Cleanup across the board

Mainly driven by clang-tidy and SonarCloud warnings (sadly, SonarCloud
doesn't store historical reports so no link can be provided here).

10 files changed, 70 insertions, 57 deletions

diff --git a/lib/connection.cpp b/lib/connection.cpp
index 4418958e..bd4d9251 100644
--- a/lib/connection.cpp
+++ b/lib/connection.cpp
@@ -219,7 +219,9 @@ public:
         }
         q->database()->saveOlmSession(senderKey, session->sessionId(), std::get<QByteArray>(pickleResult), QDateTime::currentDateTime());
     }
-    std::pair<QString, QString> sessionDecryptPrekey(const QOlmMessage& message, const QString &senderKey, std::unique_ptr<QOlmAccount>& olmAccount)
+
+    std::pair<QString, QString> sessionDecryptPrekey(const QOlmMessage& message,
+                                                     const QString& senderKey)
     {
         Q_ASSERT(message.type() == QOlmMessage::PreKey);
         for(auto& session : olmSessions[senderKey]) {
@@ -273,24 +275,19 @@ public:
     }
 
     std::pair<QString, QString> sessionDecryptMessage(
-        const QJsonObject& personalCipherObject, const QByteArray& senderKey, std::unique_ptr<QOlmAccount>& account)
+        const QJsonObject& personalCipherObject, const QByteArray& senderKey)
     {
-        QString decrypted;
-        QString olmSessionId;
-        int type = personalCipherObject.value(TypeKeyL).toInt(-1);
-        QByteArray body = personalCipherObject.value(BodyKeyL).toString().toLatin1();
-        if (type == QOlmMessage::PreKey) {
-            QOlmMessage preKeyMessage(body, QOlmMessage::PreKey);
-            auto result = sessionDecryptPrekey(preKeyMessage, senderKey, account);
-            decrypted = result.first;
-            olmSessionId = result.second;
-        } else if (type == QOlmMessage::General) {
-            QOlmMessage message(body, QOlmMessage::General);
-            auto result = sessionDecryptGeneral(message, senderKey);
-            decrypted = result.first;
-            olmSessionId = result.second;
-        }
-        return { decrypted, olmSessionId };
+        QOlmMessage message {
+            personalCipherObject.value(BodyKeyL).toString().toLatin1(),
+            static_cast<QOlmMessage::Type>(
+                personalCipherObject.value(TypeKeyL).toInt(-1))
+        };
+        if (message.type() == QOlmMessage::PreKey)
+            return sessionDecryptPrekey(message, senderKey);
+        if (message.type() == QOlmMessage::General)
+            return sessionDecryptGeneral(message, senderKey);
+        qCWarning(E2EE) << "Olm message has incorrect type" << message.type();
+        return {};
     }
 #endif
 
@@ -310,8 +307,9 @@ public:
             qCDebug(E2EE) << "Encrypted event is not for the current device";
             return {};
         }
-        const auto [decrypted, olmSessionId] = sessionDecryptMessage(
-            personalCipherObject, encryptedEvent.senderKey().toLatin1(), olmAccount);
+        const auto [decrypted, olmSessionId] =
+            sessionDecryptMessage(personalCipherObject,
+                                  encryptedEvent.senderKey().toLatin1());
         if (decrypted.isEmpty()) {
             qCDebug(E2EE) << "Problem with new session from senderKey:"
                           << encryptedEvent.senderKey()
@@ -950,8 +948,6 @@ void Connection::Private::consumeToDeviceEvents(Events&& toDeviceEvents)
             outdatedUsers += event.senderId();
             encryptionUpdateRequired = true;
             pendingEncryptedEvents.push_back(std::make_unique<EncryptedEvent>(event.fullJson()));
-        }, [](const Event& e){
-            // Unhandled
         });
     }
 #endif
@@ -967,7 +963,7 @@ void Connection::Private::handleEncryptedToDeviceEvent(const EncryptedEvent& eve
     }
 
