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

#include "gamecenterdaemon.h"

#include <QDBusArgument>
#include <QDBusConnection>
#include <QDBusConnectionInterface>
#include <QDBusError>
#include <QDBusObjectPath>
#include <QDBusReply>
#include <QDBusVariant>
#include <QProcess>
#include <QProcessEnvironment>
#include <QStandardPaths>
#include <QTimer>
#include <QUuid>
#include <QVariantMap>

#include <QRegularExpression>

#include <utility>

static QString ensureScopeUnitName(const QString &unitName)
{
    if (unitName.endsWith(QLatin1String(".scope"))) {
        return unitName;
    }

    return unitName + QStringLiteral(".scope");
}

namespace
{

static QVariant unwrapDbusVariant(QVariant v)
{
    if (v.canConvert<QDBusVariant>()) {
        v = v.value<QDBusVariant>().variant();
    }
    return v;
}

static QVariant normalizeForDbus(QVariant v)
{
    v = unwrapDbusVariant(v);

    if (v.userType() == QMetaType::QChar) {
        return QString(v.toChar());
    }

    if (v.canConvert<QDBusArgument>()) {
        const QDBusArgument arg = v.value<QDBusArgument>();
        const QMap<QString, QString> asStringMap = qdbus_cast<QMap<QString, QString>>(arg);
        if (!asStringMap.isEmpty()) {
            QVariantMap converted;
            for (auto it = asStringMap.constBegin(); it != asStringMap.constEnd(); ++it) {
                converted.insert(it.key(), it.value());
            }
            return normalizeForDbus(converted);
        }

        const QVariantMap asMap = qdbus_cast<QVariantMap>(arg);
        if (!asMap.isEmpty()) {
            return normalizeForDbus(asMap);
        }

        const QStringList asStringList = qdbus_cast<QStringList>(arg);
        if (!asStringList.isEmpty()) {
            return asStringList;
        }
    }
    if (v.canConvert<QVariantMap>()) {
        QVariantMap m = v.toMap();
        for (auto it = m.begin(); it != m.end(); ++it) {
            it.value() = normalizeForDbus(it.value());
        }
        return m;
    }
    if (v.canConvert<QVariantList>()) {
        QVariantList list = v.toList();
        for (QVariant &item : list) {
            item = normalizeForDbus(item);
        }
        return list;
    }
    return v;
}

static QVariantMap normalizeVariantMapForDbus(const QVariantMap &map)
{
    QVariantMap out;
    for (auto it = map.constBegin(); it != map.constEnd(); ++it) {
        out.insert(it.key(), normalizeForDbus(it.value()));
    }
    return out;
}

static QString mapStringValue(const QVariantMap &map, const QStringList &keys)
{
    for (const QString &k : keys) {
        const auto it = map.constFind(k);
        if (it == map.constEnd()) {
            continue;
        }
        return unwrapDbusVariant(*it).toString();
    }
    return {};
}

static QStringList variantToStringList(QVariant v)
{
    v = unwrapDbusVariant(v);
    if (v.canConvert<QStringList>()) {
        return v.toStringList();
    }
    if (v.canConvert<QVariantList>()) {
        const QVariantList list = v.toList();
        QStringList out;
        out.reserve(list.size());
        for (const QVariant &item : list) {
            out.push_back(unwrapDbusVariant(item).toString());
        }
        return out;
    }
    if (v.canConvert<QDBusArgument>()) {
        const QDBusArgument arg = v.value<QDBusArgument>();
        const QStringList out = qdbus_cast<QStringList>(arg);
        if (!out.isEmpty()) {
            return out;
        }
    }
    const QString s = v.toString();
    if (!s.trimmed().isEmpty()) {
        return QProcess::splitCommand(s);
    }
    return {};
}

class UnitPropertiesWatcher : public QObject
{
    Q_OBJECT
public:
    explicit UnitPropertiesWatcher(const QDBusObjectPath &path, QObject *parent = nullptr)
        : QObject(parent)
        , m_path(path)
    {
    }

    QDBusObjectPath path() const
    {
        return m_path;
    }

public Q_SLOTS:
    void onPropertiesChanged(const QString &interfaceName, const QVariantMap &changedProperties, const QStringList &invalidated)
    {
        Q_UNUSED(invalidated)
        if (interfaceName != QLatin1String("org.freedesktop.systemd1.Unit")) {
            return;
        }
        Q_EMIT propertiesChanged(m_path, changedProperties);
    }

Q_SIGNALS:
    void propertiesChanged(const QDBusObjectPath &path, const QVariantMap &changedProperties);

private:
    QDBusObjectPath m_path;
};

} // namespace

void GameCenterDaemon::watchSystemdUnit(const QString &sessionId, const QString &unitName, const QDBusObjectPath &unitPath)
{
    if (unitName.isEmpty()) {
        return;
    }

    m_unitNameToSessionId.insert(unitName, sessionId);

    if (unitPath.path().isEmpty()) {
        return;
    }

    const QString unitPathKey = unitPath.path();
    m_unitPathToSessionId.insert(unitPathKey, sessionId);

    if (m_unitPathWatchers.contains(unitPathKey)) {
        return;
    }

    auto *watcher = new UnitPropertiesWatcher(unitPath, this);
    m_unitPathWatchers.insert(unitPathKey, watcher);

