TimelineModel.cpp

#include "TimelineModel.h"

#include <algorithm>
#include <thread>
#include <type_traits>

#include <QCache>
#include <QFileDialog>
#include <QMimeDatabase>
#include <QRegularExpression>
#include <QStandardPaths>

#include "ChatPage.h"
#include "EventAccessors.h"
#include "Logging.h"
#include "MainWindow.h"
#include "MatrixClient.h"
#include "MxcImageProvider.h"
#include "Olm.h"
#include "TimelineViewManager.h"
#include "Utils.h"
#include "dialogs/RawMessage.h"

Q_DECLARE_METATYPE(QModelIndex)

namespace std {
inline uint
qHash(const std::string &key, uint seed = 0)
{
        return qHash(QByteArray::fromRawData(key.data(), key.length()), seed);
}
}

namespace {
struct RoomEventType
{
        template<class T>
        qml_mtx_events::EventType operator()(const mtx::events::Event<T> &e)
        {
                using mtx::events::EventType;
                switch (e.type) {
                case EventType::RoomKeyRequest:
                        return qml_mtx_events::EventType::KeyRequest;
                case EventType::RoomAliases:
                        return qml_mtx_events::EventType::Aliases;
                case EventType::RoomAvatar:
                        return qml_mtx_events::EventType::Avatar;
                case EventType::RoomCanonicalAlias:
                        return qml_mtx_events::EventType::CanonicalAlias;
                case EventType::RoomCreate:
                        return qml_mtx_events::EventType::RoomCreate;
                case EventType::RoomEncrypted:
                        return qml_mtx_events::EventType::Encrypted;
                case EventType::RoomEncryption:
                        return qml_mtx_events::EventType::Encryption;
                case EventType::RoomGuestAccess:
                        return qml_mtx_events::EventType::RoomGuestAccess;
                case EventType::RoomHistoryVisibility:
                        return qml_mtx_events::EventType::RoomHistoryVisibility;
                case EventType::RoomJoinRules:
                        return qml_mtx_events::EventType::RoomJoinRules;
                case EventType::RoomMember:
                        return qml_mtx_events::EventType::Member;
                case EventType::RoomMessage:
                        return qml_mtx_events::EventType::UnknownMessage;
                case EventType::RoomName:
                        return qml_mtx_events::EventType::Name;
                case EventType::RoomPowerLevels:
                        return qml_mtx_events::EventType::PowerLevels;
                case EventType::RoomTopic:
                        return qml_mtx_events::EventType::Topic;
                case EventType::RoomTombstone:
                        return qml_mtx_events::EventType::Tombstone;
                case EventType::RoomRedaction:
                        return qml_mtx_events::EventType::Redaction;
                case EventType::RoomPinnedEvents:
                        return qml_mtx_events::EventType::PinnedEvents;
                case EventType::Sticker:
                        return qml_mtx_events::EventType::Sticker;
                case EventType::Tag:
                        return qml_mtx_events::EventType::Tag;
                case EventType::Unsupported:
                        return qml_mtx_events::EventType::Unsupported;
                default:
                        return qml_mtx_events::EventType::UnknownMessage;
                }
        }
        qml_mtx_events::EventType operator()(const mtx::events::Event<mtx::events::msg::Audio> &)
        {
                return qml_mtx_events::EventType::AudioMessage;
        }
        qml_mtx_events::EventType operator()(const mtx::events::Event<mtx::events::msg::Emote> &)
        {
                return qml_mtx_events::EventType::EmoteMessage;
        }
        qml_mtx_events::EventType operator()(const mtx::events::Event<mtx::events::msg::File> &)
        {
                return qml_mtx_events::EventType::FileMessage;
        }
        qml_mtx_events::EventType operator()(const mtx::events::Event<mtx::events::msg::Image> &)
        {
                return qml_mtx_events::EventType::ImageMessage;
        }
        qml_mtx_events::EventType operator()(const mtx::events::Event<mtx::events::msg::Notice> &)
        {
                return qml_mtx_events::EventType::NoticeMessage;
        }
        qml_mtx_events::EventType operator()(const mtx::events::Event<mtx::events::msg::Text> &)
        {
                return qml_mtx_events::EventType::TextMessage;
        }
        qml_mtx_events::EventType operator()(const mtx::events::Event<mtx::events::msg::Video> &)
        {
                return qml_mtx_events::EventType::VideoMessage;
        }

        qml_mtx_events::EventType operator()(const mtx::events::Event<mtx::events::msg::Redacted> &)
        {
                return qml_mtx_events::EventType::Redacted;
        }
        // ::EventType::Type operator()(const Event<mtx::events::msg::Location> &e) { return
        // ::EventType::LocationMessage; }
};
}

qml_mtx_events::EventType
toRoomEventType(const mtx::events::collections::TimelineEvents &event)
{
        return std::visit(RoomEventType{}, event);
}

