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#include "application.h"
#include "applicationipcmanager.h"
#include "applicationipcinterface.h"
#include "applicationipcinterface_p.h"
#include "qml-utilities.h"
#include "global.h"
#include "logging.h"

#if defined(AM_MULTI_PROCESS)
#  include "nativeruntime.h"
#  include <QDBusError>
#endif


/*!
    \qmltype ApplicationIPCManager
    \inqmlmodule QtApplicationManager.SystemUI
    \ingroup system-ui-singletons
    \brief Central registry for interfaces for System-UI-to-app communication.

    This singleton type is the central manager for app-to-System-UI IPC interfaces within the application manager.

    It only exports a single function towards the QML System UI: registerInterface().

    See ApplicationInterfaceExtension for information on how to access these registered IPC interfaces from
    the client (application) side.
*/

QT_BEGIN_NAMESPACE_AM

ApplicationIPCManager *ApplicationIPCManager::s_instance = nullptr;

ApplicationIPCManager::~ApplicationIPCManager()
{
    s_instance = nullptr;
}

ApplicationIPCManager *ApplicationIPCManager::createInstance()
{
    if (Q_UNLIKELY(s_instance))
        qFatal("ApplicationIPCManager::createInstance() was called a second time.");

    qmlRegisterUncreatableType<ApplicationIPCInterfaceAttached>("QtApplicationManager.SystemUI", 2, 0, "ApplicationIPCInterfaceAttached",
                                                                qSL("This type is only providing attached properties"));
    qmlRegisterType<ApplicationIPCInterface>("QtApplicationManager.SystemUI", 2, 0, "ApplicationIPCInterface");
    qmlRegisterSingletonType<ApplicationIPCManager>("QtApplicationManager.SystemUI", 2, 0, "ApplicationIPCManager",
                                                    &ApplicationIPCManager::instanceForQml);
    return s_instance = new ApplicationIPCManager();
}

ApplicationIPCManager *ApplicationIPCManager::instance()
{
    if (Q_UNLIKELY(!s_instance))
        qFatal("ApplicationIPCManager::instance() was called before createInstance().");
    return s_instance;
}

QObject *ApplicationIPCManager::instanceForQml(QQmlEngine *, QJSEngine *)
{
    QQmlEngine::setObjectOwnership(instance(), QQmlEngine::CppOwnership);
    return instance();
}

ApplicationIPCManager::ApplicationIPCManager(QObject *parent)
    : QObject(parent)
{ }

/*!
    \qmlmethod bool ApplicationIPCManager::registerInterface(ApplicationIPCInterface interface, string name, var filter)

    Registers an IPC \a interface object to extend the communication API between applications and
    the Application Manager itself. The \a interface object is an ApplicationIPCInterface item, that needs
    to stay valid during the whole lifetime of the System UI. The \a name of the interface has to
    adhere to D-Bus standards, so it needs to contain at least one period ('.') character
    (for example, \c{io.qt.test}).
    The interface is available to all applications matching the \a filter criteria (see below)
    on the private Peer-To-Peer D-Bus as a standard, typed D-Bus interface.

    Because there is no way to add type information to the parameters of JavaScript functions, the
    \a interface is scanned for special annotation properties that are only used to deduce type
    information, but are not exported to the applications:

    \c{readonly property var _decltype_<function-name>: { "<return type>": [ "<param 1 type>", "<param 2 type>", ...] }}

    The following types are supported:

    \table
    \header
        \li Type
        \li DBus Type
        \li Note
    \row
        \li \c void
        \li -
        \li Only valid as return type.
    \row
        \li \c int
        \li \c INT32
        \li
    \row
        \li \c string, \c url
        \li \c STRING
        \li Urls are mapped to plain strings.
    \row
        \li \c bool
        \li \c BOOLEAN
        \li
    \row
        \li \c real, \c double
        \li \c DOUBLE
        \li
    \row
        \li \c var, \c variant
        \li \c VARIANT
        \li Can also be used for lists and maps.

    \endtable

    A simple example showing how to add these annotations to a function definition:

    \code
    readonly property var _decltype_testFunction: { "var": [ "int", "string" ] }
    function testFunction(ivar, strvar) {
        return { "strvar": strvar, "intvar": intvar }
    }
    \endcode

    You can restrict the availability of the interface in applications via the \a filter parameter:
    either pass an empty JavaScript object (\c{{}}) or use any combination of these available
    field names:

    \table
    \header
        \li Key
        \li Value
        \li Description
    \row
        \li \c applicationIds
        \li list<string>
        \li A list of applications ids that are allowed to use this interface.
    \row
        \li \c categories
        \li list<string>
        \li A list of category names (see info.yaml). Any application that is part of one of these
            categories is allowed to use this interface.
    \row
        \li \c capabilities
        \li list<string>
        \li A list of applications capabilities (see info.yaml). Any application that has one of
            these capabilities is allowed to use this interface.
    \endtable

    All of the filter fields have to match, but only fields that are actually set are taken into
    consideration.

