autotarget retal; most units are aggressive now

OpenRa.Game/Traits/AutoTarget.cs

@@ -5,15 +5,24 @@ using System.Text;
 
 namespace OpenRa.Game.Traits
 {
-	class AutoTarget : ITick
+	class AutoTarget : ITick, INotifyDamage
 	{
 		public AutoTarget(Actor self) {}
 
-		public void Tick(Actor self)
+		void AttackTarget(Actor self, Actor target)
 		{
 			var attack = self.traits.WithInterface<AttackBase>().First();
-			
+			if (target != null)
+				attack.ResolveOrder(self, new Order("Attack", self, target, int2.Zero, null));
+		}
+
+		public void Tick(Actor self)
+		{
+			if (!self.IsIdle) return;
+
+			var attack = self.traits.WithInterface<AttackBase>().First();
 			var range = Rules.WeaponInfo[self.Info.Primary].Range;
+			
 			if (attack.target == null || 
 				(attack.target.Location - self.Location).LengthSquared > range * range + 2)
 				attack.target = ChooseTarget(self, range);
@@ -27,5 +36,20 @@ namespace OpenRa.Game.Traits
 				.OrderBy(a => (a.Location - self.Location).LengthSquared)
 				.FirstOrDefault();
 		}
+
+		public void Damaged(Actor self, AttackInfo e)
+		{
+			// not a lot we can do about things we can't hurt... although maybe we should automatically run away?
+			if (!Combat.HasAnyValidWeapons(self, e.Attacker))
+				return;
+
+			if (e.Attacker.Owner == self.Owner)
+				return;	// don't retaliate against own units force-firing on us. it's usually not what the player wanted.
+
+			var attack = self.traits.WithInterface<AttackBase>().First();
+			if (attack.target != null) return;
+
+			AttackTarget(self, e.Attacker);
+		}
 	}
 }