QString
toRoomEventTypeString(const mtx::events::collections::TimelineEvents &event)
{
        return std::visit([](const auto &e) { return QString::fromStdString(to_string(e.type)); },
                          event);
}

TimelineModel::TimelineModel(TimelineViewManager *manager, QString room_id, QObject *parent)
  : QAbstractListModel(parent)
  , room_id_(room_id)
  , manager_(manager)
{
        connect(
          this, &TimelineModel::oldMessagesRetrieved, this, &TimelineModel::addBackwardsEvents);
        connect(this, &TimelineModel::messageFailed, this, [this](QString txn_id) {
                nhlog::ui()->error("Failed to send {}, retrying", txn_id.toStdString());

                QTimer::singleShot(5000, this, [this]() { emit nextPendingMessage(); });
        });
        connect(this, &TimelineModel::messageSent, this, [this](QString txn_id, QString event_id) {
                pending.removeOne(txn_id);

                int idx = idToIndex(txn_id);
                if (idx < 0) {
                        // transaction already received via sync
                        return;
                }
                eventOrder[idx] = event_id;
                auto ev         = events.value(txn_id);
                ev              = std::visit(
                  [event_id](const auto &e) -> mtx::events::collections::TimelineEvents {
                          auto eventCopy     = e;
                          eventCopy.event_id = event_id.toStdString();
                          return eventCopy;
                  },
                  ev);

                events.remove(txn_id);
                events.insert(event_id, ev);

                // mark our messages as read
                readEvent(event_id.toStdString());

                // ask to be notified for read receipts
                cache::addPendingReceipt(room_id_, event_id);

                emit dataChanged(index(idx, 0), index(idx, 0));

                if (pending.size() > 0)
                        emit nextPendingMessage();
        });
        connect(this, &TimelineModel::redactionFailed, this, [](const QString &msg) {
                emit ChatPage::instance()->showNotification(msg);
        });

        connect(
          this, &TimelineModel::nextPendingMessage, this, &TimelineModel::processOnePendingMessage);
        connect(this, &TimelineModel::newMessageToSend, this, &TimelineModel::addPendingMessage);

        connect(this,
                &TimelineModel::eventFetched,
                this,
                [this](QString requestingEvent, mtx::events::collections::TimelineEvents event) {
                        events.insert(QString::fromStdString(mtx::accessors::event_id(event)),
                                      event);
                        auto idx = idToIndex(requestingEvent);
                        if (idx >= 0)
                                emit dataChanged(index(idx, 0), index(idx, 0));
                });
}

QHash<int, QByteArray>
TimelineModel::roleNames() const
{
        return {
          {Section, "section"},
          {Type, "type"},
          {TypeString, "typeString"},
          {Body, "body"},
          {FormattedBody, "formattedBody"},
          {UserId, "userId"},
          {UserName, "userName"},
          {Timestamp, "timestamp"},
          {Url, "url"},
          {ThumbnailUrl, "thumbnailUrl"},
          {Blurhash, "blurhash"},
          {Filename, "filename"},
          {Filesize, "filesize"},
          {MimeType, "mimetype"},
          {Height, "height"},
          {Width, "width"},
          {ProportionalHeight, "proportionalHeight"},
          {Id, "id"},
          {State, "state"},
          {IsEncrypted, "isEncrypted"},
          {ReplyTo, "replyTo"},
          {RoomId, "roomId"},
          {RoomName, "roomName"},
          {RoomTopic, "roomTopic"},
          {Dump, "dump"},
        };
}
int
TimelineModel::rowCount(const QModelIndex &parent) const
{
        Q_UNUSED(parent);
        return (int)this->eventOrder.size();
}

QVariantMap
TimelineModel::getDump(QString eventId) const
{
        if (events.contains(eventId))
                return data(eventId, Dump).toMap();
        return {};
}

