Initial support for local echo

The Room class has gained a new internal container, unsyncedEvents, storing
locally-created Event objects that are about to be sent or are sent but not yet synced.
These objects are supposed to be complete enough to be displayed by clients
in a usual way; access to them is provided by Room::pendingEvents() accessor.
A set of pendingEvent* signals has been added to notify clients about changes
in this container (adding, removal, status update). Yet unsent events don't
have Event::id() at all; sent but yet unsynced ones have Event::id() but have
almost nothing else except the content for now (probably a sender and an
(at least local) timestamp are worth adding).

Also: SendEventJob is removed in favor of GTAD-generated SendMessageJob.

8 files changed, 127 insertions, 121 deletions

diff --git a/lib/connection.cpp b/lib/connection.cpp
index 8007cea1..d3a53cf4 100644
--- a/lib/connection.cpp
+++ b/lib/connection.cpp
@@ -30,7 +30,7 @@
 #include "csapi/account-data.h"
 #include "csapi/joining.h"
 #include "csapi/to_device.h"
-#include "jobs/sendeventjob.h"
+#include "csapi/room_send.h"
 #include "jobs/syncjob.h"
 #include "jobs/mediathumbnailjob.h"
 #include "jobs/downloadfilejob.h"
@@ -405,11 +405,6 @@ void Connection::stopSync()
     }
 }
 
-void Connection::postMessage(Room* room, const QString& type, const QString& message) const
-{
-    callApi<SendEventJob>(room->id(), type, message);
-}
-
 PostReceiptJob* Connection::postReceipt(Room* room, RoomEvent* event) const
 {
     return callApi<PostReceiptJob>(room->id(), "m.read", event->id());
@@ -645,6 +640,14 @@ SendToDeviceJob* Connection::sendToDevices(const QString& eventType,
                 eventType, generateTxnId(), json);
 }
 
+SendMessageJob* Connection::sendMessage(const QString& roomId, const RoomEvent& event) const
+{
+    const auto txnId = event.transactionId().isEmpty()
+                            ? generateTxnId() : event.transactionId();
+    return callApi<SendMessageJob>(roomId, event.matrixType(),
+                                   txnId, event.contentJson());
+}
+
 QUrl Connection::homeserver() const
 {
     return d->data->baseUrl();
diff --git a/lib/connection.h b/lib/connection.h
index 7adab883..48ca2232 100644
--- a/lib/connection.h
+++ b/lib/connection.h
@@ -47,6 +47,7 @@ namespace QMatrixClient
     class GetContentJob;
     class DownloadFileJob;
     class SendToDeviceJob;
+    class SendMessageJob;
 
     /** Create a single-shot connection that triggers on the signal and
      * then self-disconnects
@@ -421,11 +422,11 @@ namespace QMatrixClient
             SendToDeviceJob* sendToDevices(const QString& eventType,
                     const UsersToDevicesToEvents& eventsMap) const;
 
+            SendMessageJob* sendMessage(const QString& roomId,
+                                        const RoomEvent& event) const;
+
             // Old API that will be abolished any time soon. DO NOT USE.
 
-            /** @deprecated Use callApi<PostMessageJob>() or Room::postMessage() instead */
-            virtual void postMessage(Room* room, const QString& type,
-                                                 const QString& message) const;
             /** @deprecated Use callApi<PostReceiptJob>() or Room::postReceipt() instead */
             virtual PostReceiptJob* postReceipt(Room* room,
                                                 RoomEvent* event) const;
diff --git a/lib/events/roomevent.cpp b/lib/events/roomevent.cpp
index 3d09af8a..75850772 100644
--- a/lib/events/roomevent.cpp
+++ b/lib/events/roomevent.cpp
@@ -75,6 +75,11 @@ QString RoomEvent::redactionReason() const
     return isRedacted() ? _redactedBecause->reason() : QString{};
 }
 
