// SPDX-License-Identifier: GPL-3.0-or-later
// SPDX-FileCopyrightText: 2026 A-La-Karte Contributors

#include "systemdusermanager.h"

#include <QDBusArgument>
#include <QDBusConnection>
#include <QDBusInterface>
#include <QDBusMessage>
#include <QDBusMetaType>
#include <QDBusVariant>

static QDBusArgument &operator<<(QDBusArgument &argument, const SystemdProperty &prop)
{
    argument.beginStructure();
    argument << prop.name << QDBusVariant(prop.value);
    argument.endStructure();
    return argument;
}

static const QDBusArgument &operator>>(const QDBusArgument &argument, SystemdProperty &prop)
{
    QDBusVariant variant;

    argument.beginStructure();
    argument >> prop.name >> variant;
    argument.endStructure();

    prop.value = variant.variant();
    return argument;
}

static QDBusArgument &operator<<(QDBusArgument &argument, const SystemdAuxUnit &unit)
{
    argument.beginStructure();
    argument << unit.name << unit.properties;
    argument.endStructure();
    return argument;
}

static const QDBusArgument &operator>>(const QDBusArgument &argument, SystemdAuxUnit &unit)
{
    argument.beginStructure();
    argument >> unit.name >> unit.properties;
    argument.endStructure();
    return argument;
}

static QDBusArgument &operator<<(QDBusArgument &argument, const SystemdUnitInfo &info)
{
    argument.beginStructure();
    argument << info.name << info.description << info.loadState << info.activeState << info.subState << info.following << info.objectPath << info.jobId
             << info.jobType << info.jobPath;
    argument.endStructure();
    return argument;
}

static const QDBusArgument &operator>>(const QDBusArgument &argument, SystemdUnitInfo &info)
{
    argument.beginStructure();
    argument >> info.name >> info.description >> info.loadState >> info.activeState >> info.subState >> info.following >> info.objectPath >> info.jobId
        >> info.jobType >> info.jobPath;
    argument.endStructure();
    return argument;
}

SystemdUserManager::SystemdUserManager(QObject *parent)
    : QObject(parent)
{
    ensureTypesRegistered();
}

void SystemdUserManager::ensureTypesRegistered()
{
    static bool registered = false;
    if (registered) {
        return;
    }

    qDBusRegisterMetaType<SystemdProperty>();
    qDBusRegisterMetaType<SystemdProperties>();
    qDBusRegisterMetaType<SystemdAuxUnit>();
    qDBusRegisterMetaType<SystemdAuxUnits>();
    qDBusRegisterMetaType<SystemdUnitInfo>();
    qDBusRegisterMetaType<SystemdUnitInfoList>();

    registered = true;
}

bool SystemdUserManager::isAvailable() const
{
    QDBusInterface manager(QStringLiteral("org.freedesktop.systemd1"),
                           QStringLiteral("/org/freedesktop/systemd1"),
                           QStringLiteral("org.freedesktop.systemd1.Manager"),
                           QDBusConnection::sessionBus());

    return manager.isValid();
}

QDBusReply<QDBusObjectPath> SystemdUserManager::startTransientScope(const QString &unitName, const QList<uint> &pids, const QString &description)
{
    QDBusInterface manager(QStringLiteral("org.freedesktop.systemd1"),
                           QStringLiteral("/org/freedesktop/systemd1"),
                           QStringLiteral("org.freedesktop.systemd1.Manager"),
                           QDBusConnection::sessionBus());

    SystemdProperties props;
    props.push_back({QStringLiteral("Description"), description});
    props.push_back({QStringLiteral("PIDs"), QVariant::fromValue(pids)});
    props.push_back({QStringLiteral("CollectMode"), QStringLiteral("inactive-or-failed")});
    props.push_back({QStringLiteral("KillMode"), QStringLiteral("control-group")});
    props.push_back({QStringLiteral("SendSIGKILL"), true});
    props.push_back({QStringLiteral("TimeoutStopUSec"), static_cast<qulonglong>(10) * 1000 * 1000});

    const SystemdAuxUnits aux;

    const QDBusMessage reply =
        manager.call(QStringLiteral("StartTransientUnit"), unitName, QStringLiteral("replace"), QVariant::fromValue(props), QVariant::fromValue(aux));
    return QDBusReply<QDBusObjectPath>(reply);
}

QDBusReply<QDBusObjectPath> SystemdUserManager::stopUnit(const QString &unitName, const QString &mode)
{
    QDBusInterface manager(QStringLiteral("org.freedesktop.systemd1"),
                           QStringLiteral("/org/freedesktop/systemd1"),
                           QStringLiteral("org.freedesktop.systemd1.Manager"),
                           QDBusConnection::sessionBus());

    const QDBusMessage reply = manager.call(QStringLiteral("StopUnit"), unitName, mode);
    return QDBusReply<QDBusObjectPath>(reply);
}

QDBusReply<QDBusObjectPath> SystemdUserManager::getUnit(const QString &unitName)
{
    QDBusInterface manager(QStringLiteral("org.freedesktop.systemd1"),
                           QStringLiteral("/org/freedesktop/systemd1"),
                           QStringLiteral("org.freedesktop.systemd1.Manager"),
                           QDBusConnection::sessionBus());

    const QDBusMessage reply = manager.call(QStringLiteral("GetUnit"), unitName);
    return QDBusReply<QDBusObjectPath>(reply);
}

QDBusReply<SystemdUnitInfoList> SystemdUserManager::listUnits()
{
    QDBusInterface manager(QStringLiteral("org.freedesktop.systemd1"),
                           QStringLiteral("/org/freedesktop/systemd1"),
                           QStringLiteral("org.freedesktop.systemd1.Manager"),
                           QDBusConnection::sessionBus());

    const QDBusMessage reply = manager.call(QStringLiteral("ListUnits"));
    return QDBusReply<SystemdUnitInfoList>(reply);
}

QList<uint> SystemdUserManager::scopePids(const QDBusObjectPath &unitPath)
{
    QDBusInterface unit(QStringLiteral("org.freedesktop.systemd1"),
                        unitPath.path(),
                        QStringLiteral("org.freedesktop.systemd1.Unit"),
                        QDBusConnection::sessionBus());

    const QDBusMessage reply = unit.call(QStringLiteral("GetProcesses"));
    if (reply.type() != QDBusMessage::ReplyMessage || reply.arguments().isEmpty()) {
        return {};
    }

    QList<uint> pids;
    const QDBusArgument arg = reply.arguments().first().value<QDBusArgument>();
    arg.beginArray();
    while (!arg.atEnd()) {
        arg.beginStructure();
        QString cgroupPath;
        uint pid = 0;
        QString cmdline;
        arg >> cgroupPath >> pid >> cmdline;
        arg.endStructure();
        if (pid > 0) {
            pids.push_back(pid);
        }
    }
    arg.endArray();
    return pids;
}