    QDBusConnection bus = QDBusConnection::sessionBus();
    bus.connect(QStringLiteral("org.freedesktop.systemd1"),
                unitPath.path(),
                QStringLiteral("org.freedesktop.DBus.Properties"),
                QStringLiteral("PropertiesChanged"),
                watcher,
                SLOT(onPropertiesChanged(QString, QVariantMap, QStringList)));

    connect(watcher, &UnitPropertiesWatcher::propertiesChanged, this, &GameCenterDaemon::handleSystemdUnitPropertiesChanged);
}

void GameCenterDaemon::unwatchSystemdUnit(const QString &unitName, const QDBusObjectPath &unitPath)
{
    if (!unitName.isEmpty()) {
        m_unitNameToSessionId.remove(unitName);
    }

    if (!unitPath.path().isEmpty()) {
        const QString unitPathKey = unitPath.path();
        m_unitPathToSessionId.remove(unitPathKey);
        if (QObject *watcher = m_unitPathWatchers.take(unitPathKey)) {
            watcher->deleteLater();
        }
    }
}

void GameCenterDaemon::handleSystemdUnitNew(const QString &unitName, const QDBusObjectPath &unitPath)
{
    const auto it = m_unitNameToSessionId.constFind(unitName);
    if (it == m_unitNameToSessionId.constEnd()) {
        return;
    }

    const QString sessionId = it.value();
    auto sit = m_sessions.find(sessionId);
    if (sit == m_sessions.end()) {
        return;
    }

    if (sit.value().unitPath.path().isEmpty() && !unitPath.path().isEmpty()) {
        sit.value().unitPath = unitPath;
        watchSystemdUnit(sessionId, unitName, unitPath);
    }
}

void GameCenterDaemon::handleSystemdUnitRemoved(const QString &unitName, const QDBusObjectPath &unitPath)
{
    QString sessionId;

    if (!unitPath.path().isEmpty()) {
        const auto it = m_unitPathToSessionId.constFind(unitPath.path());
        if (it != m_unitPathToSessionId.constEnd()) {
            sessionId = it.value();
        }
    }

    if (sessionId.isEmpty() && !unitName.isEmpty()) {
        const auto it = m_unitNameToSessionId.constFind(unitName);
        if (it != m_unitNameToSessionId.constEnd()) {
            sessionId = it.value();
        }
    }

    if (sessionId.isEmpty()) {
        return;
    }

    auto sit = m_sessions.find(sessionId);
    if (sit == m_sessions.end()) {
        unwatchSystemdUnit(unitName, unitPath);
        return;
    }

    unwatchSystemdUnit(sit.value().unitName, sit.value().unitPath);
    removeSessionInternal(sessionId, sit.value().stopping ? QStringLiteral("Stopped") : QStringLiteral("Exited"));
}

void GameCenterDaemon::handleSystemdUnitPropertiesChanged(const QDBusObjectPath &unitPath, const QVariantMap &changedProperties)
{
    if (unitPath.path().isEmpty()) {
        return;
    }

    const auto sidIt = m_unitPathToSessionId.constFind(unitPath.path());
    if (sidIt == m_unitPathToSessionId.constEnd()) {
        return;
    }
    const QString sessionId = sidIt.value();

    auto sit = m_sessions.find(sessionId);
    if (sit == m_sessions.end()) {
        return;
    }

    QVariant activeStateV = changedProperties.value(QStringLiteral("ActiveState"));
    if (activeStateV.canConvert<QDBusVariant>()) {
        activeStateV = activeStateV.value<QDBusVariant>().variant();
    }
    if (!activeStateV.isValid()) {
        return;
    }
    const QString activeState = activeStateV.toString();

    if (activeState == QLatin1String("active") || activeState == QLatin1String("activating") || activeState == QLatin1String("deactivating")) {
        const QList<uint> pids = m_systemd.scopePids(unitPath);
        if (!pids.isEmpty()) {
            sit.value().mainPid = pids.first();
        }
        Q_EMIT SessionChanged(sessionToVariantMap(sit.value(), sessionState(sit.value())));
        return;
    }

    const QString finalState =
        sit.value().stopping ? QStringLiteral("Stopped") : (activeState == QLatin1String("failed") ? QStringLiteral("Failed") : QStringLiteral("Exited"));
    unwatchSystemdUnit(sit.value().unitName, sit.value().unitPath);
    removeSessionInternal(sessionId, finalState);
}

void GameCenterDaemon::removeSessionInternal(const QString &sessionId, const QString &finalState)
{
    auto it = m_sessions.find(sessionId);
    if (it == m_sessions.end()) {
        return;
    }

    QVariantMap finalMap = sessionToVariantMap(it.value(), finalState);
    if (it.value().hasExitInfo) {
        finalMap.insert(QStringLiteral("exitCode"), it.value().exitCode);
        finalMap.insert(QStringLiteral("exitStatus"), it.value().exitStatus);
    }

    if (it.value().process) {
        it.value().process->deleteLater();
        it.value().process = nullptr;
    }
    if (it.value().scanner) {
        it.value().scanner->cancel();
        it.value().scanner->deleteLater();
        it.value().scanner = nullptr;
    }

