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

#include "inputserviceclient.h"

#include <QCoreApplication>
#include <QDBusConnection>
#include <QDBusConnectionInterface>
#include <QDBusError>
#include <QDBusInterface>
#include <QDBusReply>
#include <QDBusServiceWatcher>
#include <QDBusVariant>

static const QString kInputService = QStringLiteral("org.kde.ALaKarte.Input1");
static const QString kInputPath = QStringLiteral("/org/kde/ALaKarte/Input1");
static const QString kInputInterface = QStringLiteral("org.kde.ALaKarte.Input1");

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

static QVariantMap unwrapVariantMap(QVariant v)
{
    v = unwrapDbusVariant(v);
    if (v.canConvert<QVariantMap>()) {
        return v.toMap();
    }
    return {};
}

static QVariantMap normalizeMap(QVariantMap m)
{
    for (auto it = m.begin(); it != m.end(); ++it) {
        it.value() = unwrapDbusVariant(it.value());
    }
    return m;
}
}

InputServiceClient::InputServiceClient(QObject *parent)
    : QObject(parent)
{
    QDBusConnection bus = QDBusConnection::sessionBus();
    if (bus.isConnected()) {
        m_watcher = new QDBusServiceWatcher(kInputService, bus, QDBusServiceWatcher::WatchForRegistration | QDBusServiceWatcher::WatchForUnregistration, this);
        connect(m_watcher, &QDBusServiceWatcher::serviceRegistered, this, [this]() {
            setAvailable(true);
            connectSignals();
            refresh();
        });
        connect(m_watcher, &QDBusServiceWatcher::serviceUnregistered, this, [this]() {
            setAvailable(false);
            m_controllers.clear();
            m_profiles.clear();
            Q_EMIT controllersChanged();
            Q_EMIT profilesChanged();
        });
    }

    if (QCoreApplication::instance()) {
        connect(QCoreApplication::instance(), &QCoreApplication::aboutToQuit, this, [this]() {
            m_connectedSignals = false;
        });
    }

    ensureService();
    refresh();
}

InputServiceClient::~InputServiceClient() = default;

bool InputServiceClient::available() const
{
    return m_available;
}

QString InputServiceClient::lastError() const
{
    return m_lastError;
}

QVariantList InputServiceClient::controllers() const
{
    return m_controllers;
}

QVariantList InputServiceClient::profiles() const
{
    return m_profiles;
}

void InputServiceClient::setAvailable(bool available)
{
    if (m_available == available) {
        return;
    }
    m_available = available;
    Q_EMIT availableChanged();
}

void InputServiceClient::setLastError(const QString &error)
{
    if (m_lastError == error) {
        return;
    }
    m_lastError = error;
    Q_EMIT lastErrorChanged();
}

void InputServiceClient::ensureService()
{
    QDBusConnection bus = QDBusConnection::sessionBus();
    if (!bus.isConnected() || !bus.interface()) {
        setAvailable(false);
        setLastError(QStringLiteral("session bus not available"));
        return;
    }

    if (bus.interface()->isServiceRegistered(kInputService)) {
        setAvailable(true);
        connectSignals();
        return;
    }

    bool activatable = false;
    {
        const QDBusReply<QStringList> names = bus.interface()->activatableServiceNames();
        if (names.isValid()) {
            activatable = names.value().contains(kInputService);
        }
    }

    const QDBusReply<void> reply = bus.interface()->startService(kInputService);
    if (reply.isValid() || bus.interface()->isServiceRegistered(kInputService)) {
        setAvailable(true);
        connectSignals();
        return;
    }

    setAvailable(false);
    if (activatable) {
        setLastError(reply.error().message());
    } else {
        setLastError(QStringLiteral("Input service is not available (missing DBus activation for org.kde.ALaKarte.Input1)"));
    }
}

void InputServiceClient::connectSignals()
{
    if (m_connectedSignals) {
        return;
    }

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

    const bool ok1 = bus.connect(kInputService, kInputPath, kInputInterface, QStringLiteral("ControllerAdded"), this, SLOT(onControllerAdded(QVariantMap)));

    const bool ok2 = bus.connect(kInputService, kInputPath, kInputInterface, QStringLiteral("ControllerChanged"), this, SLOT(onControllerChanged(QVariantMap)));

    const bool ok3 = bus.connect(kInputService, kInputPath, kInputInterface, QStringLiteral("ControllerRemoved"), this, SLOT(onControllerRemoved(QString)));

    const bool ok4 = bus.connect(kInputService, kInputPath, kInputInterface, QStringLiteral("ProfilesChanged"), this, SLOT(onProfilesChanged()));

