Better chats list entries management.

Make unread counts and last message base::optional<>.
Remove ChannelHistory.

Telegram/Resources/langs/lang.strings

@@ -1420,6 +1420,8 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 "lng_feed_group" = "Group in feed";
 "lng_feed_ungroup" = "Ungroup from feed";
+"lng_feed_channel_added" = "Channel added to your feed.";
+"lng_feed_channel_removed" = "Channel removed from your feed.";
 
 "lng_info_feed_title" = "Feed Info";
 

Telegram/SourceFiles/apiwrap.cpp

@@ -172,9 +172,10 @@ void ApiWrap::savePinnedOrder() {
 
 void ApiWrap::toggleChannelGrouping(
 		not_null<ChannelData*> channel,
-		bool group) {
+		bool group,
+		base::lambda<void()> callback) {
 	if (const auto already = _channelGroupingRequests.take(channel)) {
-		request(*already).cancel();
+		request(already->first).cancel();
 	}
 	const auto feedId = Data::Feed::kId;
 	const auto flags = group
@@ -185,15 +186,18 @@ void ApiWrap::toggleChannelGrouping(
 		channel->inputChannel,
 		MTP_int(feedId)
 	)).done([=](const MTPBool &result) {
-		_channelGroupingRequests.remove(channel);
 		if (group) {
 			channel->setFeed(Auth().data().feed(feedId));
 		} else {
 			channel->clearFeed();
 		}
+		if (const auto data = _channelGroupingRequests.take(channel)) {
+			data->second();
+		}
 	}).fail([=](const RPCError &error) {
 		_channelGroupingRequests.remove(channel);
 	}).send();
+	_channelGroupingRequests.emplace(channel, requestId, callback);
 }
 
 void ApiWrap::sendMessageFail(const RPCError &error) {
@@ -362,6 +366,124 @@ void ApiWrap::requestContacts() {
 	}).send();
 }
 
+void ApiWrap::requestDialogEntry(not_null<Data::Feed*> feed) {
+	if (_dialogFeedRequests.contains(feed)) {
+		return;
+	}
+	_dialogFeedRequests.emplace(feed);
+
+	auto peers = QVector<MTPInputDialogPeer>(
+		1,
+		MTP_inputDialogPeerFeed(MTP_int(feed->id())));
+	if (feed->channelsLoaded()) {
+		const auto &channels = feed->channels();
+		peers.reserve(channels.size() + 1);
+		for (const auto history : feed->channels()) {
+			peers.push_back(MTP_inputDialogPeer(history->peer->input));
+		}
+	} else {
+		request(MTPmessages_GetDialogs(
+			MTP_flags(MTPmessages_GetDialogs::Flag::f_feed_id),
+			MTP_int(feed->id()),
+			MTP_int(0), // offset_date
+			MTP_int(0), // offset_id
+			MTP_inputPeerEmpty(), // offset_peer
+			MTP_int(Data::Feed::kChannelsLimit)
+		)).done([=](const MTPmessages_Dialogs &result) {
+		//	applyFeedChannels(result);
+		}).send();
+	}
+	request(MTPmessages_GetPeerDialogs(
+		MTP_vector(std::move(peers))
+	)).done([=](const MTPmessages_PeerDialogs &result) {
+		applyPeerDialogs(result);
+		_dialogFeedRequests.remove(feed);
+	}).fail([=](const RPCError &error) {
+		_dialogFeedRequests.remove(feed);
+	}).send();
+}
+
+void ApiWrap::requestDialogEntry(not_null<History*> history) {
+	if (_dialogRequests.contains(history)) {
+		return;
+	}
+	_dialogRequests.emplace(history);
+	auto peers = QVector<MTPInputDialogPeer>(
+		1,
+		MTP_inputDialogPeer(history->peer->input));
+	request(MTPmessages_GetPeerDialogs(
+		MTP_vector(std::move(peers))
+	)).done([=](const MTPmessages_PeerDialogs &result) {
+		applyPeerDialogs(result);
+
+		if (history->lastMessage()) {
+			if (!history->chatsListDate().isNull()
+				&& history->loadedAtBottom()) {
+				if (const auto channel = history->peer->asChannel()) {
+					const auto inviter = channel->inviter;
+					if (inviter != 0
+						&& history->chatsListDate() <= channel->inviteDate
+						&& channel->amIn()) {
+						if (const auto from = App::userLoaded(inviter)) {
+							history->insertJoinedMessage(true);
+						}
+					}
+				}
+			}
+			history->updateChatListExistence();
+		} else {
+			if (const auto chat = history->peer->asChat()) {
+				if (!chat->haveLeft()) {
+					Local::addSavedPeer(
+						history->peer,
+						history->chatsListDate());
+				}
+			} else if (const auto channel = history->peer->asChannel()) {
+				const auto inviter = channel->inviter;
+				if (inviter != 0 && channel->amIn()) {
+					if (const auto from = App::userLoaded(inviter)) {
+						history->unloadBlocks();
+						history->addNewerSlice(QVector<MTPMessage>());
+						history->insertJoinedMessage(
+							true);
+					}
+				}
+			} else {
+				App::main()->deleteConversation(history->peer, false);
+			}
+		}
+		_dialogRequests.remove(history);
+	}).fail([=](const RPCError &error) {
+		_dialogRequests.remove(history);
+	}).send();
+}
+
+void ApiWrap::applyPeerDialogs(const MTPmessages_PeerDialogs &dialogs) {
+	Expects(dialogs.type() == mtpc_messages_peerDialogs);
+
+	const auto &data = dialogs.c_messages_peerDialogs();
+	App::feedUsers(data.vusers);
+	App::feedChats(data.vchats);
+	App::feedMsgs(data.vmessages, NewMessageLast);
+	for (const auto &dialog : data.vdialogs.v) {
+		switch (dialog.type()) {
+		case mtpc_dialog: {
+			const auto &fields = dialog.c_dialog();
+			if (const auto peerId = peerFromMTP(fields.vpeer)) {
+				App::history(peerId)->applyDialog(fields);
+			}
+		} break;
+
+		case mtpc_dialogFeed: {
+			const auto &fields = dialog.c_dialogFeed();
+			const auto feed = Auth().data().feed(fields.vfeed_id.v);
+			feed->applyDialog(fields);
+		} break;
+		}
+	}
+	_session->data().sendHistoryChangeNotifications();
+}
+
 void ApiWrap::requestFullPeer(PeerData *peer) {
 	if (!peer || _fullPeerRequests.contains(peer)) return;
 
@@ -464,7 +586,7 @@ void ApiWrap::gotChatFull(PeerData *peer, const MTPmessages_ChatFull &result, mt
 				if (auto h = App::historyLoaded(cfrom->id)) {
 					if (auto hto = App::historyLoaded(channel->id)) {
 						if (!h->isEmpty()) {
-							h->clear(true);
+							h->unloadBlocks();
 						}
 						if (hto->inChatList(Dialogs::Mode::All) && h->inChatList(Dialogs::Mode::All)) {
 							App::main()->removeDialog(h);
@@ -495,14 +617,12 @@ void ApiWrap::gotChatFull(PeerData *peer, const MTPmessages_ChatFull &result, mt
 		channel->setRestrictedCount(f.has_banned_count() ? f.vbanned_count.v : 0);
 		channel->setKickedCount(f.has_kicked_count() ? f.vkicked_count.v : 0);
 		channel->setInviteLink((f.vexported_invite.type() == mtpc_chatInviteExported) ? qs(f.vexported_invite.c_chatInviteExported().vlink) : QString());
-		if (auto h = App::historyLoaded(channel->id)) {
+		if (const auto history = App::historyLoaded(channel->id)) {
-			if (h->inboxReadBefore < f.vread_inbox_max_id.v + 1) {
+			history->applyDialogFields(
-				h->setUnreadCount(f.vunread_count.v);
+				f.vunread_count.v,
-				h->inboxReadBefore = f.vread_inbox_max_id.v + 1;
+				f.vread_inbox_max_id.v,
+				f.vread_outbox_max_id.v);
 		}
-			accumulate_max(h->outboxReadBefore, f.vread_outbox_max_id.v + 1);
-		}
-		ranges::overload([] {}, [](int a) {});
 		if (f.has_pinned_msg_id()) {
 			channel->setPinnedMessageId(f.vpinned_msg_id.v);
 		} else {
@@ -1063,7 +1183,9 @@ void ApiWrap::unblockParticipant(
 		not_null<ChannelData*> channel,
 		not_null<UserData*> user) {
 	const auto kick = KickRequest(channel, user);
-	if (_kickRequests.contains(kick)) return;
+	if (_kickRequests.contains(kick)) {
+		return;
+	}
 
 	const auto requestId = request(MTPchannels_EditBanned(
 		channel->inputChannel,
@@ -1085,6 +1207,43 @@ void ApiWrap::unblockParticipant(
 	_kickRequests.emplace(kick, requestId);
 }
 