QVariant
TimelineModel::data(const QString &id, int role) const
{
        using namespace mtx::accessors;
        namespace acc                                  = mtx::accessors;
        mtx::events::collections::TimelineEvents event = events.value(id);

        if (auto e =
              std::get_if<mtx::events::EncryptedEvent<mtx::events::msg::Encrypted>>(&event)) {
                event = decryptEvent(*e).event;
        }

        switch (role) {
        case UserId:
                return QVariant(QString::fromStdString(acc::sender(event)));
        case UserName:
                return QVariant(displayName(QString::fromStdString(acc::sender(event))));

        case Timestamp:
                return QVariant(origin_server_ts(event));
        case Type:
                return QVariant(toRoomEventType(event));
        case TypeString:
                return QVariant(toRoomEventTypeString(event));
        case Body:
                return QVariant(utils::replaceEmoji(QString::fromStdString(body(event))));
        case FormattedBody: {
                const static QRegularExpression replyFallback(
                  "<mx-reply>.*</mx-reply>", QRegularExpression::DotMatchesEverythingOption);

                bool isReply = !in_reply_to_event(event).empty();

                auto formattedBody_ = QString::fromStdString(formatted_body(event));
                if (formattedBody_.isEmpty()) {
                        auto body_ = QString::fromStdString(body(event));

                        if (isReply) {
                                while (body_.startsWith("> "))
                                        body_ = body_.right(body_.size() - body_.indexOf('\n') - 1);
                                if (body_.startsWith('\n'))
                                        body_ = body_.right(body_.size() - 1);
                        }
                        formattedBody_ = body_.toHtmlEscaped().replace('\n', "<br>");
                } else {
                        if (isReply)
                                formattedBody_ = formattedBody_.remove(replyFallback);
                }
                return QVariant(utils::replaceEmoji(
                  utils::linkifyMessage(utils::escapeBlacklistedHtml(formattedBody_))));
        }
        case Url:
                return QVariant(QString::fromStdString(url(event)));
        case ThumbnailUrl:
                return QVariant(QString::fromStdString(thumbnail_url(event)));
        case Blurhash:
                return QVariant(QString::fromStdString(blurhash(event)));
        case Filename:
                return QVariant(QString::fromStdString(filename(event)));
        case Filesize:
                return QVariant(utils::humanReadableFileSize(filesize(event)));
        case MimeType:
                return QVariant(QString::fromStdString(mimetype(event)));
        case Height:
                return QVariant(qulonglong{media_height(event)});
        case Width:
                return QVariant(qulonglong{media_width(event)});
        case ProportionalHeight: {
                auto w = media_width(event);
                if (w == 0)
                        w = 1;

                double prop = media_height(event) / (double)w;

                return QVariant(prop > 0 ? prop : 1.);
        }
        case Id:
                return id;
        case State:
                // only show read receipts for messages not from us
                if (acc::sender(event) != http::client()->user_id().to_string())
                        return qml_mtx_events::Empty;
                else if (pending.contains(id))
                        return qml_mtx_events::Sent;
                else if (read.contains(id) || cache::readReceipts(id, room_id_).size() > 1)
                        return qml_mtx_events::Read;
                else
                        return qml_mtx_events::Received;
        case IsEncrypted: {
                return std::holds_alternative<
                  mtx::events::EncryptedEvent<mtx::events::msg::Encrypted>>(events[id]);
        }
        case ReplyTo:
                return QVariant(QString::fromStdString(in_reply_to_event(event)));
        case RoomId:
                return QVariant(QString::fromStdString(room_id(event)));
        case RoomName:
                return QVariant(QString::fromStdString(room_name(event)));
        case RoomTopic:
                return QVariant(QString::fromStdString(room_topic(event)));
        case Dump: {
                QVariantMap m;
                auto names = roleNames();

