argument-parser/src/headers/parser/parser_v2.hpp

#pragma once
#include <argument_parser.hpp>
#include <array>
#include <cstdlib>
#include <fake_parser.hpp>
#include <initializer_list>
#include <memory>
#include <optional>
#include <stdexcept>
#include <string>
#include <string_view>
#include <unordered_map>
#include <variant>
#include <vector>

namespace argument_parser::v2 {
	namespace internal {
		static inline fake_parser fake_parser{};
	}

	enum class add_argument_flags { ShortArgument, LongArgument, HelpText, Action, Required };

	namespace flags {
		constexpr static inline add_argument_flags ShortArgument = add_argument_flags::ShortArgument;
		constexpr static inline add_argument_flags LongArgument = add_argument_flags::LongArgument;
		constexpr static inline add_argument_flags HelpText = add_argument_flags::HelpText;
		constexpr static inline add_argument_flags Action = add_argument_flags::Action;
		constexpr static inline add_argument_flags Required = add_argument_flags::Required;
	} // namespace flags

	class base_parser : private argument_parser::base_parser {
	public:
		template <typename T> using typed_flag_value = std::variant<std::string, parametered_action<T>, bool>;
		using non_typed_flag_value = std::variant<std::string, non_parametered_action, bool>;

		template <typename T> using typed_argument_pair = std::pair<add_argument_flags, typed_flag_value<T>>;
		using non_typed_argument_pair = std::pair<add_argument_flags, non_typed_flag_value>;

		template <typename T>
		void add_argument(std::unordered_map<add_argument_flags, typed_flag_value<T>> const &argument_pairs) {
			add_argument_impl<true, parametered_action<T>, T>(argument_pairs);
		}

		template <typename T> void add_argument(std::initializer_list<typed_argument_pair<T>> const &pairs) {
			std::unordered_map<add_argument_flags, typed_flag_value<T>> args;

			for (auto &[k, v] : pairs) {
				args[k] = v;
			}

			add_argument<T>(args);
		}

		void add_argument(std::initializer_list<non_typed_argument_pair> const &pairs) {
			std::unordered_map<add_argument_flags, non_typed_flag_value> args;

			for (auto &[k, v] : pairs) {
				args[k] = v;
			}

			add_argument(args);
		}

		void add_argument(std::unordered_map<add_argument_flags, non_typed_flag_value> const &argument_pairs) {
			add_argument_impl<false, non_parametered_action, void>(argument_pairs);
		}

		argument_parser::base_parser &to_v1() {
			return *this;
		}

		void handle_arguments(std::initializer_list<conventions::convention const *const> convention_types) {
			base::handle_arguments(convention_types);
		}

		template <typename T> std::optional<T> get_optional(std::string const &arg) {
			return base::get_optional<T>(arg);
		}

		void on_complete(std::function<void(argument_parser::base_parser const &)> const &action) {
			base::on_complete(action);
		}

	protected:
		void set_program_name(std::string p) {
			base::program_name = std::move(p);
		}

		std::vector<std::string> &ref_parsed_args() {
			return base::parsed_arguments;
		}

	private:
		template <bool IsTyped, typename ActionType, typename T, typename ArgsMap>
		void add_argument_impl(ArgsMap const &argument_pairs) {
			std::unordered_map<extended_add_argument_flags, bool> found_params{
				{extended_add_argument_flags::IsTyped, IsTyped}};

			std::string short_arg, long_arg, help_text;
			std::unique_ptr<action_base> action;
			bool required = false;

			if (argument_pairs.find(add_argument_flags::ShortArgument) != argument_pairs.end()) {
				found_params[extended_add_argument_flags::ShortArgument] = true;
				short_arg = get_or_throw<std::string>(argument_pairs.at(add_argument_flags::ShortArgument), "short");
			}
			if (argument_pairs.find(add_argument_flags::LongArgument) != argument_pairs.end()) {
				found_params[extended_add_argument_flags::LongArgument] = true;
				long_arg = get_or_throw<std::string>(argument_pairs.at(add_argument_flags::LongArgument), "long");
				if (short_arg.empty())
					short_arg = long_arg;
			} else {
				if (!short_arg.empty())
					long_arg = short_arg;
			}

