Merge branch 'kitsune-room-versions'

10 files changed, 462 insertions, 17 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9729811b..d2d8c218 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -90,6 +90,8 @@ set(libqmatrixclient_SRCS
     lib/events/roomevent.cpp
     lib/events/stateevent.cpp
     lib/events/eventcontent.cpp
+    lib/events/roomcreateevent.cpp
+    lib/events/roomtombstoneevent.cpp
     lib/events/roommessageevent.cpp
     lib/events/roommemberevent.cpp
     lib/events/typingevent.cpp
diff --git a/lib/connection.cpp b/lib/connection.cpp
index 63b0a31d..4c0fe6b8 100644
--- a/lib/connection.cpp
+++ b/lib/connection.cpp
@@ -24,6 +24,7 @@
 #include "room.h"
 #include "settings.h"
 #include "csapi/login.h"
+#include "csapi/capabilities.h"
 #include "csapi/logout.h"
 #include "csapi/receipts.h"
 #include "csapi/leaving.h"
@@ -92,6 +93,9 @@ class Connection::Private
         QString userId;
         int syncLoopTimeout = -1;
 
+        GetCapabilitiesJob* capabilitiesJob = nullptr;
+        GetCapabilitiesJob::Capabilities capabilities;
+
         SyncJob* syncJob = nullptr;
 
         bool cacheState = true;
@@ -244,6 +248,39 @@ void Connection::connectWithToken(const QString& userId,
         [=] { d->connectWithToken(userId, accessToken, deviceId); });
 }
 
+void Connection::reloadCapabilities()
+{
+    d->capabilitiesJob = callApi<GetCapabilitiesJob>(BackgroundRequest);
+    connect(d->capabilitiesJob, &BaseJob::finished, this, [this] {
+        if (d->capabilitiesJob->error() == BaseJob::Success)
+            d->capabilities = d->capabilitiesJob->capabilities();
+        else if (d->capabilitiesJob->error() == BaseJob::IncorrectRequestError)
+            qCDebug(MAIN) << "Server doesn't support /capabilities";
+
+        if (d->capabilities.roomVersions.omitted())
+        {
+            qCWarning(MAIN) << "Pinning supported room version to 1";
+            d->capabilities.roomVersions = { "1", {{ "1", "stable" }} };
+        } else {
+            qCDebug(MAIN) << "Room versions:"
+                << defaultRoomVersion() << "is default, full list:"
+                << availableRoomVersions();
+        }
+        Q_ASSERT(!d->capabilities.roomVersions.omitted());
+        emit capabilitiesLoaded();
+        for (auto* r: d->roomMap)
+            if (r->joinState() == JoinState::Join && r->successorId().isEmpty())
+                r->checkVersion();
+    });
+}
+
+bool Connection::loadingCapabilities() const
+{
+    // (Ab)use the fact that room versions cannot be omitted after
+    // the capabilities have been loaded (see reloadCapabilities() above).
+    return d->capabilities.roomVersions.omitted();
+}
+
 void Connection::Private::connectWithToken(const QString& user,
                                            const QString& accessToken,
                                            const QString& deviceId)
@@ -256,7 +293,7 @@ void Connection::Private::connectWithToken(const QString& user,
                   << "by user" << userId << "from device" << deviceId;
     emit q->stateChanged();
     emit q->connected();
-
+    q->reloadCapabilities();
 }
 
 void Connection::checkAndConnect(const QString& userId,
@@ -356,8 +393,14 @@ void Connection::onSyncSuccess(SyncData &&data, bool fromCache) {
             d->pendingStateRoomIds.removeOne(roomData.roomId);
             r->updateData(std::move(roomData), fromCache);
             if (d->firstTimeRooms.removeOne(r))
+            {
                 emit loadedRoomState(r);
+                if (!d->capabilities.roomVersions.omitted())
+                    r->checkVersion();
+                // Otherwise, the version will be checked in reloadCapabilities()
+            }
         }
+        // Let UI update itself after updating each room
         QCoreApplication::processEvents();
     }
     for (auto&& accountEvent: data.takeAccountData())
@@ -550,7 +593,8 @@ DownloadFileJob* Connection::downloadFile(const QUrl& url,
 