                // m.insert(names[Section], data(id, static_cast<int>(Section)));
                m.insert(names[Type], data(id, static_cast<int>(Type)));
                m.insert(names[TypeString], data(id, static_cast<int>(TypeString)));
                m.insert(names[Body], data(id, static_cast<int>(Body)));
                m.insert(names[FormattedBody], data(id, static_cast<int>(FormattedBody)));
                m.insert(names[UserId], data(id, static_cast<int>(UserId)));
                m.insert(names[UserName], data(id, static_cast<int>(UserName)));
                m.insert(names[Timestamp], data(id, static_cast<int>(Timestamp)));
                m.insert(names[Url], data(id, static_cast<int>(Url)));
                m.insert(names[ThumbnailUrl], data(id, static_cast<int>(ThumbnailUrl)));
                m.insert(names[Blurhash], data(id, static_cast<int>(Blurhash)));
                m.insert(names[Filename], data(id, static_cast<int>(Filename)));
                m.insert(names[Filesize], data(id, static_cast<int>(Filesize)));
                m.insert(names[MimeType], data(id, static_cast<int>(MimeType)));
                m.insert(names[Height], data(id, static_cast<int>(Height)));
                m.insert(names[Width], data(id, static_cast<int>(Width)));
                m.insert(names[ProportionalHeight], data(id, static_cast<int>(ProportionalHeight)));
                m.insert(names[Id], data(id, static_cast<int>(Id)));
                m.insert(names[State], data(id, static_cast<int>(State)));
                m.insert(names[IsEncrypted], data(id, static_cast<int>(IsEncrypted)));
                m.insert(names[ReplyTo], data(id, static_cast<int>(ReplyTo)));
                m.insert(names[RoomName], data(id, static_cast<int>(RoomName)));
                m.insert(names[RoomTopic], data(id, static_cast<int>(RoomTopic)));

                return QVariant(m);
        }
        default:
                return QVariant();
        }
}

QVariant
TimelineModel::data(const QModelIndex &index, int role) const
{
        using namespace mtx::accessors;
        namespace acc = mtx::accessors;
        if (index.row() < 0 && index.row() >= (int)eventOrder.size())
                return QVariant();

        QString id = eventOrder[index.row()];

        mtx::events::collections::TimelineEvents event = events.value(id);

        if (role == Section) {
                QDateTime date = origin_server_ts(event);
                date.setTime(QTime());

                std::string userId = acc::sender(event);

                for (size_t r = index.row() + 1; r < eventOrder.size(); r++) {
                        auto tempEv        = events.value(eventOrder[r]);
                        QDateTime prevDate = origin_server_ts(tempEv);
                        prevDate.setTime(QTime());
                        if (prevDate != date)
                                return QString("%2 %1")
                                  .arg(date.toMSecsSinceEpoch())
                                  .arg(QString::fromStdString(userId));

                        std::string prevUserId = acc::sender(tempEv);
                        if (userId != prevUserId)
                                break;
                }

                return QString("%1").arg(QString::fromStdString(userId));
        }

        return data(id, role);
}

bool
TimelineModel::canFetchMore(const QModelIndex &) const
{
        if (eventOrder.empty())
                return true;
        if (!std::holds_alternative<mtx::events::StateEvent<mtx::events::state::Create>>(
              events[eventOrder.back()]))
                return true;
        else

                return false;
}

void
TimelineModel::fetchMore(const QModelIndex &)
{
        if (paginationInProgress) {
                nhlog::ui()->warn("Already loading older messages");
                return;
        }

        paginationInProgress = true;
        mtx::http::MessagesOpts opts;
        opts.room_id = room_id_.toStdString();
        opts.from    = prev_batch_token_.toStdString();

        nhlog::ui()->debug("Paginating room {}", opts.room_id);

        http::client()->messages(
          opts, [this, opts](const mtx::responses::Messages &res, mtx::http::RequestErr err) {
                  if (err) {
                          nhlog::net()->error("failed to call /messages ({}): {} - {} - {}",
                                              opts.room_id,
                                              mtx::errors::to_string(err->matrix_error.errcode),
                                              err->matrix_error.error,
                                              err->parse_error);
                          paginationInProgress = false;
                          return;
                  }

                  emit oldMessagesRetrieved(std::move(res));
                  paginationInProgress = false;
          });
}

void
TimelineModel::addEvents(const mtx::responses::Timeline &timeline)
{
        if (isInitialSync) {
                prev_batch_token_ = QString::fromStdString(timeline.prev_batch);
                isInitialSync     = false;
        }

        if (timeline.events.empty())
                return;

        std::vector<QString> ids = internalAddEvents(timeline.events);

        if (ids.empty())
                return;

        beginInsertRows(QModelIndex(), 0, static_cast<int>(ids.size() - 1));
        this->eventOrder.insert(this->eventOrder.begin(), ids.rbegin(), ids.rend());
        endInsertRows();