    Q_EMIT SessionRemoved(sessionId, finalMap);
    m_sessions.erase(it);
}
GameCenterDaemon::GameCenterDaemon(QObject *parent)
    : QObject(parent)
{
}

bool GameCenterDaemon::init()
{
    QDBusConnection bus = QDBusConnection::sessionBus();
    if (!bus.isConnected()) {
        return false;
    }

    if (!bus.registerService(QStringLiteral("org.kde.GameCenter1"))) {
        return false;
    }

    if (!bus.registerObject(QStringLiteral("/org/kde/GameCenter1"), this, QDBusConnection::ExportAllSlots | QDBusConnection::ExportAllSignals)) {
        return false;
    }

    setupSystemdSubscriptions();

    recoverExistingSessions();

    return true;
}

void GameCenterDaemon::setupSystemdSubscriptions()
{
    if (!m_systemd.isAvailable()) {
        return;
    }

    QDBusConnection bus = QDBusConnection::sessionBus();
    if (!bus.isConnected()) {
        return;
    }

    bus.connect(QStringLiteral("org.freedesktop.systemd1"),
                QStringLiteral("/org/freedesktop/systemd1"),
                QStringLiteral("org.freedesktop.systemd1.Manager"),
                QStringLiteral("UnitNew"),
                this,
                SLOT(handleSystemdUnitNew(QString, QDBusObjectPath)));

    bus.connect(QStringLiteral("org.freedesktop.systemd1"),
                QStringLiteral("/org/freedesktop/systemd1"),
                QStringLiteral("org.freedesktop.systemd1.Manager"),
                QStringLiteral("UnitRemoved"),
                this,
                SLOT(handleSystemdUnitRemoved(QString, QDBusObjectPath)));
}

QString GameCenterDaemon::Ping() const
{
    return QStringLiteral("ok");
}

void GameCenterDaemon::Version(uint &major, uint &minor) const
{
    major = 1;
    minor = 0;
}

QVariantMap GameCenterDaemon::GetCapabilities() const
{
    QVariantMap caps;
    caps.insert(QStringLiteral("supportsSystemd"), m_systemd.isAvailable());
    caps.insert(QStringLiteral("supportsSystemBus"), false);
    const bool systemdAvailable = m_systemd.isAvailable();
    const bool steamAvailable = !QStandardPaths::findExecutable(QStringLiteral("steam")).isEmpty();
    const bool lutrisAvailable = !QStandardPaths::findExecutable(QStringLiteral("lutris")).isEmpty();
    caps.insert(QStringLiteral("supportsSteamAttach"), systemdAvailable && steamAvailable);
    caps.insert(QStringLiteral("supportsLutrisAttach"), systemdAvailable && lutrisAvailable);
    return caps;
}

QVariantList GameCenterDaemon::ListSessions() const
{
    QVariantList sessions;
    sessions.reserve(m_sessions.size());

    for (const auto &session : m_sessions) {
        sessions.push_back(sessionToVariantMap(session, sessionState(session)));
    }

    return sessions;
}

QVariantMap GameCenterDaemon::GetSession(const QString &sessionId) const
{
    const auto it = m_sessions.constFind(sessionId);
    if (it == m_sessions.constEnd()) {
        return {};
    }
    return sessionToVariantMap(it.value(), sessionState(it.value()));
}

void GameCenterDaemon::SetPolicy(const QVariantMap &policy)
{
    if (policy.contains(QStringLiteral("maxConcurrent"))) {
        QVariant v = policy.value(QStringLiteral("maxConcurrent"));
        if (v.canConvert<QDBusVariant>()) {
            v = v.value<QDBusVariant>().variant();
        }
        m_maxConcurrent = v.toInt();
    }
}

QVariantMap GameCenterDaemon::GetPolicy() const
{
    return {
        {QStringLiteral("maxConcurrent"), m_maxConcurrent},
    };
}

QString GameCenterDaemon::Launch(const QVariantMap &launchSpec)
{
    if (!m_systemd.isAvailable()) {
        failLaunch(QStringLiteral("systemd user manager is not available"), launchSpec);
        return {};
    }

    if (m_maxConcurrent > 0 && m_sessions.size() >= m_maxConcurrent) {
        QVariantMap ctx = launchSpec;
        ctx.insert(QStringLiteral("maxConcurrent"), m_maxConcurrent);
        ctx.insert(QStringLiteral("activeSessions"), m_sessions.size());
        failLaunch(QStringLiteral("max concurrent session limit reached"), ctx);
        return {};
    }

    const QString provider = detectProvider(launchSpec);

    if (provider == QLatin1String("steam") || provider == QLatin1String("lutris")) {
        return launchMonitored(launchSpec, provider);
    }

