/*
    SPDX-FileCopyrightText: 2000 Matthias Ettrich <ettrich@kde.org>
    SPDX-FileCopyrightText: 2005 Lubos Lunak <l.lunak@kde.org>
    SPDX-FileCopyrightText: 2018 David Edmundson <davidedmundson@kde.org>

    SPDX-FileContributor: Oswald Buddenhagen <ob6@inf.tu-dresden.de>

    some code taken from the dcopserver (part of the KDE libraries), which is
    SPDX-FileCopyrightText: 1999 Matthias Ettrich <ettrich@kde.org>
    SPDX-FileCopyrightText: 1999 Preston Brown <pbrown@kde.org>

    SPDX-License-Identifier: MIT
*/

#include "startup.h"

#include "debug.h"

#include <unistd.h>

#include "kcminit_interface.h"
#include "ksmserver_interface.h"

#include <KCompositeJob>
#include <KConfig>
#include <KConfigGroup>
#include <KIO/ApplicationLauncherJob>
#include <KProcess>
#include <KService>

#include <QDBusConnection>
#include <QDBusMessage>
#include <QDBusPendingCall>
#include <QDir>
#include <QProcess>
#include <QStandardPaths>
#include <QTimer>

#include "sessiontrack.h"
#include "startupadaptor.h"

#include "../config-startplasma.h"
#include "startplasma.h"

class Phase : public KCompositeJob
{
    Q_OBJECT
public:
    Phase(const AutoStart &autostart, QObject *parent)
        : KCompositeJob(parent)
        , m_autostart(autostart)
    {
    }

    bool addSubjob(KJob *job) override
    {
        bool rc = KCompositeJob::addSubjob(job);
        job->start();
        return rc;
    }

    void slotResult(KJob *job) override
    {
        KCompositeJob::slotResult(job);
        if (!hasSubjobs()) {
            emitResult();
        }
    }

protected:
    const AutoStart m_autostart;
};

class StartupPhase0 : public Phase
{
    Q_OBJECT
public:
    StartupPhase0(const AutoStart &autostart, QObject *parent)
        : Phase(autostart, parent)
    {
    }
    void start() override
    {
        qCDebug(PLASMA_SESSION) << "Phase 0";
        addSubjob(new AutoStartAppsJob(m_autostart, 0));
        addSubjob(new KCMInitJob());
        addSubjob(new SleepJob());
    }
};

class StartupPhase1 : public Phase
{
    Q_OBJECT
public:
    StartupPhase1(const AutoStart &autostart, QObject *parent)
        : Phase(autostart, parent)
    {
    }
    void start() override
    {
        qCDebug(PLASMA_SESSION) << "Phase 1";
        addSubjob(new AutoStartAppsJob(m_autostart, 1));
    }
};

class StartupPhase2 : public Phase
{
    Q_OBJECT
public:
    StartupPhase2(const AutoStart &autostart, QObject *parent)
        : Phase(autostart, parent)
    {
    }

    void start() override
    {
        qCDebug(PLASMA_SESSION) << "Phase 2";
        addSubjob(new AutoStartAppsJob(m_autostart, 2));
    }
};

SleepJob::SleepJob() = default;

void SleepJob::start()
{
    auto t = new QTimer(this);
    connect(t, &QTimer::timeout, this, [this]() {
        emitResult();
    });
    t->start(100);
}

Startup::Startup(QObject *parent)
    : QObject(parent)
{
    Q_ASSERT(!s_self);
    s_self = this;
    new StartupAdaptor(this);
    QDBusConnection::sessionBus().registerObject(QStringLiteral("/Startup"), QStringLiteral("org.kde.Startup"), this);
    QDBusConnection::sessionBus().registerService(QStringLiteral("org.kde.Startup"));

    const AutoStart autostart;

    KJob *x11WindowManagerJob = nullptr;
    {
        QString windowManager;
        if (qEnvironmentVariableIsSet("KDEWM")) {
            windowManager = qEnvironmentVariable("KDEWM");
        }
        if (windowManager.isEmpty()) {
            windowManager = QStringLiteral(KWIN_BIN);
        }

        if (windowManager == QLatin1String(KWIN_BIN)) {
            x11WindowManagerJob = new StartServiceJob(windowManager, {}, QStringLiteral("org.kde.KWin"));
        } else {
            x11WindowManagerJob = new StartServiceJob(windowManager, {}, {});
        }
    }

    KJob *phase1 = nullptr;
    m_lock.reset(new QEventLoopLocker);

    const QList<KJob *> sequence = {
        new StartProcessJob(QStringLiteral("kcminit_startup"), {}),
        new StartServiceJob(QStringLiteral("kded6"), {}, QStringLiteral("org.kde.kded6"), {}),
        x11WindowManagerJob,
        new StartServiceJob(QStringLiteral("ksmserver"), QCoreApplication::instance()->arguments().mid(1), QStringLiteral("org.kde.ksmserver")),
        new StartupPhase0(autostart, this),
        phase1 = new StartupPhase1(autostart, this),
        new RestoreSessionJob(),
        new StartupPhase2(autostart, this),
    };
    KJob *last = nullptr;
    for (KJob *job : sequence) {
        if (!job) {
            continue;
        }
        if (last) {
            connect(last, &KJob::finished, job, &KJob::start);
        }
        last = job;
    }

    connect(sequence.last(), &KJob::finished, this, &Startup::finishStartup);
    sequence.first()->start();

