#pragma once

#include <filesystem>
#include <charconv>
#include <string_view>

#include "glm/mat4x4.hpp"
#include "util/result.hpp"
#include "util/string_list.hpp"
#include "assets/data_stores.hpp"
#include "assets/path_id_lookups.hpp"

#include "assets/data/point_cloud_data.hpp"
#include "assets/data_stores/point_cloud_store.hpp"

namespace assets
{

template<bool Normal, bool Color, bool Reflectance>
struct generic_3dtk_loader
{
	using data_type = point_cloud_data;
	using store_type = point_cloud_data;
	using lookup_type = point_cloud_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::vector<mesh_vertex_components::position> m_position_buffer{};
		std::vector<mesh_vertex_components::normal> m_normal_buffer{};
		std::vector<mesh_vertex_components::tex_coord> m_tex_coord_buffer{};
		std::unordered_map<component_indices, z3d::vertex_index> m_vertex_comp_indices_to_vertex_index{};
	};

	[[nodiscard]] static ztu::result<pose_prefetch_lookup::index_type> parse_index(
		std::string_view filename
	);

	ztu::result<std::pair<ztu::u32, std::chars_format>> analyze_component_format(
		std::string_view line
	);

	void transform_point_cloud(
		std::span<point_cloud_vertex_components::position::value_type> points,
		const glm::mat4& pose
	);

private:
	std::error_code read_point_file(
		const std::filesystem::path& filename,
		dynamic_point_cloud_buffer& point_cloud
	);

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

}

#define INCLUDE_GENERIC_3DTK_LOADER_IMPLEMENTATION
#include "assets/file_parsers/generic/generic_3dtk_loader.ipp"
#undef INCLUDE_GENERIC_3DTK_LOADER_IMPLEMENTATION