+void ApiWrap::deleteAllFromUser(
+		not_null<ChannelData*> channel,
+		not_null<UserData*> from) {
+	const auto history = App::historyLoaded(channel->id);
+	const auto ids = history
+		? history->collectMessagesFromUserToDelete(from)
+		: QVector<MsgId>();
+	const auto channelId = peerToChannel(channel->id);
+	for (const auto msgId : ids) {
+		if (const auto item = App::histItemById(channelId, msgId)) {
+			item->destroy();
+		}
+	}
+
+	Auth().data().sendHistoryChangeNotifications();
+
+	deleteAllFromUserSend(channel, from);
+}
+
+void ApiWrap::deleteAllFromUserSend(
+		not_null<ChannelData*> channel,
+		not_null<UserData*> from) {
+	request(MTPchannels_DeleteUserHistory(
+		channel->inputChannel,
+		from->inputUser
+	)).done([=](const MTPmessages_AffectedHistory &result) {
+		const auto offset = applyAffectedHistory(channel, result);
+		if (offset > 0) {
+			deleteAllFromUserSend(channel, from);
+		} else if (const auto history = App::historyLoaded(channel)) {
+			if (!history->lastMessageKnown()) {
+				Auth().api().requestDialogEntry(history);
+			}
+		}
+	}).send();
+}
+
 void ApiWrap::requestChannelMembersForAdd(
 		not_null<ChannelData*> channel,
 		base::lambda<void(const MTPchannels_ChannelParticipants&)> callback) {
@@ -1505,23 +1664,23 @@ int ApiWrap::onlineTillFromStatus(const MTPUserStatus &status, int currentOnline
 }
 
 void ApiWrap::clearHistory(not_null<PeerData*> peer) {
-	auto lastMsgId = MsgId(0);
+	auto deleteTillId = MsgId(0);
 	if (auto history = App::historyLoaded(peer->id)) {
-		if (history->lastMsg) {
+		if (const auto last = history->lastMessage()) {
-			lastMsgId = history->lastMsg->id;
+			deleteTillId = last->id;
-			Local::addSavedPeer(history->peer, history->lastMsg->date);
+			Local::addSavedPeer(history->peer, last->date);
 		}
 		history->clear();
 		history->newLoaded = history->oldLoaded = true;
 	}
-	if (auto channel = peer->asChannel()) {
+	if (const auto channel = peer->asChannel()) {
-		if (auto migrated = peer->migrateFrom()) {
+		if (const auto migrated = peer->migrateFrom()) {
 			clearHistory(migrated);
 		}
-		if (IsServerMsgId(lastMsgId)) {
+		if (IsServerMsgId(deleteTillId)) {
 			request(MTPchannels_DeleteHistory(
 				channel->inputChannel,
-				MTP_int(lastMsgId)
+				MTP_int(deleteTillId)
 			)).send();
 		}
 	} else {
@@ -1530,7 +1689,7 @@ void ApiWrap::clearHistory(not_null<PeerData*> peer) {
 			peer->input,
 			MTP_int(0)
 		)).done([=](const MTPmessages_AffectedHistory &result) {
-			auto offset = applyAffectedHistory(peer, result);
+			const auto offset = applyAffectedHistory(peer, result);
 			if (offset > 0) {
 				clearHistory(peer);
 			}
@@ -1775,6 +1934,94 @@ void ApiWrap::requestParticipantsCountDelayed(
 		[this, channel] { channel->updateFullForced(); });
 }
 
+void ApiWrap::requestChannelRangeDifference(not_null<History*> history) {
+	Expects(history->isChannel());
+
+	const auto channel = history->peer->asChannel();
+	if (const auto requestId = _rangeDifferenceRequests.take(channel)) {
+		request(*requestId).cancel();
+	}
+	const auto range = history->rangeForDifferenceRequest();
+	if (!(range.from < range.till) || !channel->pts()) {
+		return;
+	}
+
+	MTP_LOG(0, ("getChannelDifference { good - "
+		"after channelDifferenceTooLong was received, "
+		"validating history part }%1").arg(cTestMode() ? " TESTMODE" : ""));
+	channelRangeDifferenceSend(channel, range, channel->pts());
+}
+
+void ApiWrap::channelRangeDifferenceSend(
+		not_null<ChannelData*> channel,
+		MsgRange range,
+		int32 pts) {
+	Expects(range.from < range.till);
+
+	const auto limit = range.till - range.from;
+	const auto filter = MTP_channelMessagesFilter(
+		MTP_flags(0),
+		MTP_vector<MTPMessageRange>(1, MTP_messageRange(
+			MTP_int(range.from),
+			MTP_int(range.till - 1))));
+	const auto requestId = request(MTPupdates_GetChannelDifference(
+		MTP_flags(MTPupdates_GetChannelDifference::Flag::f_force),
+		channel->inputChannel,
+		filter,
+		MTP_int(pts),
+		MTP_int(limit)
+	)).done([=](const MTPupdates_ChannelDifference &result) {
+		_rangeDifferenceRequests.remove(channel);
+		channelRangeDifferenceDone(channel, range, result);
+	}).fail([=](const RPCError &error) {
+		_rangeDifferenceRequests.remove(channel);
+	}).send();
+	_rangeDifferenceRequests.emplace(channel, requestId);
+}
+
+void ApiWrap::channelRangeDifferenceDone(
+		not_null<ChannelData*> channel,
+		MsgRange range,
+		const MTPupdates_ChannelDifference &result) {
+	auto nextRequestPts = int32(0);
+	auto isFinal = true;
+
+	switch (result.type()) {
+	case mtpc_updates_channelDifferenceEmpty: {
+		const auto &d = result.c_updates_channelDifferenceEmpty();
+		nextRequestPts = d.vpts.v;
+		isFinal = d.is_final();
+	} break;
+
+	case mtpc_updates_channelDifferenceTooLong: {
+		const auto &d = result.c_updates_channelDifferenceTooLong();
+
+		App::feedUsers(d.vusers);
+		App::feedChats(d.vchats);
+
+		nextRequestPts = d.vpts.v;
+		isFinal = d.is_final();
+	} break;
+
+	case mtpc_updates_channelDifference: {
+		const auto &d = result.c_updates_channelDifference();
+
+		App::main()->feedChannelDifference(d);
+
+		nextRequestPts = d.vpts.v;
+		isFinal = d.is_final();
+	} break;
+	}
+
+	if (!isFinal) {
+		MTP_LOG(0, ("getChannelDifference { "
+			"good - after not final channelDifference was received, "
+			"validating history part }%1"
+			).arg(cTestMode() ? " TESTMODE" : ""));
+		channelRangeDifferenceSend(channel, range, nextRequestPts);
+	}
+}
+
 void ApiWrap::gotWebPages(ChannelData *channel, const MTPmessages_Messages &msgs, mtpRequestId req) {
 	const QVector<MTPMessage> *v = 0;
 	switch (msgs.type()) {
@@ -3438,7 +3685,11 @@ void ApiWrap::readServerHistory(not_null<History*> history) {
 
 void ApiWrap::readServerHistoryForce(not_null<History*> history) {
 	const auto peer = history->peer;
-	const auto upTo = history->inboxRead(0);
+	const auto upTo = history->readInbox();
+	if (!upTo) {
+		return;
+	}
+
 	if (const auto channel = peer->asChannel()) {
 		if (!channel->amIn()) {
 			return; // no read request for channels that I didn't join

