App.hpp

#pragma once

// Distributed under the 3-Clause BSD License.  See accompanying
// file LICENSE or https://github.com/CLIUtils/CLI11 for details.

#include <algorithm>
#include <deque>
#include <functional>
#include <iostream>
#include <iterator>
#include <memory>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <utility>
#include <vector>

// CLI Library includes
#include "CLI/ConfigFwd.hpp"
#include "CLI/Error.hpp"
#include "CLI/FormatterFwd.hpp"
#include "CLI/Macros.hpp"
#include "CLI/Option.hpp"
#include "CLI/Split.hpp"
#include "CLI/StringTools.hpp"
#include "CLI/TypeTools.hpp"

namespace CLI {

#ifndef CLI11_PARSE
#define CLI11_PARSE(app, argc, argv)                                                                                   \
    try {                                                                                                              \
        (app).parse((argc), (argv));                                                                                   \
    } catch(const CLI::ParseError &e) {                                                                                \
        return (app).exit(e);                                                                                          \
    }
#endif

namespace detail {
enum class Classifier { NONE, POSITIONAL_MARK, SHORT, LONG, WINDOWS, SUBCOMMAND, SUBCOMMAND_TERMINATOR };
struct AppFriend;
} // namespace detail

namespace FailureMessage {
std::string simple(const App *app, const Error &e);
std::string help(const App *app, const Error &e);
} // namespace FailureMessage

class App;

using App_p = std::shared_ptr<App>;

class Option_group;

class App {
    friend Option;
    friend detail::AppFriend;

  protected:
    // This library follows the Google style guide for member names ending in underscores


    std::string name_;

    std::string description_;

    bool allow_extras_{false};

    bool allow_config_extras_{false};

    bool prefix_command_{false};

    bool has_automatic_name_{false};

    bool required_{false};

    bool disabled_{false};

    bool pre_parse_called_{false};

    bool immediate_callback_{false};

    std::function<void(size_t)> pre_parse_callback_;

    std::function<void()> callback_;


    OptionDefaults option_defaults_;

    std::vector<Option_p> options_;


    std::string footer_;

    Option *help_ptr_{nullptr};

    Option *help_all_ptr_{nullptr};

    std::shared_ptr<FormatterBase> formatter_{new Formatter()};

    std::function<std::string(const App *, const Error &e)> failure_message_ = FailureMessage::simple;


    using missing_t = std::vector<std::pair<detail::Classifier, std::string>>;

    missing_t missing_;

    std::vector<Option *> parse_order_;

    std::vector<App *> parsed_subcommands_;

    std::set<App *> exclude_subcommands_;

    std::set<Option *> exclude_options_;


    std::vector<App_p> subcommands_;

    bool ignore_case_{false};

    bool ignore_underscore_{false};

    bool fallthrough_{false};

    bool allow_windows_style_options_{
#ifdef _WIN32
        true
#else
        false
#endif
    };
    bool positionals_at_end_{false};

    bool disabled_by_default_{false};
    bool enabled_by_default_{false};
    bool validate_positionals_{false};
    App *parent_{nullptr};

    size_t parsed_ = 0;

    size_t require_subcommand_min_ = 0;

    size_t require_subcommand_max_ = 0;

    size_t require_option_min_ = 0;

    size_t require_option_max_ = 0;

    std::string group_{"Subcommands"};


    std::string config_name_;

    bool config_required_{false};

    Option *config_ptr_{nullptr};

    std::shared_ptr<Config> config_formatter_{new ConfigINI()};


    App(std::string app_description, std::string app_name, App *parent)
        : name_(std::move(app_name)), description_(std::move(app_description)), parent_(parent) {
        // Inherit if not from a nullptr
        if(parent_ != nullptr) {
            if(parent_->help_ptr_ != nullptr)
                set_help_flag(parent_->help_ptr_->get_name(false, true), parent_->help_ptr_->get_description());
            if(parent_->help_all_ptr_ != nullptr)
                set_help_all_flag(parent_->help_all_ptr_->get_name(false, true),
                                  parent_->help_all_ptr_->get_description());

            option_defaults_ = parent_->option_defaults_;

            // INHERITABLE
            failure_message_ = parent_->failure_message_;
            allow_extras_ = parent_->allow_extras_;
            allow_config_extras_ = parent_->allow_config_extras_;
            prefix_command_ = parent_->prefix_command_;
            immediate_callback_ = parent_->immediate_callback_;
            ignore_case_ = parent_->ignore_case_;
            ignore_underscore_ = parent_->ignore_underscore_;
            fallthrough_ = parent_->fallthrough_;
            validate_positionals_ = parent_->validate_positionals_;
            allow_windows_style_options_ = parent_->allow_windows_style_options_;
            group_ = parent_->group_;
            footer_ = parent_->footer_;
            formatter_ = parent_->formatter_;
            config_formatter_ = parent_->config_formatter_;
            require_subcommand_max_ = parent_->require_subcommand_max_;
        }
    }

  public:

    explicit App(std::string app_description = "", std::string app_name = "")
        : App(app_description, app_name, nullptr) {
        set_help_flag("-h,--help", "Print this help message and exit");
    }

    virtual ~App() = default;

    App *callback(std::function<void()> app_callback) {
        callback_ = std::move(app_callback);
        return this;
    }

    App *preparse_callback(std::function<void(size_t)> pp_callback) {
        pre_parse_callback_ = std::move(pp_callback);
        return this;
    }

    App *name(std::string app_name = "") {
        name_ = app_name;
        has_automatic_name_ = false;
        return this;
    }

    App *allow_extras(bool allow = true) {
        allow_extras_ = allow;
        return this;
    }

    App *required(bool require = true) {
        required_ = require;
        return this;
    }

    App *disabled(bool disable = true) {
        disabled_ = disable;
        return this;
    }

    App *disabled_by_default(bool disable = true) {
        disabled_by_default_ = disable;
        return this;
    }

    App *enabled_by_default(bool enable = true) {
        enabled_by_default_ = enable;
        return this;
    }

    App *immediate_callback(bool immediate = true) {
        immediate_callback_ = immediate;
        return this;
    }

    App *validate_positionals(bool validate = true) {
        validate_positionals_ = validate;
        return this;
    }

    App *allow_config_extras(bool allow = true) {
        allow_extras(allow);
        allow_config_extras_ = allow;
        return this;
    }

    App *prefix_command(bool allow = true) {
        prefix_command_ = allow;
        return this;
    }

    App *ignore_case(bool value = true) {
        ignore_case_ = value;
        if(parent_ != nullptr && !name_.empty()) {
            for(const auto &subc : parent_->subcommands_) {
                if(subc.get() != this && (this->check_name(subc->name_) || subc->check_name(this->name_)))
                    throw OptionAlreadyAdded(subc->name_);
            }
        }
        return this;
    }

    App *allow_windows_style_options(bool value = true) {
        allow_windows_style_options_ = value;
        return this;
    }

    App *positionals_at_end(bool value = true) {
        positionals_at_end_ = value;
        return this;
    }

    App *ignore_underscore(bool value = true) {
        ignore_underscore_ = value;
        if(parent_ != nullptr && !name_.empty()) {
            for(const auto &subc : parent_->subcommands_) {
                if(subc.get() != this && (this->check_name(subc->name_) || subc->check_name(this->name_)))
                    throw OptionAlreadyAdded(subc->name_);
            }
        }
        return this;
    }

    App *formatter(std::shared_ptr<FormatterBase> fmt) {
        formatter_ = fmt;
        return this;
    }

    App *formatter_fn(std::function<std::string(const App *, std::string, AppFormatMode)> fmt) {
        formatter_ = std::make_shared<FormatterLambda>(fmt);
        return this;
    }

    App *config_formatter(std::shared_ptr<Config> fmt) {
        config_formatter_ = fmt;
        return this;
    }

    bool parsed() const { return parsed_ > 0; }

    OptionDefaults *option_defaults() { return &option_defaults_; }


    Option *add_option(std::string option_name,
                       callback_t option_callback,
                       std::string option_description = "",
                       bool defaulted = false,
                       std::function<std::string()> func = {}) {
        Option myopt{option_name, option_description, option_callback, this};

        if(std::find_if(std::begin(options_), std::end(options_), [&myopt](const Option_p &v) {
               return *v == myopt;
           }) == std::end(options_)) {
            options_.emplace_back();
            Option_p &option = options_.back();
            option.reset(new Option(option_name, option_description, option_callback, this));

            // Set the default string capture function
            option->default_function(func);

            // For compatibility with CLI11 1.7 and before, capture the default string here
            if(defaulted)
                option->capture_default_str();

            // Transfer defaults to the new option
            option_defaults_.copy_to(option.get());

            // Don't bother to capture if we already did
            if(!defaulted && option->get_always_capture_default())
                option->capture_default_str();

            return option.get();

        } else
            throw OptionAlreadyAdded(myopt.get_name());
    }

    template <typename T, enable_if_t<!is_vector<T>::value & !std::is_const<T>::value, detail::enabler> = detail::dummy>
    Option *add_option(std::string option_name,
                       T &variable, 
                       std::string option_description = "",
                       bool defaulted = false) {

        auto fun = [&variable](CLI::results_t res) { return detail::lexical_cast(res[0], variable); };

