#pragma once

#include <unordered_map>
#include <bit>
#include <format>
#include <ranges>
#include <bits/ranges_algo.h>

#include "assets/data_stores/shader_source_store.hpp"
#include "opengl/shader_program_lookup.hpp"
#include "opengl/handles/shader_handle.hpp"
#include "util/string_lookup.hpp"
#include "shader_source_manager.hpp"
#include "assets/data_stores.hpp"
#include "opengl/metadata/shader_metadata.hpp"
#include "opengl/data/shader_data.hpp"
#include "opengl/handles/shader_handle_set.hpp"
#include "opengl/shading/requirements/shader_requirements.hpp"
#include "opengl/metadata/shader_set_metadata.hpp"
#include "opengl/shading/requirements/shader_set_requirements.hpp"

namespace zgl
{
class shader_manager
{
	using metadata_type = shader_metadata;
	using data_type = shader_data;
	using handle_type = shader_handle;
	using entry_type = std::pair<metadata_type, data_type>;
	using entry_view_type = std::pair<metadata_type, handle_type>;

public:

	void process(const assets::data_stores& stores);

	void get_handles(
		const assets::shader_source_store& shader_sources,
		std::span<const shading::shader_set_requirements> requirements,
		std::span<shader_set_metadata> metadata,
		std::span<shader_handle_set> shader_sets
	);

protected:
	std::optional<entry_view_type> find_shader(
		const shading::shader_requirements& requirements
	);

	static bool compile_shader(
		GLenum shader_type,
		std::span<const char*> source_strings,
		shader_data& shader
	);


	shader_source_manager m_preprocessor{};
	std::vector<entry_type> m_shader_lookup{};

private:
	std::vector<shading::shader_source_requirements> m_source_requirement_buffer{};
	std::vector<preprocessed_shader_source_metadata> m_preprocessed_shader_source_metadata_buffer{};
	std::vector<const char*> m_source_strings_buffer{};
};
}