Telegram/SourceFiles/apiwrap.h

@@ -56,7 +56,10 @@ public:
 	void applyUpdates(const MTPUpdates &updates, uint64 sentMessageRandomId = 0);
 
 	void savePinnedOrder();
-	void toggleChannelGrouping(not_null<ChannelData*> channel, bool group);
+	void toggleChannelGrouping(
+		not_null<ChannelData*> channel,
+		bool group,
+		base::lambda<void()> callback);
 
 	using RequestMessageDataCallback = base::lambda<void(ChannelData*, MsgId)>;
 	void requestMessageData(
@@ -65,6 +68,8 @@ public:
 		RequestMessageDataCallback callback);
 
 	void requestContacts();
+	void requestDialogEntry(not_null<Data::Feed*> feed);
+	void requestDialogEntry(not_null<History*> history);
 
 	void requestFullPeer(PeerData *peer);
 	void requestPeer(PeerData *peer);
@@ -73,6 +78,7 @@ public:
 	void requestBots(not_null<ChannelData*> channel);
 	void requestAdmins(not_null<ChannelData*> channel);
 	void requestParticipantsCountDelayed(not_null<ChannelData*> channel);
+	void requestChannelRangeDifference(not_null<History*> history);
 
 	void requestChangelog(
 		const QString &sinceVersion,
@@ -96,6 +102,9 @@ public:
 	void unblockParticipant(
 		not_null<ChannelData*> channel,
 		not_null<UserData*> user);
+	void deleteAllFromUser(
+		not_null<ChannelData*> channel,
+		not_null<UserData*> from);
 
 	void requestWebPageDelayed(WebPageData *page);
 	void clearWebPageRequest(WebPageData *page);
@@ -269,6 +278,7 @@ private:
 
 	QVector<MTPint> collectMessageIds(const MessageDataRequests &requests);
 	MessageDataRequests *messageDataRequests(ChannelData *channel, bool onlyExisting = false);
+	void applyPeerDialogs(const MTPmessages_PeerDialogs &dialogs);
 
 	void gotChatFull(PeerData *peer, const MTPmessages_ChatFull &result, mtpRequestId req);
 	void gotUserFull(UserData *user, const MTPUserFull &result, mtpRequestId req);
@@ -285,10 +295,24 @@ private:
 		int availableCount,
 		const QVector<MTPChannelParticipant> &list);
 	void resolveWebPages();
-	void gotWebPages(ChannelData *channel, const MTPmessages_Messages &result, mtpRequestId req);
+	void gotWebPages(
+		ChannelData *channel,
+		const MTPmessages_Messages &result,
+		mtpRequestId req);
 	void gotStickerSet(uint64 setId, const MTPmessages_StickerSet &result);
 
-	PeerData *notifySettingReceived(MTPInputNotifyPeer peer, const MTPPeerNotifySettings &settings);
+	void channelRangeDifferenceSend(
+		not_null<ChannelData*> channel,
+		MsgRange range,
+		int32 pts);
+	void channelRangeDifferenceDone(
+		not_null<ChannelData*> channel,
+		MsgRange range,
+		const MTPupdates_ChannelDifference &result);
+
+	PeerData *notifySettingReceived(
+		MTPInputNotifyPeer peer,
+		const MTPPeerNotifySettings &settings);
 
 	void stickerSetDisenabled(mtpRequestId requestId);
 	void stickersSaveOrder();
@@ -347,6 +371,11 @@ private:
 	void applyAffectedMessages(
 		not_null<PeerData*> peer,
 		const MTPmessages_AffectedMessages &result);
+
+	void deleteAllFromUserSend(
+		not_null<ChannelData*> channel,
+		not_null<UserData*> from);
+
 	void sendMessageFail(const RPCError &error);
 	void uploadAlbumMedia(
 		not_null<HistoryItem*> item,
@@ -391,7 +420,7 @@ private:
 		const MTPchannels_ChannelParticipants&)> _channelMembersForAddCallback;
 	base::flat_map<
 		not_null<ChannelData*>,
-		mtpRequestId> _channelGroupingRequests;
+		std::pair<mtpRequestId,base::lambda<void()>>> _channelGroupingRequests;
 
 	using KickRequest = std::pair<
 		not_null<ChannelData*>,
@@ -400,6 +429,10 @@ private:
 
 	QMap<ChannelData*, mtpRequestId> _selfParticipantRequests;
 
+	base::flat_map<
+		not_null<ChannelData*>,
+		mtpRequestId> _rangeDifferenceRequests;
+
 	QMap<WebPageData*, mtpRequestId> _webPagesPending;
 	base::Timer _webPagesTimer;
 
@@ -432,6 +465,8 @@ private:
 
 	mtpRequestId _contactsRequestId = 0;
 	mtpRequestId _contactsStatusesRequestId = 0;
+	base::flat_set<not_null<Data::Feed*>> _dialogFeedRequests;
+	base::flat_set<not_null<History*>> _dialogRequests;
 
 	base::flat_map<not_null<History*>, mtpRequestId> _unreadMentionsRequests;
 

Telegram/SourceFiles/app.cpp

@@ -459,7 +459,7 @@ namespace {
 					if (auto h = App::historyLoaded(cdata->id)) {
 						if (auto hto = App::historyLoaded(channel->id)) {
 							if (!h->isEmpty()) {
-								h->clear(true);
+								h->unloadBlocks();
 							}
 							if (hto->inChatList(Dialogs::Mode::All) && h->inChatList(Dialogs::Mode::All)) {
 								App::main()->removeDialog(h);
@@ -1019,7 +1019,7 @@ namespace {
 	}
 
 	void feedInboxRead(const PeerId &peer, MsgId upTo) {
-		if (auto history = App::historyLoaded(peer)) {
+		if (const auto history = App::historyLoaded(peer)) {
 			history->inboxRead(upTo);
 		}
 	}
@@ -1027,17 +1027,8 @@ namespace {
 	void feedOutboxRead(const PeerId &peer, MsgId upTo, TimeId when) {
 		if (auto history = App::historyLoaded(peer)) {
 			history->outboxRead(upTo);
-			if (history->lastMsg
+			if (const auto user = history->peer->asUser()) {
-				&& history->lastMsg->out()
+				user->madeAction(when);
-				&& history->lastMsg->id <= upTo) {
-				if (const auto main = App::main()) {
-					main->repaintDialogRow(history, history->lastMsg->id);
-				}
-			}
-			history->updateChatListEntry();
-
-			if (history->peer->isUser()) {
-				history->peer->asUser()->madeAction(when);
 			}
 		}
 	}
@@ -1055,37 +1046,31 @@ namespace {
 		return &(*i);
 	}
 
-	void feedWereDeleted(ChannelId channelId, const QVector<MTPint> &msgsIds) {
+	void feedWereDeleted(
+			ChannelId channelId,
+			const QVector<MTPint> &msgsIds) {
 		const auto data = fetchMsgsData(channelId, false);
 		if (!data) return;
 
-		const auto channelHistory = (channelId != NoChannel)
+		const auto affectedHistory = (channelId != NoChannel)
-			? App::history(peerFromChannel(channelId))->asChannelHistory()
+			? App::history(peerFromChannel(channelId)).get()
 			: nullptr;
 