 CreateRoomJob* Connection::createRoom(RoomVisibility visibility,
     const QString& alias, const QString& name, const QString& topic,
-    QStringList invites, const QString& presetName, bool isDirect,
+    QStringList invites, const QString& presetName,
+    const QString& roomVersion, bool isDirect,
     const QVector<CreateRoomJob::StateEvent>& initialState,
     const QVector<CreateRoomJob::Invite3pid>& invite3pids,
     const QJsonObject& creationContent)
@@ -559,7 +603,7 @@ CreateRoomJob* Connection::createRoom(RoomVisibility visibility,
     auto job = callApi<CreateRoomJob>(
             visibility == PublishRoom ? QStringLiteral("public")
                                       : QStringLiteral("private"),
-            alias, name, topic, invites, invite3pids, QString(/*TODO: #233*/),
+            alias, name, topic, invites, invite3pids, roomVersion,
             creationContent, initialState, presetName, isDirect);
     connect(job, &BaseJob::success, this, [this,job] {
         emit createdRoom(provideRoom(job->roomId(), JoinState::Join));
@@ -661,7 +705,7 @@ CreateRoomJob* Connection::createDirectChat(const QString& userId,
     const QString& topic, const QString& name)
 {
     return createRoom(UnpublishRoom, "", name, topic, {userId},
-                      "trusted_private_chat", true);
+                      "trusted_private_chat", {}, true);
 }
 
 ForgetRoomJob* Connection::forgetRoom(const QString& id)
@@ -1258,9 +1302,54 @@ void QMatrixClient::Connection::setLazyLoading(bool newValue)
 
 void Connection::getTurnServers()
 {
-  auto job = callApi<GetTurnServerJob>();
-  connect( job, &GetTurnServerJob::success, [=] {
-      emit turnServersChanged(job->data());
-  });
+    auto job = callApi<GetTurnServerJob>();
+    connect(job, &GetTurnServerJob::success,
+            this, [=] { emit turnServersChanged(job->data()); });
+}
+
+const QString Connection::SupportedRoomVersion::StableTag =
+        QStringLiteral("stable");
+
+QString Connection::defaultRoomVersion() const
+{
+    Q_ASSERT(!d->capabilities.roomVersions.omitted());
+    return d->capabilities.roomVersions->defaultVersion;
+}
+
+QStringList Connection::stableRoomVersions() const
+{
+    Q_ASSERT(!d->capabilities.roomVersions.omitted());
+    QStringList l;
+    const auto& allVersions = d->capabilities.roomVersions->available;
+    for (auto it = allVersions.begin(); it != allVersions.end(); ++it)
+        if (it.value() == SupportedRoomVersion::StableTag)
+            l.push_back(it.key());
+    return l;
+}
+
+inline bool roomVersionLess(const Connection::SupportedRoomVersion& v1,
+                            const Connection::SupportedRoomVersion& v2)
+{
+    bool ok1 = false, ok2 = false;
+    const auto vNum1 = v1.id.toFloat(&ok1);
+    const auto vNum2 = v2.id.toFloat(&ok2);
+    return ok1 && ok2 ? vNum1 < vNum2 : v1.id < v2.id;
+}
 
+QVector<Connection::SupportedRoomVersion> Connection::availableRoomVersions() const
+{
+    Q_ASSERT(!d->capabilities.roomVersions.omitted());
+    QVector<SupportedRoomVersion> result;
+    result.reserve(d->capabilities.roomVersions->available.size());
+    for (auto it = d->capabilities.roomVersions->available.begin();
+         it != d->capabilities.roomVersions->available.end(); ++it)
+        result.push_back({ it.key(), it.value() });
+    // Put stable versions over unstable; within each group,
+    // sort numeric versions as numbers, the rest as strings.
+    const auto mid = std::partition(result.begin(), result.end(),
+                                    std::mem_fn(&SupportedRoomVersion::isStable));
+    std::sort(result.begin(), mid, roomVersionLess);
+    std::sort(mid, result.end(), roomVersionLess);
+
+    return result;
 }
diff --git a/lib/connection.h b/lib/connection.h
index 45b691e1..1faee255 100644
--- a/lib/connection.h
+++ b/lib/connection.h
@@ -102,6 +102,7 @@ namespace QMatrixClient
             Q_PROPERTY(QString localUserId READ userId NOTIFY stateChanged)
             Q_PROPERTY(QString deviceId READ deviceId NOTIFY stateChanged)
             Q_PROPERTY(QByteArray accessToken READ accessToken NOTIFY stateChanged)
+            Q_PROPERTY(QString defaultRoomVersion READ defaultRoomVersion NOTIFY capabilitiesLoaded)
             Q_PROPERTY(QUrl homeserver READ homeserver WRITE setHomeserver NOTIFY homeserverChanged)
             Q_PROPERTY(bool cacheState READ cacheState WRITE setCacheState NOTIFY cacheStateChanged)
             Q_PROPERTY(bool lazyLoading READ lazyLoading WRITE setLazyLoading NOTIFY lazyLoadingChanged)
@@ -257,6 +258,44 @@ namespace QMatrixClient
             Q_INVOKABLE QString token() const;
             Q_INVOKABLE void getTurnServers();
 
