MigratorsRegister.hpp

//------------------------------------------------------------------------------
/*
    This file is part of clio: https://github.com/XRPLF/clio
    Copyright (c) 2024, the clio developers.
 
    Permission to use, copy, modify, and distribute this software for any
    purpose with or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.
 
    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
 
#pragma once
 
#include "data/BackendInterface.hpp"
#include "migration/MigratiorStatus.hpp"
#include "migration/impl/Spec.hpp"
#include "util/Assert.hpp"
#include "util/Concepts.hpp"
#include "util/log/Logger.hpp"
#include "util/newconfig/ObjectView.hpp"
 
#include <algorithm>
#include <array>
#include <iterator>
#include <memory>
#include <optional>
#include <ranges>
#include <string>
#include <string_view>
#include <tuple>
#include <utility>
#include <vector>
 
namespace migration::impl {
 
template <typename BackendType, typename MigratorType>
concept MigrationBackend = requires { requires std::same_as<typename MigratorType::Backend, BackendType>; };
 
template <typename Backend, typename... MigratorType>
concept BackendMatchAllMigrators = (MigrationBackend<Backend, MigratorType> && ...);
 
template <typename T>
concept HasCanBlockClio = requires(T t) {
    { t.kCAN_BLOCK_CLIO };
};
 
template <typename Backend, typename... MigratorType>
    requires AllMigratorSpec<MigratorType...>
class MigratorsRegister {
    static_assert(util::hasNoDuplicateNames<MigratorType...>());
 
    util::Logger log_{"Migration"};
    std::shared_ptr<Backend> backend_;
 
    template <typename Migrator>
    void
    callMigration(std::string const& name, util::config::ObjectView const& config)
    {
        if (name == Migrator::kNAME) {
            LOG(log_.info()) << "Running migration: " << name;
            Migrator::runMigration(backend_, config);
            backend_->writeMigratorStatus(name, MigratorStatus(MigratorStatus::Migrated).toString());
            LOG(log_.info()) << "Finished migration: " << name;
        }
    }
 
    template <typename T>
    static constexpr std::string_view
    getDescriptionIfMatch(std::string_view targetName)
    {
        return (T::kNAME == targetName) ? T::kDESCRIPTION : "";
    }
 
    template <typename First, typename... Rest>
    static constexpr bool
    canBlockClioHelper(std::string_view targetName)
    {
        if (targetName == First::kNAME) {
            if constexpr (HasCanBlockClio<First>) {
                return First::kCAN_BLOCK_CLIO;
            }
            return false;
        }
        if constexpr (sizeof...(Rest) > 0) {
            return canBlockClioHelper<Rest...>(targetName);
        }
        ASSERT(false, "The migrator name is not found");
        std::unreachable();
    }
 
public:
    using BackendType = Backend;
 
    MigratorsRegister(std::shared_ptr<BackendType> backend) : backend_{std::move(backend)}
    {
    }
 
    void
    runMigrator(std::string const& name, util::config::ObjectView const& config)
        requires BackendMatchAllMigrators<BackendType, MigratorType...>
    {
        (callMigration<MigratorType>(name, config), ...);
    }
 
    std::vector<std::tuple<std::string, MigratorStatus>>
    getMigratorsStatus() const
    {
        auto const fullList = getMigratorNames();
 
        std::vector<std::tuple<std::string, MigratorStatus>> status;
 
        std::ranges::transform(fullList, std::back_inserter(status), [&](auto const& migratorName) {
            auto const migratorNameStr = std::string(migratorName);
            return std::make_tuple(migratorNameStr, getMigratorStatus(migratorNameStr));
        });
        return status;
    }
 
    MigratorStatus
    getMigratorStatus(std::string const& name) const
    {
        auto const fullList = getMigratorNames();
        if (std::ranges::find(fullList, name) == fullList.end()) {
            return MigratorStatus::NotKnown;
        }
        auto const statusStringOpt =
            data::synchronous([&](auto yield) { return backend_->fetchMigratorStatus(name, yield); });
 
        return statusStringOpt ? MigratorStatus::fromString(statusStringOpt.value()) : MigratorStatus::NotMigrated;
    }
 
    constexpr auto
    getMigratorNames() const
    {
        return std::array<std::string_view, sizeof...(MigratorType)>{MigratorType::kNAME...};
    }
 
    std::string
    getMigratorDescription(std::string const& name) const
    {
        if constexpr (sizeof...(MigratorType) == 0) {
            return "No Description";
        } else {
            // Fold expression to search through all types
            std::string const result = ([](std::string const& name) {
                return std::string(getDescriptionIfMatch<MigratorType>(name));
            }(name) + ...);
 
            return result.empty() ? "No Description" : result;
        }
    }
 
    std::optional<bool>
    canMigratorBlockClio(std::string_view name) const
    {
        if constexpr (sizeof...(MigratorType) == 0) {
            return std::nullopt;
        } else {
            auto const migratiors = getMigratorNames();
            if (std::ranges::find(migratiors, name) == migratiors.end())
                return std::nullopt;
 
            return canBlockClioHelper<MigratorType...>(name);
        }
    }
};
 
}  // namespace migration::impl