-		base::flat_set<not_null<History*>> historiesToCheck;
+		auto historiesToCheck = base::flat_set<not_null<History*>>();
 		for (const auto msgId : msgsIds) {
 			auto j = data->constFind(msgId.v);
 			if (j != data->cend()) {
-				const auto h = (*j)->history();
+				const auto history = (*j)->history();
 				(*j)->destroy();
-				if (!h->lastMsg) {
+				if (!history->lastMessageKnown()) {
-					historiesToCheck.emplace(h);
+					historiesToCheck.emplace(history);
 				}
-			} else {
+			} else if (affectedHistory) {
-				if (channelHistory) {
+				affectedHistory->unknownMessageDeleted(msgId.v);
-					if (channelHistory->unreadCount() > 0
-						&& msgId.v >= channelHistory->inboxReadBefore) {
-						channelHistory->setUnreadCount(
-							channelHistory->unreadCount() - 1);
 			}
 		}
-			}
-		}
-		if (main()) {
 		for (const auto history : historiesToCheck) {
-				main()->checkPeerHistory(history->peer);
+			Auth().api().requestDialogEntry(history);
-			}
 		}
 	}
 
@@ -1222,10 +1207,6 @@ namespace {
 		return ::histories.findOrInsert(peer);
 	}
 
-	not_null<History*> historyFromDialog(const PeerId &peer, int32 unreadCnt, int32 maxInboxRead, int32 maxOutboxRead) {
-		return ::histories.findOrInsert(peer, unreadCnt, maxInboxRead, maxOutboxRead);
-	}
-
 	History *historyLoaded(const PeerId &peer) {
 		if (!peer) {
 			return nullptr;

Telegram/SourceFiles/app.h

@@ -148,7 +148,6 @@ namespace App {
 
 	Histories &histories();
 	not_null<History*> history(const PeerId &peer);
-	not_null<History*> historyFromDialog(const PeerId &peer, int32 unreadCnt, int32 maxInboxRead, int32 maxOutboxRead);
 	History *historyLoaded(const PeerId &peer);
 	HistoryItem *histItemById(ChannelId channelId, MsgId itemId);
 	inline not_null<History*> history(const PeerData *peer) {

Telegram/SourceFiles/boxes/confirm_box.cpp

@@ -568,7 +568,7 @@ void DeleteMessagesBox::deleteAndClear() {
 					MTP_vector<MTPint>(1, MTP_int(_ids[0].msg))));
 		}
 		if (_deleteAll && _deleteAll->checked()) {
-			App::main()->deleteAllFromUser(
+			Auth().api().deleteAllFromUser(
 				_moderateInChannel,
 				_moderateFrom);
 		}
@@ -583,13 +583,13 @@ void DeleteMessagesBox::deleteAndClear() {
 		if (auto item = App::histItemById(itemId)) {
 			auto history = item->history();
 			auto wasOnServer = (item->id > 0);
-			auto wasLast = (history->lastMsg == item);
+			auto wasLast = (history->lastMessage() == item);
 			item->destroy();
 
 			if (wasOnServer) {
 				idsByPeer[history->peer].push_back(MTP_int(itemId.msg));
 			} else if (wasLast) {
-				App::main()->checkPeerHistory(history->peer);
+				Auth().api().requestDialogEntry(history);
 			}
 		}
 	}

Telegram/SourceFiles/boxes/peer_list_controllers.cpp

@@ -372,6 +372,7 @@ std::unique_ptr<PeerListRow> ContactsBoxController::createSearchRow(not_null<Pee
 }
 
 void ContactsBoxController::rowClicked(not_null<PeerListRow*> row) {
+	Auth().api().requestDialogEntry(App::history(row->peer()));
 	Ui::showPeerHistory(row->peer(), ShowAtUnreadMsgId);
 }
 

Telegram/SourceFiles/data/data_feed.cpp

@@ -72,8 +72,10 @@ void Feed::registerOne(not_null<ChannelData*> channel) {
 	if (!base::contains(_channels, history)) {
 		const auto invisible = (_channels.size() < 2);
 		_channels.push_back(history);
-		if (history->lastMsg) {
+		if (history->lastMessageKnown()) {
-			updateLastMessage(history->lastMsg);
+			recountLastMessage();
+		} else if (_channelsLoaded) {
+			_parent->session().api().requestDialogEntry(history);
 		}
 		_parent->session().storage().remove(
 			Storage::FeedMessagesInvalidate(_id));
@@ -96,8 +98,10 @@ void Feed::unregisterOne(not_null<ChannelData*> channel) {
 	if (i != end(_channels)) {
 		const auto visible = (_channels.size() > 1);
 		_channels.erase(i, end(_channels));
-		if (_lastMessage && _lastMessage->history() == history) {
+		if (const auto last = lastMessage()) {
-			messageRemoved(_lastMessage);
+			if (last->history() == history) {
+				recountLastMessage();
+			}
 		}
 		_parent->session().storage().remove(
 			Storage::FeedMessagesRemoveAll(_id, channel->bareId()));
@@ -115,8 +119,10 @@ void Feed::unregisterOne(not_null<ChannelData*> channel) {
 }
 
 void Feed::updateLastMessage(not_null<HistoryItem*> item) {
-	if (justSetLastMessage(item)) {
+	if (justUpdateLastMessage(item)) {
-		setChatsListDate(_lastMessage->date);
+		if (_lastMessage && *_lastMessage) {
+			setChatsListDate((*_lastMessage)->date);
+		}
 	}
 }
 
@@ -207,8 +213,11 @@ void Feed::setChannels(std::vector<not_null<ChannelData*>> channels) {
 	_parent->notifyFeedUpdated(this, FeedUpdateFlag::Channels);
 }
 
-bool Feed::justSetLastMessage(not_null<HistoryItem*> item) {
+bool Feed::justUpdateLastMessage(not_null<HistoryItem*> item) {
-	if (_lastMessage && item->position() <= _lastMessage->position()) {
+	if (!_lastMessage) {
+		return false;
+	} else if (*_lastMessage
+		&& item->position() <= (*_lastMessage)->position()) {
 		return false;
 	}
 	_lastMessage = item;
@@ -216,36 +225,106 @@ bool Feed::justSetLastMessage(not_null<HistoryItem*> item) {
 }
 
 void Feed::messageRemoved(not_null<HistoryItem*> item) {
-	if (_lastMessage == item) {
+	if (lastMessage() == item) {
+		_lastMessage = base::none;
 		recountLastMessage();
 	}
 }
 
 void Feed::historyCleared(not_null<History*> history) {
-	if (_lastMessage->history() == history) {
+	if (const auto last = lastMessage()) {
-		recountLastMessage();
+		if (last->history() == history) {
+			messageRemoved(last);
+		}
 	}
 }
 
 void Feed::recountLastMessage() {
+	for (const auto history : _channels) {
+		if (!history->lastMessageKnown()) {
+			return;
+		}
+	}
 	_lastMessage = nullptr;
 	for (const auto history : _channels) {
-		if (const auto last = history->lastMsg) {
+		if (const auto last = history->lastMessage()) {
-			justSetLastMessage(last);
+			justUpdateLastMessage(last);
 		}
 	}
-	if (_lastMessage) {
+	updateChatsListDate();
-		setChatsListDate(_lastMessage->date);
+}
+
+void Feed::updateChatsListDate() {
+	if (_lastMessage && *_lastMessage) {
+		setChatsListDate((*_lastMessage)->date);
 	}
 }
 