+QString RoomEvent::stateKey() const
+{
+    return fullJson()["state_key"_ls].toString();
+}
+
 void RoomEvent::addId(const QString& newId)
 {
     Q_ASSERT(id().isEmpty()); Q_ASSERT(!newId.isEmpty());
diff --git a/lib/events/roomevent.h b/lib/events/roomevent.h
index d2bc6edc..fcbb33e5 100644
--- a/lib/events/roomevent.h
+++ b/lib/events/roomevent.h
@@ -57,6 +57,7 @@ namespace QMatrixClient {
             }
             QString redactionReason() const;
             const QString& transactionId() const { return _txnId; }
+            QString stateKey() const;
 
             /**
              * Sets the transaction id for locally created events. This should be
diff --git a/lib/jobs/sendeventjob.cpp b/lib/jobs/sendeventjob.cpp
deleted file mode 100644
index e5852c65..00000000
--- a/lib/jobs/sendeventjob.cpp
+++ /dev/null
@@ -1,45 +0,0 @@
-/******************************************************************************
- * Copyright (C) 2015 Felix Rohrbach <kde@fxrh.de>
- *
- * 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 "sendeventjob.h"
-
-#include "events/roommessageevent.h"
-
-using namespace QMatrixClient;
-
-SendEventJob::SendEventJob(const QString& roomId, const QString& type,
-                           const QString& plainText)
-    : SendEventJob(roomId, RoomMessageEvent(plainText, type))
-{ }
-
-void SendEventJob::beforeStart(const ConnectionData* connData)
-{
-    BaseJob::beforeStart(connData);
-    setApiEndpoint(apiEndpoint() + connData->generateTxnId());
-}
-
-BaseJob::Status SendEventJob::parseJson(const QJsonDocument& data)
-{
-    _eventId = data.object().value("event_id"_ls).toString();
-    if (!_eventId.isEmpty())
-        return Success;
-
-    qCDebug(JOBS) << data;
-    return { UserDefinedError, "No event_id in the JSON response" };
-}
-
diff --git a/lib/jobs/sendeventjob.h b/lib/jobs/sendeventjob.h
deleted file mode 100644
index af81ae26..00000000
--- a/lib/jobs/sendeventjob.h
+++ /dev/null
@@ -1,57 +0,0 @@
-/******************************************************************************
- * Copyright (C) 2015 Felix Rohrbach <kde@fxrh.de>
- *
- * 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 "basejob.h"
-
-#include "connectiondata.h"
-
-namespace QMatrixClient
-{
-    class SendEventJob: public BaseJob
-    {
-        public:
-            /** Constructs a job that sends an arbitrary room event */
-            template <typename EvT>
-            SendEventJob(const QString& roomId, const EvT& event)
-                : BaseJob(HttpVerb::Put, QStringLiteral("SendEventJob"),
-                          QStringLiteral("_matrix/client/r0/rooms/%1/send/%2/")
-                              .arg(roomId, EvT::matrixTypeId()), // See also beforeStart()
-                          Query(),
-                          Data(event.contentJson()))
-            { }
-
-            /**
-             * Constructs a plain text message job (for compatibility with
-             * the old PostMessageJob API).
-             */
-            SendEventJob(const QString& roomId, const QString& type,
-                         const QString& plainText);
-
-            QString eventId() const { return _eventId; }
-
-        protected:
-            Status parseJson(const QJsonDocument& data) override;
-
-        private:
-            QString _eventId;
-
-            void beforeStart(const ConnectionData* connData) override;
-    };
-}  // namespace QMatrixClient
diff --git a/lib/room.cpp b/lib/room.cpp
index a8007f20..ca29eca5 100644
--- a/lib/room.cpp
+++ b/lib/room.cpp
@@ -27,13 +27,13 @@
 #include "csapi/account-data.h"
 #include "csapi/message_pagination.h"
 #include "csapi/room_state.h"
+#include "csapi/room_send.h"
 #include "events/simplestateevents.h"
 #include "events/roomavatarevent.h"
 #include "events/roommemberevent.h"
 #include "events/typingevent.h"
 #include "events/receiptevent.h"
 #include "events/redactionevent.h"
-#include "jobs/sendeventjob.h"
 #include "jobs/mediathumbnailjob.h"
 #include "jobs/downloadfilejob.h"
 #include "jobs/postreadmarkersjob.h"
@@ -88,6 +88,7 @@ class Room::Private
 