        updateLastMessage();
}

template<typename T>
auto
isMessage(const mtx::events::RoomEvent<T> &e)
  -> std::enable_if_t<std::is_same<decltype(e.content.msgtype), std::string>::value, bool>
{
        return true;
}

template<typename T>
auto
isMessage(const mtx::events::Event<T> &)
{
        return false;
}

void
TimelineModel::updateLastMessage()
{
        for (auto it = eventOrder.begin(); it != eventOrder.end(); ++it) {
                auto event = events.value(*it);
                if (auto e = std::get_if<mtx::events::EncryptedEvent<mtx::events::msg::Encrypted>>(
                      &event)) {
                        event = decryptEvent(*e).event;
                }

                if (!std::visit([](const auto &e) -> bool { return isMessage(e); }, event))
                        continue;

                auto description = utils::getMessageDescription(
                  event, QString::fromStdString(http::client()->user_id().to_string()), room_id_);
                emit manager_->updateRoomsLastMessage(room_id_, description);
                return;
        }
}

std::vector<QString>
TimelineModel::internalAddEvents(
  const std::vector<mtx::events::collections::TimelineEvents> &timeline)
{
        std::vector<QString> ids;
        for (auto e : timeline) {
                QString id = QString::fromStdString(mtx::accessors::event_id(e));

                if (this->events.contains(id)) {
                        this->events.insert(id, e);
                        int idx = idToIndex(id);
                        emit dataChanged(index(idx, 0), index(idx, 0));
                        continue;
                }

                QString txid = QString::fromStdString(mtx::accessors::transaction_id(e));
                if (this->pending.removeOne(txid)) {
                        this->events.insert(id, e);
                        this->events.remove(txid);
                        int idx = idToIndex(txid);
                        if (idx < 0) {
                                nhlog::ui()->warn("Received index out of range");
                                continue;
                        }
                        eventOrder[idx] = id;
                        emit dataChanged(index(idx, 0), index(idx, 0));
                        continue;
                }

                if (auto redaction =
                      std::get_if<mtx::events::RedactionEvent<mtx::events::msg::Redaction>>(&e)) {
                        QString redacts = QString::fromStdString(redaction->redacts);
                        auto redacted   = std::find(eventOrder.begin(), eventOrder.end(), redacts);

                        if (redacted != eventOrder.end()) {
                                auto redactedEvent = std::visit(
                                  [](const auto &ev)
                                    -> mtx::events::RoomEvent<mtx::events::msg::Redacted> {
                                          mtx::events::RoomEvent<mtx::events::msg::Redacted>
                                            replacement                = {};
                                          replacement.event_id         = ev.event_id;
                                          replacement.room_id          = ev.room_id;
                                          replacement.sender           = ev.sender;
                                          replacement.origin_server_ts = ev.origin_server_ts;
                                          replacement.type             = ev.type;
                                          return replacement;
                                  },
                                  e);
                                events.insert(redacts, redactedEvent);

                                int row = (int)std::distance(eventOrder.begin(), redacted);
                                emit dataChanged(index(row, 0), index(row, 0));
                        }

                        continue; // don't insert redaction into timeline
                }

                if (auto event =
                      std::get_if<mtx::events::EncryptedEvent<mtx::events::msg::Encrypted>>(&e)) {
                        auto e_      = decryptEvent(*event).event;
                        auto encInfo = mtx::accessors::file(e_);

                        if (encInfo)
                                emit newEncryptedImage(encInfo.value());
                }

                this->events.insert(id, e);
                ids.push_back(id);

                auto replyTo  = mtx::accessors::in_reply_to_event(e);
                auto qReplyTo = QString::fromStdString(replyTo);
                if (!replyTo.empty() && !events.contains(qReplyTo)) {
                        http::client()->get_event(
                          this->room_id_.toStdString(),
                          replyTo,
                          [this, id, replyTo](
                            const mtx::events::collections::TimelineEvents &timeline,
                            mtx::http::RequestErr err) {
                                  if (err) {
                                          nhlog::net()->error(
                                            "Failed to retrieve event with id {}, which was "
                                            "requested to show the replyTo for event {}",
                                            replyTo,
                                            id.toStdString());
                                          return;
                                  }
                                  emit eventFetched(id, timeline);
                          });
                }
        }
        return ids;
}