    return launchDirect(launchSpec);
}

QString GameCenterDaemon::launchDirect(const QVariantMap &launchSpec)
{
    const QString gameId = mapStringValue(launchSpec, {QStringLiteral("gameId"), QStringLiteral("id")});
    const QString displayName = mapStringValue(launchSpec, {QStringLiteral("displayName"), QStringLiteral("name"), QStringLiteral("title")});
    const QString workingDirectory = mapStringValue(launchSpec, {QStringLiteral("workingDirectory"), QStringLiteral("cwd"), QStringLiteral("workingDir")});

    const QString command = mapStringValue(launchSpec, {QStringLiteral("command"), QStringLiteral("launchCommand")});
    QString program = mapStringValue(launchSpec, {QStringLiteral("program"), QStringLiteral("executable"), QStringLiteral("exe")});
    QStringList args;
    if (launchSpec.contains(QStringLiteral("args"))) {
        args = variantToStringList(launchSpec.value(QStringLiteral("args")));
    } else if (launchSpec.contains(QStringLiteral("argv"))) {
        args = variantToStringList(launchSpec.value(QStringLiteral("argv")));
    } else if (launchSpec.contains(QStringLiteral("arguments"))) {
        args = variantToStringList(launchSpec.value(QStringLiteral("arguments")));
    }

    if (program.trimmed().isEmpty()) {
        if (command.trimmed().isEmpty()) {
            failLaunch(QStringLiteral("launchSpec.command or launchSpec.program is required"), launchSpec);
            return {};
        }

        const QStringList argv = QProcess::splitCommand(command);
        if (argv.isEmpty()) {
            failLaunch(QStringLiteral("failed to parse command"), launchSpec);
            return {};
        }

        program = argv.first();
        args = argv.mid(1);
    }

    QVariantMap envOverrides;
    auto extractVariantMap = [](QVariant v) {
        if (v.canConvert<QDBusVariant>()) {
            v = v.value<QDBusVariant>().variant();
        }
        if (v.canConvert<QVariantMap>()) {
            return v.toMap();
        }
        if (v.canConvert<QDBusArgument>()) {
            const QDBusArgument arg = v.value<QDBusArgument>();
            const QMap<QString, QString> asStringMap = qdbus_cast<QMap<QString, QString>>(arg);
            if (!asStringMap.isEmpty()) {
                QVariantMap converted;
                for (auto it = asStringMap.constBegin(); it != asStringMap.constEnd(); ++it) {
                    converted.insert(it.key(), it.value());
                }
                return converted;
            }

            QVariantMap asMap = qdbus_cast<QVariantMap>(arg);
            if (!asMap.isEmpty()) {
                return asMap;
            }
        }
        return QVariantMap{};
    };

    if (launchSpec.contains(QStringLiteral("env"))) {
        envOverrides = extractVariantMap(launchSpec.value(QStringLiteral("env")));
    } else if (launchSpec.contains(QStringLiteral("environment"))) {
        envOverrides = extractVariantMap(launchSpec.value(QStringLiteral("environment")));
    } else if (launchSpec.contains(QStringLiteral("envOverrides"))) {
        envOverrides = extractVariantMap(launchSpec.value(QStringLiteral("envOverrides")));
    }

    const QString sessionId = QUuid::createUuid().toString(QUuid::WithoutBraces);
    const QString unitName = ensureScopeUnitName(QStringLiteral("alakarte-game-%1").arg(sessionId));

    auto *process = new QProcess(this);
    if (!workingDirectory.isEmpty()) {
        process->setWorkingDirectory(workingDirectory);
    }

    if (!envOverrides.isEmpty()) {
        QProcessEnvironment env = QProcessEnvironment::systemEnvironment();
        for (auto it = envOverrides.constBegin(); it != envOverrides.constEnd(); ++it) {
            const QString key = it.key();
            if (key.isEmpty() || key.contains(QLatin1Char('='))) {
                continue;
            }

            QVariant value = it.value();
            if (value.canConvert<QDBusVariant>()) {
                value = value.value<QDBusVariant>().variant();
            }
            env.insert(key, value.toString());
        }
        process->setProcessEnvironment(env);
    }

    process->start(program, args);
    if (!process->waitForStarted()) {
        const QVariantMap ctx = {
            {QStringLiteral("command"), command},
            {QStringLiteral("program"), program},
            {QStringLiteral("args"), args},
            {QStringLiteral("gameId"), gameId},
            {QStringLiteral("workingDirectory"), workingDirectory},
            {QStringLiteral("envOverrides"), envOverrides},
            {QStringLiteral("error"), process->errorString()},
        };
        process->deleteLater();
        failLaunch(QStringLiteral("failed to start process"), ctx);
        return {};
    }

    const QList<uint> pids = {static_cast<uint>(process->processId())};
    const QString description = gameId.isEmpty() ? QStringLiteral("A-La-Karte game") : QStringLiteral("A-La-Karte game %1").arg(gameId);

    const QDBusReply<QDBusObjectPath> startReply = m_systemd.startTransientScope(unitName, pids, description);
    if (!startReply.isValid()) {
        const QVariantMap ctx = {
            {QStringLiteral("command"), command},
            {QStringLiteral("program"), program},
            {QStringLiteral("args"), args},
            {QStringLiteral("gameId"), gameId},
            {QStringLiteral("workingDirectory"), workingDirectory},
            {QStringLiteral("envOverrides"), envOverrides},
            {QStringLiteral("unit"), unitName},
            {QStringLiteral("error"), startReply.error().message()},
        };
        process->kill();
        process->deleteLater();
        failLaunch(QStringLiteral("failed to create transient scope"), ctx);
        return {};
    }