         Connection* connection;
         Timeline timeline;
+        RoomEvents unsyncedEvents;
         QHash<QString, TimelineItem::index_t> eventsIndex;
         QString id;
         QStringList aliases;
@@ -199,9 +200,20 @@ class Room::Private
 
         void markMessagesAsRead(rev_iter_t upToMarker);
 
+        void sendEvent(RoomEventPtr&& event);
+
+        template <typename EventT, typename... ArgTs>
+        void sendEvent(ArgTs&&... eventArgs)
+        {
+            sendEvent(makeEvent<EventT>(std::forward<ArgTs>(eventArgs)...));
+        }
+
+        void deleteLocalEcho(const RoomEventPtr& remoteEcho);
+
         template <typename EvT>
         auto requestSetState(const QString& stateKey, const EvT& event)
         {
+            // TODO: Queue up state events sending (see #133).
             return connection->callApi<SetRoomStateWithKeyJob>(
                         id, EvT::matrixTypeId(), stateKey, event.contentJson());
         }
@@ -274,6 +286,11 @@ const Room::Timeline& Room::messageEvents() const
     return d->timeline;
 }
 
+const RoomEvents& Room::pendingEvents() const
+{
+    return d->unsyncedEvents;
+}
+
 QString Room::name() const
 {
     return d->name;
@@ -1073,32 +1090,64 @@ void Room::updateData(SyncRoomData&& data)
     }
 }
 
+void Room::Private::sendEvent(RoomEventPtr&& event)
+{
+    auto* pEvent = rawPtr(event);
+    emit q->pendingEventAboutToAdd();
+    unsyncedEvents.emplace_back(move(event));
+    emit q->pendingEventAdded();
+
+    if (pEvent->transactionId().isEmpty())
+        pEvent->setTransactionId(connection->generateTxnId());
+    // TODO: Enqueue the job rather than immediately trigger it
+    auto call = connection->sendMessage(id, *pEvent);
+    Room::connect(call, &BaseJob::success, q, [this,call,pEvent]
+    {
+        const auto comparator =
+            [pEvent] (const auto& eptr) { return rawPtr(eptr) == pEvent; };
+
+        // Find an event by the pointer saved in the lambda
+        auto it = std::find_if(unsyncedEvents.begin(), unsyncedEvents.end(),
+                               comparator);
+        if (it == unsyncedEvents.end())
+            return; // The event is already synced, nothing to do
+
+        pEvent->addId(call->eventId());
+        emit q->pendingEventChanged(it - unsyncedEvents.begin());
+    });
+}
+
 void Room::postMessage(const QString& type, const QString& plainText)
 {
-    postMessage(RoomMessageEvent { plainText, type });
+    d->sendEvent<RoomMessageEvent>(plainText, type);
 }
 
 void Room::postMessage(const QString& plainText, MessageEventType type)
 {
-    postMessage(RoomMessageEvent { plainText, type });
+    d->sendEvent<RoomMessageEvent>(plainText, type);
 }
 
 void Room::postHtmlMessage(const QString& plainText, const QString& htmlText,
                            MessageEventType type)
 {
-    postMessage(RoomMessageEvent { plainText, type,
-        new EventContent::TextContent(htmlText, QStringLiteral("text/html")) });
-
+    d->sendEvent<RoomMessageEvent>(plainText, type,
+        new EventContent::TextContent(htmlText, QStringLiteral("text/html")));
 }
 
-void Room::postMessage(const RoomMessageEvent& event)
+void Room::postMessage(RoomEvent* event)
 {
     if (usesEncryption())
     {
         qCCritical(MAIN) << "Room" << displayName()
             << "enforces encryption; sending encrypted messages is not supported yet";
     }
-    connection()->callApi<SendEventJob>(id(), event);
+    d->sendEvent(RoomEventPtr(event));
+}
+
+void Room::postMessage(const QString& matrixType,
+                       const QJsonObject& eventContent)
+{
+    d->sendEvent(loadEvent<RoomEvent>(basicEventJson(matrixType, eventContent)));
 }
 
 void Room::setName(const QString& newName)
@@ -1116,6 +1165,41 @@ void Room::setTopic(const QString& newTopic)
     d->requestSetState(RoomTopicEvent(newTopic));
 }
 