        Option *opt = add_option(option_name, fun, option_description, defaulted, [&variable]() {
            return std::string(CLI::detail::to_string(variable));
        });
        opt->type_name(detail::type_name<T>());

        return opt;
    }

    template <typename T, enable_if_t<!is_vector<T>::value, detail::enabler> = detail::dummy>
    Option *add_option_function(std::string option_name,
                                const std::function<void(const T &)> &func, 
                                std::string option_description = "") {

        auto fun = [func](CLI::results_t res) {
            T variable;
            bool result = detail::lexical_cast(res[0], variable);
            if(result) {
                func(variable);
            }
            return result;
        };

        Option *opt = add_option(option_name, std::move(fun), option_description, false);
        opt->type_name(detail::type_name<T>());
        return opt;
    }

    Option *add_option(std::string option_name) {
        return add_option(option_name, CLI::callback_t(), std::string{}, false);
    }

    template <typename T,
              enable_if_t<std::is_const<T>::value && std::is_constructible<std::string, T>::value, detail::enabler> =
                  detail::dummy>
    Option *add_option(std::string option_name, T &option_description) {
        return add_option(option_name, CLI::callback_t(), option_description, false);
    }

    template <typename T>
    Option *add_option(std::string option_name,
                       std::vector<T> &variable, 
                       std::string option_description = "",
                       bool defaulted = false) {

        auto fun = [&variable](CLI::results_t res) {
            bool retval = true;
            variable.clear();
            variable.reserve(res.size());
            for(const auto &elem : res) {

                variable.emplace_back();
                retval &= detail::lexical_cast(elem, variable.back());
            }
            return (!variable.empty()) && retval;
        };

        auto default_function = [&variable]() {
            std::vector<std::string> defaults;
            defaults.resize(variable.size());
            std::transform(variable.begin(), variable.end(), defaults.begin(), [](T &val) {
                return std::string(CLI::detail::to_string(val));
            });
            return std::string("[" + detail::join(defaults) + "]");
        };

        Option *opt = add_option(option_name, fun, option_description, defaulted, default_function);
        opt->type_name(detail::type_name<T>())->type_size(-1);

        return opt;
    }

    template <typename T, enable_if_t<is_vector<T>::value, detail::enabler> = detail::dummy>
    Option *add_option_function(std::string option_name,
                                const std::function<void(const T &)> &func, 
                                std::string option_description = "") {

        CLI::callback_t fun = [func](CLI::results_t res) {
            T values;
            bool retval = true;
            values.reserve(res.size());
            for(const auto &elem : res) {
                values.emplace_back();
                retval &= detail::lexical_cast(elem, values.back());
            }
            if(retval) {
                func(values);
            }
            return retval;
        };

        Option *opt = add_option(option_name, std::move(fun), std::move(option_description), false);
        opt->type_name(detail::type_name<T>())->type_size(-1);
        return opt;
    }

    Option *set_help_flag(std::string flag_name = "", const std::string &help_description = "") {
        // take flag_description by const reference otherwise add_flag tries to assign to help_description
        if(help_ptr_ != nullptr) {
            remove_option(help_ptr_);
            help_ptr_ = nullptr;
        }

        // Empty name will simply remove the help flag
        if(!flag_name.empty()) {
            help_ptr_ = add_flag(flag_name, help_description);
            help_ptr_->configurable(false);
        }

        return help_ptr_;
    }

    Option *set_help_all_flag(std::string help_name = "", const std::string &help_description = "") {
        // take flag_description by const reference otherwise add_flag tries to assign to flag_description
        if(help_all_ptr_ != nullptr) {
            remove_option(help_all_ptr_);
            help_all_ptr_ = nullptr;
        }

        // Empty name will simply remove the help all flag
        if(!help_name.empty()) {
            help_all_ptr_ = add_flag(help_name, help_description);
            help_all_ptr_->configurable(false);
        }

        return help_all_ptr_;
    }

  private:
    Option *_add_flag_internal(std::string flag_name, CLI::callback_t fun, std::string flag_description) {
        Option *opt;
        if(detail::has_default_flag_values(flag_name)) {
            // check for default values and if it has them
            auto flag_defaults = detail::get_default_flag_values(flag_name);
            detail::remove_default_flag_values(flag_name);
            opt = add_option(std::move(flag_name), std::move(fun), std::move(flag_description), false);
            for(const auto &fname : flag_defaults)
                opt->fnames_.push_back(fname.first);
            opt->default_flag_values_ = std::move(flag_defaults);
        } else {
            opt = add_option(std::move(flag_name), std::move(fun), std::move(flag_description), false);
        }
        // flags cannot have positional values
        if(opt->get_positional()) {
            auto pos_name = opt->get_name(true);
            remove_option(opt);
            throw IncorrectConstruction::PositionalFlag(pos_name);
        }

        opt->type_size(0);
        return opt;
    }

  public:
    Option *add_flag(std::string flag_name) { return _add_flag_internal(flag_name, CLI::callback_t(), std::string{}); }

    template <typename T,
              enable_if_t<std::is_const<T>::value && std::is_constructible<std::string, T>::value, detail::enabler> =
                  detail::dummy>
    Option *add_flag(std::string flag_name, T &flag_description) {
        return _add_flag_internal(flag_name, CLI::callback_t(), flag_description);
    }

    template <typename T,
              enable_if_t<std::is_integral<T>::value && !is_bool<T>::value, detail::enabler> = detail::dummy>
    Option *add_flag(std::string flag_name,
                     T &flag_count, 
                     std::string flag_description = "") {
        flag_count = 0;
        CLI::callback_t fun = [&flag_count](CLI::results_t res) {
            try {
                detail::sum_flag_vector(res, flag_count);
            } catch(const std::invalid_argument &) {
                return false;
            }
            return true;
        };
        return _add_flag_internal(flag_name, std::move(fun), std::move(flag_description));
    }

    template <typename T,
              enable_if_t<!is_vector<T>::value && !std::is_const<T>::value &&
                              (!std::is_integral<T>::value || is_bool<T>::value) &&
                              !std::is_constructible<std::function<void(int)>, T>::value,
                          detail::enabler> = detail::dummy>
    Option *add_flag(std::string flag_name,
                     T &flag_result, 
                     std::string flag_description = "") {

        CLI::callback_t fun = [&flag_result](CLI::results_t res) {
            if(res.size() != 1) {
                return false;
            }
            return CLI::detail::lexical_cast(res[0], flag_result);
        };
        Option *opt = _add_flag_internal(flag_name, std::move(fun), std::move(flag_description));
        opt->multi_option_policy(CLI::MultiOptionPolicy::TakeLast);
        return opt;
    }

    template <typename T,
              enable_if_t<!std::is_assignable<std::function<void(int64_t)>, T>::value, detail::enabler> = detail::dummy>
    Option *add_flag(std::string flag_name,
                     std::vector<T> &flag_results, 
                     std::string flag_description = "") {
        CLI::callback_t fun = [&flag_results](CLI::results_t res) {
            bool retval = true;
            for(const auto &elem : res) {
                flag_results.emplace_back();
                retval &= detail::lexical_cast(elem, flag_results.back());
            }
            return retval;
        };
        return _add_flag_internal(flag_name, std::move(fun), std::move(flag_description));
    }

    Option *add_flag_callback(std::string flag_name,
                              std::function<void(void)> function, 
                              std::string flag_description = "") {

        CLI::callback_t fun = [function](CLI::results_t res) {
            if(res.size() != 1) {
                return false;
            }
            bool trigger;
            auto result = CLI::detail::lexical_cast(res[0], trigger);
            if(trigger)
                function();
            return result;
        };
        Option *opt = _add_flag_internal(flag_name, std::move(fun), std::move(flag_description));
        opt->multi_option_policy(CLI::MultiOptionPolicy::TakeLast);
        return opt;
    }

    Option *add_flag_function(std::string flag_name,
                              std::function<void(int64_t)> function, 
                              std::string flag_description = "") {

        CLI::callback_t fun = [function](CLI::results_t res) {
            int64_t flag_count = 0;
            detail::sum_flag_vector(res, flag_count);
            function(flag_count);
            return true;
        };
        return _add_flag_internal(flag_name, std::move(fun), std::move(flag_description));
    }

#ifdef CLI11_CPP14
    Option *add_flag(std::string flag_name,
                     std::function<void(int64_t)> function, 
                     std::string flag_description = "") {
        return add_flag_function(std::move(flag_name), std::move(function), std::move(flag_description));
    }
#endif

    template <typename T>
    Option *add_set(std::string option_name,
                    T &member,           
                    std::set<T> options, 
                    std::string option_description = "") {

        Option *opt = add_option(option_name, member, std::move(option_description));
        opt->check(IsMember{options});
        return opt;
    }

    template <typename T>
    Option *add_mutable_set(std::string option_name,
                            T &member,                  
                            const std::set<T> &options, 
                            std::string option_description = "") {

        Option *opt = add_option(option_name, member, std::move(option_description));
        opt->check(IsMember{&options});
        return opt;
    }

    template <typename T>
    Option *add_set(std::string option_name,
                    T &member,           
                    std::set<T> options, 
                    std::string option_description,
                    bool defaulted) {