    QDBusObjectPath unitPath;
    const QDBusReply<QDBusObjectPath> getUnitReply = m_systemd.getUnit(unitName);
    if (getUnitReply.isValid()) {
        unitPath = getUnitReply.value();
    }

    Session session;
    session.sessionId = sessionId;
    session.gameId = gameId;
    session.displayName = displayName;
    session.unitName = unitName;
    session.unitPath = unitPath;
    session.provider = QStringLiteral("manual");
    session.startTime = QDateTime::currentDateTimeUtc();
    session.process = process;
    session.mainPid = static_cast<uint>(process->processId());
    m_sessions.insert(sessionId, session);

    watchSystemdUnit(sessionId, unitName, unitPath);

    Q_EMIT SessionAdded(sessionToVariantMap(session, QStringLiteral("Running")));

    connect(process, qOverload<int, QProcess::ExitStatus>(&QProcess::finished), this, [this, sessionId](int exitCode, QProcess::ExitStatus exitStatus) {
        const auto it = m_sessions.find(sessionId);
        if (it == m_sessions.end()) {
            return;
        }
        it.value().hasExitInfo = true;
        it.value().exitCode = exitCode;
        it.value().exitStatus = static_cast<int>(exitStatus);
        if (it.value().process) {
            it.value().process->deleteLater();
            it.value().process = nullptr;
        }
    });

    return sessionId;
}

QString GameCenterDaemon::launchMonitored(const QVariantMap &launchSpec, const QString &provider)
{
    const QString gameId = mapStringValue(launchSpec, {QStringLiteral("gameId"), QStringLiteral("id")});
    const QString displayName = mapStringValue(launchSpec, {QStringLiteral("displayName"), QStringLiteral("name"), QStringLiteral("title")});
    const QString command = mapStringValue(launchSpec, {QStringLiteral("command"), QStringLiteral("launchCommand")});

    const QString sessionId = QUuid::createUuid().toString(QUuid::WithoutBraces);

    // Determine bootstrap command and scanner matcher
    QString bootstrapProgram;
    QStringList bootstrapArgs;
    std::function<QList<ProcessScanner::Match>()> matcher;

    if (provider == QLatin1String("steam")) {
        const QString appId = extractSteamAppId(command);
        if (appId.isEmpty()) {
            failLaunch(QStringLiteral("could not extract Steam appId from command"), launchSpec);
            return {};
        }

        bootstrapProgram = QStringLiteral("steam");
        bootstrapArgs = {QStringLiteral("-silent"), QStringLiteral("-applaunch"), appId};

        matcher = [appId]() -> QList<ProcessScanner::Match> {
            // Primary: look for SteamAppId=<appId> in environ
            QList<ProcessScanner::Match> results = ProcessScanner::findByEnvironment(QStringLiteral("SteamAppId"), appId);
            if (results.isEmpty()) {
                results = ProcessScanner::findByEnvironment(QStringLiteral("SteamGameId"), appId);
            }
            // Filter out the steam client itself
            QList<ProcessScanner::Match> filtered;
            for (const auto &m : std::as_const(results)) {
                if (!m.exe.contains(QLatin1String("steam")) || m.exe.contains(QLatin1String("proton"))) {
                    filtered.push_back(m);
                }
            }
            return filtered.isEmpty() ? results : filtered;
        };

    } else if (provider == QLatin1String("lutris")) {
        const QString lutrisId = extractLutrisId(command);
        if (lutrisId.isEmpty()) {
            failLaunch(QStringLiteral("could not extract Lutris ID from command"), launchSpec);
            return {};
        }

        bootstrapProgram = QStringLiteral("lutris");
        bootstrapArgs = {QStringLiteral("lutris:rungameid/%1").arg(lutrisId)};

        // For Lutris, look for child processes with the game slug or lutris game env
        matcher = [lutrisId]() -> QList<ProcessScanner::Match> {
            QList<ProcessScanner::Match> results = ProcessScanner::findByEnvironment(QStringLiteral("LUTRIS_GAME_SLUG"), lutrisId);
            if (results.isEmpty()) {
                results = ProcessScanner::findByCmdline(lutrisId);
                // Filter out lutris itself
                QList<ProcessScanner::Match> filtered;
                for (const auto &m : std::as_const(results)) {
                    if (!m.exe.endsWith(QLatin1String("/lutris")) && !m.exe.endsWith(QLatin1String("/python3"))) {
                        filtered.push_back(m);
                    }
                }
                if (!filtered.isEmpty()) {
                    results = filtered;
                }
            }
            return results;
        };
    }

    if (bootstrapProgram.isEmpty() || !matcher) {
        QVariantMap ctx = launchSpec;
        ctx.insert(QStringLiteral("provider"), provider);
        failLaunch(QStringLiteral("unsupported monitored provider"), ctx);
        return {};
    }

    if (QStandardPaths::findExecutable(bootstrapProgram).isEmpty()) {
        const QVariantMap ctx = {
            {QStringLiteral("gameId"), gameId},
            {QStringLiteral("provider"), provider},
            {QStringLiteral("program"), bootstrapProgram},
        };
        failLaunch(QStringLiteral("bootstrap executable not found"), ctx);
        return {};
    }