+            struct SupportedRoomVersion
+            {
+                QString id;
+                QString status;
+
+                static const QString StableTag; // "stable", as of CS API 0.5
+                bool isStable() const { return status == StableTag; }
+
+                // Pretty-printing
+
+                friend QDebug operator<<(QDebug dbg,
+                                         const SupportedRoomVersion& v)
+                {
+                    QDebugStateSaver _(dbg);
+                    return dbg.nospace() << v.id << '/' << v.status;
+                }
+
+                friend QDebug operator<<(QDebug dbg,
+                                         const QVector<SupportedRoomVersion>& vs)
+                {
+                    return QtPrivate::printSequentialContainer(
+                                dbg, "", vs);
+                }
+            };
+
+            /// Get the room version recommended by the server
+            /** Only works after server capabilities have been loaded.
+             * \sa loadingCapabilities */
+            QString defaultRoomVersion() const;
+            /// Get the room version considered stable by the server
+            /** Only works after server capabilities have been loaded.
+             * \sa loadingCapabilities */
+            QStringList stableRoomVersions() const;
+            /// Get all room versions supported by the server
+            /** Only works after server capabilities have been loaded.
+             * \sa loadingCapabilities */
+            QVector<SupportedRoomVersion> availableRoomVersions() const;
+
             /**
              * Call this before first sync to load from previously saved file.
              *
@@ -365,6 +404,11 @@ namespace QMatrixClient
                                  const QString& deviceId = {});
             void connectWithToken(const QString& userId, const QString& accessToken,
                                   const QString& deviceId);
+            /// Explicitly request capabilities from the server
+            void reloadCapabilities();
+
+            /// Find out if capabilites are still loading from the server
+            bool loadingCapabilities() const;
 
             /** @deprecated Use stopSync() instead */
             void disconnectFromServer() { stopSync(); }
@@ -404,7 +448,7 @@ namespace QMatrixClient
             CreateRoomJob* createRoom(RoomVisibility visibility,
                 const QString& alias, const QString& name, const QString& topic,
                 QStringList invites, const QString& presetName = {},
-                bool isDirect = false,
+                const QString& roomVersion = {}, bool isDirect = false,
                 const QVector<CreateRoomJob::StateEvent>& initialState = {},
                 const QVector<CreateRoomJob::Invite3pid>& invite3pids = {},
                 const QJsonObject& creationContent = {});
@@ -501,6 +545,7 @@ namespace QMatrixClient
             void resolveError(QString error);
 
             void homeserverChanged(QUrl baseUrl);
+            void capabilitiesLoaded();
 