     switchOnType(*decryptedEvent,
-        [this, senderKey = event.senderKey(), &event, olmSessionId = olmSessionId](const RoomKeyEvent& roomKeyEvent) {
+        [this, &event, olmSessionId = olmSessionId](const RoomKeyEvent& roomKeyEvent) {
             if (auto* detectedRoom = q->room(roomKeyEvent.roomId())) {
                 detectedRoom->handleRoomKeyEvent(roomKeyEvent, event.senderId(), olmSessionId);
             } else {
@@ -2074,12 +2070,13 @@ void Connection::Private::loadOutdatedUserDevices()
         saveDevicesList();
 
         for(size_t i = 0; i < pendingEncryptedEvents.size();) {
-            if (q->isKnownCurveKey(pendingEncryptedEvents[i]->fullJson()[SenderKeyL].toString(), pendingEncryptedEvents[i]->contentJson()["sender_key"].toString())) {
-                handleEncryptedToDeviceEvent(*(pendingEncryptedEvents[i].get()));
+            if (q->isKnownCurveKey(
+                    pendingEncryptedEvents[i]->fullJson()[SenderKeyL].toString(),
+                    pendingEncryptedEvents[i]->contentPart<QString>("sender_key"_ls))) {
+                handleEncryptedToDeviceEvent(*pendingEncryptedEvents[i]);
                 pendingEncryptedEvents.erase(pendingEncryptedEvents.begin() + i);
-            } else {
-                i++;
-            }
+            } else
+                ++i;
         }
     });
 }
@@ -2188,13 +2185,10 @@ void Connection::saveOlmAccount()
 #ifdef Quotient_E2EE_ENABLED
 QJsonObject Connection::decryptNotification(const QJsonObject &notification)
 {
-    auto room = this->room(notification["room_id"].toString());
+    auto r = room(notification["room_id"].toString());
     auto event = makeEvent<EncryptedEvent>(notification["event"].toObject());
-    auto decrypted = room->decryptMessage(*event);
-    if(!decrypted) {
-        return QJsonObject();
-    }
-    return decrypted->fullJson();
+    const auto decrypted = r->decryptMessage(*event);
+    return decrypted ? decrypted->fullJson() : QJsonObject();
 }
 
 Database* Connection::database()
@@ -2202,14 +2196,18 @@ Database* Connection::database()
     return d->database;
 }
 
-UnorderedMap<QString, QOlmInboundGroupSessionPtr> Connection::loadRoomMegolmSessions(Room* room)
+UnorderedMap<QString, QOlmInboundGroupSessionPtr>
+Connection::loadRoomMegolmSessions(const Room* room)
 {
     return database()->loadMegolmSessions(room->id(), picklingMode());
 }
 
-void Connection::saveMegolmSession(Room* room, QOlmInboundGroupSession* session)
+void Connection::saveMegolmSession(const Room* room,
+                                   const QOlmInboundGroupSession& session)
 {
-    database()->saveMegolmSession(room->id(), session->sessionId(), session->pickle(picklingMode()), session->senderId(), session->olmSessionId());
+    database()->saveMegolmSession(room->id(), session.sessionId(),
+                                  session.pickle(picklingMode()),
+                                  session.senderId(), session.olmSessionId());
 }
 
 QStringList Connection::devicesForUser(User* user) const
diff --git a/lib/connection.h b/lib/connection.h
index 29731593..b75bd5b5 100644
--- a/lib/connection.h
+++ b/lib/connection.h
@@ -317,8 +317,10 @@ public:
 #ifdef Quotient_E2EE_ENABLED
     QOlmAccount* olmAccount() const;
     Database* database();
-    UnorderedMap<QString, QOlmInboundGroupSessionPtr> loadRoomMegolmSessions(Room* room);
-    void saveMegolmSession(Room* room, QOlmInboundGroupSession* session);
+    UnorderedMap<QString, QOlmInboundGroupSessionPtr> loadRoomMegolmSessions(
+        const Room* room);
+    void saveMegolmSession(const Room* room,
+                           const QOlmInboundGroupSession& session);
 #endif // Quotient_E2EE_ENABLED
     Q_INVOKABLE Quotient::SyncJob* syncJob() const;
     Q_INVOKABLE int millisToReconnect() const;
diff --git a/lib/converters.h b/lib/converters.h
index 6515310a..5e3becb8 100644
--- a/lib/converters.h
+++ b/lib/converters.h
@@ -163,6 +163,14 @@ inline qint64 fromJson(const QJsonValue& jv) { return qint64(jv.toDouble()); }
 template <>
 inline QString fromJson(const QJsonValue& jv) { return jv.toString(); }
 
