#pragma once

#include <memory>
#include <tuple>
#include <type_traits>
#include <utility>
#include <vector>

#include "mfem/fem/gridfunc.hpp"
#include "serif/backend/mfem/mapping/domain_mapper.hpp"
#include "serif/utils/dependencies/dependency_context.hpp"
#include "serif/utils/dependencies/key_list_operations.hpp"

namespace serif::discretization::backend::mfem {
    /** @brief Own meshes and finite-element resources in reverse dependency order, for creation and archive restoration. */
    struct Resources {
        std::vector<std::unique_ptr<::mfem::Mesh>> meshes;
        std::vector<std::unique_ptr<::mfem::FiniteElementCollection>> collections;
        std::vector<std::unique_ptr<::mfem::FiniteElementSpace>> spaces;
        std::unique_ptr<::mfem::GridFunction> compactification;
        std::unique_ptr<mapping::DomainMapper> mapper;
    };

    template <typename Context, typename Keys = typename Context::Keys>
    struct OwnedBindings;

    /** @brief Keep typed bindings alive beside the resources they borrow; neither copying a configuration nor restoring it copies these resources. */
    template <typename Context, typename... Keys>
    struct OwnedBindings<Context, utils::dependencies::KeyList<Keys...>> {
        template <typename Key>
        using Binding = std::remove_cvref_t<decltype(std::declval<Context>().template get<Key>())>;

        Resources resources;
        std::tuple<std::unique_ptr<Binding<Keys>>...> bindings;

        /** @brief Borrow each stable binding through the existing computational-graph input vocabulary. */
        [[nodiscard]] auto context() const {
            using namespace utils::dependencies;

            return make_dependency_context(borrow<Keys>(*std::get<key_index<Keys, KeyList<Keys...>>()>(bindings))...);
        }
    };
}