rublon-ssh/PAM/ssh/include/rublon/check_application.hpp

#pragma once

#include <rapidjson/prettywriter.h>
#include <rapidjson/rapidjson.h>

#include <rublon/core_handler.hpp>
#include <rublon/curl.hpp>
#include <rublon/json.hpp>
#include <rublon/utils.hpp>

#include <string_view>

namespace rublon {

class Status {
    std::string_view _statusDirPath  = "/var/lib/rublon";
    std::string_view _statusFilePath = "/var/lib/rublon/install.json";

    RapidJSONPMRStackAlloc< 4 * 1024 > _alloc;
    Document _data;
    bool _statusUpdated;

    std::string_view _appVersionKey       = "/appVer";
    std::string_view _appTypeKey          = "/type";
    std::string_view _paramSystemName     = "/params/os";
    std::string_view _paramSSHDUsePamName = "/params/sshd_config/usePam";

  public:
    Status() : _data{&_alloc} {
        if(not details::exists(_statusFilePath.data())) {
            log(LogLevel::Info, "application first run, creating status file at %s", _statusFilePath.data());
            details::mkdir(_statusDirPath.data());
            details::touch(_statusFilePath.data());
        }

        std::ifstream ifs{_statusFilePath.data()};
        if(!ifs.is_open()) {
            /// TODO handle no file error
        }

        rapidjson::IStreamWrapper isw{ifs};
        _data.ParseStream(isw);
    }

    void updateAppVersion(std::string_view newVersion) {
        RapidJSONPMRStackAlloc< 128 > stackAlloc;
        auto version = JSONPointer{_appVersionKey.data(), &stackAlloc}.Get(_data);
        if(not version || version->GetString() != newVersion) {
            _statusUpdated = true;
            auto version   = Value{newVersion.data(), _data.GetAllocator()};
            JSONPointer{_appVersionKey.data(), &stackAlloc}.Set(_data, version);
        }
    }

    void updateSystemVersion(std::string_view system) {
        RapidJSONPMRStackAlloc< 128 > stackAlloc;
        auto version = JSONPointer{_paramSystemName.data(), &stackAlloc}.Get(_data);
        if(not version || version->GetString() != system) {
            _statusUpdated = true;
            auto version   = Value{system.data(), _data.GetAllocator()};
            JSONPointer{_paramSystemName.data(), &stackAlloc}.Set(_data, version);
        }
    }

    bool updated() const {
        return _statusUpdated;
    }

    void save() {
        if(updated()) {
            memory::Monotonic_1k_HeapResource tmpResource;
            RapidJSONPMRAlloc alloc{&tmpResource};
            FileWriter s{_statusFilePath};
            rapidjson::PrettyWriter< FileWriter, rapidjson::UTF8<>, rapidjson::UTF8<>, RapidJSONPMRAlloc > writer{s, &alloc};
            writer.SetIndent(' ', 2);
            _data.Accept(writer);
        }
    }

    Document & data() {
        return _data;
    }
};

class CheckApplication {
    tl::expected< bool, Error > persistStatus(Status & status) const {
        status.data().RemoveMember("systemToken");
        status.save();
        return true;
    }

  public:
    template < typename Hander_t >
    tl::expected< int, Error > call(const CoreHandlerInterface< Hander_t > & coreHandler, std::string_view systemToken) const {
        memory::Monotonic_1k_HeapResource mr;
        RapidJSONPMRStackAlloc< 2048 > alloc{};
        constexpr std::string_view api = "/api/app/init";
        Status status;

        const auto persist = [&](const auto /*ok*/) { return this->persistStatus(status); };

        status.updateAppVersion("2.0.2");
        status.updateSystemVersion(details::osName(&mr));

        if(status.updated()) {
            auto & alloc = status.data().GetAllocator();
            status.data().AddMember("systemToken", Value{systemToken.data(), alloc}, alloc);
            return coreHandler.request(alloc, api, status.data()).and_then(persist);
        }
        return 0;
    }
};

} // namespace rublon