-void Feed::setUnreadCounts(int unreadCount, int unreadMutedCount) {
+HistoryItem *Feed::lastMessage() const {
-	_unreadCount = unreadCount;
+	return _lastMessage ? *_lastMessage : nullptr;
+}
+
+bool Feed::lastMessageKnown() const {
+	return !!_lastMessage;
+}
+
+void Feed::applyDialog(const MTPDdialogFeed &data) {
+	const auto addChannel = [&](ChannelId channelId) {
+		if (const auto channel = App::channelLoaded(channelId)) {
+			channel->setFeed(this);
+		}
+	};
+	for (const auto &channelId : data.vfeed_other_channels.v) {
+		addChannel(channelId.v);
+	}
+
+	_lastMessage = nullptr;
+	if (const auto peerId = peerFromMTP(data.vpeer)) {
+		if (const auto channelId = peerToChannel(peerId)) {
+			addChannel(channelId);
+			const auto fullId = FullMsgId(channelId, data.vtop_message.v);
+			if (const auto item = App::histItemById(fullId)) {
+				justUpdateLastMessage(item);
+			}
+		}
+	}
+	updateChatsListDate();
+
+	setUnreadCounts(
+		data.vunread_count.v,
+		data.vunread_muted_count.v);
+	if (data.has_read_max_position()) {
+		setUnreadPosition(FeedPositionFromMTP(data.vread_max_position));
+	}
+}
+
+void Feed::setUnreadCounts(int unreadNonMutedCount, int unreadMutedCount) {
+	_unreadCount = unreadNonMutedCount + unreadMutedCount;
 	_unreadMutedCount = unreadMutedCount;
 }
 
 void Feed::setUnreadPosition(const MessagePosition &position) {
+	if (_unreadPosition.current() < position) {
 		_unreadPosition = position;
+	}
+}
+
+void Feed::unreadCountChanged(
+		base::optional<int> unreadCountDelta,
+		int mutedCountDelta) {
+	if (!_unreadCount) {
+		return;
+	}
+	if (unreadCountDelta) {
+		*_unreadCount = std::max(*_unreadCount + *unreadCountDelta, 0);
+		_unreadMutedCount = snap(
+			_unreadMutedCount + mutedCountDelta,
+			0,
+			*_unreadCount);
+		updateChatListEntry();
+	} else {
+		_parent->session().api().requestDialogEntry(this);
+	}
 }
 
 MessagePosition Feed::unreadPosition() const {
@@ -265,15 +344,15 @@ bool Feed::shouldBeInChatList() const {
 }
 
 int Feed::chatListUnreadCount() const {
-	return _unreadCount;
+	return _unreadCount ? *_unreadCount : 0;
 }
 
 bool Feed::chatListMutedBadge() const {
-	return _unreadCount <= _unreadMutedCount;
+	return _unreadCount ? (*_unreadCount <= _unreadMutedCount) : false;
 }
 
 HistoryItem *Feed::chatsListItem() const {
-	return _lastMessage;
+	return lastMessage();
 }
 
 const QString &Feed::chatsListName() const {

Telegram/SourceFiles/data/data_feed.h

@@ -32,6 +32,7 @@ MessagePosition FeedPositionFromMTP(const MTPFeedPosition &position);
 class Feed : public Dialogs::Entry {
 public:
 	static constexpr auto kId = 1;
+	static constexpr auto kChannelsLimit = 1000;
 
 	Feed(FeedId id, not_null<Data::Session*> parent);
 
@@ -43,11 +44,18 @@ public:
 	void messageRemoved(not_null<HistoryItem*> item);
 	void historyCleared(not_null<History*> history);
 
-	void setUnreadCounts(int unreadCount, int unreadMutedCount);
+	void applyDialog(const MTPDdialogFeed &data);
+	void setUnreadCounts(int unreadNonMutedCount, int unreadMutedCount);
 	void setUnreadPosition(const MessagePosition &position);
+	void unreadCountChanged(
+		base::optional<int> unreadCountDelta,
+		int mutedCountDelta);
 	MessagePosition unreadPosition() const;
 	rpl::producer<MessagePosition> unreadPositionChanges() const;
 
+	HistoryItem *lastMessage() const;
+	bool lastMessageKnown() const;
+
 	bool toImportant() const override;
 	bool shouldBeInChatList() const override;
 	int chatListUnreadCount() const override;
@@ -73,7 +81,8 @@ public:
 private:
 	void indexNameParts();
 	void recountLastMessage();
-	bool justSetLastMessage(not_null<HistoryItem*> item);
+	bool justUpdateLastMessage(not_null<HistoryItem*> item);
+	void updateChatsListDate();
 
 	FeedId _id = 0;
 	not_null<Data::Session*> _parent;
@@ -83,10 +92,10 @@ private:
 	QString _name;
 	base::flat_set<QString> _nameWords;
 	base::flat_set<QChar> _nameFirstLetters;
-	HistoryItem *_lastMessage = nullptr;
+	base::optional<HistoryItem*> _lastMessage;
 
 	rpl::variable<MessagePosition> _unreadPosition;
-	int _unreadCount = 0;
+	base::optional<int> _unreadCount;
 	int _unreadMutedCount = 0;
 
 };

Telegram/SourceFiles/data/data_peer.cpp

@@ -849,13 +849,22 @@ void ChannelData::setAvailableMinId(MsgId availableMinId) {
 		if (auto history = App::historyLoaded(this)) {
 			history->clearUpTill(availableMinId);
 		}
+		if (_pinnedMessageId <= _availableMinId) {
+			_pinnedMessageId = MsgId(0);
+			Notify::peerUpdatedDelayed(
+				this,
+				Notify::PeerUpdate::Flag::ChannelPinnedChanged);
+		}
 	}
 }
 
 void ChannelData::setPinnedMessageId(MsgId messageId) {
+	messageId = (messageId > _availableMinId) ? messageId : MsgId(0);
 	if (_pinnedMessageId != messageId) {
 		_pinnedMessageId = messageId;
-		Notify::peerUpdatedDelayed(this, Notify::PeerUpdate::Flag::ChannelPinnedChanged);
+		Notify::peerUpdatedDelayed(
+			this,
+			Notify::PeerUpdate::Flag::ChannelPinnedChanged);
 	}
 }
 

Telegram/SourceFiles/dialogs/dialogs_inner_widget.cpp

@@ -1726,76 +1726,32 @@ void DialogsInner::applyDialog(const MTPDdialog &dialog) {
 		return;
 	}
 
-	const auto history = App::historyFromDialog(
+	const auto history = App::history(peerId);
-		peerId,
+	history->applyDialog(dialog);
-		dialog.vunread_count.v,
-		dialog.vread_inbox_max_id.v,
-		dialog.vread_outbox_max_id.v);
-	history->setUnreadMentionsCount(dialog.vunread_mentions_count.v);
-	const auto peer = history->peer;
-	if (const auto channel = peer->asChannel()) {
-		if (dialog.has_pts()) {
-			channel->ptsReceived(dialog.vpts.v);
-		}
-		if (!channel->amCreator()) {
-			const auto topMsgId = FullMsgId(
-				peerToChannel(channel->id),
-				dialog.vtop_message.v);
-			if (const auto topMsg = App::histItemById(topMsgId)) {
-				if (topMsg->date <= date(channel->date)) {
-					Auth().api().requestSelfParticipant(channel);
-				}
-			}
-		}
-	}
-	App::main()->applyNotifySetting(
-		MTP_notifyPeer(dialog.vpeer),
-		dialog.vnotify_settings,
-		history);
 
 	if (!history->isPinnedDialog() && !history->chatsListDate().isNull()) {
 		addSavedPeersAfter(history->chatsListDate());
 	}
 	_contactsNoDialogs->del(history);
-	if (peer->migrateFrom()) {
+	if (const auto from = history->peer->migrateFrom()) {
-		if (const auto historyFrom = App::historyLoaded(peer->migrateFrom())) {
+		if (const auto historyFrom = App::historyLoaded(from)) {
 			removeDialog(historyFrom);
 		}
-	} else if (peer->migrateTo() && peer->migrateTo()->amIn()) {
+	} else if (const auto to = history->peer->migrateTo()) {
+		if (to->amIn()) {
 			removeDialog(history);
 		}
-
-	if (dialog.has_draft() && dialog.vdraft.type() == mtpc_draftMessage) {
-		const auto &draft = dialog.vdraft.c_draftMessage();
-		Data::applyPeerCloudDraft(peerId, draft);
 	}
 }
 