+//! Use fromJson<QString> and use toLatin1()/toUtf8()/... to make QByteArray
+//!
+//! QJsonValue can only convert to QString and there's ambiguity whether
+//! conversion to QByteArray should use (fast but very limited) toLatin1() or
+//! (all encompassing and conforming to the JSON spec but slow) toUtf8().
+template <>
+inline QByteArray fromJson(const QJsonValue& jv) = delete;
+
 template <>
 inline QJsonArray fromJson(const QJsonValue& jv) { return jv.toArray(); }
 
diff --git a/lib/e2ee/qolminboundsession.cpp b/lib/e2ee/qolminboundsession.cpp
index 60d871ef..62856831 100644
--- a/lib/e2ee/qolminboundsession.cpp
+++ b/lib/e2ee/qolminboundsession.cpp
@@ -154,9 +154,9 @@ QString QOlmInboundGroupSession::olmSessionId() const
 {
     return m_olmSessionId;
 }
-void QOlmInboundGroupSession::setOlmSessionId(const QString& olmSessionId)
+void QOlmInboundGroupSession::setOlmSessionId(const QString& newOlmSessionId)
 {
-    m_olmSessionId = olmSessionId;
+    m_olmSessionId = newOlmSessionId;
 }
 
 QString QOlmInboundGroupSession::senderId() const
diff --git a/lib/e2ee/qolminboundsession.h b/lib/e2ee/qolminboundsession.h
index 32112b97..13515434 100644
--- a/lib/e2ee/qolminboundsession.h
+++ b/lib/e2ee/qolminboundsession.h
@@ -44,7 +44,7 @@ public:
     //! The olm session that this session was received from.
     //! Required to get the device this session is from.
     QString olmSessionId() const;
-    void setOlmSessionId(const QString& setOlmSessionId);
+    void setOlmSessionId(const QString& newOlmSessionId);
 
     //! The sender of this session.
     QString senderId() const;
diff --git a/lib/events/callinviteevent.cpp b/lib/events/callinviteevent.cpp
index 11d50768..2f26a1cb 100644
--- a/lib/events/callinviteevent.cpp
+++ b/lib/events/callinviteevent.cpp
@@ -33,7 +33,7 @@ CallInviteEvent::CallInviteEvent(const QJsonObject& obj)
     qCDebug(EVENTS) << "Call Invite event";
 }
 
-CallInviteEvent::CallInviteEvent(const QString& callId, const int lifetime,
+CallInviteEvent::CallInviteEvent(const QString& callId, int lifetime,
                                  const QString& sdp)
     : CallEventBase(
         typeId(), matrixTypeId(), callId, 0,
diff --git a/lib/events/callinviteevent.h b/lib/events/callinviteevent.h
index 1b1f4f0f..5b4ca0df 100644
--- a/lib/events/callinviteevent.h
+++ b/lib/events/callinviteevent.h
@@ -13,10 +13,10 @@ public:
 
     explicit CallInviteEvent(const QJsonObject& obj);
 
-    explicit CallInviteEvent(const QString& callId, const int lifetime,
+    explicit CallInviteEvent(const QString& callId, int lifetime,
                              const QString& sdp);
 
-    QUO_CONTENT_GETTER(int, lifetime) // FIXME: Omittable<>?
+    QUO_CONTENT_GETTER(int, lifetime)
     QString sdp() const
     {
         return contentPart<QJsonObject>("offer"_ls).value("sdp"_ls).toString();
diff --git a/lib/events/roomkeyevent.h b/lib/events/roomkeyevent.h
index c4df7936..ed4c9440 100644
--- a/lib/events/roomkeyevent.h
+++ b/lib/events/roomkeyevent.h
@@ -16,7 +16,10 @@ public:
     QString algorithm() const { return contentPart<QString>("algorithm"_ls); }
     QString roomId() const { return contentPart<QString>(RoomIdKeyL); }
     QString sessionId() const { return contentPart<QString>("session_id"_ls); }
-    QString sessionKey() const { return contentPart<QString>("session_key"_ls); }
+    QByteArray sessionKey() const
+    {
+        return contentPart<QString>("session_key"_ls).toLatin1();
+    }
 };
 REGISTER_EVENT_TYPE(RoomKeyEvent)
 } // namespace Quotient
diff --git a/lib/room.cpp b/lib/room.cpp
index 993455be..0a997b9c 100644
--- a/lib/room.cpp
+++ b/lib/room.cpp
@@ -339,14 +339,16 @@ public:
 #ifdef Quotient_E2EE_ENABLED
     UnorderedMap<QString, QOlmInboundGroupSessionPtr> groupSessions;
 