             void connected();
             void reconnected(); //< \deprecated Use connected() instead
diff --git a/lib/events/roomcreateevent.cpp b/lib/events/roomcreateevent.cpp
new file mode 100644
index 00000000..8fd0f1de
--- /dev/null
+++ b/lib/events/roomcreateevent.cpp
@@ -0,0 +1,45 @@
+/******************************************************************************
+* Copyright (C) 2019 QMatrixClient project
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation; either
+* version 2.1 of the License, or (at your option) any later version.
+*
+* This library is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this library; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include "roomcreateevent.h"
+
+using namespace QMatrixClient;
+
+bool RoomCreateEvent::isFederated() const
+{
+    return fromJson<bool>(contentJson()["m.federate"_ls]);
+}
+
+QString RoomCreateEvent::version() const
+{
+    return fromJson<QString>(contentJson()["room_version"_ls]);
+}
+
+RoomCreateEvent::Predecessor RoomCreateEvent::predecessor() const
+{
+    const auto predJson = contentJson()["predecessor"_ls].toObject();
+    return {
+        fromJson<QString>(predJson["room_id"_ls]),
+        fromJson<QString>(predJson["event_id"_ls])
+    };
+}
+
+bool RoomCreateEvent::isUpgrade() const
+{
+    return contentJson().contains("predecessor"_ls);
+}
diff --git a/lib/events/roomcreateevent.h b/lib/events/roomcreateevent.h
new file mode 100644
index 00000000..0a8f27cc
--- /dev/null
+++ b/lib/events/roomcreateevent.h
@@ -0,0 +1,49 @@
+/******************************************************************************
+* Copyright (C) 2019 QMatrixClient project
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation; either
+* version 2.1 of the License, or (at your option) any later version.
+*
+* This library is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this library; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#pragma once
+
+#include "stateevent.h"
+
+namespace QMatrixClient
+{
+    class RoomCreateEvent : public StateEventBase
+    {
+        public:
+            DEFINE_EVENT_TYPEID("m.room.create", RoomCreateEvent)
+
+            explicit RoomCreateEvent()
+                : StateEventBase(typeId(), matrixTypeId())
+            { }
+            explicit RoomCreateEvent(const QJsonObject& obj)
+                : StateEventBase(typeId(), obj)
+            { }
+
+            struct Predecessor
+            {
+                QString roomId;
+                QString eventId;
+            };
+
+            bool isFederated() const;
+            QString version() const;
+            Predecessor predecessor() const;
+            bool isUpgrade() const;
+    };
+    REGISTER_EVENT_TYPE(RoomCreateEvent)
+}
diff --git a/lib/events/roomtombstoneevent.cpp b/lib/events/roomtombstoneevent.cpp
new file mode 100644
index 00000000..9c3bafd4
--- /dev/null
+++ b/lib/events/roomtombstoneevent.cpp
@@ -0,0 +1,31 @@
+/******************************************************************************
+* Copyright (C) 2019 QMatrixClient project
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation; either
+* version 2.1 of the License, or (at your option) any later version.
+*
+* This library is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this library; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include "roomtombstoneevent.h"
+
+using namespace QMatrixClient;
+
+QString RoomTombstoneEvent::serverMessage() const
+{
+    return fromJson<QString>(contentJson()["body"_ls]);
+}
+
+QString RoomTombstoneEvent::successorRoomId() const
+{
+    return fromJson<QString>(contentJson()["replacement_room"_ls]);
+}
diff --git a/lib/events/roomtombstoneevent.h b/lib/events/roomtombstoneevent.h
new file mode 100644
index 00000000..c7008ec4
--- /dev/null
+++ b/lib/events/roomtombstoneevent.h
@@ -0,0 +1,41 @@
+/******************************************************************************
+* Copyright (C) 2019 QMatrixClient project
+*
+* This library is free software; you can redistribute it and/or
+* modify it under the terms of the GNU Lesser General Public
+* License as published by the Free Software Foundation; either
+* version 2.1 of the License, or (at your option) any later version.
+*
+* This library is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+* Lesser General Public License for more details.
+*
+* You should have received a copy of the GNU Lesser General Public
+* License along with this library; if not, write to the Free Software
+* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#pragma once
+
+#include "stateevent.h"
+
+namespace QMatrixClient
+{
+    class RoomTombstoneEvent : public StateEventBase
+    {
+        public:
+            DEFINE_EVENT_TYPEID("m.room.tombstone", RoomTombstoneEvent)
+
+            explicit RoomTombstoneEvent()
+                : StateEventBase(typeId(), matrixTypeId())
+            { }
+            explicit RoomTombstoneEvent(const QJsonObject& obj)
+                : StateEventBase(typeId(), obj)
+            { }
+
+            QString serverMessage() const;
+            QString successorRoomId() const;
+    };
+    REGISTER_EVENT_TYPE(RoomTombstoneEvent)
+}
diff --git a/lib/room.cpp b/lib/room.cpp
index d806183f..f6956d82 100644
--- a/lib/room.cpp
+++ b/lib/room.cpp
@@ -29,7 +29,10 @@
 #include "csapi/room_send.h"
 #include "csapi/rooms.h"
 #include "csapi/tags.h"
+#include "csapi/room_upgrades.h"
 #include "events/simplestateevents.h"
+#include "events/roomcreateevent.h"
+#include "events/roomtombstoneevent.h"
 #include "events/roomavatarevent.h"
 #include "events/roommemberevent.h"
 #include "events/typingevent.h"
@@ -250,11 +253,17 @@ class Room::Private
                 const QString& txnId, BaseJob* call = nullptr);
 