void
TimelineModel::setCurrentIndex(int index)
{
        auto oldIndex = idToIndex(currentId);
        currentId     = indexToId(index);
        emit currentIndexChanged(index);

        if ((oldIndex > index || oldIndex == -1) && !pending.contains(currentId) &&
            ChatPage::instance()->isActiveWindow()) {
                readEvent(currentId.toStdString());
        }
}

void
TimelineModel::readEvent(const std::string &id)
{
        http::client()->read_event(room_id_.toStdString(), id, [this](mtx::http::RequestErr err) {
                if (err) {
                        nhlog::net()->warn("failed to read_event ({}, {})",
                                           room_id_.toStdString(),
                                           currentId.toStdString());
                }
        });
}

void
TimelineModel::addBackwardsEvents(const mtx::responses::Messages &msgs)
{
        std::vector<QString> ids = internalAddEvents(msgs.chunk);

        if (!ids.empty()) {
                beginInsertRows(QModelIndex(),
                                static_cast<int>(this->eventOrder.size()),
                                static_cast<int>(this->eventOrder.size() + ids.size() - 1));
                this->eventOrder.insert(this->eventOrder.end(), ids.begin(), ids.end());
                endInsertRows();
        }

        prev_batch_token_ = QString::fromStdString(msgs.end);
}

QString
TimelineModel::displayName(QString id) const
{
        return cache::displayName(room_id_, id).toHtmlEscaped();
}

QString
TimelineModel::avatarUrl(QString id) const
{
        return cache::avatarUrl(room_id_, id);
}

QString
TimelineModel::formatDateSeparator(QDate date) const
{
        auto now = QDateTime::currentDateTime();

        QString fmt = QLocale::system().dateFormat(QLocale::LongFormat);

        if (now.date().year() == date.year()) {
                QRegularExpression rx("[^a-zA-Z]*y+[^a-zA-Z]*");
                fmt = fmt.remove(rx);
        }

        return date.toString(fmt);
}

QString
TimelineModel::escapeEmoji(QString str) const
{
        return utils::replaceEmoji(str);
}

void
TimelineModel::viewRawMessage(QString id) const
{
        std::string ev = utils::serialize_event(events.value(id)).dump(4);
        auto dialog    = new dialogs::RawMessage(QString::fromStdString(ev));
        Q_UNUSED(dialog);
}

void

TimelineModel::openUserProfile(QString userid) const
{
        MainWindow::instance()->openUserProfile(userid, room_id_);
}

DecryptionResult
TimelineModel::decryptEvent(const mtx::events::EncryptedEvent<mtx::events::msg::Encrypted> &e) const
{
        static QCache<std::string, DecryptionResult> decryptedEvents{300};

        if (auto cachedEvent = decryptedEvents.object(e.event_id))
                return *cachedEvent;

        MegolmSessionIndex index;
        index.room_id    = room_id_.toStdString();
        index.session_id = e.content.session_id;
        index.sender_key = e.content.sender_key;

        mtx::events::RoomEvent<mtx::events::msg::Notice> dummy;
        dummy.origin_server_ts = e.origin_server_ts;
        dummy.event_id         = e.event_id;
        dummy.sender           = e.sender;
        dummy.content.body =
          tr("-- Encrypted Event (No keys found for decryption) --",
             "Placeholder, when the message was not decrypted yet or can't be decrypted.")
            .toStdString();

        try {
                if (!cache::inboundMegolmSessionExists(index)) {
                        nhlog::crypto()->info("Could not find inbound megolm session ({}, {}, {})",
                                              index.room_id,
                                              index.session_id,
                                              e.sender);
                        // TODO: request megolm session_id & session_key from the sender.
                        decryptedEvents.insert(
                          dummy.event_id, new DecryptionResult{dummy, false}, 1);
                        return {dummy, false};
                }
        } catch (const lmdb::error &e) {
                nhlog::db()->critical("failed to check megolm session's existence: {}", e.what());
                dummy.content.body = tr("-- Decryption Error (failed to communicate with DB) --",
                                        "Placeholder, when the message can't be decrypted, because "
                                        "the DB access failed when trying to lookup the session.")
                                       .toStdString();
                decryptedEvents.insert(dummy.event_id, new DecryptionResult{dummy, false}, 1);
                return {dummy, false};
        }