 void DialogsInner::applyFeedDialog(const MTPDdialogFeed &dialog) {
-	const auto peerId = peerFromMTP(dialog.vpeer);
 	const auto feedId = dialog.vfeed_id.v;
 	const auto feed = Auth().data().feed(feedId);
-	const auto addChannel = [&](ChannelId channelId) {
+	feed->applyDialog(dialog);
-		if (const auto channel = App::channelLoaded(channelId)) {
+
-			channel->setFeed(feed);
-		}
-	};
-	if (peerId && peerIsChannel(peerId)) {
-		addChannel(peerToChannel(peerId));
-	}
-	for (const auto &channelId : dialog.vfeed_other_channels.v) {
-		addChannel(channelId.v);
-	}
-	feed->setUnreadCounts(
-		dialog.vunread_count.v,
-		dialog.vunread_muted_count.v);
 	if (!feed->isPinnedDialog() && !feed->chatsListDate().isNull()) {
 		addSavedPeersAfter(feed->chatsListDate());
 	}
-	if (dialog.has_read_max_position()) {
-		feed->setUnreadPosition(
-			Data::FeedPositionFromMTP(dialog.vread_max_position));
-	}
 }
 
 void DialogsInner::addSavedPeersAfter(const QDateTime &date) {

Telegram/SourceFiles/history/history.h

@@ -18,7 +18,6 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "base/flags.h"
 
 class History;
-class ChannelHistory;
 class HistoryBlock;
 class HistoryItem;
 class HistoryMessage;
@@ -50,12 +49,7 @@ enum NewMessageType : char {
 
 class Histories {
 public:
-	using Map = QHash<PeerId, History*>;
+	Histories();
-	Map map;
-
-	Histories() : _a_typings(animation(this, &Histories::step_typings)) {
-		_selfDestructTimer.setCallback([this] { checkSelfDestructItems(); });
-	}
 
 	void registerSendAction(
 		not_null<History*> history,
@@ -64,20 +58,16 @@ public:
 		TimeId when);
 	void step_typings(TimeMs ms, bool timer);
 
-	History *find(const PeerId &peerId);
+	History *find(PeerId peerId) const;
-	not_null<History*> findOrInsert(const PeerId &peerId);
+	not_null<History*> findOrInsert(PeerId peerId);
-	not_null<History*> findOrInsert(
-		const PeerId &peerId,
-		int unreadCount,
-		MsgId maxInboxRead,
-		MsgId maxOutboxRead);
 
 	void clear();
 	void remove(const PeerId &peer);
 
 	HistoryItem *addNewMessage(const MTPMessage &msg, NewMessageType type);
 
-	typedef QMap<History*, TimeMs> TypingHistories; // when typing in this history started
+	// When typing in this history started.
+	typedef QMap<History*, TimeMs> TypingHistories;
 	TypingHistories typing;
 	BasicAnimation _a_typings;
 
@@ -114,6 +104,8 @@ public:
 private:
 	void checkSelfDestructItems();
 
+	std::unordered_map<PeerId, std::unique_ptr<History>> _map;
+
 	int _unreadFull = 0;
 	int _unreadMuted = 0;
 	base::Observable<SendActionAnimationUpdate> _sendActionAnimationUpdated;
@@ -136,29 +128,24 @@ public:
 	History(const History &) = delete;
 	History &operator=(const History &) = delete;
 
-	ChannelId channelId() const {
+	ChannelId channelId() const;
-		return peerToChannel(peer->id);
+	bool isChannel() const;
-	}
+	bool isMegagroup() const;
-	bool isChannel() const {
-		return peerIsChannel(peer->id);
-	}
-	bool isMegagroup() const {
-		return peer->isMegagroup();
-	}
-	ChannelHistory *asChannelHistory();
-	const ChannelHistory *asChannelHistory() const;
-
 	not_null<History*> migrateToOrMe() const;
 	History *migrateFrom() const;
+	MsgRange rangeForDifferenceRequest() const;
+	HistoryService *insertJoinedMessage(bool unread);
+	void checkJoinedMessage(bool createUnread = false);
 
-	bool isEmpty() const {
+	bool isEmpty() const;
-		return blocks.empty();
-	}
 	bool isDisplayedEmpty() const;
 	bool hasOrphanMediaGroupPart() const;
 	bool removeOrphanMediaGroupPart();
+	QVector<MsgId> collectMessagesFromUserToDelete(
+		not_null<UserData*> user) const;
 
-	void clear(bool leaveItems = false);
+	void clear();
+	void unloadBlocks();
 	void clearUpTill(MsgId availableMinId);
 
 	void applyGroupAdminChanges(const base::flat_map<UserId, bool> &changes);
@@ -184,18 +171,17 @@ public:
 	void newItemAdded(not_null<HistoryItem*> item);
 
 	int countUnread(MsgId upTo);
-	MsgId inboxRead(MsgId upTo);
+	MsgId readInbox();
-	MsgId inboxRead(HistoryItem *wasRead);
+	void inboxRead(MsgId upTo);
-	MsgId outboxRead(MsgId upTo);
+	void inboxRead(not_null<const HistoryItem*> wasRead);
-	MsgId outboxRead(HistoryItem *wasRead);
+	void outboxRead(MsgId upTo);
+	void outboxRead(not_null<const HistoryItem*> wasRead);
+	bool isServerSideUnread(not_null<const HistoryItem*> item) const;
+	MsgId loadAroundId() const;
 
-	int unreadCount() const {
+	int unreadCount() const;
-		return _unreadCount;
-	}
 	void setUnreadCount(int newUnreadCount);
-	bool mute() const {
+	bool mute() const;
-		return _mute;
-	}
 	bool changeMute(bool newMute);
 	void addUnreadBar();
 	void destroyUnreadBar();
@@ -212,46 +198,34 @@ public:
 	bool isReadyFor(MsgId msgId); // has messages for showing history at msgId
 	void getReadyFor(MsgId msgId);
 
-	void setLastMessage(HistoryItem *msg);
+	HistoryItem *lastMessage() const;
-	void fixLastMessage(bool wasAtBottom);
+	bool lastMessageKnown() const;
+	void unknownMessageDeleted(MsgId messageId);
+	void applyDialogTopMessage(MsgId topMessageId);
+	void applyDialog(const MTPDdialog &data);
+	void applyDialogFields(
+		int unreadCount,
+		MsgId maxInboxRead,
+		MsgId maxOutboxRead);
 
 	MsgId minMsgId() const;
 	MsgId maxMsgId() const;
 	MsgId msgIdForRead() const;
 
 	void resizeToWidth(int newWidth);
+	int height() const;
 
-	void removeNotification(HistoryItem *item) {
+	void itemRemoved(not_null<HistoryItem*> item);
-		if (!notifies.isEmpty()) {
+	void itemVanished(not_null<HistoryItem*> item);
-			for (auto i = notifies.begin(), e = notifies.end(); i != e; ++i) {
-				if ((*i) == item) {
-					notifies.erase(i);
-					break;
-				}
-			}
-		}
-	}
-	HistoryItem *currentNotification() {
-		return notifies.isEmpty() ? 0 : notifies.front();
-	}
-	bool hasNotification() const {
-		return !notifies.isEmpty();
-	}
-	void skipNotification() {
-		if (!notifies.isEmpty()) {
-			notifies.pop_front();
-		}
-	}
-	void popNotification(HistoryItem *item) {
-		if (!notifies.isEmpty() && notifies.back() == item) notifies.pop_back();
-	}
 
-	bool hasPendingResizedItems() const {
+	HistoryItem *currentNotification();
-		return _flags & Flag::f_has_pending_resized_items;
+	bool hasNotification() const;
-	}
+	void skipNotification();
+	void popNotification(HistoryItem *item);
+
+	bool hasPendingResizedItems() const;
 	void setHasPendingResizedItems();
 
-	void paintDialog(Painter &p, int32 w, bool sel) const;
 	bool mySendActionUpdated(SendAction::Type type, bool doing);
 	bool paintSendAction(Painter &p, int x, int y, int availableWidth, int outerWidth, style::color color, TimeMs ms);
 
@@ -345,15 +319,9 @@ public:
 	// Still public data.
 	std::deque<std::unique_ptr<HistoryBlock>> blocks;
 
-	int height() const;
-	int32 msgCount = 0;
-	MsgId inboxReadBefore = 1;
-	MsgId outboxReadBefore = 1;
-
 	not_null<PeerData*> peer;
 	bool oldLoaded = false;
 	bool newLoaded = true;
-	HistoryItem *lastMsg = nullptr;
 	HistoryItem *lastSentMsg = nullptr;
 
 	typedef QList<HistoryItem*> NotifyQueue;
@@ -379,7 +347,17 @@ public:
 