    // Create session in Launching state
    Session session;
    session.sessionId = sessionId;
    session.gameId = gameId;
    session.displayName = displayName;
    session.provider = provider;
    session.startTime = QDateTime::currentDateTimeUtc();
    m_sessions.insert(sessionId, session);

    Q_EMIT SessionAdded(sessionToVariantMap(session, QStringLiteral("Launching")));

    // Start bootstrap process (e.g. steam -applaunch or lutris ...)
    auto *bootstrap = new QProcess(this);
    bootstrap->start(bootstrapProgram, bootstrapArgs);

    if (!bootstrap->waitForStarted(5000)) {
        const QVariantMap ctx = {
            {QStringLiteral("gameId"), gameId},
            {QStringLiteral("provider"), provider},
            {QStringLiteral("command"), command},
            {QStringLiteral("error"), bootstrap->errorString()},
        };
        bootstrap->deleteLater();
        QVariantMap finalState = sessionToVariantMap(session, QStringLiteral("Failed"));
        Q_EMIT SessionRemoved(sessionId, finalState);
        m_sessions.remove(sessionId);
        failLaunch(QStringLiteral("failed to start bootstrap process"), ctx);
        return {};
    }

    session.process = bootstrap;
    m_sessions[sessionId] = session;

    connect(bootstrap, qOverload<int, QProcess::ExitStatus>(&QProcess::finished), this, [this, sessionId](int, QProcess::ExitStatus) {
        const auto it = m_sessions.find(sessionId);
        if (it == m_sessions.end()) {
            return;
        }
        if (it.value().scanner || it.value().stopping) {
            return;
        }
        if (it.value().process) {
            it.value().process->deleteLater();
            it.value().process = nullptr;
        }
    });

    // Start polling for game PID
    auto *scanner = new ProcessScanner(this);
    m_sessions[sessionId].scanner = scanner;

    connect(scanner, &ProcessScanner::found, this, [this, sessionId](const QList<ProcessScanner::Match> &matches) {
        QList<uint> pids;
        pids.reserve(matches.size());
        for (const auto &m : matches) {
            pids.push_back(m.pid);
        }
        attachPidsToSession(sessionId, pids);
    });

    connect(scanner, &ProcessScanner::timedOut, this, [this, sessionId, launchSpec]() {
        auto it = m_sessions.find(sessionId);
        if (it == m_sessions.end()) {
            return;
        }

        const bool stopping = it.value().stopping;
        const QVariantMap ctx = {
            {QStringLiteral("gameId"), it.value().gameId},
            {QStringLiteral("provider"), it.value().provider},
        };

        QVariantMap finalState = sessionToVariantMap(it.value(), stopping ? QStringLiteral("Stopped") : QStringLiteral("Failed"));

        if (it.value().scanner) {
            it.value().scanner->cancel();
            it.value().scanner->deleteLater();
        }
        if (it.value().process) {
            it.value().process->deleteLater();
        }
        Q_EMIT SessionRemoved(sessionId, finalState);
        m_sessions.erase(it);

        if (!stopping) {
            failLaunch(QStringLiteral("timed out waiting for game process"), ctx);
        }
    });

    scanner->pollUntilFound(std::move(matcher), 500, 20000);

    return sessionId;
}

void GameCenterDaemon::attachPidsToSession(const QString &sessionId, const QList<uint> &pids)
{
    auto it = m_sessions.find(sessionId);
    if (it == m_sessions.end() || pids.isEmpty()) {
        return;
    }

    if (it.value().scanner) {
        it.value().scanner->cancel();
        it.value().scanner->deleteLater();
        it.value().scanner = nullptr;
    }

    it.value().mainPid = pids.first();

    const QString unitName = ensureScopeUnitName(QStringLiteral("alakarte-game-%1").arg(sessionId));
    const QString description = it.value().gameId.isEmpty() ? QStringLiteral("A-La-Karte game") : QStringLiteral("A-La-Karte game %1").arg(it.value().gameId);

    const QDBusReply<QDBusObjectPath> reply = m_systemd.startTransientScope(unitName, pids, description);
    if (!reply.isValid()) {
        const QVariantMap ctx = {
            {QStringLiteral("gameId"), it.value().gameId},
            {QStringLiteral("provider"), it.value().provider},
            {QStringLiteral("unit"), unitName},
            {QStringLiteral("error"), reply.error().message()},
        };

