#pragma once

#include "core/io/resource.h"
#include "core/math/expression.h"
#include "core/object/object.h"
#include "modules/noise/noise.h"
#include "terrain_editor/macros.h"

class TerrainPrimitive : public Resource {
	GDCLASS(TerrainPrimitive, Resource);
	static void _bind_methods();

public:
	GDENUM(BlendMode,
			Peak,
			Valley,
			Both)

protected:
	float blend(float under, float over) const;

public:
	// evaluate the height of this primitive at point, returns the weight of the effect, out_height will be set to the closest point on the primitive
	virtual void evaluate(Vector2 at, float &io_height) const;

	void set_blend_mode(BlendMode mode);
	BlendMode get_blend_mode() const;
	void set_blend_range(float blend_range);
	float get_blend_range() const;

private:
	float blend_range{ 4.f };
	BlendMode blend_mode{ Peak };
};

MAKE_TYPE_INFO(TerrainPrimitive::BlendMode, Variant::INT);

class PlanePrimitive : public TerrainPrimitive {
	GDCLASS(PlanePrimitive, TerrainPrimitive);
	static void _bind_methods();

public:
	void evaluate(Vector2 at, float &io_height) const override;
	void set_baseline(float value);
	float get_baseline() const;

private:
	float baseline{ 1.f };
};

class PointPrimitive : public TerrainPrimitive {
	GDCLASS(PointPrimitive, TerrainPrimitive);
	static void _bind_methods();

public:
	void evaluate(Vector2 at, float &io_height) const override;
	void set_center(Vector2 center);
	Vector2 get_center() const;
	void set_slope(float radius);
	float get_slope() const;
	void set_height(float height);
	float get_height() const;

private:
	Vector2 center{ 0.f, 0.f };
	float slope{ -1.f };
	float height{ 10.f };
};

class NoisePrimitive : public TerrainPrimitive {
	GDCLASS(NoisePrimitive, TerrainPrimitive);
	static void _bind_methods();

public:
	void evaluate(Vector2 at, float &io_height) const override;
	void set_noise(Ref<Noise> noise);
	Ref<Noise> get_noise() const;
	void set_noise_scale(float pixels_per_meter);
	float get_noise_scale() const;
	void set_noise_amplitude(float height);
	float get_noise_amplitude() const;

private:
	Ref<Noise> noise{};
	float noise_scale{ 1.f };
	float noise_amplitude{ 1.f };
};

class ExpressionPrimitive : public TerrainPrimitive {
	GDCLASS(ExpressionPrimitive, TerrainPrimitive);
	static void _bind_methods();

public:
	void evaluate(Vector2 at, float &io_height) const override;
	void set_expression(String expression);
	String get_expression() const;

private:
	Ref<Expression> expression{ memnew(Expression) };
	String expression_string{ "height" };
	bool valid{ false };
};