 	Text cloudDraftTextCache;
 
-protected:
+private:
+	friend class HistoryBlock;
+
+	enum class Flag {
+		f_has_pending_resized_items = (1 << 0),
+	};
+	using Flags = base::flags<Flag>;
+	friend inline constexpr auto is_flag_type(Flag) {
+		return true;
+	};
+
 	// when this item is destroyed scrollTopItem just points to the next one
 	// and scrollTopOffset remains the same
 	// if we are at the bottom of the window scrollTopItem == nullptr and
@@ -389,7 +367,6 @@ protected:
 	// helper method for countScrollState(int top)
 	void countScrollTopItem(int top);
 
-	void clearOnDestroy();
 	HistoryItem *addNewToLastBlock(const MTPMessage &msg, NewMessageType type);
 
 	// this method just removes a block from the blocks list
@@ -429,25 +406,18 @@ protected:
 		return _buildingFrontBlock != nullptr;
 	}
 
-private:
-	friend class HistoryBlock;
-
-	enum class Flag {
-		f_has_pending_resized_items = (1 << 0),
-	};
-	using Flags = base::flags<Flag>;
-	friend inline constexpr auto is_flag_type(Flag) {
-		return true;
-	};
-
 	void mainViewRemoved(
 		not_null<HistoryBlock*> block,
 		not_null<Element*> view);
+	void removeNotification(not_null<HistoryItem*> item);
 
 	QDateTime adjustChatListDate() const override;
 	void changedInChatListHook(Dialogs::Mode list, bool added) override;
 	void changedChatListPinHook() override;
 
+	void setInboxReadTill(MsgId upTo);
+	void setOutboxReadTill(MsgId upTo);
+
 	void applyMessageChanges(
 		not_null<HistoryItem*> item,
 		const MTPMessage &original);
@@ -455,14 +425,13 @@ private:
 		not_null<HistoryItem*> item,
 		const MTPDmessageService &data);
 
-	// After adding a new history slice check the lastMsg and newLoaded.
+	// After adding a new history slice check the lastMessage and newLoaded.
-	void checkLastMsg();
+	void checkLastMessage();
+	void setLastMessage(HistoryItem *item);
 
 	// Add all items to the unread mentions if we were not loaded at bottom and now are.
 	void checkAddAllToUnreadMentions();
 
-	template <int kSharedMediaTypeCount>
-	void addToSharedMedia(std::vector<MsgId> (&medias)[kSharedMediaTypeCount], bool force);
 	void addToSharedMedia(const std::vector<not_null<HistoryItem*>> &items);
 	void addEdgesToSharedMedia();
 
@@ -480,14 +449,18 @@ private:
 
 	Flags _flags = 0;
 	bool _mute = false;
-	int _unreadCount = 0;
 	int _width = 0;
 	int _height = 0;
 	Element *_unreadBarView = nullptr;
 	Element *_firstUnreadView = nullptr;
+	HistoryService *_joinedMessage = nullptr;
 
+	base::optional<MsgId> _inboxReadBefore;
+	base::optional<MsgId> _outboxReadBefore;
+	base::optional<int> _unreadCount;
 	base::optional<int> _unreadMentionsCount;
 	base::flat_set<MsgId> _unreadMentions;
+	base::optional<HistoryItem*> _lastMessage;
 
 	// A pointer to the block that is currently being built.
 	// We hold this pointer so we can destroy it while building
@@ -517,37 +490,6 @@ private:
 
  };
 
-class ChannelHistory : public History {
-public:
-	using History::History;
-
-	void messageDetached(not_null<HistoryItem*> message);
-
-	void getRangeDifference();
-	void getRangeDifferenceNext(int32 pts);
-
-	HistoryService *insertJoinedMessage(bool unread);
-	void checkJoinedMessage(bool createUnread = false);
-	const QDateTime &maxReadMessageDate();
-
-	~ChannelHistory();
-
-private:
-	friend class History;
-
-	void checkMaxReadMessageDate();
-	void cleared(bool leaveItems);
-
-	QDateTime _maxReadMessageDate;
-
-	HistoryService *_joinedMessage = nullptr;
-
-	MsgId _rangeDifferenceFromId, _rangeDifferenceToId;
-	int32 _rangeDifferencePts;
-	mtpRequestId _rangeDifferenceRequestId;
-
-};
-
 class HistoryBlock {
 public:
 	using Element = HistoryView::Element;
@@ -559,7 +501,6 @@ public:
 
 	std::vector<std::unique_ptr<Element>> messages;
 
-	void clear(bool leaveItems = false);
 	void remove(not_null<Element*> view);
 	void refreshView(not_null<Element*> view);
 

Telegram/SourceFiles/history/history_inner_widget.cpp

@@ -178,11 +178,15 @@ HistoryInner::HistoryInner(
 	}, lifetime());
 }
 
-void HistoryInner::messagesReceived(PeerData *peer, const QVector<MTPMessage> &messages) {
+void HistoryInner::messagesReceived(
+		PeerData *peer,
+		const QVector<MTPMessage> &messages) {
 	if (_history && _history->peer == peer) {
 		_history->addOlderSlice(messages);
 	} else if (_migrated && _migrated->peer == peer) {
-		bool newLoaded = (_migrated && _migrated->isEmpty() && !_history->isEmpty());
+		const auto newLoaded = _migrated
+			&& _migrated->isEmpty()
+			&& !_history->isEmpty();
 		_migrated->addOlderSlice(messages);
 		if (newLoaded) {
 			_migrated->addNewerSlice(QVector<MTPMessage>());

Telegram/SourceFiles/history/history_item.cpp

@@ -148,19 +148,7 @@ void HistoryItem::invalidateChatsListEntry() {
 
 void HistoryItem::finishEditionToEmpty() {
 	finishEdition(-1);
-
+	_history->itemVanished(this);
-	_history->removeNotification(this);
-	if (auto channel = history()->peer->asChannel()) {
-		if (channel->pinnedMessageId() == id) {
-			channel->clearPinnedMessage();
-		}
-	}
-	if (history()->lastKeyboardId == id) {
-		history()->clearLastKeyboard();
-	}
-	if ((!out() || isPost()) && unread() && history()->unreadCount() > 0) {
-		history()->setUnreadCount(history()->unreadCount() - 1);
-	}
 }
 
 bool HistoryItem::isMediaUnread() const {
@@ -244,7 +232,7 @@ void HistoryItem::destroy() {
 	if (isLogEntry()) {
 		Assert(!mainView());
 	} else {
-		// All this must be done for all items manually in History::clear(false)!
+		// All this must be done for all items manually in History::clear()!
 		eraseFromUnreadMentions();
 		if (IsServerMsgId(id)) {
 			if (const auto types = sharedMediaTypes()) {
@@ -256,32 +244,7 @@ void HistoryItem::destroy() {
 		} else {
 			Auth().api().cancelLocalItem(this);
 		}
-
+		_history->itemRemoved(this);
-		const auto wasAtBottom = history->loadedAtBottom();
-		history->removeNotification(this);
-
-		removeMainView();
-
-		if (history->lastMsg == this) {
-			history->fixLastMessage(wasAtBottom);
-		}
-		if (history->lastKeyboardId == id) {
-			history->clearLastKeyboard();
-		}
-		if ((!out() || isPost()) && unread() && history->unreadCount() > 0) {
-			history->setUnreadCount(history->unreadCount() - 1);
-		}
-		if (const auto channel = history->peer->asChannel()) {
-			if (channel->pinnedMessageId() == id) {
-				channel->clearPinnedMessage();
-			}
-			if (const auto feed = channel->feed()) {
-				// Must be after histroy->lastMsg is cleared.
-				// Otherwise feed last message will be this value again.
-				feed->messageRemoved(this);
-				// #TODO feeds unread
-			}
-		}
 	}
 	delete this;
 }
@@ -295,9 +258,6 @@ void HistoryItem::refreshMainView() {
 
 void HistoryItem::removeMainView() {
 	if (const auto view = mainView()) {
-		if (const auto channelHistory = _history->asChannelHistory()) {
-			channelHistory->messageDetached(this);
-		}
 		Auth().data().notifyHistoryChangeDelayed(_history);
 		view->removeFromBlock();
 	}
@@ -551,11 +511,11 @@ bool HistoryItem::unread() const {
 			return false;
 		}
 
