Refactor the entity out.

entity.cpp

@@ -0,0 +1,37 @@
+#include "entity.hpp"
+
+void Entity::move(Point loc) {
+  location = loc;
+}
+
+void Entity::event(EntityEvent ev) {
+  switch(_state) {
+    FSM_STATE(EntityState, START, ev);
+    FSM_STATE(EntityState, HUNTING, ev);
+    FSM_STATE(EntityState, DEAD, ev);
+  }
+}
+
+void Entity::START(EntityEvent ev) {
+  state(EntityState::HUNTING);
+}
+
+void Entity::HUNTING(EntityEvent ev) {
+  switch(ev) {
+    case EntityEvent::HIT:
+      hp -= damage;
+      break;
+    default:
+      state(EntityState::HUNTING);
+  }
+
+  if(hp <= 0) {
+    state(EntityState::DEAD);
+  } else {
+    state(EntityState::HUNTING);
+  }
+}
+
+void Entity::DEAD(EntityEvent ev) {
+  state(EntityState::DEAD);
+}