			if (argument_pairs.find(add_argument_flags::Action) != argument_pairs.end()) {
				found_params[extended_add_argument_flags::Action] = true;
				action = get_or_throw<ActionType>(argument_pairs.at(add_argument_flags::Action), "action").clone();
			}
			if (argument_pairs.find(add_argument_flags::HelpText) != argument_pairs.end()) {
				help_text = get_or_throw<std::string>(argument_pairs.at(add_argument_flags::HelpText), "help");
			} else {
				help_text = short_arg + ", " + long_arg;
			}

			if (argument_pairs.find(add_argument_flags::Required) != argument_pairs.end() &&
				get_or_throw<bool>(argument_pairs.at(add_argument_flags::Required), "required")) {
				required = true;
			}

			auto suggested_add = suggest_candidate(found_params);
			if (suggested_add == candidate_type::unknown) {
				throw std::runtime_error("Could not match any add argument overload to given parameters. Are you "
										 "missing some required parameter?");
			}

			if constexpr (IsTyped) {
				switch (suggested_add) {
				case candidate_type::typed_action:
					base::add_argument(short_arg, long_arg, help_text, *static_cast<ActionType *>(&(*action)),
									   required);
					break;
				case candidate_type::store_other:
					base::add_argument<T>(short_arg, long_arg, help_text, required);
					break;
				default:
					throw std::runtime_error("Could not match the arguments against any overload.");
				}
			} else {
				switch (suggested_add) {
				case candidate_type::non_typed_action:
					base::add_argument(short_arg, long_arg, help_text, *static_cast<ActionType *>(&(*action)),
									   required);
					break;
				case candidate_type::store_boolean:
					base::add_argument(short_arg, long_arg, help_text, required);
					break;
				default:
					throw std::runtime_error(
						"Could not match the arguments against any overload. The suggested candidate was: " +
						std::to_string((int(suggested_add))));
				}
			}
		}

		using base = argument_parser::base_parser;
		enum class extended_add_argument_flags { ShortArgument, LongArgument, Action, IsTyped };

		enum class candidate_type { store_boolean, store_other, typed_action, non_typed_action, unknown };

		template <typename T, size_t S>
		bool satisfies_at_least_one(std::array<T, S> const &arr, std::unordered_map<T, bool> const &map) {
			for (const auto &req : arr) {
				if (map.find(req) != map.end())
					return true;
			}
			return false;
		}

		candidate_type suggest_candidate(std::unordered_map<extended_add_argument_flags, bool> const &available_vars) {
			auto constexpr required_at_least_one = std::array<extended_add_argument_flags, 2>{
				extended_add_argument_flags::ShortArgument, extended_add_argument_flags::LongArgument};
			if (!satisfies_at_least_one(required_at_least_one, available_vars))
				return candidate_type::unknown;

			if (available_vars.find(extended_add_argument_flags::Action) != available_vars.end()) {
				if (available_vars.at(extended_add_argument_flags::IsTyped))
					return candidate_type::typed_action;
				else
					return candidate_type::non_typed_action;
			}

			if (available_vars.at(extended_add_argument_flags::IsTyped))
				return candidate_type::store_other;
			return candidate_type::store_boolean;
		}

		template <typename T, typename I> T get_or_throw(typed_flag_value<I> const &v, std::string_view key) {
			if (auto p = std::get_if<T>(&v))
				return *p;
			throw std::invalid_argument(std::string("variant type mismatch for key: ") + std::string(key));
		}

		template <typename T> T get_or_throw(non_typed_flag_value const &v, std::string_view key) {
			if (auto p = std::get_if<T>(&v))
				return *p;
			throw std::invalid_argument(std::string("variant type mismatch for key: ") + std::string(key));
		}
	};
} // namespace argument_parser::v2