    \qml
    import QtQuick 2.0
    import QtApplicationManager.SystemUI 2.0

    ApplicationIPCInterface {
        id: extension

        property bool pbool: true
        property double pdouble: 3.14

        signal testSignal(string str, variant list)

        readonly property var _decltype_testFunction: { "void": [ "int", "string" ] }
        function testFunction(foo, bar) {
            console.log("testFunction was called: " + foo + " " + bar)
        }

        Component.onCompleted: {
            ApplicationIPCManager.registerInterface(extension, "io.qt.test.interface",
                                                    { "capabilities": [ "media", "camera" ] })
        }
    }
    \endqml

    Returns \c true if the registration was successful, \c false otherwise.
*/
bool ApplicationIPCManager::registerInterface(QT_PREPEND_NAMESPACE_AM(ApplicationIPCInterface*) interface,
                                              const QString &name, const QVariantMap &filter)
{
    if (!interface || name.isEmpty()) {
        qCWarning(LogQmlIpc) << "Application IPC interfaces need a valid object as well as interface name";
        return false;
    }
    if (!name.contains(QLatin1Char('.'))) {
        qCWarning(LogQmlIpc) << "Application IPC interface name" << name << "is not a valid D-Bus interface name";
        return false;
    }
    for (const auto &ext : qAsConst(m_interfaces)) {
        if (ext->interfaceName() == name) {
            qCWarning(LogQmlIpc) << "Application IPC interface name" << name << "was already registered";
            return false;
        }
    }

    auto createPathFromName = [](const QString &name) -> QString {
        QString path;

        const QChar *c = name.unicode();
        for (int i = 0; i < name.length(); ++i) {
            ushort u = c[i].unicode();
            path += QChar(((u >= 'a' && u <= 'z')
                           || (u >= 'A' && u <= 'Z')
                           || (u >= '0' && u <= '9')
                           || (u == '_')) ? u : '_');
        }
        return qSL("/ExtensionInterfaces/") + path;
    };

    interface->m_ipcProxy = new IpcProxyObject(interface->serviceObject(), QString(), createPathFromName(name), name, filter);
    m_interfaces.append(interface);
    emit interfaceCreated(interface);
    return true;
}

QVector<ApplicationIPCInterface *> ApplicationIPCManager::interfaces() const
{
    return m_interfaces;
}

#if defined(AM_MULTI_PROCESS)

static void registerInterfaceHelper(const QDBusConnection &connection, ApplicationIPCInterface *iface,
                                    Application *application, NativeRuntime *runtime)
{
    if (iface->isValidForApplication(application)) {
        if (!iface->dbusRegister(application, connection)) {
            qCWarning(LogSystem) << "ERROR: could not register the application IPC interface"
                                 << iface->interfaceName() << "at" << iface->pathName()
                                 << "on the peer DBus:" << connection.lastError().name()
                                 << connection.lastError().message();
        } else {
            // this should not be in NativeRuntime, but in a separate object
            emit runtime->interfaceCreated(iface->interfaceName());
        }

#ifdef EXPORT_P2PBUS_OBJECTS_TO_SESSION_BUS
        iface->dbusRegister(application, QDBusConnection::sessionBus(),
                            qSL("/Application%1").arg(applicationProcessId()));
#endif
    }
}

#endif // defined(AM_MULTI_PROCESS)

void ApplicationIPCManager::attachToRuntime(AbstractRuntime *runtime)
{
#if defined(AM_MULTI_PROCESS)
    if (NativeRuntime *nativeRuntime = qobject_cast<NativeRuntime *>(runtime)) {
        if (!nativeRuntime->isQuickLauncher()) {
            connect(nativeRuntime, &NativeRuntime::applicationConnectedToPeerDBus, this,
                    [this, nativeRuntime](const QDBusConnection &connection, Application *application) {
                registerInterfaces(nativeRuntime, connection, application);
            });
        }
    }
#else
    Q_UNUSED(runtime)
#endif
}

void ApplicationIPCManager::registerInterfaces(AbstractRuntime *runtime, const QDBusConnection &connection,
                                               Application *application)
{
#if defined(AM_MULTI_PROCESS)
    if (NativeRuntime *nativeRuntime = qobject_cast<NativeRuntime *>(runtime)) {
        Q_ASSERT(application);
        Q_ASSERT(connection.isConnected());

        // register all known extension interfaces
        for (ApplicationIPCInterface *iface : qAsConst(m_interfaces))
            registerInterfaceHelper(connection, iface, application, nativeRuntime);

        // make sure that future extension interfaces get registered as well
        connect(this, &ApplicationIPCManager::interfaceCreated,
                this, [connection, nativeRuntime](ApplicationIPCInterface *iface) {
            registerInterfaceHelper(connection, iface, nativeRuntime->application(), nativeRuntime);
        });

        connect(nativeRuntime, &NativeRuntime::applicationDisconnectedFromPeerDBus,
                this, [this](const QDBusConnection &connection, Application *) {
            // unregister all extension interfaces
            for (ApplicationIPCInterface *iface : qAsConst(m_interfaces))
                iface->dbusUnregister(connection);
        });
    }
#else
    Q_UNUSED(runtime)
    Q_UNUSED(application)
    Q_UNUSED(connection)
#endif
}

QT_END_NAMESPACE_AM