        Option *opt = add_option(option_name, member, std::move(option_description), defaulted);
        opt->check(IsMember{options});
        return opt;
    }

    template <typename T>
    Option *add_mutable_set(std::string option_name,
                            T &member,                  
                            const std::set<T> &options, 
                            std::string option_description,
                            bool defaulted) {

        Option *opt = add_option(option_name, member, std::move(option_description), defaulted);
        opt->check(IsMember{&options});
        return opt;
    }

    CLI11_DEPRECATED("Use ->transform(CLI::IsMember(..., CLI::ignore_case)) instead")
    Option *add_set_ignore_case(std::string option_name,
                                std::string &member,           
                                std::set<std::string> options, 
                                std::string option_description = "") {

        Option *opt = add_option(option_name, member, std::move(option_description));
        opt->transform(IsMember{options, CLI::ignore_case});
        return opt;
    }

    CLI11_DEPRECATED("Use ->transform(CLI::IsMember(..., CLI::ignore_case)) with a (shared) pointer instead")
    Option *add_mutable_set_ignore_case(std::string option_name,
                                        std::string &member,                  
                                        const std::set<std::string> &options, 
                                        std::string option_description = "") {

        Option *opt = add_option(option_name, member, std::move(option_description));
        opt->transform(IsMember{&options, CLI::ignore_case});
        return opt;
    }

    CLI11_DEPRECATED("Use ->transform(CLI::IsMember(..., CLI::ignore_case)) instead")
    Option *add_set_ignore_case(std::string option_name,
                                std::string &member,           
                                std::set<std::string> options, 
                                std::string option_description,
                                bool defaulted) {

        Option *opt = add_option(option_name, member, std::move(option_description), defaulted);
        opt->transform(IsMember{options, CLI::ignore_case});
        return opt;
    }

    CLI11_DEPRECATED("Use ->transform(CLI::IsMember(...)) with a (shared) pointer instead")
    Option *add_mutable_set_ignore_case(std::string option_name,
                                        std::string &member,                  
                                        const std::set<std::string> &options, 
                                        std::string option_description,
                                        bool defaulted) {

        Option *opt = add_option(option_name, member, std::move(option_description), defaulted);
        opt->transform(IsMember{&options, CLI::ignore_case});
        return opt;
    }

    CLI11_DEPRECATED("Use ->transform(CLI::IsMember(..., CLI::ignore_underscore)) instead")
    Option *add_set_ignore_underscore(std::string option_name,
                                      std::string &member,           
                                      std::set<std::string> options, 
                                      std::string option_description = "") {

        Option *opt = add_option(option_name, member, std::move(option_description));
        opt->transform(IsMember{options, CLI::ignore_underscore});
        return opt;
    }

    CLI11_DEPRECATED("Use ->transform(CLI::IsMember(..., CLI::ignore_underscore)) with a (shared) pointer instead")
    Option *add_mutable_set_ignore_underscore(std::string option_name,
                                              std::string &member,                  
                                              const std::set<std::string> &options, 
                                              std::string option_description = "") {

        Option *opt = add_option(option_name, member, std::move(option_description));
        opt->transform(IsMember{options, CLI::ignore_underscore});
        return opt;
    }

    CLI11_DEPRECATED("Use ->transform(CLI::IsMember(..., CLI::ignore_underscore)) instead")
    Option *add_set_ignore_underscore(std::string option_name,
                                      std::string &member,           
                                      std::set<std::string> options, 
                                      std::string option_description,
                                      bool defaulted) {

        Option *opt = add_option(option_name, member, std::move(option_description), defaulted);
        opt->transform(IsMember{options, CLI::ignore_underscore});
        return opt;
    }

    CLI11_DEPRECATED("Use ->transform(CLI::IsMember(..., CLI::ignore_underscore)) with a (shared) pointer instead")
    Option *add_mutable_set_ignore_underscore(std::string option_name,
                                              std::string &member,                  
                                              const std::set<std::string> &options, 
                                              std::string option_description,
                                              bool defaulted) {

        Option *opt = add_option(option_name, member, std::move(option_description), defaulted);
        opt->transform(IsMember{&options, CLI::ignore_underscore});
        return opt;
    }

    CLI11_DEPRECATED("Use ->transform(CLI::IsMember(..., CLI::ignore_case, CLI::ignore_underscore)) instead")
    Option *add_set_ignore_case_underscore(std::string option_name,
                                           std::string &member,           
                                           std::set<std::string> options, 
                                           std::string option_description = "") {

        Option *opt = add_option(option_name, member, std::move(option_description));
        opt->transform(IsMember{options, CLI::ignore_underscore, CLI::ignore_case});
        return opt;
    }

    CLI11_DEPRECATED(
        "Use ->transform(CLI::IsMember(..., CLI::ignore_case, CLI::ignore_underscore)) with a (shared) pointer instead")
    Option *add_mutable_set_ignore_case_underscore(std::string option_name,
                                                   std::string &member, 
                                                   const std::set<std::string> &options, 
                                                   std::string option_description = "") {

        Option *opt = add_option(option_name, member, std::move(option_description));
        opt->transform(IsMember{&options, CLI::ignore_underscore, CLI::ignore_case});
        return opt;
    }

    CLI11_DEPRECATED("Use ->transform(CLI::IsMember(..., CLI::ignore_case, CLI::ignore_underscore)) instead")
    Option *add_set_ignore_case_underscore(std::string option_name,
                                           std::string &member,           
                                           std::set<std::string> options, 
                                           std::string option_description,
                                           bool defaulted) {

        Option *opt = add_option(option_name, member, std::move(option_description), defaulted);
        opt->transform(IsMember{options, CLI::ignore_underscore, CLI::ignore_case});
        return opt;
    }

    CLI11_DEPRECATED(
        "Use ->transform(CLI::IsMember(..., CLI::ignore_case, CLI::ignore_underscore)) with a (shared) pointer instead")
    Option *add_mutable_set_ignore_case_underscore(std::string option_name,
                                                   std::string &member, 
                                                   const std::set<std::string> &options, 
                                                   std::string option_description,
                                                   bool defaulted) {

        Option *opt = add_option(option_name, member, std::move(option_description), defaulted);
        opt->transform(IsMember{&options, CLI::ignore_underscore, CLI::ignore_case});
        return opt;
    }

    template <typename T>
    Option *add_complex(std::string option_name,
                        T &variable,
                        std::string option_description = "",
                        bool defaulted = false,
                        std::string label = "COMPLEX") {

        std::string simple_name = CLI::detail::split(option_name, ',').at(0);
        CLI::callback_t fun = [&variable, simple_name, label](results_t res) {
            if(res[1].back() == 'i')
                res[1].pop_back();
            double x, y;
            bool worked = detail::lexical_cast(res[0], x) && detail::lexical_cast(res[1], y);
            if(worked)
                variable = T(x, y);
            return worked;
        };

        auto default_function = [&variable]() {
            std::stringstream out;
            out << variable;
            return out.str();
        };

        CLI::Option *opt =
            add_option(option_name, std::move(fun), std::move(option_description), defaulted, default_function);

        opt->type_name(label)->type_size(2);
        return opt;
    }

    Option *set_config(std::string option_name = "",
                       std::string default_filename = "",
                       std::string help_message = "Read an ini file",
                       bool config_required = false) {

        // Remove existing config if present
        if(config_ptr_ != nullptr)
            remove_option(config_ptr_);

        // Only add config if option passed
        if(!option_name.empty()) {
            config_name_ = default_filename;
            config_required_ = config_required;
            config_ptr_ = add_option(option_name, config_name_, help_message, !default_filename.empty());
            config_ptr_->configurable(false);
        }

        return config_ptr_;
    }

    bool remove_option(Option *opt) {
        // Make sure no links exist
        for(Option_p &op : options_) {
            op->remove_needs(opt);
            op->remove_excludes(opt);
        }

        if(help_ptr_ == opt)
            help_ptr_ = nullptr;
        if(help_all_ptr_ == opt)
            help_all_ptr_ = nullptr;

        auto iterator =
            std::find_if(std::begin(options_), std::end(options_), [opt](const Option_p &v) { return v.get() == opt; });
        if(iterator != std::end(options_)) {
            options_.erase(iterator);
            return true;
        }
        return false;
    }

    template <typename T = Option_group>
    T *add_option_group(std::string group_name, std::string group_description = "") {
        auto option_group = std::make_shared<T>(std::move(group_description), group_name, nullptr);
        auto ptr = option_group.get();
        // move to App_p for overload resolution on older gcc versions
        App_p app_ptr = std::dynamic_pointer_cast<App>(option_group);
        add_subcommand(std::move(app_ptr));
        return ptr;
    }


    App *add_subcommand(std::string subcommand_name = "", std::string subcommand_description = "") {
        CLI::App_p subcom = std::shared_ptr<App>(new App(std::move(subcommand_description), subcommand_name, this));
        return add_subcommand(std::move(subcom));
    }