-    bool addInboundGroupSession(QString sessionId, QString sessionKey, const QString& senderId, const QString& olmSessionId)
+    bool addInboundGroupSession(QString sessionId, QByteArray sessionKey,
+                                const QString& senderId,
+                                const QString& olmSessionId)
     {
-        if (groupSessions.find(sessionId) != groupSessions.end()) {
+        if (groupSessions.contains(sessionId)) {
             qCWarning(E2EE) << "Inbound Megolm session" << sessionId << "already exists";
             return false;
         }
 
-        auto megolmSession = QOlmInboundGroupSession::create(sessionKey.toLatin1());
+        auto megolmSession = QOlmInboundGroupSession::create(sessionKey);
         if (megolmSession->sessionId() != sessionId) {
             qCWarning(E2EE) << "Session ID mismatch in m.room_key event";
             return false;
@@ -354,13 +356,12 @@ public:
         megolmSession->setSenderId(senderId);
         megolmSession->setOlmSessionId(olmSessionId);
         qCWarning(E2EE) << "Adding inbound session";
-        connection->saveMegolmSession(q, megolmSession.get());
+        connection->saveMegolmSession(q, *megolmSession);
         groupSessions[sessionId] = std::move(megolmSession);
         return true;
     }
 
     QString groupSessionDecryptMessage(QByteArray cipher,
-                                       const QString& senderKey,
                                        const QString& sessionId,
                                        const QString& eventId,
                                        QDateTime timestamp,
@@ -1478,9 +1479,9 @@ RoomEventPtr Room::decryptMessage(const EncryptedEvent& encryptedEvent)
         return {};
     }
     QString decrypted = d->groupSessionDecryptMessage(
-        encryptedEvent.ciphertext(), encryptedEvent.senderKey(),
-        encryptedEvent.sessionId(), encryptedEvent.id(),
-        encryptedEvent.originTimestamp(), encryptedEvent.senderId());
+        encryptedEvent.ciphertext(), encryptedEvent.sessionId(),
+        encryptedEvent.id(), encryptedEvent.originTimestamp(),
+        encryptedEvent.senderId());
     if (decrypted.isEmpty()) {
         // qCWarning(E2EE) << "Encrypted message is empty";
         return {};
@@ -1509,7 +1510,8 @@ void Room::handleRoomKeyEvent(const RoomKeyEvent& roomKeyEvent,
                         << roomKeyEvent.algorithm() << "in m.room_key event";
     }
     if (d->addInboundGroupSession(roomKeyEvent.sessionId(),
-                                  roomKeyEvent.sessionKey(), senderId, olmSessionId)) {
+                                  roomKeyEvent.sessionKey(), senderId,
+                                  olmSessionId)) {
         qCWarning(E2EE) << "added new inboundGroupSession:"
                       << d->groupSessions.size();
         auto undecryptedEvents = d->undecryptedEvents[roomKeyEvent.sessionId()];
diff --git a/lib/room.h b/lib/room.h
index 2e2ebf9a..6e6071f0 100644
--- a/lib/room.h
+++ b/lib/room.h
@@ -871,8 +871,8 @@ public Q_SLOTS:
     void inviteCall(const QString& callId, const int lifetime,
                     const QString& sdp);
     void sendCallCandidates(const QString& callId, const QJsonArray& candidates);
-    [[deprecated("Lifetime argument is no more in use here; "
-                 "use 2-arg Room::answerCall() instead")]]
+    //! \deprecated Lifetime argument is no more passed; use 2-arg
+    //!             Room::answerCall() instead
     void answerCall(const QString& callId, int lifetime, const QString& sdp);
     void answerCall(const QString& callId, const QString& sdp);
     void hangupCall(const QString& callId);