         template <typename EvT>
-        auto requestSetState(const QString& stateKey, const EvT& event)
+        SetRoomStateWithKeyJob* requestSetState(const QString& stateKey,
+                                                const EvT& event)
         {
-            // TODO: Queue up state events sending (see #133).
-            return connection->callApi<SetRoomStateWithKeyJob>(
+            if (q->successorId().isEmpty())
+            {
+                // TODO: Queue up state events sending (see #133).
+                return connection->callApi<SetRoomStateWithKeyJob>(
                         id, EvT::matrixTypeId(), stateKey, event.contentJson());
+            }
+            qCWarning(MAIN) << q << "has been upgraded, state won't be set";
+            return nullptr;
         }
 
         template <typename EvT>
@@ -296,6 +305,12 @@ Room::Room(Connection* connection, QString id, JoinState initialJoinState)
     // https://marcmutz.wordpress.com/translated-articles/pimp-my-pimpl-%E2%80%94-reloaded/
     d->q = this;
     d->displayname = d->calculateDisplayname(); // Set initial "Empty room" name
+    connectUntil(connection, &Connection::loadedRoomState, this,
+        [this] (Room* r) {
+            if (this == r)
+                emit baseStateLoaded();
+            return this == r; // loadedRoomState fires only once per room
+        });
     qCDebug(MAIN) << "New" << toCString(initialJoinState) << "Room:" << id;
 }
 
@@ -309,6 +324,28 @@ const QString& Room::id() const
     return d->id;
 }
 
+QString Room::version() const
+{
+    const auto v = d->getCurrentState<RoomCreateEvent>()->version();
+    return v.isEmpty() ? "1" : v;
+}
+
+bool Room::isUnstable() const
+{
+    return !connection()->loadingCapabilities() &&
+            !connection()->stableRoomVersions().contains(version());
+}
+
+QString Room::predecessorId() const
+{
+    return d->getCurrentState<RoomCreateEvent>()->predecessor().roomId;
+}
+
+QString Room::successorId() const
+{
+    return d->getCurrentState<RoomTombstoneEvent>()->successorRoomId();
+}
+
 const Room::Timeline& Room::messageEvents() const
 {
     return d->timeline;
@@ -543,6 +580,26 @@ void Room::markAllMessagesAsRead()
         d->markMessagesAsRead(d->timeline.crbegin());
 }
 
+bool Room::canSwitchVersions() const
+{
+    // TODO, #276: m.room.power_levels
+    const auto* plEvt =
+            d->currentState.value({"m.room.power_levels", ""});
+    if (!plEvt)
+        return true;
+
+    const auto plJson = plEvt->contentJson();
+    const auto currentUserLevel =
+        plJson.value("users"_ls).toObject()
+        .value(localUser()->id()).toInt(
+            plJson.value("users_default"_ls).toInt());
+    const auto tombstonePowerLevel =
+        plJson.value("events").toObject()
+        .value("m.room.tombstone"_ls).toInt(
+            plJson.value("state_default"_ls).toInt());
+    return currentUserLevel >= tombstonePowerLevel;
+}
+
 bool Room::hasUnreadMessages() const
 {
     return unreadCount() >= 0;
@@ -762,6 +819,14 @@ void Room::resetHighlightCount()
     emit highlightCountChanged(this);
 }
 
