#pragma once

#include <filesystem>
#include <system_error>
#include <string_view>
#include <unordered_map>

#include "assets/data_stores.hpp"
#include "assets/data/mesh_data.hpp"
#include "assets/data_stores.hpp"
#include "assets/path_id_lookups.hpp"
#include "util/vector_hash.hpp"

namespace assets
{

struct stl_loader
{
	static constexpr auto name = std::string_view("stl");
	using data_type = mesh_data;
	using store_type = mesh_store;
	using lookup_type = mesh_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(
			path_id_lookups& m_id_lookups,
			data_stores& m_stores
		);

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

	protected:
		void reset();

		z3d::vertex_index find_or_push_vertex(const component_indices& vertex_comp_indices);

		[[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_id_lookups;
		data_stores* m_stores;
		data_type m_mesh{};
		std::unordered_map<mesh_vertex_components::position, z3d::vertex_index> m_vertex_index_lookup{};
	};

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

}