#pragma once

#include <filesystem>
#include <system_error>

#include "assets/data_stores.hpp"
#include "assets/path_id_lookups.hpp"
#include "assets/prefetch_lookup.hpp"
#include "assets/prefetch_queue.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 parser_context
	{
	public:
		parser_context(
			const texture_id_lookup& texture_id_lookup,
			material_id_lookup& material_id_lookup,
			material_store& material_store,
			store_type& store
		);

		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:
		const texture_id_lookup* m_texture_id_lookup;
		material_id_lookup* m_material_id_lookup;
		material_store* m_material_store;
		store_type* m_store;
		data_type m_buffer{};
	};

	static void find_textures(
		std::span<char> buffer,
		std::filesystem::path& path_buffer,
		const std::filesystem::path& base_directory,
		std::ifstream& in,
		ztu::string_list& texture_filenames
	);

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

}