feat: implemented enemies spawning based on current region difficulty

modules/wave_survival/enemy_spawner.h

@@ -0,0 +1,43 @@
+#ifndef ENEMY_SPAWNER_H
+#define ENEMY_SPAWNER_H
+
+#include "core/io/resource.h"
+#include "core/templates/hash_map.h"
+#include "scene/3d/node_3d.h"
+class MapRegion;
+class PatrolPath;
+
+class SpawnData : public Resource {
+	GDCLASS(SpawnData, Resource);
+	static void _bind_methods();
+
+public:
+	void set_difficulty_spawns(Dictionary dict);
+	Dictionary get_difficulty_spawns() const;
+
+public:
+	HashMap<int, Ref<PackedScene>> difficulty_spawns{};
+};
+
+class EnemySpawner : public Node3D {
+	GDCLASS(EnemySpawner, Node3D);
+	static void _bind_methods();
+	void on_phase_change(bool hunt);
+	void ready();
+
+protected:
+	void _notification(int what);
+
+public:
+	void set_spawn_data(Ref<SpawnData> data);
+	Ref<SpawnData> get_spawn_data() const;
+	void set_patrol_path(PatrolPath *path);
+	PatrolPath *get_patrol_path() const;
+
+private:
+	Ref<SpawnData> spawn_data{};
+	PatrolPath *patrol_path{ nullptr };
+	MapRegion *region{ nullptr };
+};
+
+#endif // !ENEMY_SPAWNER_H