+void Room::Private::deleteLocalEcho(const RoomEventPtr& remoteEcho)
+{
+    if (remoteEcho->senderId() == connection->userId())
+    {
+        auto localEchoIt =
+            std::find_if(unsyncedEvents.begin(), unsyncedEvents.end(),
+                 [&remoteEcho] (const RoomEventPtr& le)
+                 {
+                     if (le->type() != remoteEcho->type())
+                         return false;
+
+                     if (!le->id().isEmpty())
+                         return le->id() == remoteEcho->id();
+                     if (!le->transactionId().isEmpty())
+                         return le->transactionId() ==
+                            remoteEcho->transactionId();
+
+                     // This one is not reliable (there can be two unsynced
+                     // events with the same type, sender and state key) but
+                     // it's the best we have for state events.
+                     if (le->isStateEvent())
+                         return le->stateKey() == remoteEcho->stateKey();
+
+                     // Empty id and no state key, hmm... (shrug)
+                     return le->contentJson() == remoteEcho->contentJson();
+                 });
+        if (localEchoIt != unsyncedEvents.end())
+        {
+            emit q->pendingEventAboutToRemove(localEchoIt - unsyncedEvents.begin());
+            unsyncedEvents.erase(localEchoIt);
+            emit q->pendingEventRemoved();
+        }
+    }
+}
+
 void Room::getPreviousContent(int limit)
 {
     d->getPreviousContent(limit);
@@ -1399,7 +1483,12 @@ void Room::Private::addNewMessageEvents(RoomEvents&& events)
 #endif
 
     if (!normalEvents.empty())
+    {
+        for (const auto& e: normalEvents)
+            deleteLocalEcho(e);
+
         emit q->aboutToAddNewMessages(normalEvents);
+    }
     const auto insertedSize = moveEventsToTimeline(normalEvents, Newer);
     const auto from = timeline.cend() - insertedSize;
     if (insertedSize > 0)
@@ -1648,7 +1737,7 @@ void Room::processAccountDataEvent(EventPtr&& event)
     // efficient; maaybe do it another day
     if (!currentData || currentData->contentJson() != event->contentJson())
     {
-        currentData = std::move(event);
+        currentData = move(event);
         qCDebug(MAIN) << "Updated account data of type"
                       << currentData->matrixType();
         emit accountDataChanged(currentData->matrixType());
diff --git a/lib/room.h b/lib/room.h
index e7f260dd..01a7389c 100644
--- a/lib/room.h
+++ b/lib/room.h
@@ -216,6 +216,7 @@ namespace QMatrixClient
             Q_INVOKABLE QString roomMembername(const QString& userId) const;
 
             const Timeline& messageEvents() const;
+            const RoomEvents& pendingEvents() const;
             /**
              * A convenience method returning the read marker to the before-oldest
              * message
@@ -350,7 +351,10 @@ namespace QMatrixClient
                              MessageEventType type = MessageEventType::Text);
             void postHtmlMessage(const QString& plainText, const QString& htmlText,
                              MessageEventType type = MessageEventType::Text);
-            void postMessage(const RoomMessageEvent& event);
+            /** Post a pre-created room message event; takes ownership of the event */
+            void postMessage(RoomEvent* event);
+            void postMessage(const QString& matrixType,
+                             const QJsonObject& eventContent);
             /** @deprecated If you have a custom event type, construct the event
              * and pass it as a whole to postMessage() */
             void postMessage(const QString& type, const QString& plainText);
@@ -384,6 +388,11 @@ namespace QMatrixClient
             void aboutToAddHistoricalMessages(RoomEventsRange events);
             void aboutToAddNewMessages(RoomEventsRange events);
             void addedMessages();
+            void pendingEventAboutToAdd();
+            void pendingEventAdded();
+            void pendingEventAboutToRemove(int pendingEventIndex);
+            void pendingEventRemoved();
+            void pendingEventChanged(int pendingEventIndex);
 
             /**
              * @brief The room name, the canonical alias or other aliases changed