        std::string msg_str;
        try {
                auto session = cache::getInboundMegolmSession(index);
                auto res     = olm::client()->decrypt_group_message(session, e.content.ciphertext);
                msg_str      = std::string((char *)res.data.data(), res.data.size());
        } catch (const lmdb::error &e) {
                nhlog::db()->critical("failed to retrieve megolm session with index ({}, {}, {})",
                                      index.room_id,
                                      index.session_id,
                                      index.sender_key,
                                      e.what());
                dummy.content.body =
                  tr("-- Decryption Error (failed to retrieve megolm keys from db) --",
                     "Placeholder, when the message can't be decrypted, because the DB access "
                     "failed.")
                    .toStdString();
                decryptedEvents.insert(dummy.event_id, new DecryptionResult{dummy, false}, 1);
                return {dummy, false};
        } catch (const mtx::crypto::olm_exception &e) {
                nhlog::crypto()->critical("failed to decrypt message with index ({}, {}, {}): {}",
                                          index.room_id,
                                          index.session_id,
                                          index.sender_key,
                                          e.what());
                dummy.content.body =
                  tr("-- Decryption Error (%1) --",
                     "Placeholder, when the message can't be decrypted. In this case, the Olm "
                     "decrytion returned an error, which is passed ad %1.")
                    .arg(e.what())
                    .toStdString();
                decryptedEvents.insert(dummy.event_id, new DecryptionResult{dummy, false}, 1);
                return {dummy, false};
        }

        // Add missing fields for the event.
        json body                = json::parse(msg_str);
        body["event_id"]         = e.event_id;
        body["sender"]           = e.sender;
        body["origin_server_ts"] = e.origin_server_ts;
        body["unsigned"]         = e.unsigned_data;

        // relations are unencrypted in content...
        if (json old_ev = e; old_ev["content"].count("m.relates_to") != 0)
                body["content"]["m.relates_to"] = old_ev["content"]["m.relates_to"];

        json event_array = json::array();
        event_array.push_back(body);

        std::vector<mtx::events::collections::TimelineEvents> temp_events;
        mtx::responses::utils::parse_timeline_events(event_array, temp_events);

        if (temp_events.size() == 1) {
                decryptedEvents.insert(e.event_id, new DecryptionResult{temp_events[0], true}, 1);
                return {temp_events[0], true};
        }

        dummy.content.body =
          tr("-- Encrypted Event (Unknown event type) --",
             "Placeholder, when the message was decrypted, but we couldn't parse it, because "
             "Nheko/mtxclient don't support that event type yet.")
            .toStdString();
        decryptedEvents.insert(dummy.event_id, new DecryptionResult{dummy, false}, 1);
        return {dummy, false};
}

void
TimelineModel::replyAction(QString id)
{
        setReply(id);
        ChatPage::instance()->focusMessageInput();
}

RelatedInfo
TimelineModel::relatedInfo(QString id)
{
        if (!events.contains(id))
                return {};

        auto event = events.value(id);
        if (auto e =
              std::get_if<mtx::events::EncryptedEvent<mtx::events::msg::Encrypted>>(&event)) {
                event = decryptEvent(*e).event;
        }

        RelatedInfo related           = {};
        related.quoted_user           = QString::fromStdString(mtx::accessors::sender(event));
        related.related_event         = mtx::accessors::event_id(event);
        related.type                  = mtx::accessors::msg_type(event);
        related.quoted_body           = QString::fromStdString(mtx::accessors::body(event));
        related.quoted_body           = utils::getQuoteBody(related);
        related.quoted_formatted_body = mtx::accessors::formattedBodyWithFallback(event);
        related.quoted_formatted_body.remove(QRegularExpression(
          "<mx-reply>.*</mx-reply>", QRegularExpression::DotMatchesEverythingOption));
        related.room = room_id_;

        return related;
}

void
TimelineModel::readReceiptsAction(QString id) const
{
        MainWindow::instance()->openReadReceiptsDialog(id);
}

void
TimelineModel::redactEvent(QString id)
{
        if (!id.isEmpty())
                http::client()->redact_event(
                  room_id_.toStdString(),
                  id.toStdString(),
                  [this, id](const mtx::responses::EventId &, mtx::http::RequestErr err) {
                          if (err) {
                                  emit redactionFailed(
                                    tr("Message redaction failed: %1")
                                      .arg(QString::fromStdString(err->matrix_error.error)));
                                  return;
                          }

