#pragma once

#include "EditorAttachment.hpp"
#include "RcPtr.hpp"
#include "Shader.hpp"
#include "Texture.hpp"

#include <glad/glad.h>
#include <cstddef>
#include <cstdint>
#include <filesystem>
#include <glm/glm.hpp>
#include <memory>
#include <span>
#include <string_view>
#include <vector>

class MaterialManager;
class Material : public RefCounted {
public: // NOTE: public for internal helpers and editor
	// NOTE: specialize between scalar vs matrix vs vector to save memory

	struct ScalarUniform {
		union {
			float floatValue;
			int32_t intValue;
			uint32_t uintValue;
		};
		GLenum actualType;
		/* Saves 'name' */ int infoUniformIndex;
		/* Transient */ GLint location;
	};

	struct VectorUniform {
		float value[4];
		int actualLength;
		/* Saves 'name' */ int infoUniformIndex;
		/* Transient */ GLint location;
	};

	struct MatrixUniform {
		float value[16];
		int actualWidth;
		int actualHeight;
		/* Saves 'name' */ int infoUniformIndex;
		/* Transient */ GLint location;
	};

	struct TextureUniform {
		RcPtr<Texture> value;
		/* Saves 'name' */ int infoUniformIndex;
		/* Transient */ GLint location;
	};

	std::string mName;
	std::unique_ptr<EditorAttachment> mEditorAttachment;
	RcPtr<Shader> mShader;
	std::vector<ScalarUniform> mBoundScalars;
	std::vector<VectorUniform> mBoundVectors;
	std::vector<MatrixUniform> mBoundMatrices;
	std::vector<TextureUniform> mBoundTextures;

public:
	// NOTE: constructs invalid object
	Material() = default;
	Material(Shader* shader, std::string name = "");

	void SetFloat(const char* name, float value);
	void SetInt(const char* name, int32_t value);
	void SetUInt(const char* name, uint32_t value);

	/// Instanciated for length == 1, 2, 3, 4
	template <int length>
	void SetVector(const char* name, const glm::vec<length, float>& vec);

	/// Instanciated for sizes (2,2) (3,3) (4,4) (2,3) (3,2) (2,4) (4,2) (3,4) (4,3)
	template <int width, int height>
	void SetMatrix(const char* name, const glm::mat<width, height, float>& mat);

	void SetTexture(const char* name, Texture* texture);

	std::span<const VectorUniform> GetVectors() const;
	std::span<const MatrixUniform> GetMatrices() const;
	std::span<const TextureUniform> GetTextures() const;
	Shader* GetShader() const;
	void SetShader(Shader* shader);
	const std::string& GetName() const;

	bool IsAnnoymous() const;
	bool IsValid() const;

	void UseUniforms() const;

	EditorAttachment* GetEditorAttachment() const { return mEditorAttachment.get(); }
	void SetEditorAttachment(EditorAttachment* attachment) { mEditorAttachment.reset(attachment); }

	void GetDesignatedPath(char* buffer, int bufferSize);
	std::filesystem::path GetDesignatedPath();

	bool SaveToFile(const std::filesystem::path& filePath) const;
	bool LoadFromFile(const std::filesystem::path& filePath);
};

class MaterialManager {
public:
	static inline MaterialManager* instance = nullptr;

private:
	absl::flat_hash_map<std::string_view, RcPtr<Material>> mMaterials;

public:
	void DiscoverMaterials();

	std::pair<Material*, bool> SaveMaterial(Material* mat);
	void DeleteMaterial(Material* mat, bool onDisk = false);
	Material* LoadMaterial(std::string_view name);
	bool RenameMaterial(Material* mat, std::string newName);

	const auto& GetMaterials() const { return mMaterials; }
	Material* FindMaterial(std::string_view name);
};