    App *add_subcommand(CLI::App_p subcom) {
        if(!subcom)
            throw IncorrectConstruction("passed App is not valid");
        if(!subcom->name_.empty()) {
            for(const auto &subc : subcommands_)
                if(subc->check_name(subcom->name_) || subcom->check_name(subc->name_))
                    throw OptionAlreadyAdded(subc->name_);
        }
        subcom->parent_ = this;
        subcommands_.push_back(std::move(subcom));
        return subcommands_.back().get();
    }

    bool remove_subcommand(App *subcom) {
        // Make sure no links exist
        for(App_p &sub : subcommands_) {
            sub->remove_excludes(subcom);
        }

        auto iterator = std::find_if(
            std::begin(subcommands_), std::end(subcommands_), [subcom](const App_p &v) { return v.get() == subcom; });
        if(iterator != std::end(subcommands_)) {
            subcommands_.erase(iterator);
            return true;
        }
        return false;
    }
    App *get_subcommand(App *subcom) const {
        if(subcom == nullptr)
            throw OptionNotFound("nullptr passed");
        for(const App_p &subcomptr : subcommands_)
            if(subcomptr.get() == subcom)
                return subcom;
        throw OptionNotFound(subcom->get_name());
    }

    App *get_subcommand(std::string subcom) const {
        auto subc = _find_subcommand(subcom, false, false);
        if(subc == nullptr)
            throw OptionNotFound(subcom);
        return subc;
    }
    App *get_subcommand(int index = 0) const {
        if(index >= 0) {
            auto uindex = static_cast<unsigned>(index);
            if(uindex < subcommands_.size())
                return subcommands_[uindex].get();
        }
        throw OptionNotFound(std::to_string(index));
    }

    CLI::App_p get_subcommand_ptr(App *subcom) const {
        if(subcom == nullptr)
            throw OptionNotFound("nullptr passed");
        for(const App_p &subcomptr : subcommands_)
            if(subcomptr.get() == subcom)
                return subcomptr;
        throw OptionNotFound(subcom->get_name());
    }

    CLI::App_p get_subcommand_ptr(std::string subcom) const {
        for(const App_p &subcomptr : subcommands_)
            if(subcomptr->check_name(subcom))
                return subcomptr;
        throw OptionNotFound(subcom);
    }

    CLI::App_p get_subcommand_ptr(int index = 0) const {
        if(index >= 0) {
            auto uindex = static_cast<unsigned>(index);
            if(uindex < subcommands_.size())
                return subcommands_[uindex];
        }
        throw OptionNotFound(std::to_string(index));
    }

    App *get_option_group(std::string group_name) const {
        for(const App_p &app : subcommands_) {
            if(app->name_.empty() && app->group_ == group_name) {
                return app.get();
            }
        }
        throw OptionNotFound(group_name);
    }

    size_t count() const { return parsed_; }

    size_t count_all() const {
        size_t cnt{0};
        for(auto &opt : options_) {
            cnt += opt->count();
        }
        for(auto &sub : subcommands_) {
            cnt += sub->count_all();
        }
        if(!get_name().empty()) { // for named subcommands add the number of times the subcommand was called
            cnt += parsed_;
        }
        return cnt;
    }

    App *group(std::string group_name) {
        group_ = group_name;
        return this;
    }

    App *require_subcommand() {
        require_subcommand_min_ = 1;
        require_subcommand_max_ = 0;
        return this;
    }

    App *require_subcommand(int value) {
        if(value < 0) {
            require_subcommand_min_ = 0;
            require_subcommand_max_ = static_cast<size_t>(-value);
        } else {
            require_subcommand_min_ = static_cast<size_t>(value);
            require_subcommand_max_ = static_cast<size_t>(value);
        }
        return this;
    }

    App *require_subcommand(size_t min, size_t max) {
        require_subcommand_min_ = min;
        require_subcommand_max_ = max;
        return this;
    }

    App *require_option() {
        require_option_min_ = 1;
        require_option_max_ = 0;
        return this;
    }

    App *require_option(int value) {
        if(value < 0) {
            require_option_min_ = 0;
            require_option_max_ = static_cast<size_t>(-value);
        } else {
            require_option_min_ = static_cast<size_t>(value);
            require_option_max_ = static_cast<size_t>(value);
        }
        return this;
    }

    App *require_option(size_t min, size_t max) {
        require_option_min_ = min;
        require_option_max_ = max;
        return this;
    }

    App *fallthrough(bool value = true) {
        fallthrough_ = value;
        return this;
    }

    operator bool() const { return parsed_ > 0; }


    virtual void pre_callback() {}

    //
    void clear() {

        parsed_ = 0;
        pre_parse_called_ = false;

        missing_.clear();
        parsed_subcommands_.clear();
        for(const Option_p &opt : options_) {
            opt->clear();
        }
        for(const App_p &subc : subcommands_) {
            subc->clear();
        }
    }

    void parse(int argc, const char *const *argv) {
        // If the name is not set, read from command line
        if(name_.empty() || has_automatic_name_) {
            has_automatic_name_ = true;
            name_ = argv[0];
        }

        std::vector<std::string> args;
        args.reserve(static_cast<size_t>(argc - 1));
        for(int i = argc - 1; i > 0; i--)
            args.emplace_back(argv[i]);
        parse(std::move(args));
    }

    void parse(std::string commandline, bool program_name_included = false) {

        if(program_name_included) {
            auto nstr = detail::split_program_name(commandline);
            if((name_.empty()) || (has_automatic_name_)) {
                has_automatic_name_ = true;
                name_ = nstr.first;
            }
            commandline = std::move(nstr.second);
        } else
            detail::trim(commandline);
        // the next section of code is to deal with quoted arguments after an '=' or ':' for windows like operations
        if(!commandline.empty()) {
            commandline = detail::find_and_modify(commandline, "=", detail::escape_detect);
            if(allow_windows_style_options_)
                commandline = detail::find_and_modify(commandline, ":", detail::escape_detect);
        }

        auto args = detail::split_up(std::move(commandline));
        // remove all empty strings
        args.erase(std::remove(args.begin(), args.end(), std::string{}), args.end());
        std::reverse(args.begin(), args.end());

        parse(std::move(args));
    }

    void parse(std::vector<std::string> &args) {
        // Clear if parsed
        if(parsed_ > 0)
            clear();

        // parsed_ is incremented in commands/subcommands,
        // but placed here to make sure this is cleared when
        // running parse after an error is thrown, even by _validate or _configure.
        parsed_ = 1;
        _validate();
        _configure();
        // set the parent as nullptr as this object should be the top now
        parent_ = nullptr;
        parsed_ = 0;

        _parse(args);
        run_callback();
    }

    void parse(std::vector<std::string> &&args) {
        // Clear if parsed
        if(parsed_ > 0)
            clear();

        // parsed_ is incremented in commands/subcommands,
        // but placed here to make sure this is cleared when
        // running parse after an error is thrown, even by _validate or _configure.
        parsed_ = 1;
        _validate();
        _configure();
        // set the parent as nullptr as this object should be the top now
        parent_ = nullptr;
        parsed_ = 0;

        _parse(std::move(args));
        run_callback();
    }

    void failure_message(std::function<std::string(const App *, const Error &e)> function) {
        failure_message_ = function;
    }

    int exit(const Error &e, std::ostream &out = std::cout, std::ostream &err = std::cerr) const {

        if(dynamic_cast<const CLI::RuntimeError *>(&e) != nullptr)
            return e.get_exit_code();

        if(dynamic_cast<const CLI::CallForHelp *>(&e) != nullptr) {
            out << help();
            return e.get_exit_code();
        }

        if(dynamic_cast<const CLI::CallForAllHelp *>(&e) != nullptr) {
            out << help("", AppFormatMode::All);
            return e.get_exit_code();
        }

        if(e.get_exit_code() != static_cast<int>(ExitCodes::Success)) {
            if(failure_message_)
                err << failure_message_(this, e) << std::flush;
        }

        return e.get_exit_code();
    }


    size_t count(std::string option_name) const { return get_option(option_name)->count(); }

    std::vector<App *> get_subcommands() const { return parsed_subcommands_; }

    std::vector<const App *> get_subcommands(const std::function<bool(const App *)> &filter) const {
        std::vector<const App *> subcomms(subcommands_.size());
        std::transform(std::begin(subcommands_), std::end(subcommands_), std::begin(subcomms), [](const App_p &v) {
            return v.get();
        });

        if(filter) {
            subcomms.erase(std::remove_if(std::begin(subcomms),
                                          std::end(subcomms),
                                          [&filter](const App *app) { return !filter(app); }),
                           std::end(subcomms));
        }

        return subcomms;
    }

    std::vector<App *> get_subcommands(const std::function<bool(App *)> &filter) {
        std::vector<App *> subcomms(subcommands_.size());
        std::transform(std::begin(subcommands_), std::end(subcommands_), std::begin(subcomms), [](const App_p &v) {
            return v.get();
        });

        if(filter) {
            subcomms.erase(
                std::remove_if(std::begin(subcomms), std::end(subcomms), [&filter](App *app) { return !filter(app); }),
                std::end(subcomms));
        }

        return subcomms;
    }

    bool got_subcommand(App *subcom) const {
        // get subcom needed to verify that this was a real subcommand
        return get_subcommand(subcom)->parsed_ > 0;
    }

    bool got_subcommand(std::string subcommand_name) const { return get_subcommand(subcommand_name)->parsed_ > 0; }

    App *excludes(Option *opt) {
        if(opt == nullptr) {
            throw OptionNotFound("nullptr passed");
        }
        exclude_options_.insert(opt);
        return this;
    }