                          emit eventRedacted(id);
                  });
}

int
TimelineModel::idToIndex(QString id) const
{
        if (id.isEmpty())
                return -1;
        for (int i = 0; i < (int)eventOrder.size(); i++)
                if (id == eventOrder[i])
                        return i;
        return -1;
}

QString
TimelineModel::indexToId(int index) const
{
        if (index < 0 || index >= (int)eventOrder.size())
                return "";
        return eventOrder[index];
}

// Note: this will only be called for our messages
void
TimelineModel::markEventsAsRead(const std::vector<QString> &event_ids)
{
        for (const auto &id : event_ids) {
                read.insert(id);
                int idx = idToIndex(id);
                if (idx < 0) {
                        nhlog::ui()->warn("Read index out of range");
                        return;
                }
                emit dataChanged(index(idx, 0), index(idx, 0));
        }
}

void
TimelineModel::sendEncryptedMessage(const std::string &txn_id, nlohmann::json content)
{
        const auto room_id = room_id_.toStdString();

        using namespace mtx::events;
        using namespace mtx::identifiers;

        json doc = {{"type", "m.room.message"}, {"content", content}, {"room_id", room_id}};

        try {
                // Check if we have already an outbound megolm session then we can use.
                if (cache::outboundMegolmSessionExists(room_id)) {
                        auto data =
                          olm::encrypt_group_message(room_id, http::client()->device_id(), doc);

                        http::client()->send_room_message<msg::Encrypted, EventType::RoomEncrypted>(
                          room_id,
                          txn_id,
                          data,
                          [this, txn_id](const mtx::responses::EventId &res,
                                         mtx::http::RequestErr err) {
                                  if (err) {
                                          const int status_code =
                                            static_cast<int>(err->status_code);
                                          nhlog::net()->warn("[{}] failed to send message: {} {}",
                                                             txn_id,
                                                             err->matrix_error.error,
                                                             status_code);
                                          emit messageFailed(QString::fromStdString(txn_id));
                                  }
                                  emit messageSent(
                                    QString::fromStdString(txn_id),
                                    QString::fromStdString(res.event_id.to_string()));
                          });
                        return;
                }

                nhlog::ui()->debug("creating new outbound megolm session");

                // Create a new outbound megolm session.
                auto outbound_session  = olm::client()->init_outbound_group_session();
                const auto session_id  = mtx::crypto::session_id(outbound_session.get());
                const auto session_key = mtx::crypto::session_key(outbound_session.get());

                // TODO: needs to be moved in the lib.
                auto megolm_payload = json{{"algorithm", "m.megolm.v1.aes-sha2"},
                                           {"room_id", room_id},
                                           {"session_id", session_id},
                                           {"session_key", session_key}};

                // Saving the new megolm session.
                // TODO: Maybe it's too early to save.
                OutboundGroupSessionData session_data;
                session_data.session_id    = session_id;
                session_data.session_key   = session_key;
                session_data.message_index = 0; // TODO Update me
                cache::saveOutboundMegolmSession(
                  room_id, session_data, std::move(outbound_session));

                const auto members = cache::roomMembers(room_id);
                nhlog::ui()->info("retrieved {} members for {}", members.size(), room_id);

                auto keeper =
                  std::make_shared<StateKeeper>([megolm_payload, room_id, doc, txn_id, this]() {
                          try {
                                  auto data = olm::encrypt_group_message(
                                    room_id, http::client()->device_id(), doc);

                                  http::client()
                                    ->send_room_message<msg::Encrypted, EventType::RoomEncrypted>(
                                      room_id,
                                      txn_id,
                                      data,
                                      [this, txn_id](const mtx::responses::EventId &res,
                                                     mtx::http::RequestErr err) {
                                              if (err) {
                                                      const int status_code =
                                                        static_cast<int>(err->status_code);
                                                      nhlog::net()->warn(
                                                        "[{}] failed to send message: {} {}",
                                                        txn_id,
                                                        err->matrix_error.error,
                                                        status_code);
                                                      emit messageFailed(
                                                        QString::fromStdString(txn_id));
                                              }
                                              emit messageSent(
                                                QString::fromStdString(txn_id),
                                                QString::fromStdString(res.event_id.to_string()));
                                      });
                          } catch (const lmdb::error &e) {
                                  nhlog::db()->critical(
                                    "failed to save megolm outbound session: {}", e.what());
                                  emit messageFailed(QString::fromStdString(txn_id));