/github/dockyardmc/entity/Zombie.kt

@@ -0,0 +1,33 @@
+package io.github.dockyardmc.entity
+
+import cz.lukynka.bindables.Bindable
+import io.github.dockyardmc.entity.metadata.EntityMetaValue
+import io.github.dockyardmc.entity.metadata.EntityMetadata
+import io.github.dockyardmc.entity.metadata.EntityMetadataType
+import io.github.dockyardmc.location.Location
+import io.github.dockyardmc.protocol.packets.play.clientbound.ClientboundPlayerAnimationPacket
+import io.github.dockyardmc.protocol.packets.play.clientbound.EntityAnimation
+import io.github.dockyardmc.registry.EntityTypes
+import io.github.dockyardmc.registry.registries.EntityType
+
+open class Zombie(location: Location) : Entity(location) {
+    override var type: EntityType = EntityTypes.ZOMBIE
+    override val health: Bindable<Float> = bindablePool.provideBindable(20f)
+    override var inventorySize: Int = 0
+
+    val raisedArms: Bindable<Boolean> = bindablePool.provideBindable(false)
+
+    fun swingHands() {
+        this.sendPacketToViewers(ClientboundPlayerAnimationPacket(this, EntityAnimation.SWING_MAIN_ARM))
+    }
+
+    init {
+        raisedArms.valueChanged { event ->
+            if (event.newValue) {
+                this.metadata[EntityMetadataType.ZOMBIE_RAISED_ARMS] = EntityMetadata(EntityMetadataType.ZOMBIE_RAISED_ARMS, EntityMetaValue.BYTE, 0x0)
+            } else {
+                this.metadata.remove(EntityMetadataType.ZOMBIE_RAISED_ARMS)
+            }
+        }
+    }
+}