    App *excludes(App *app) {
        if((app == this) || (app == nullptr)) {
            throw OptionNotFound("nullptr passed");
        }
        auto res = exclude_subcommands_.insert(app);
        // subcommand exclusion should be symmetric
        if(res.second) {
            app->exclude_subcommands_.insert(this);
        }
        return this;
    }

    bool remove_excludes(Option *opt) {
        auto iterator = std::find(std::begin(exclude_options_), std::end(exclude_options_), opt);
        if(iterator != std::end(exclude_options_)) {
            exclude_options_.erase(iterator);
            return true;
        } else {
            return false;
        }
    }

    bool remove_excludes(App *app) {
        auto iterator = std::find(std::begin(exclude_subcommands_), std::end(exclude_subcommands_), app);
        if(iterator != std::end(exclude_subcommands_)) {
            auto other_app = *iterator;
            exclude_subcommands_.erase(iterator);
            other_app->remove_excludes(this);
            return true;
        } else {
            return false;
        }
    }


    App *footer(std::string footer_string) {
        footer_ = std::move(footer_string);
        return this;
    }

    std::string config_to_str(bool default_also = false, bool write_description = false) const {
        return config_formatter_->to_config(this, default_also, write_description, "");
    }

    std::string help(std::string prev = "", AppFormatMode mode = AppFormatMode::Normal) const {
        if(prev.empty())
            prev = get_name();
        else
            prev += " " + get_name();

        // Delegate to subcommand if needed
        auto selected_subcommands = get_subcommands();
        if(!selected_subcommands.empty())
            return selected_subcommands.at(0)->help(prev, mode);
        else
            return formatter_->make_help(this, prev, mode);
    }


    std::shared_ptr<FormatterBase> get_formatter() const { return formatter_; }

    std::shared_ptr<Config> get_config_formatter() const { return config_formatter_; }

    std::string get_description() const { return description_; }

    App *description(std::string app_description) {
        description_ = std::move(app_description);
        return this;
    }

    std::vector<const Option *> get_options(const std::function<bool(const Option *)> filter = {}) const {
        std::vector<const Option *> options(options_.size());
        std::transform(std::begin(options_), std::end(options_), std::begin(options), [](const Option_p &val) {
            return val.get();
        });

        if(filter) {
            options.erase(std::remove_if(std::begin(options),
                                         std::end(options),
                                         [&filter](const Option *opt) { return !filter(opt); }),
                          std::end(options));
        }

        return options;
    }

    Option *get_option_no_throw(std::string option_name) noexcept {
        for(Option_p &opt : options_) {
            if(opt->check_name(option_name)) {
                return opt.get();
            }
        }
        for(auto &subc : subcommands_) {
            // also check down into nameless subcommands
            if(subc->get_name().empty()) {
                auto opt = subc->get_option_no_throw(option_name);
                if(opt != nullptr) {
                    return opt;
                }
            }
        }
        return nullptr;
    }

    const Option *get_option_no_throw(std::string option_name) const noexcept {
        for(const Option_p &opt : options_) {
            if(opt->check_name(option_name)) {
                return opt.get();
            }
        }
        for(const auto &subc : subcommands_) {
            // also check down into nameless subcommands
            if(subc->get_name().empty()) {
                auto opt = subc->get_option_no_throw(option_name);
                if(opt != nullptr) {
                    return opt;
                }
            }
        }
        return nullptr;
    }

    const Option *get_option(std::string option_name) const {
        auto opt = get_option_no_throw(option_name);
        if(opt == nullptr) {
            throw OptionNotFound(option_name);
        }
        return opt;
    }

    Option *get_option(std::string option_name) {
        auto opt = get_option_no_throw(option_name);
        if(opt == nullptr) {
            throw OptionNotFound(option_name);
        }
        return opt;
    }

    const Option *operator[](const std::string &option_name) const { return get_option(option_name); }

    const Option *operator[](const char *option_name) const { return get_option(option_name); }

    bool get_ignore_case() const { return ignore_case_; }

    bool get_ignore_underscore() const { return ignore_underscore_; }

    bool get_fallthrough() const { return fallthrough_; }

    bool get_allow_windows_style_options() const { return allow_windows_style_options_; }

    bool get_positionals_at_end() const { return positionals_at_end_; }

    const std::string &get_group() const { return group_; }

    const std::string &get_footer() const { return footer_; }

    size_t get_require_subcommand_min() const { return require_subcommand_min_; }

    size_t get_require_subcommand_max() const { return require_subcommand_max_; }

    size_t get_require_option_min() const { return require_option_min_; }

    size_t get_require_option_max() const { return require_option_max_; }

    bool get_prefix_command() const { return prefix_command_; }

    bool get_allow_extras() const { return allow_extras_; }

    bool get_required() const { return required_; }

    bool get_disabled() const { return disabled_; }

    bool get_immediate_callback() const { return immediate_callback_; }

    bool get_disabled_by_default() const { return disabled_by_default_; }

    bool get_enabled_by_default() const { return enabled_by_default_; }
    bool get_validate_positionals() const { return validate_positionals_; }

    bool get_allow_config_extras() const { return allow_config_extras_; }

    Option *get_help_ptr() { return help_ptr_; }

    const Option *get_help_ptr() const { return help_ptr_; }

    const Option *get_help_all_ptr() const { return help_all_ptr_; }

    Option *get_config_ptr() { return config_ptr_; }

    const Option *get_config_ptr() const { return config_ptr_; }

    App *get_parent() { return parent_; }

    const App *get_parent() const { return parent_; }

    std::string get_name() const { return name_; }

    std::string get_display_name() const { return (!name_.empty()) ? name_ : "[Option Group: " + get_group() + "]"; }

    bool check_name(std::string name_to_check) const {
        std::string local_name = name_;
        if(ignore_underscore_) {
            local_name = detail::remove_underscore(name_);
            name_to_check = detail::remove_underscore(name_to_check);
        }
        if(ignore_case_) {
            local_name = detail::to_lower(name_);
            name_to_check = detail::to_lower(name_to_check);
        }

        return local_name == name_to_check;
    }

    std::vector<std::string> get_groups() const {
        std::vector<std::string> groups;

        for(const Option_p &opt : options_) {
            // Add group if it is not already in there
            if(std::find(groups.begin(), groups.end(), opt->get_group()) == groups.end()) {
                groups.push_back(opt->get_group());
            }
        }

        return groups;
    }

    const std::vector<Option *> &parse_order() const { return parse_order_; }

    std::vector<std::string> remaining(bool recurse = false) const {
        std::vector<std::string> miss_list;
        for(const std::pair<detail::Classifier, std::string> &miss : missing_) {
            miss_list.push_back(std::get<1>(miss));
        }
        // Get from a subcommand that may allow extras
        if(recurse) {
            if(!allow_extras_) {
                for(const auto &sub : subcommands_) {
                    if(sub->name_.empty() && !sub->missing_.empty()) {
                        for(const std::pair<detail::Classifier, std::string> &miss : sub->missing_) {
                            miss_list.push_back(std::get<1>(miss));
                        }
                    }
                }
            }
            // Recurse into subcommands

            for(const App *sub : parsed_subcommands_) {
                std::vector<std::string> output = sub->remaining(recurse);
                std::copy(std::begin(output), std::end(output), std::back_inserter(miss_list));
            }
        }
        return miss_list;
    }

    std::vector<std::string> remaining_for_passthrough(bool recurse = false) const {
        std::vector<std::string> miss_list = remaining(recurse);
        std::reverse(std::begin(miss_list), std::end(miss_list));
        return miss_list;
    }

    size_t remaining_size(bool recurse = false) const {
        auto remaining_options = static_cast<size_t>(std::count_if(
            std::begin(missing_), std::end(missing_), [](const std::pair<detail::Classifier, std::string> &val) {
                return val.first != detail::Classifier::POSITIONAL_MARK;
            }));

        if(recurse) {
            for(const App_p &sub : subcommands_) {
                remaining_options += sub->remaining_size(recurse);
            }
        }
        return remaining_options;
    }


  protected:
    void _validate() const {
        auto pcount = std::count_if(std::begin(options_), std::end(options_), [](const Option_p &opt) {
            return opt->get_items_expected() < 0 && opt->get_positional();
        });
        if(pcount > 1)
            throw InvalidError(name_);

        size_t nameless_subs{0};
        for(const App_p &app : subcommands_) {
            app->_validate();
            if(app->get_name().empty())
                ++nameless_subs;
        }

        if(require_option_min_ > 0) {
            if(require_option_max_ > 0) {
                if(require_option_max_ < require_option_min_) {
                    throw(InvalidError("Required min options greater than required max options",
                                       ExitCodes::InvalidError));
                }
            }
            if(require_option_min_ > (options_.size() + nameless_subs)) {
                throw(InvalidError("Required min options greater than number of available options",
                                   ExitCodes::InvalidError));
            }
        }
    }