+void Room::switchVersion(QString newVersion)
+{
+    auto* job = connection()->callApi<UpgradeRoomJob>(id(), newVersion);
+    connect(job, &BaseJob::failure, this, [this,job] {
+        emit upgradeFailed(job->errorString());
+    });
+}
+
 bool Room::hasAccountData(const QString& type) const
 {
     return d->accountData.find(type) != d->accountData.end();
@@ -1300,6 +1365,8 @@ RoomEvent* Room::Private::addAsPending(RoomEventPtr&& event)
         event->setTransactionId(connection->generateTxnId());
     auto* pEvent = rawPtr(event);
     emit q->pendingEventAboutToAdd(pEvent);
+    // FIXME: This sometimes causes a bad read:
+    // https://travis-ci.org/QMatrixClient/libqmatrixclient/jobs/492156899#L2596
     unsyncedEvents.emplace_back(move(event));
     emit q->pendingEventAdded();
     return pEvent;
@@ -1307,7 +1374,11 @@ RoomEvent* Room::Private::addAsPending(RoomEventPtr&& event)
 
 QString Room::Private::sendEvent(RoomEventPtr&& event)
 {
-    return doSendEvent(addAsPending(std::move(event)));
+    if (q->successorId().isEmpty())
+        return doSendEvent(addAsPending(std::move(event)));
+
+    qCWarning(MAIN) << q << "has been upgraded, event won't be sent";
+    return {};
 }
 
 QString Room::Private::doSendEvent(const RoomEvent* pEvent)
@@ -1569,7 +1640,24 @@ bool isEchoEvent(const RoomEventPtr& le, const PendingEventItem& re)
 
 bool Room::supportsCalls() const
 {
-  return joinedCount() == 2;
+    return joinedCount() == 2;
+}
+
+void Room::checkVersion()
+{
+    const auto defaultVersion = connection()->defaultRoomVersion();
+    const auto stableVersions = connection()->stableRoomVersions();
+    Q_ASSERT(!defaultVersion.isEmpty() && successorId().isEmpty());
+    // This method is only called after the base state has been loaded
+    // or the server capabilities have been loaded.
+    emit stabilityUpdated(defaultVersion, stableVersions);
+    if (!stableVersions.contains(version()))
+    {
+        qCDebug(MAIN) << this << "version is" << version()
+                      << "which the server doesn't count as stable";
+        if (canSwitchVersions())
+            qCDebug(MAIN) << "The current user has enough privileges to fix it";
+    }
 }
 
 void Room::inviteCall(const QString& callId, const int lifetime,
@@ -1799,7 +1887,7 @@ RoomEventPtr makeRedacted(const RoomEvent& target,
 
         std::vector<std::pair<Event::Type, QStringList>> keepContentKeysMap
         { { RoomMemberEvent::typeId(), { QStringLiteral("membership") } }
-//        , { RoomCreateEvent::typeId(),    { QStringLiteral("creator") } }
+        , { RoomCreateEvent::typeId(),    { QStringLiteral("creator") } }
 //        , { RoomJoinRules::typeId(), { QStringLiteral("join_rule") } }
 //        , { RoomPowerLevels::typeId(),
 //            { QStringLiteral("ban"), QStringLiteral("events"),
@@ -2123,7 +2211,23 @@ Room::Changes Room::processStateEvent(const RoomEvent& e)
         }
         , [this] (const EncryptionEvent&) {
             emit encryption(); // It can only be done once, so emit it here.
-            return EncryptionOn;
+            return OtherChange;
+        }
+        , [this] (const RoomTombstoneEvent& evt) {
+            const auto successorId = evt.successorRoomId();
+            if (auto* successor = connection()->room(successorId))
+                emit upgraded(evt.serverMessage(), successor);
+            else
+                connectUntil(connection(), &Connection::loadedRoomState, this,
+                    [this,successorId,serverMsg=evt.serverMessage()]
+                    (Room* newRoom) {
+                        if (newRoom->id() != successorId)
+                            return false;
+                        emit upgraded(serverMsg, newRoom);
+                        return true;
+                    });
+
+            return OtherChange;
         }
     );
 }
diff --git a/lib/room.h b/lib/room.h
index 029f87b7..197926e7 100644
--- a/lib/room.h
+++ b/lib/room.h
@@ -80,6 +80,10 @@ namespace QMatrixClient
             Q_PROPERTY(Connection* connection READ connection CONSTANT)
             Q_PROPERTY(User* localUser READ localUser CONSTANT)
             Q_PROPERTY(QString id READ id CONSTANT)
+            Q_PROPERTY(QString version READ version NOTIFY baseStateLoaded)
+            Q_PROPERTY(bool isUnstable READ isUnstable NOTIFY stabilityUpdated)
+            Q_PROPERTY(QString predecessorId READ predecessorId NOTIFY baseStateLoaded)
+            Q_PROPERTY(QString successorId READ successorId NOTIFY upgraded)
             Q_PROPERTY(QString name READ name NOTIFY namesChanged)
             Q_PROPERTY(QStringList aliases READ aliases NOTIFY namesChanged)
             Q_PROPERTY(QString canonicalAlias READ canonicalAlias NOTIFY namesChanged)
@@ -125,7 +129,7 @@ namespace QMatrixClient
                 JoinStateChange = 0x20,
                 TagsChange = 0x40,
                 MembersChange = 0x80,
-                EncryptionOn = 0x100,
+                /* = 0x100, */
                 AccountDataChange = 0x200,
                 SummaryChange = 0x400,
                 ReadMarkerChange = 0x800,
@@ -143,6 +147,10 @@ namespace QMatrixClient
             Connection* connection() const;
             User* localUser() const;
             const QString& id() const;
+            QString version() const;
+            bool isUnstable() const;
+            QString predecessorId() const;
+            QString successorId() const;
             QString name() const;
             QStringList aliases() const;
             QString canonicalAlias() const;
@@ -371,6 +379,9 @@ namespace QMatrixClient
             Q_INVOKABLE bool supportsCalls() const;
 
