config_node_with_preset_.hpp

#pragma once

#include "./config_node.hpp"

namespace sim {

class ConfigNodeWithPresetExpected;

// Config node that supports preset inheritance.
class ConfigNodeWithPreset {
public:
    explicit ConfigNodeWithPreset(
        ConfigNode a_node,
        std::optional<ConfigNode> a_presets_node = std::nullopt,
        std::optional<ConfigNode> a_preset = std::nullopt);

    ConfigNodeWithPresetExpected operator[](std::string_view key) const;

    [[nodiscard]] bool IsMap() const noexcept;

    friend std::ostream& operator<<(std::ostream& out,
                                    const ConfigNodeWithPreset& node);

    // Returns the base config node.
    const ConfigNode& get_node() const noexcept;

    [[nodiscard]] const std::optional<std::string>& get_name() const;

    // Converts m_node to type T. Probably this method will return message about
    // error
    template <typename T>
    [[nodiscard]] utils::StrExpected<T> as() const noexcept {
        return m_node.as<T>();
    }

    template <typename T>
    T as_or_throw() const {
        return as<T>().value_or_throw();
    }

    [[nodiscard]] const std::string& get_name_or_throw() const;

    const std::optional<ConfigNode> get_presets_node() const noexcept;

    std::runtime_error create_parsing_error(std::string_view error) const;

    class Iterator {
    public:
        Iterator(YAML::const_iterator a_it);

        Iterator& operator++();

        Iterator operator++(int);

        bool operator==(const Iterator& rhs) const;

        bool operator!=(const Iterator& rhs) const;

        ConfigNodeWithPreset operator*() const;

    private:
        // Invariant: m_stacktrace_node is not null
        YAML::const_iterator m_iterator;
    };

    Iterator begin() const;
    Iterator end() const;

private:
    // m_node contains information about config node and probably preset name
    // m_preset - preset node which that is used to supplement fields of m_node
    // m_presets_node - node it which preset node should be searched (id it
    // needs)
    const ConfigNode m_node;
    const std::optional<ConfigNode> m_presets_node;
    mutable std::optional<ConfigNode> m_preset;
};

ConfigNodeWithPreset load_file_with_presets(std::filesystem::path path);

}  // namespace sim