    void _configure() {
        if(disabled_by_default_) {
            disabled_ = true;
        }
        if(enabled_by_default_) {
            disabled_ = false;
        }
        for(const App_p &app : subcommands_) {
            if(app->has_automatic_name_) {
                app->name_.clear();
            }
            if(app->name_.empty()) {
                app->fallthrough_ = false; // make sure fallthrough_ is false to prevent infinite loop
                app->prefix_command_ = false;
            }
            // make sure the parent is set to be this object in preparation for parse
            app->parent_ = this;
            app->_configure();
        }
    }
    void run_callback() {
        pre_callback();
        // run the callbacks for the received subcommands
        for(App *subc : get_subcommands()) {
            if(!subc->immediate_callback_)
                subc->run_callback();
        }
        // now run callbacks for option_groups
        for(auto &subc : subcommands_) {
            if(!subc->immediate_callback_ && subc->name_.empty() && subc->count_all() > 0) {
                subc->run_callback();
            }
        }
        // finally run the main callback
        if(callback_ && (parsed_ > 0)) {
            if(!name_.empty() || count_all() > 0) {
                callback_();
            }
        }
    }

    bool _valid_subcommand(const std::string &current, bool ignore_used = true) const {
        // Don't match if max has been reached - but still check parents
        if(require_subcommand_max_ != 0 && parsed_subcommands_.size() >= require_subcommand_max_) {
            return parent_ != nullptr && parent_->_valid_subcommand(current, ignore_used);
        }
        auto com = _find_subcommand(current, true, ignore_used);
        if(com != nullptr) {
            return true;
        }
        // Check parent if exists, else return false
        return parent_ != nullptr && parent_->_valid_subcommand(current, ignore_used);
    }

    detail::Classifier _recognize(const std::string &current, bool ignore_used_subcommands = true) const {
        std::string dummy1, dummy2;

        if(current == "--")
            return detail::Classifier::POSITIONAL_MARK;
        if(_valid_subcommand(current, ignore_used_subcommands))
            return detail::Classifier::SUBCOMMAND;
        if(detail::split_long(current, dummy1, dummy2))
            return detail::Classifier::LONG;
        if(detail::split_short(current, dummy1, dummy2))
            return detail::Classifier::SHORT;
        if((allow_windows_style_options_) && (detail::split_windows_style(current, dummy1, dummy2)))
            return detail::Classifier::WINDOWS;
        if((current == "++") && !name_.empty() && parent_ != nullptr)
            return detail::Classifier::SUBCOMMAND_TERMINATOR;
        return detail::Classifier::NONE;
    }

    // The parse function is now broken into several parts, and part of process

    void _process_ini() {
        // Process an INI file
        if(config_ptr_ != nullptr) {
            if(*config_ptr_) {
                config_ptr_->run_callback();
                config_required_ = true;
            }
            if(!config_name_.empty()) {
                try {
                    std::vector<ConfigItem> values = config_formatter_->from_file(config_name_);
                    _parse_config(values);
                } catch(const FileError &) {
                    if(config_required_)
                        throw;
                }
            }
        }
    }

    void _process_env() {
        for(const Option_p &opt : options_) {
            if(opt->count() == 0 && !opt->envname_.empty()) {
                char *buffer = nullptr;
                std::string ename_string;

#ifdef _MSC_VER
                // Windows version
                size_t sz = 0;
                if(_dupenv_s(&buffer, &sz, opt->envname_.c_str()) == 0 && buffer != nullptr) {
                    ename_string = std::string(buffer);
                    free(buffer);
                }
#else
                // This also works on Windows, but gives a warning
                buffer = std::getenv(opt->envname_.c_str());
                if(buffer != nullptr)
                    ename_string = std::string(buffer);
#endif

                if(!ename_string.empty()) {
                    opt->add_result(ename_string);
                }
            }
        }

        for(App_p &sub : subcommands_) {
            if(sub->get_name().empty() || !sub->immediate_callback_)
                sub->_process_env();
        }
    }

    void _process_callbacks() {

        for(App_p &sub : subcommands_) {
            // process the priority option_groups first
            if(sub->get_name().empty() && sub->immediate_callback_) {
                if(sub->count_all() > 0) {
                    sub->_process_callbacks();
                    sub->run_callback();
                }
            }
        }

        for(const Option_p &opt : options_) {
            if(opt->count() > 0 && !opt->get_callback_run()) {
                opt->run_callback();
            }
        }

        for(App_p &sub : subcommands_) {
            if(!sub->immediate_callback_) {
                sub->_process_callbacks();
            }
        }
    }

    void _process_help_flags(bool trigger_help = false, bool trigger_all_help = false) const {
        const Option *help_ptr = get_help_ptr();
        const Option *help_all_ptr = get_help_all_ptr();

        if(help_ptr != nullptr && help_ptr->count() > 0)
            trigger_help = true;
        if(help_all_ptr != nullptr && help_all_ptr->count() > 0)
            trigger_all_help = true;

        // If there were parsed subcommands, call those. First subcommand wins if there are multiple ones.
        if(!parsed_subcommands_.empty()) {
            for(const App *sub : parsed_subcommands_)
                sub->_process_help_flags(trigger_help, trigger_all_help);

            // Only the final subcommand should call for help. All help wins over help.
        } else if(trigger_all_help) {
            throw CallForAllHelp();
        } else if(trigger_help) {
            throw CallForHelp();
        }
    }

    void _process_requirements() {
        // check excludes
        bool excluded{false};
        std::string excluder;
        for(auto &opt : exclude_options_) {
            if(opt->count() > 0) {
                excluded = true;
                excluder = opt->get_name();
            }
        }
        for(auto &subc : exclude_subcommands_) {
            if(subc->count_all() > 0) {
                excluded = true;
                excluder = subc->get_display_name();
            }
        }
        if(excluded) {
            if(count_all() > 0) {
                throw ExcludesError(get_display_name(), excluder);
            }
            // if we are excluded but didn't receive anything, just return
            return;
        }
        size_t used_options = 0;
        for(const Option_p &opt : options_) {

            if(opt->count() != 0) {
                ++used_options;
            }
            // Required or partially filled
            if(opt->get_required() || opt->count() != 0) {
                // Make sure enough -N arguments parsed (+N is already handled in parsing function)
                if(opt->get_items_expected() < 0 && opt->count() < static_cast<size_t>(-opt->get_items_expected()))
                    throw ArgumentMismatch::AtLeast(opt->get_name(), -opt->get_items_expected());

                // Required but empty
                if(opt->get_required() && opt->count() == 0)
                    throw RequiredError(opt->get_name());
            }
            // Requires
            for(const Option *opt_req : opt->needs_)
                if(opt->count() > 0 && opt_req->count() == 0)
                    throw RequiresError(opt->get_name(), opt_req->get_name());
            // Excludes
            for(const Option *opt_ex : opt->excludes_)
                if(opt->count() > 0 && opt_ex->count() != 0)
                    throw ExcludesError(opt->get_name(), opt_ex->get_name());
        }
        // check for the required number of subcommands
        if(require_subcommand_min_ > 0) {
            auto selected_subcommands = get_subcommands();
            if(require_subcommand_min_ > selected_subcommands.size())
                throw RequiredError::Subcommand(require_subcommand_min_);
        }

        // Max error cannot occur, the extra subcommand will parse as an ExtrasError or a remaining item.

        // run this loop to check how many unnamed subcommands were actually used since they are considered options from
        // the perspective of an App
        for(App_p &sub : subcommands_) {
            if(sub->disabled_)
                continue;
            if(sub->name_.empty() && sub->count_all() > 0) {
                ++used_options;
            }
        }

        if(require_option_min_ > used_options || (require_option_max_ > 0 && require_option_max_ < used_options)) {
            auto option_list = detail::join(options_, [](const Option_p &ptr) { return ptr->get_name(false, true); });
            if(option_list.compare(0, 10, "-h,--help,") == 0) {
                option_list.erase(0, 10);
            }
            auto subc_list = get_subcommands([](App *app) { return ((app->get_name().empty()) && (!app->disabled_)); });
            if(!subc_list.empty()) {
                option_list += "," + detail::join(subc_list, [](const App *app) { return app->get_display_name(); });
            }
            throw RequiredError::Option(require_option_min_, require_option_max_, used_options, option_list);
        }

        // now process the requirements for subcommands if needed
        for(App_p &sub : subcommands_) {
            if(sub->disabled_)
                continue;
            if(sub->name_.empty() && sub->required_ == false) {
                if(sub->count_all() == 0) {
                    if(require_option_min_ > 0 && require_option_min_ <= used_options) {
                        continue;
                        // if we have met the requirement and there is nothing in this option group skip checking
                        // requirements
                    }
                    if(require_option_max_ > 0 && used_options >= require_option_min_) {
                        continue;
                        // if we have met the requirement and there is nothing in this option group skip checking
                        // requirements
                    }
                }
            }
            if(sub->count() > 0 || sub->name_.empty()) {
                sub->_process_requirements();
            }

            if(sub->required_ && sub->count_all() == 0) {
                throw(CLI::RequiredError(sub->get_display_name()));
            }
        }
    }

    void _process() {
        _process_ini();
        _process_env();
        _process_callbacks();
        _process_help_flags();
        _process_requirements();
    }

    void _process_extras() {
        if(!(allow_extras_ || prefix_command_)) {
            size_t num_left_over = remaining_size();
            if(num_left_over > 0) {
                throw ExtrasError(remaining(false));
            }
        }

        for(App_p &sub : subcommands_) {
            if(sub->count() > 0)
                sub->_process_extras();
        }
    }

    void _process_extras(std::vector<std::string> &args) {
        if(!(allow_extras_ || prefix_command_)) {
            size_t num_left_over = remaining_size();
            if(num_left_over > 0) {
                args = remaining(false);
                throw ExtrasError(args);
            }
        }

        for(App_p &sub : subcommands_) {
            if(sub->count() > 0)
                sub->_process_extras(args);
        }
    }

    void increment_parsed() {
        ++parsed_;
        for(App_p &sub : subcommands_) {
            if(sub->get_name().empty())
                sub->increment_parsed();
        }
    }
    void _parse(std::vector<std::string> &args) {
        increment_parsed();
        _trigger_pre_parse(args.size());
        bool positional_only = false;

        while(!args.empty()) {
            if(!_parse_single(args, positional_only)) {
                break;
            }
        }

        if(parent_ == nullptr) {
            _process();