         public slots:
+            /** Check whether the room should be upgraded */
+            void checkVersion();
+
             QString postMessage(const QString& plainText, MessageEventType type);
             QString postPlainText(const QString& plainText);
             QString postHtmlMessage(const QString& plainText,
@@ -415,7 +426,22 @@ namespace QMatrixClient
             /// Mark all messages in the room as read
             void markAllMessagesAsRead();
 
+            /// Whether the current user is allowed to upgrade the room
+            bool canSwitchVersions() const;
+
+            /// Switch the room's version (aka upgrade)
+            void switchVersion(QString newVersion);
+
         signals:
+            /// Initial set of state events has been loaded
+            /**
+             * The initial set is what comes from the initial sync for the room.
+             * This includes all basic things like RoomCreateEvent,
+             * RoomNameEvent, a (lazy-loaded, not full) set of RoomMemberEvents
+             * etc. This is a per-room reflection of Connection::loadedRoomState
+             * \sa Connection::loadedRoomState
+             */
+            void baseStateLoaded();
             void eventsHistoryJobChanged();
             void aboutToAddHistoricalMessages(RoomEventsRange events);
             void aboutToAddNewMessages(RoomEventsRange events);
@@ -513,6 +539,15 @@ namespace QMatrixClient
             void fileTransferCancelled(QString id);
 
             void callEvent(Room* room, const RoomEvent* event);
+
+            /// The room's version stability may have changed
+            void stabilityUpdated(QString recommendedDefault,
+                                  QStringList stableVersions);
+            /// This room has been upgraded and won't receive updates anymore
+            void upgraded(QString serverMessage, Room* successor);
+            /// An attempted room upgrade has failed
+            void upgradeFailed(QString errorMessage);
+
             /// The room is about to be deleted
             void beforeDestruction(Room*);
 
diff --git a/libqmatrixclient.pri b/libqmatrixclient.pri
index f523f3a2..be568bd2 100644
--- a/libqmatrixclient.pri
+++ b/libqmatrixclient.pri
@@ -26,6 +26,8 @@ HEADERS += \
     $$SRCPATH/events/eventcontent.h \
     $$SRCPATH/events/roommessageevent.h \
     $$SRCPATH/events/simplestateevents.h \
+    $$SRCPATH/events/roomcreateevent.h \
+    $$SRCPATH/events/roomtombstoneevent.h \
     $$SRCPATH/events/roommemberevent.h \
     $$SRCPATH/events/roomavatarevent.h \
     $$SRCPATH/events/typingevent.h \
@@ -68,6 +70,8 @@ SOURCES += \
     $$SRCPATH/events/roomevent.cpp \
     $$SRCPATH/events/stateevent.cpp \
     $$SRCPATH/events/eventcontent.cpp \
+    $$SRCPATH/events/roomcreateevent.cpp \
+    $$SRCPATH/events/roomtombstoneevent.cpp \
     $$SRCPATH/events/roommessageevent.cpp \
     $$SRCPATH/events/roommemberevent.cpp \
     $$SRCPATH/events/typingevent.cpp \