    // app will be closed when all KJobs finish thanks to the QEventLoopLocker in each KJob
}

void Startup::finishStartup()
{
    qCDebug(PLASMA_SESSION) << "Finished";

    playStartupSound();
    new SessionTrack(m_processes);
    deleteLater();
}

void Startup::updateLaunchEnv(const QString &key, const QString &value)
{
    qputenv(key.toLatin1().constData(), value.toLatin1());
}

bool Startup::startDetached(QProcess *process)
{
    process->setProcessChannelMode(QProcess::ForwardedChannels);
    process->start();
    const bool ret = process->waitForStarted();
    if (ret) {
        m_processes << process;
    }
    return ret;
}

Startup *Startup::s_self = nullptr;

KCMInitJob::KCMInitJob()
    : KJob()
{
}

void KCMInitJob::start()
{
    org::kde::KCMInit kcminit(QStringLiteral("org.kde.kcminit"), QStringLiteral("/kcminit"), QDBusConnection::sessionBus());
    kcminit.setTimeout(10 * 1000);

    QDBusPendingReply<void> pending = kcminit.runPhase1();
    auto *watcher = new QDBusPendingCallWatcher(pending, this);
    connect(watcher, &QDBusPendingCallWatcher::finished, this, [this]() {
        emitResult();
    });
    connect(watcher, &QDBusPendingCallWatcher::finished, watcher, &QObject::deleteLater);
}

RestoreSessionJob::RestoreSessionJob()
    : KJob()
{
}

void RestoreSessionJob::start()
{
    OrgKdeKSMServerInterfaceInterface ksmserverIface(QStringLiteral("org.kde.ksmserver"), QStringLiteral("/KSMServer"), QDBusConnection::sessionBus());
    auto pending = ksmserverIface.restoreSession();

    auto *watcher = new QDBusPendingCallWatcher(pending, this);
    connect(watcher, &QDBusPendingCallWatcher::finished, this, [this]() {
        emitResult();
    });
    connect(watcher, &QDBusPendingCallWatcher::finished, watcher, &QObject::deleteLater);
}

AutoStartAppsJob::AutoStartAppsJob(const AutoStart &autostart, int phase)
    : m_autoStart(autostart)
{
    m_autoStart.setPhase(phase);
}

void AutoStartAppsJob::start()
{
    qCDebug(PLASMA_SESSION);

    QTimer::singleShot(0, this, [this]() {
        do {
            QString serviceName = m_autoStart.startService();
            if (serviceName.isEmpty()) {
                // Done
                if (!m_autoStart.phaseDone()) {
                    m_autoStart.setPhaseDone();
                }
                emitResult();
                return;
            }
            auto job = new KIO::ApplicationLauncherJob(KService::Ptr(new KService(serviceName)), this);
            job->start();
        } while (true);
    });
}

StartServiceJob::StartServiceJob(const QString &process, const QStringList &args, const QString &serviceId, const QProcessEnvironment &additionalEnv)
    : KJob()
    , m_process(new QProcess)
    , m_serviceId(serviceId)
    , m_additionalEnv(additionalEnv)
{
    m_process->setProgram(process);
    m_process->setArguments(args);

    auto watcher = new QDBusServiceWatcher(serviceId, QDBusConnection::sessionBus(), QDBusServiceWatcher::WatchForRegistration, this);
    connect(watcher, &QDBusServiceWatcher::serviceRegistered, this, &StartServiceJob::emitResult);
}

void StartServiceJob::start()
{
    auto env = QProcessEnvironment::systemEnvironment();
    env.insert(m_additionalEnv);
    m_process->setProcessEnvironment(env);

    if (!m_serviceId.isEmpty() && QDBusConnection::sessionBus().interface()->isServiceRegistered(m_serviceId)) {
        qCDebug(PLASMA_SESSION) << m_process << "already running";
        emitResult();
        return;
    }
    qCDebug(PLASMA_SESSION) << "Starting " << m_process->program() << m_process->arguments();
    if (!Startup::self()->startDetached(m_process)) {
        qCWarning(PLASMA_SESSION) << "error starting process" << m_process->program() << m_process->arguments();
        emitResult();
    }

    if (m_serviceId.isEmpty()) {
        emitResult();
    }
}

StartProcessJob::StartProcessJob(const QString &process, const QStringList &args, const QProcessEnvironment &additionalEnv)
    : KJob()
    , m_process(new QProcess(this))
{
    m_process->setProgram(process);
    m_process->setArguments(args);
    m_process->setProcessChannelMode(QProcess::ForwardedChannels);
    auto env = QProcessEnvironment::systemEnvironment();
    env.insert(additionalEnv);
    m_process->setProcessEnvironment(env);

    connect(m_process, &QProcess::finished, [this](int exitCode) {
        qCInfo(PLASMA_SESSION) << "process job " << m_process->program() << "finished with exit code " << exitCode;
        emitResult();
    });
}

void StartProcessJob::start()
{
    qCDebug(PLASMA_SESSION) << "Starting " << m_process->program() << m_process->arguments();

    m_process->start();
}

#include "startup.moc"

#include "moc_startup.cpp"