            // Throw error if any items are left over (depending on settings)
            _process_extras(args);

            // Convert missing (pairs) to extras (string only) ready for processing in another app
            args = remaining_for_passthrough(false);
        } else if(immediate_callback_) {
            _process_env();
            _process_callbacks();
            _process_help_flags();
            _process_requirements();
            run_callback();
        }
    }

    void _parse(std::vector<std::string> &&args) {
        // this can only be called by the top level in which case parent == nullptr by definition
        // operation is simplified
        increment_parsed();
        _trigger_pre_parse(args.size());
        bool positional_only = false;

        while(!args.empty()) {
            _parse_single(args, positional_only);
        }
        _process();

        // Throw error if any items are left over (depending on settings)
        _process_extras();
    }

    void _parse_config(std::vector<ConfigItem> &args) {
        for(ConfigItem item : args) {
            if(!_parse_single_config(item) && !allow_config_extras_)
                throw ConfigError::Extras(item.fullname());
        }
    }

    bool _parse_single_config(const ConfigItem &item, size_t level = 0) {
        if(level < item.parents.size()) {
            try {
                auto subcom = get_subcommand(item.parents.at(level));
                return subcom->_parse_single_config(item, level + 1);
            } catch(const OptionNotFound &) {
                return false;
            }
        }

        Option *op = get_option_no_throw("--" + item.name);
        if(op == nullptr) {
            // If the option was not present
            if(get_allow_config_extras())
                // Should we worry about classifying the extras properly?
                missing_.emplace_back(detail::Classifier::NONE, item.fullname());
            return false;
        }

        if(!op->get_configurable())
            throw ConfigError::NotConfigurable(item.fullname());

        if(op->empty()) {
            // Flag parsing
            if(op->get_type_size() == 0) {
                auto res = config_formatter_->to_flag(item);
                res = op->get_flag_value(item.name, res);

                op->add_result(res);

            } else {
                op->add_result(item.inputs);
                op->run_callback();
            }
        }

        return true;
    }

    bool _parse_single(std::vector<std::string> &args, bool &positional_only) {
        bool retval = true;
        detail::Classifier classifier = positional_only ? detail::Classifier::NONE : _recognize(args.back());
        switch(classifier) {
        case detail::Classifier::POSITIONAL_MARK:
            args.pop_back();
            positional_only = true;
            if((!_has_remaining_positionals()) && (parent_ != nullptr)) {
                retval = false;
            } else {
                _move_to_missing(classifier, "--");
            }
            break;
        case detail::Classifier::SUBCOMMAND_TERMINATOR:
            // treat this like a positional mark if in the parent app
            args.pop_back();
            retval = false;
            break;
        case detail::Classifier::SUBCOMMAND:
            retval = _parse_subcommand(args);
            break;
        case detail::Classifier::LONG:
        case detail::Classifier::SHORT:
        case detail::Classifier::WINDOWS:
            // If already parsed a subcommand, don't accept options_
            _parse_arg(args, classifier);
            break;
        case detail::Classifier::NONE:
            // Probably a positional or something for a parent (sub)command
            retval = _parse_positional(args);
            if(retval && positionals_at_end_) {
                positional_only = true;
            }
            break;

            // LCOV_EXCL_START
        default:
            HorribleError("unrecognized classifier (you should not see this!)");
            // LCOV_EXCL_END
        }
        return retval;
    }

    size_t _count_remaining_positionals(bool required_only = false) const {
        size_t retval = 0;
        for(const Option_p &opt : options_)
            if(opt->get_positional() && (!required_only || opt->get_required()) && opt->get_items_expected() > 0 &&
               static_cast<int>(opt->count()) < opt->get_items_expected())
                retval = static_cast<size_t>(opt->get_items_expected()) - opt->count();

        return retval;
    }

    bool _has_remaining_positionals() const {
        for(const Option_p &opt : options_)
            if(opt->get_positional() &&
               ((opt->get_items_expected() < 0) || ((static_cast<int>(opt->count()) < opt->get_items_expected()))))
                return true;

        return false;
    }

    bool _parse_positional(std::vector<std::string> &args) {

        const std::string &positional = args.back();
        for(const Option_p &opt : options_) {
            // Eat options, one by one, until done
            if(opt->get_positional() &&
               (static_cast<int>(opt->count()) < opt->get_items_expected() || opt->get_items_expected() < 0)) {
                if(validate_positionals_) {
                    std::string pos = positional;
                    pos = opt->_validate(pos);
                    if(!pos.empty()) {
                        continue;
                    }
                }
                opt->add_result(positional);
                parse_order_.push_back(opt.get());
                args.pop_back();
                return true;
            }
        }

        for(auto &subc : subcommands_) {
            if((subc->name_.empty()) && (!subc->disabled_)) {
                if(subc->_parse_positional(args)) {
                    if(!subc->pre_parse_called_) {
                        subc->_trigger_pre_parse(args.size());
                    }
                    return true;
                }
            }
        }
        // let the parent deal with it if possible
        if(parent_ != nullptr && fallthrough_)
            return _get_fallthrough_parent()->_parse_positional(args);

        auto com = _find_subcommand(args.back(), true, false);
        if(com != nullptr && (require_subcommand_max_ == 0 || require_subcommand_max_ > parsed_subcommands_.size())) {
            args.pop_back();
            com->_parse(args);
            return true;
        }
        auto parent_app = (parent_ != nullptr) ? _get_fallthrough_parent() : this;
        com = parent_app->_find_subcommand(args.back(), true, false);
        if(com != nullptr && (com->parent_->require_subcommand_max_ == 0 ||
                              com->parent_->require_subcommand_max_ > com->parent_->parsed_subcommands_.size())) {
            return false;
        }

        if(positionals_at_end_) {
            throw CLI::ExtrasError(args);
        }
        if(parent_ != nullptr && name_.empty()) {
            return false;
        }
        _move_to_missing(detail::Classifier::NONE, positional);
        args.pop_back();
        if(prefix_command_) {
            while(!args.empty()) {
                _move_to_missing(detail::Classifier::NONE, args.back());
                args.pop_back();
            }
        }

        return true;
    }

    App *_find_subcommand(const std::string &subc_name, bool ignore_disabled, bool ignore_used) const noexcept {
        for(const App_p &com : subcommands_) {
            if(com->disabled_ && ignore_disabled)
                continue;
            if(com->get_name().empty()) {
                auto subc = com->_find_subcommand(subc_name, ignore_disabled, ignore_used);
                if(subc != nullptr) {
                    return subc;
                }
            } else if(com->check_name(subc_name)) {
                if((!*com) || !ignore_used)
                    return com.get();
            }
        }
        return nullptr;
    }

    bool _parse_subcommand(std::vector<std::string> &args) {
        if(_count_remaining_positionals(/* required */ true) > 0) {
            _parse_positional(args);
            return true;
        }
        auto com = _find_subcommand(args.back(), true, true);
        if(com != nullptr) {
            args.pop_back();
            parsed_subcommands_.push_back(com);
            com->_parse(args);
            auto parent_app = com->parent_;
            while(parent_app != this) {
                parent_app->_trigger_pre_parse(args.size());
                parent_app->parsed_subcommands_.push_back(com);
                parent_app = parent_app->parent_;
            }
            return true;
        }

        if(parent_ == nullptr)
            throw HorribleError("Subcommand " + args.back() + " missing");
        return false;
    }

    bool _parse_arg(std::vector<std::string> &args, detail::Classifier current_type) {

        std::string current = args.back();

        std::string arg_name;
        std::string value;
        std::string rest;

        switch(current_type) {
        case detail::Classifier::LONG:
            if(!detail::split_long(current, arg_name, value))
                throw HorribleError("Long parsed but missing (you should not see this):" + args.back());
            break;
        case detail::Classifier::SHORT:
            if(!detail::split_short(current, arg_name, rest))
                throw HorribleError("Short parsed but missing! You should not see this");
            break;
        case detail::Classifier::WINDOWS:
            if(!detail::split_windows_style(current, arg_name, value))
                throw HorribleError("windows option parsed but missing! You should not see this");
            break;
        case detail::Classifier::SUBCOMMAND:
        case detail::Classifier::POSITIONAL_MARK:
        case detail::Classifier::NONE:
        default:
            throw HorribleError("parsing got called with invalid option! You should not see this");
        }

        auto op_ptr =
            std::find_if(std::begin(options_), std::end(options_), [arg_name, current_type](const Option_p &opt) {
                if(current_type == detail::Classifier::LONG)
                    return opt->check_lname(arg_name);
                if(current_type == detail::Classifier::SHORT)
                    return opt->check_sname(arg_name);
                // this will only get called for detail::Classifier::WINDOWS
                return opt->check_lname(arg_name) || opt->check_sname(arg_name);
            });