        QVariantMap finalState = sessionToVariantMap(it.value(), QStringLiteral("Failed"));
        if (it.value().process) {
            it.value().process->deleteLater();
        }
        Q_EMIT SessionRemoved(sessionId, finalState);
        m_sessions.erase(it);

        failLaunch(QStringLiteral("failed to create transient scope for monitored game"), ctx);
        return;
    }

    it.value().unitName = unitName;

    const QDBusReply<QDBusObjectPath> getUnitReply = m_systemd.getUnit(unitName);
    if (getUnitReply.isValid()) {
        it.value().unitPath = getUnitReply.value();
    }

    watchSystemdUnit(sessionId, unitName, it.value().unitPath);

    if (it.value().process) {
        it.value().process->deleteLater();
        it.value().process = nullptr;
    }

    if (it.value().stopping) {
        m_systemd.stopUnit(it.value().unitName);
        QVariantMap finalState = sessionToVariantMap(it.value(), QStringLiteral("Stopped"));
        Q_EMIT SessionRemoved(sessionId, finalState);
        unwatchSystemdUnit(unitName, it.value().unitPath);
        m_sessions.erase(it);
        return;
    }

    Q_EMIT SessionChanged(sessionToVariantMap(it.value(), QStringLiteral("Running")));
}

QString GameCenterDaemon::detectProvider(const QVariantMap &launchSpec)
{
    // Explicit provider hint takes priority
    QString explicit_provider;
    {
        QVariant v = launchSpec.value(QStringLiteral("provider"));
        if (v.canConvert<QDBusVariant>()) {
            v = v.value<QDBusVariant>().variant();
        }
        explicit_provider = v.toString().toLower();
    }
    if (!explicit_provider.isEmpty()) {
        return explicit_provider;
    }

    // Auto-detect from command
    const QString command = mapStringValue(launchSpec, {QStringLiteral("command"), QStringLiteral("launchCommand")});
    if (command.contains(QLatin1String("steam://rungameid/")) || command.contains(QLatin1String("steam -applaunch"))) {
        return QStringLiteral("steam");
    }
    if (command.startsWith(QLatin1String("lutris ")) || command.contains(QLatin1String("lutris:rungame"))) {
        return QStringLiteral("lutris");
    }

    return QStringLiteral("manual");
}

QString GameCenterDaemon::extractSteamAppId(const QString &command)
{
    // steam://rungameid/<appid>
    static const QRegularExpression steamUrlRe(QStringLiteral("steam://rungameid/(\\d+)"));
    QRegularExpressionMatch match = steamUrlRe.match(command);
    if (match.hasMatch()) {
        return match.captured(1);
    }

    // steam -applaunch <appid>
    static const QRegularExpression applaunchRe(QStringLiteral("-applaunch\\s+(\\d+)"));
    match = applaunchRe.match(command);
    if (match.hasMatch()) {
        return match.captured(1);
    }

    return {};
}

QString GameCenterDaemon::extractLutrisId(const QString &command)
{
    // lutris:rungameid/<id> or lutris:rungame/<slug>
    static const QRegularExpression lutrisRe(QStringLiteral("lutris:rungame(?:id)?/([^\\s]+)"));
    QRegularExpressionMatch match = lutrisRe.match(command);
    if (match.hasMatch()) {
        return match.captured(1);
    }

    // "lutris lutris:rungameid/<id>" form
    static const QRegularExpression lutrisCmdRe(QStringLiteral("lutris\\s+lutris:rungame(?:id)?/([^\\s]+)"));
    match = lutrisCmdRe.match(command);
    if (match.hasMatch()) {
        return match.captured(1);
    }

    return {};
}

void GameCenterDaemon::Stop(const QString &sessionId)
{
    auto it = m_sessions.find(sessionId);
    if (it == m_sessions.end()) {
        return;
    }

    it.value().stopping = true;

    if (it.value().scanner) {
        Q_EMIT SessionChanged(sessionToVariantMap(it.value(), QStringLiteral("Stopping")));

        if (it.value().scanner) {
            it.value().scanner->cancel();
            it.value().scanner->deleteLater();
            it.value().scanner = nullptr;
        }

        QPointer<QProcess> proc = it.value().process;
        it.value().process = nullptr;
        if (proc) {
            connect(proc, qOverload<int, QProcess::ExitStatus>(&QProcess::finished), proc, &QObject::deleteLater);
            if (proc->state() != QProcess::NotRunning) {
                proc->terminate();
                QTimer::singleShot(5000, proc, [proc]() {
                    if (proc && proc->state() != QProcess::NotRunning) {
                        proc->kill();
                    }
                });
            } else {
                proc->deleteLater();
            }
        }

        QVariantMap finalState = sessionToVariantMap(it.value(), QStringLiteral("Stopped"));
        Q_EMIT SessionRemoved(sessionId, finalState);
        m_sessions.erase(it);
        return;
    }

    if (it.value().unitName.isEmpty()) {
        QVariantMap finalState = sessionToVariantMap(it.value(), QStringLiteral("Stopped"));
        if (it.value().process) {
            it.value().process->kill();
            it.value().process->deleteLater();
        }
        Q_EMIT SessionRemoved(sessionId, finalState);
        m_sessions.erase(it);
        return;
    }

    const QDBusReply<QDBusObjectPath> reply = m_systemd.stopUnit(it.value().unitName);
    if (!reply.isValid()) {
        if (it.value().process && it.value().process->state() != QProcess::NotRunning) {
            it.value().process->terminate();
            QTimer::singleShot(5000, it.value().process, [process = it.value().process]() {
                if (process && process->state() != QProcess::NotRunning) {
                    process->kill();
                }
            });
            Q_EMIT SessionChanged(sessionToVariantMap(it.value(), QStringLiteral("Stopping")));
        } else {
            Q_EMIT SessionChanged(sessionToVariantMap(it.value(), QStringLiteral("Error")));
        }
        return;
    }

