#pragma once

#include "RcPtr.hpp"

#include <glad/glad.h>
#include <glm/glm.hpp>
#include <memory>

// TODO abstract texture traits such as component sizes from OpenGL

class TextureInfo {
public:
	glm::ivec2 size;
	bool isAtlas = false;
};

class Texture : public RefCounted {
	friend class TextureStitcher;

private:
	TextureInfo mInfo;
	GLuint mHandle = 0;

public:
	Texture() = default;
	~Texture();

	Texture(const Texture&) = delete;
	Texture& operator=(const Texture&) = delete;
	Texture(Texture&&) = default;
	Texture& operator=(Texture&&) = default;

	enum Filtering {
		LinearFilter,
		NearestFilter,
	};

	struct TextureProperties {
		Filtering minifyingFilter = LinearFilter;
		Filtering magnifyingFilter = LinearFilter;
	};

	bool InitFromFile(const char* filePath, const TextureProperties& props, bool flipVertically = false);
	// bool InitFromImage(const Image& image, const TextureProperties& props, bool flipVertically = false);

	const TextureInfo& GetInfo() const;
	GLuint GetHandle() const;

	bool IsValid() const;
};

/// A pure numerical subregion of a texture. u0/v0 are the UV coordinates of bottom left
/// corner, and u1/v1 are the top left corner.
struct Subregion {
	/// Bottom left corner
	float u0 = 0.0f;
	float v0 = 0.0f;
	/// Top right corner
	float u1 = 0.0f;
	float v1 = 0.0f;
};

/// A subregion of a specific texture.
struct TextureSubregion : public Subregion {
	RcPtr<Texture> atlasTexture;
};