        // Option not found
        if(op_ptr == std::end(options_)) {
            for(auto &subc : subcommands_) {
                if(subc->name_.empty() && !subc->disabled_) {
                    if(subc->_parse_arg(args, current_type)) {
                        if(!subc->pre_parse_called_) {
                            subc->_trigger_pre_parse(args.size());
                        }
                        return true;
                    }
                }
            }
            // If a subcommand, try the master command
            if(parent_ != nullptr && fallthrough_)
                return _get_fallthrough_parent()->_parse_arg(args, current_type);
            // don't capture missing if this is a nameless subcommand
            if(parent_ != nullptr && name_.empty()) {
                return false;
            }
            // Otherwise, add to missing
            args.pop_back();
            _move_to_missing(current_type, current);
            return true;
        }

        args.pop_back();

        // Get a reference to the pointer to make syntax bearable
        Option_p &op = *op_ptr;

        int num = op->get_items_expected();

        // Make sure we always eat the minimum for unlimited vectors
        int collected = 0;
        int result_count = 0;
        // deal with flag like things
        if(num == 0) {
            auto res = op->get_flag_value(arg_name, value);
            op->add_result(res);
            parse_order_.push_back(op.get());
        }
        // --this=value
        else if(!value.empty()) {
            op->add_result(value, result_count);
            parse_order_.push_back(op.get());
            collected += result_count;
            // If exact number expected
            if(num > 0)
                num = (num >= result_count) ? num - result_count : 0;

            // -Trest
        } else if(!rest.empty()) {
            op->add_result(rest, result_count);
            parse_order_.push_back(op.get());
            rest = "";
            collected += result_count;
            // If exact number expected
            if(num > 0)
                num = (num >= result_count) ? num - result_count : 0;
        }

        // Unlimited vector parser
        if(num < 0) {
            while(!args.empty() && _recognize(args.back(), false) == detail::Classifier::NONE) {
                if(collected >= -num) {
                    // We could break here for allow extras, but we don't

                    // If any positionals remain, don't keep eating
                    if(_count_remaining_positionals() > 0)
                        break;
                }
                op->add_result(args.back(), result_count);
                parse_order_.push_back(op.get());
                args.pop_back();
                collected += result_count;
            }

            // Allow -- to end an unlimited list and "eat" it
            if(!args.empty() && _recognize(args.back()) == detail::Classifier::POSITIONAL_MARK)
                args.pop_back();

        } else {
            while(num > 0 && !args.empty()) {
                std::string current_ = args.back();
                args.pop_back();
                op->add_result(current_, result_count);
                parse_order_.push_back(op.get());
                num -= result_count;
            }

            if(num > 0) {
                throw ArgumentMismatch::TypedAtLeast(op->get_name(), num, op->get_type_name());
            }
        }

        if(!rest.empty()) {
            rest = "-" + rest;
            args.push_back(rest);
        }
        return true;
    }

    void _trigger_pre_parse(size_t remaining_args) {
        if(!pre_parse_called_) {
            pre_parse_called_ = true;
            if(pre_parse_callback_) {
                pre_parse_callback_(remaining_args);
            }
        } else if(immediate_callback_) {
            if(!name_.empty()) {
                auto pcnt = parsed_;
                auto extras = std::move(missing_);
                clear();
                parsed_ = pcnt;
                pre_parse_called_ = true;
                missing_ = std::move(extras);
            }
        }
    }

    App *_get_fallthrough_parent() {
        if(parent_ == nullptr) {
            throw(HorribleError("No Valid parent"));
        }
        auto fallthrough_parent = parent_;
        while((fallthrough_parent->parent_ != nullptr) && (fallthrough_parent->get_name().empty())) {
            fallthrough_parent = fallthrough_parent->parent_;
        }
        return fallthrough_parent;
    }

    void _move_to_missing(detail::Classifier val_type, const std::string &val) {
        if(allow_extras_ || subcommands_.empty()) {
            missing_.emplace_back(val_type, val);
            return;
        }
        // allow extra arguments to be places in an option group if it is allowed there
        for(auto &subc : subcommands_) {
            if(subc->name_.empty() && subc->allow_extras_) {
                subc->missing_.emplace_back(val_type, val);
                return;
            }
        }
        // if we haven't found any place to put them yet put them in missing
        missing_.emplace_back(val_type, val);
    }

  public:
    void _move_option(Option *opt, App *app) {
        if(opt == nullptr) {
            throw OptionNotFound("the option is NULL");
        }
        // verify that the give app is actually a subcommand
        bool found = false;
        for(auto &subc : subcommands_) {
            if(app == subc.get()) {
                found = true;
            }
        }
        if(!found) {
            throw OptionNotFound("The Given app is not a subcommand");
        }

        if((help_ptr_ == opt) || (help_all_ptr_ == opt))
            throw OptionAlreadyAdded("cannot move help options");

        if(config_ptr_ == opt)
            throw OptionAlreadyAdded("cannot move config file options");

        auto iterator =
            std::find_if(std::begin(options_), std::end(options_), [opt](const Option_p &v) { return v.get() == opt; });
        if(iterator != std::end(options_)) {
            const auto &opt_p = *iterator;
            if(std::find_if(std::begin(app->options_), std::end(app->options_), [&opt_p](const Option_p &v) {
                   return (*v == *opt_p);
               }) == std::end(app->options_)) {
                // only erase after the insertion was successful
                app->options_.push_back(std::move(*iterator));
                options_.erase(iterator);
            } else {
                throw OptionAlreadyAdded(opt->get_name());
            }
        } else {
            throw OptionNotFound("could not locate the given App");
        }
    }
};

class Option_group : public App {
  public:
    Option_group(std::string group_description, std::string group_name, App *parent)
        : App(std::move(group_description), "", parent) {
        group(group_name);
        // option groups should have automatic fallthrough
    }
    using App::add_option;
    Option *add_option(Option *opt) {
        if(get_parent() == nullptr) {
            throw OptionNotFound("Unable to locate the specified option");
        }
        get_parent()->_move_option(opt, this);
        return opt;
    }
    void add_options(Option *opt) { add_option(opt); }
    template <typename... Args> void add_options(Option *opt, Args... args) {
        add_option(opt);
        add_options(args...);
    }
    using App::add_subcommand;
    App *add_subcommand(App *subcom) {
        App_p subc = subcom->get_parent()->get_subcommand_ptr(subcom);
        subc->get_parent()->remove_subcommand(subcom);
        add_subcommand(std::move(subc));
        return subcom;
    }
};
inline void TriggerOn(App *trigger_app, App *app_to_enable) {
    app_to_enable->enabled_by_default(false);
    app_to_enable->disabled_by_default();
    trigger_app->preparse_callback([app_to_enable](size_t) { app_to_enable->disabled(false); });
}

inline void TriggerOn(App *trigger_app, std::vector<App *> apps_to_enable) {
    for(auto &app : apps_to_enable) {
        app->enabled_by_default(false);
        app->disabled_by_default();
    }

    trigger_app->preparse_callback([apps_to_enable](size_t) {
        for(auto &app : apps_to_enable) {
            app->disabled(false);
        }
    });
}

inline void TriggerOff(App *trigger_app, App *app_to_enable) {
    app_to_enable->disabled_by_default(false);
    app_to_enable->enabled_by_default();
    trigger_app->preparse_callback([app_to_enable](size_t) { app_to_enable->disabled(); });
}

inline void TriggerOff(App *trigger_app, std::vector<App *> apps_to_enable) {
    for(auto &app : apps_to_enable) {
        app->disabled_by_default(false);
        app->enabled_by_default();
    }

    trigger_app->preparse_callback([apps_to_enable](size_t) {
        for(auto &app : apps_to_enable) {
            app->disabled();
        }
    });
}

namespace FailureMessage {

inline std::string simple(const App *app, const Error &e) {
    std::string header = std::string(e.what()) + "\n";
    std::vector<std::string> names;

    // Collect names
    if(app->get_help_ptr() != nullptr)
        names.push_back(app->get_help_ptr()->get_name());

    if(app->get_help_all_ptr() != nullptr)
        names.push_back(app->get_help_all_ptr()->get_name());

    // If any names found, suggest those
    if(!names.empty())
        header += "Run with " + detail::join(names, " or ") + " for more information.\n";

    return header;
}

inline std::string help(const App *app, const Error &e) {
    std::string header = std::string("ERROR: ") + e.get_name() + ": " + e.what() + "\n";
    header += app->help();
    return header;
}

} // namespace FailureMessage

namespace detail {
struct AppFriend {

    template <typename... Args>
    static auto parse_arg(App *app, Args &&... args) ->
        typename std::result_of<decltype (&App::_parse_arg)(App, Args...)>::type {
        return app->_parse_arg(std::forward<Args>(args)...);
    }

    template <typename... Args>
    static auto parse_subcommand(App *app, Args &&... args) ->
        typename std::result_of<decltype (&App::_parse_subcommand)(App, Args...)>::type {
        return app->_parse_subcommand(std::forward<Args>(args)...);
    }
    static App *get_fallthrough_parent(App *app) { return app->_get_fallthrough_parent(); }
};
} // namespace detail

} // namespace CLI