    m_connectedSignals = ok1 && ok2 && ok3 && ok4;
}

void InputServiceClient::onControllerAdded(QVariantMap controller)
{
    upsertController(normalizeMap(controller));
}

void InputServiceClient::onControllerChanged(QVariantMap controller)
{
    upsertController(normalizeMap(controller));
}

void InputServiceClient::onControllerRemoved(const QString &controllerId)
{
    removeControllerById(controllerId);
}

void InputServiceClient::onProfilesChanged()
{
    refreshProfiles();
}

void InputServiceClient::upsertController(const QVariantMap &controller)
{
    const QString id = controller.value(QStringLiteral("controllerId")).toString();
    if (id.isEmpty()) {
        return;
    }

    for (int i = 0; i < m_controllers.size(); ++i) {
        const QVariantMap existing = m_controllers.at(i).toMap();
        if (existing.value(QStringLiteral("controllerId")).toString() == id) {
            m_controllers[i] = controller;
            Q_EMIT controllersChanged();
            return;
        }
    }

    m_controllers.push_back(controller);
    Q_EMIT controllersChanged();
}

void InputServiceClient::removeControllerById(const QString &controllerId)
{
    if (controllerId.isEmpty()) {
        return;
    }

    for (int i = 0; i < m_controllers.size(); ++i) {
        const QVariantMap existing = m_controllers.at(i).toMap();
        if (existing.value(QStringLiteral("controllerId")).toString() == controllerId) {
            m_controllers.removeAt(i);
            Q_EMIT controllersChanged();
            return;
        }
    }
}

void InputServiceClient::refresh()
{
    refreshControllers();
    refreshProfiles();
}

void InputServiceClient::refreshControllers()
{
    ensureService();
    if (!m_available) {
        return;
    }

    QDBusInterface i(kInputService, kInputPath, kInputInterface, QDBusConnection::sessionBus());
    i.setTimeout(2000);

    const QDBusReply<bool> rescanReply = i.call(QStringLiteral("Rescan"));
    if (!rescanReply.isValid()) {
        setLastError(rescanReply.error().message());
    }

    const QDBusReply<QVariantList> reply = i.call(QStringLiteral("ListControllers"));

    if (!reply.isValid()) {
        setLastError(reply.error().message());
        return;
    }

    m_controllers.clear();
    const QVariantList list = reply.value();
    m_controllers.reserve(list.size());
    for (const QVariant &v : list) {
        m_controllers.push_back(unwrapVariantMap(v));
    }
    Q_EMIT controllersChanged();
}

void InputServiceClient::refreshProfiles()
{
    ensureService();
    if (!m_available) {
        return;
    }

    QDBusInterface i(kInputService, kInputPath, kInputInterface, QDBusConnection::sessionBus());
    i.setTimeout(2000);
    const QDBusReply<QVariantList> reply = i.call(QStringLiteral("ListProfiles"));

    if (!reply.isValid()) {
        setLastError(reply.error().message());
        return;
    }

    m_profiles.clear();
    const QVariantList list = reply.value();
    m_profiles.reserve(list.size());
    for (const QVariant &v : list) {
        m_profiles.push_back(unwrapVariantMap(v));
    }

    Q_EMIT profilesChanged();
}

bool InputServiceClient::setActiveProfile(const QString &controllerId, const QString &profileId)
{
    ensureService();
    if (!m_available) {
        return false;
    }

    QDBusInterface i(kInputService, kInputPath, kInputInterface, QDBusConnection::sessionBus());
    i.setTimeout(2000);
    const QDBusReply<bool> reply = i.call(QStringLiteral("SetActiveProfile"), controllerId, profileId);

    if (!reply.isValid()) {
        setLastError(reply.error().message());
        return false;
    }

    return reply.value();
}

QString InputServiceClient::createProfile(const QString &name)
{
    ensureService();
    if (!m_available) {
        return {};
    }

    QDBusInterface i(kInputService, kInputPath, kInputInterface, QDBusConnection::sessionBus());
    i.setTimeout(2000);
    const QDBusReply<QString> reply = i.call(QStringLiteral("CreateProfile"), name);

    if (!reply.isValid()) {
        setLastError(reply.error().message());
        return {};
    }

    refreshProfiles();
    return reply.value();
}

bool InputServiceClient::deleteProfile(const QString &profileId)
{
    ensureService();
    if (!m_available) {
        return false;
    }

    QDBusInterface i(kInputService, kInputPath, kInputInterface, QDBusConnection::sessionBus());
    i.setTimeout(2000);
    const QDBusReply<bool> reply = i.call(QStringLiteral("DeleteProfile"), profileId);

    if (!reply.isValid()) {
        setLastError(reply.error().message());
        return false;
    }

    refreshProfiles();
    refreshControllers();
    return reply.value();
}