    Q_EMIT SessionChanged(sessionToVariantMap(it.value(), QStringLiteral("Stopping")));
}

void GameCenterDaemon::StopByGameId(const QString &gameId)
{
    if (gameId.isEmpty()) {
        return;
    }

    QStringList sessionsToStop;
    sessionsToStop.reserve(m_sessions.size());

    for (const auto &session : m_sessions) {
        if (session.gameId == gameId) {
            sessionsToStop.push_back(session.sessionId);
        }
    }

    for (const QString &sessionId : sessionsToStop) {
        Stop(sessionId);
    }
}

QString GameCenterDaemon::sessionState(const Session &session)
{
    if (session.stopping) {
        return QStringLiteral("Stopping");
    }
    if (!session.unitName.isEmpty()) {
        return QStringLiteral("Running");
    }
    if (session.scanner) {
        return QStringLiteral("Launching");
    }
    if (session.process) {
        return session.process->state() == QProcess::Running ? QStringLiteral("Running") : QStringLiteral("Exited");
    }
    return QStringLiteral("Unknown");
}

QVariantMap GameCenterDaemon::sessionToVariantMap(const Session &session, const QString &state) const
{
    QVariantMap map;
    map.insert(QStringLiteral("sessionId"), session.sessionId);
    map.insert(QStringLiteral("gameId"), session.gameId);
    if (!session.displayName.isEmpty()) {
        map.insert(QStringLiteral("displayName"), session.displayName);
    }
    map.insert(QStringLiteral("unit"), session.unitName);
    map.insert(QStringLiteral("unitName"), session.unitName);
    map.insert(QStringLiteral("state"), state);
    if (!session.provider.isEmpty()) {
        map.insert(QStringLiteral("provider"), session.provider);
    }
    if (session.startTime.isValid()) {
        map.insert(QStringLiteral("startTime"), session.startTime.toString(Qt::ISODate));
    }
    if (session.process && session.process->processId() > 0) {
        map.insert(QStringLiteral("pid"), static_cast<qulonglong>(session.process->processId()));
    } else if (session.mainPid > 0) {
        map.insert(QStringLiteral("pid"), static_cast<qulonglong>(session.mainPid));
    }
    return map;
}

void GameCenterDaemon::failLaunch(const QString &reason, const QVariantMap &context)
{
    QVariantMap error;
    error.insert(QStringLiteral("error"), reason);
    if (!context.isEmpty()) {
        error.insert(QStringLiteral("context"), normalizeVariantMapForDbus(context));
        const QString gameId = mapStringValue(context, {QStringLiteral("gameId"), QStringLiteral("id")});
        if (!gameId.isEmpty()) {
            error.insert(QStringLiteral("gameId"), gameId);
        }
    }
    Q_EMIT LaunchFailed(error);
}

void GameCenterDaemon::recoverExistingSessions()
{
    if (!m_systemd.isAvailable()) {
        return;
    }

    const QDBusReply<SystemdUnitInfoList> reply = m_systemd.listUnits();
    if (!reply.isValid()) {
        return;
    }

    static const QString prefix = QStringLiteral("alakarte-game-");
    static const QString suffix = QStringLiteral(".scope");
    static const QString descPrefix = QStringLiteral("A-La-Karte game ");

    const SystemdUnitInfoList units = reply.value();
    for (const SystemdUnitInfo &unit : units) {
        if (!unit.name.startsWith(prefix) || !unit.name.endsWith(suffix)) {
            continue;
        }
        if (unit.activeState != QLatin1String("active")) {
            continue;
        }

        const QString sessionId = unit.name.mid(prefix.length(), unit.name.length() - prefix.length() - suffix.length());
        if (sessionId.isEmpty() || m_sessions.contains(sessionId)) {
            continue;
        }

        QString gameId;
        if (unit.description.startsWith(descPrefix)) {
            gameId = unit.description.mid(descPrefix.length());
        }

        Session session;
        session.sessionId = sessionId;
        session.gameId = gameId;
        session.unitName = unit.name;
        session.unitPath = unit.objectPath;

        const QList<uint> pids = m_systemd.scopePids(unit.objectPath);
        if (!pids.isEmpty()) {
            session.mainPid = pids.first();
        }

        m_sessions.insert(sessionId, session);
        watchSystemdUnit(sessionId, session.unitName, session.unitPath);
        Q_EMIT SessionAdded(sessionToVariantMap(session, QStringLiteral("Running")));
    }
}

#include "gamecenterdaemon.moc"