#pragma once

#include <filesystem>
#include <system_error>

#include "assets/data_stores.hpp"
#include "assets/path_id_lookups.hpp"
#include "assets/data/material_data.hpp"
#include "assets/data/material_library_data.hpp"
#include "assets/data_stores/material_store.hpp"
#include "assets/data_stores/material_library_store.hpp"
#include "util/result.hpp"

namespace assets
{

namespace mtl_parser_error
{
enum class codes {
	ok = 0,
	cannot_open_file,
	// TODO these are incomplete
	cannot_open_texture,
	malformed_ambient_color,
	malformed_diffuse_color,
	malformed_specular_color,
	malformed_specular_exponent,
	malformed_dissolve,
	unknown_line_begin
};
} // namespace mtl_loader_error

struct mtl_parser
{
	static constexpr auto name = std::string_view("mtl");
	using data_type = material_library_data;
	using store_type = material_library_store;
	using lookup_type = material_library_id_lookup;

	[[nodiscard]] std::error_code prefetch(
		path_id_lookups& lookups
	);

	[[nodiscard]] std::error_code load(
		path_id_lookups& lookups,
		data_stores& stores,
		bool pedantic = false
	);

protected:
	class prefetcher_context
	{
	public:
		prefetcher_context(
			path_id_lookups& lookups
		);

		void operator()(lookup_type::const_pointer entry) noexcept;

	protected:

		[[nodiscard]] std::optional<texture_id> fetch_texture_id(
			const std::filesystem::path& mtl_dir,
			std::string_view filename,
			std::string_view texture_type_name
		);

	private:
		path_id_lookups* m_lookups;
		std::vector<char> m_buffer{};
	};


	class parser_context
	{
	public:
		parser_context(
			path_id_lookups& lookups,
			data_stores& stores
		);

		void operator()(lookup_type::const_pointer entry) noexcept;

	protected:
		void reset();

		[[nodiscard]] std::optional<texture_id> fetch_texture_id(
			const std::filesystem::path& mtl_dir,
			std::string_view filename,
			std::string_view texture_type_name
		);

	private:
		path_id_lookups* m_lookups;
		data_stores* m_stores;
		data_type m_buffer{};
	};

private:
	std::vector<lookup_type::const_pointer> m_path_buffer;
};

}