#ifndef MultilevelAStarEx_H
#define MultilevelAStarEx_H

#include <gdextension_interface.h>
#include <godot_cpp/classes/ref.hpp>
#include <godot_cpp/variant/array.hpp>
#include <godot_cpp/variant/vector2i.hpp>

#include <vector>

namespace godot {

class Node {
	friend class MultilevelAStarEx;

public:
	enum NodeState
	{
		UNUSED, OPEN, CLOSED
	};

private:
	int openPass, closedPass;
	int x, y;

	Node *parent;
	int distanceFromStart;
	int distanceToEnd;

	int distanceToEndForClosest;

	static bool compare_nodes(const Node *left, const Node *right);

	Node(int x, int y);
	void open(int pass, Node *parent, int distanceFromStart, const Vector2i &end);
	void close(int pass);
	NodeState state(int pass) const;
	int total_cost() const;

public:
	Node();
};

class MultilevelAStarEx : public RefCounted
{
	GDCLASS(MultilevelAStarEx, RefCounted)

public:
	enum TerrainType
	{
		STAIRS = -1,
		BLOCKED = 0,
		GROUND = 1,
	};

private:
	bool _init;
	int _pass;
	std::vector<TerrainType> _terrain;
	std::vector<bool> _units;
	std::vector<Node> _nodes;

	Rect2i _region;
	Vector2i _trans;
	int _width, _height;

	bool can_move(const Node *current, int x, int y) const;
	TypedArray<Vector2i> generate_path(const Node *current) const;

protected:
	static void _bind_methods();

public:
	MultilevelAStarEx();
	~MultilevelAStarEx();

	void init(const Rect2i &region);
	Rect2i get_region() const;
	void set_terrain(const Vector2i &cell, TerrainType type);
	TerrainType get_terrain(const Vector2i &cell) const;
	void set_unit(const Vector2i &cell, bool blocked);
	bool get_unit(const Vector2i &cell) const;
	TypedArray<Vector2i> find_path(const Vector2i &from, const Vector2i &to, bool return_closest);
};

}

VARIANT_ENUM_CAST(MultilevelAStarEx::TerrainType);

#endif