-		if (id > 0) {
+		if (IsServerMsgId(id)) {
-			if (id < history()->outboxReadBefore) {
+			if (!history()->isServerSideUnread(this)) {
 				return false;
 			}
-			if (auto user = history()->peer->asUser()) {
+			if (const auto user = history()->peer->asUser()) {
 				if (user->botInfo) {
 					return false;
 				}
@@ -568,8 +528,8 @@ bool HistoryItem::unread() const {
 		return true;
 	}
 
-	if (id > 0) {
+	if (IsServerMsgId(id)) {
-		if (id < history()->inboxReadBefore) {
+		if (!history()->isServerSideUnread(this)) {
 			return false;
 		}
 		return true;
@@ -587,24 +547,6 @@ bool HistoryItem::isEmpty() const {
 		&& !Has<HistoryMessageLogEntryOriginal>();
 }
 
-HistoryItem *HistoryItem::previousItem() const {
-	if (const auto view = mainView()) {
-		if (const auto previous = view->previousInBlocks()) {
-			return previous->data();
-		}
-	}
-	return nullptr;
-}
-
-HistoryItem *HistoryItem::nextItem() const {
-	if (const auto view = mainView()) {
-		if (const auto next = view->nextInBlocks()) {
-			return next->data();
-		}
-	}
-	return nullptr;
-}
-
 QString HistoryItem::notificationText() const {
 	auto getText = [this]() {
 		if (_media) {

Telegram/SourceFiles/history/history_item.h

@@ -254,9 +254,6 @@ public:
 
 	MessageGroupId groupId() const;
 
-	HistoryItem *previousItem() const;
-	HistoryItem *nextItem() const;
-
 	virtual std::unique_ptr<HistoryView::Element> createView(
 		not_null<HistoryView::ElementDelegate*> delegate) = 0;
 

Telegram/SourceFiles/history/history_widget.cpp

@@ -2256,9 +2256,7 @@ void HistoryWidget::historyToDown(History *history) {
 void HistoryWidget::unreadCountChanged(not_null<History*> history) {
 	if (history == _history || history == _migrated) {
 		updateHistoryDownVisibility();
-		_historyDown->setUnreadCount(
+		_historyDown->setUnreadCount(_history->chatListUnreadCount());
-			_history->unreadCount()
-			+ (_migrated ? _migrated->unreadCount() : 0));
 	}
 }
 
@@ -2402,9 +2400,9 @@ void HistoryWidget::messagesReceived(PeerData *peer, const MTPmessages_Messages
 		if (_history->loadedAtBottom() && App::wnd()) App::wnd()->checkHistoryActivation();
 	} else if (_firstLoadRequest == requestId) {
 		if (toMigrated) {
-			_history->clear(true);
+			_history->unloadBlocks();
 		} else if (_migrated) {
-			_migrated->clear(true);
+			_migrated->unloadBlocks();
 		}
 		addMessagesToFront(peer, *histList);
 		_firstLoadRequest = 0;
@@ -2421,9 +2419,9 @@ void HistoryWidget::messagesReceived(PeerData *peer, const MTPmessages_Messages
 		historyLoaded();
 	} else if (_delayedShowAtRequest == requestId) {
 		if (toMigrated) {
-			_history->clear(true);
+			_history->unloadBlocks();
 		} else if (_migrated) {
-			_migrated->clear(true);
+			_migrated->unloadBlocks();
 		}
 
 		_delayedShowAtRequest = 0;
@@ -2506,15 +2504,15 @@ void HistoryWidget::firstLoadMessages() {
 	auto offset = 0;
 	auto loadCount = kMessagesPerPage;
 	if (_showAtMsgId == ShowAtUnreadMsgId) {
-		if (_migrated && _migrated->unreadCount()) {
+		if (const auto around = _migrated ? _migrated->loadAroundId() : 0) {
 			_history->getReadyFor(_showAtMsgId);
 			from = _migrated->peer;
 			offset = -loadCount / 2;
-			offsetId = _migrated->inboxReadBefore;
+			offsetId = around;
-		} else if (_history->unreadCount()) {
+		} else if (const auto around = _history->loadAroundId()) {
 			_history->getReadyFor(_showAtMsgId);
 			offset = -loadCount / 2;
-			offsetId = _history->inboxReadBefore;
+			offsetId = around;
 		} else {
 			_history->getReadyFor(ShowAtTheEndMsgId);
 		}
@@ -2651,13 +2649,13 @@ void HistoryWidget::delayedShowAt(MsgId showAtMsgId) {
 	auto offset = 0;
 	auto loadCount = kMessagesPerPage;
 	if (_delayedShowAtMsgId == ShowAtUnreadMsgId) {
-		if (_migrated && _migrated->unreadCount()) {
+		if (const auto around = _migrated ? _migrated->loadAroundId() : 0) {
 			from = _migrated->peer;
 			offset = -loadCount / 2;
-			offsetId = _migrated->inboxReadBefore;
+			offsetId = around;
-		} else if (_history->unreadCount()) {
+		} else if (const auto around = _history->loadAroundId()) {
 			offset = -loadCount / 2;
-			offsetId = _history->inboxReadBefore;
+			offsetId = around;
 		} else {
 			loadCount = kMessagesPerPageFirst;
 		}
@@ -3630,8 +3628,17 @@ bool HistoryWidget::inlineBotResolveFail(QString name, const RPCError &error) {
 }
 
 bool HistoryWidget::isBotStart() const {
-	if (!_peer || !_peer->isUser() || !_peer->asUser()->botInfo || !_canSendMessages) return false;
+	const auto user = _peer ? _peer->asUser() : nullptr;
-	return !_peer->asUser()->botInfo->startToken.isEmpty() || (_history->isEmpty() && !_history->lastMsg);
+	if (!user
+		|| !user->botInfo
+		|| !_canSendMessages) {
+		return false;
+	} else if (!user->botInfo->startToken.isEmpty()) {
+		return true;
+	} else if (_history->isEmpty() && !_history->lastMessage()) {
+		return true;
+	}
+	return false;
 }
 
 bool HistoryWidget::isBlocked() const {
@@ -5126,14 +5133,7 @@ void HistoryWidget::keyPressEvent(QKeyEvent *e) {
 		if (!(e->modifiers() & (Qt::ShiftModifier | Qt::MetaModifier | Qt::ControlModifier))) {
 			_scroll->keyPressEvent(e);
 		} else if ((e->modifiers() & (Qt::ShiftModifier | Qt::MetaModifier | Qt::ControlModifier)) == Qt::ControlModifier) {
-			if (_history && _history->lastMsg && !_editMsgId) {
+			replyToNextMessage();
-				if (const auto item = App::histItemById(_history->channelId(), _replyToId)) {
-					if (const auto next = item->nextItem()) {
-						Ui::showPeerHistory(_peer, next->id);
-						replyToMessage(next);
-					}
-				}
-			}
 		}
 	} else if (e->key() == Qt::Key_Up) {
 		if (!(e->modifiers() & (Qt::ShiftModifier | Qt::MetaModifier | Qt::ControlModifier))) {
@@ -5145,17 +5145,7 @@ void HistoryWidget::keyPressEvent(QKeyEvent *e) {
 			}
 			_scroll->keyPressEvent(e);
 		} else if ((e->modifiers() & (Qt::ShiftModifier | Qt::MetaModifier | Qt::ControlModifier)) == Qt::ControlModifier) {
-			if (_history && _history->lastMsg && !_editMsgId) {
+			replyToPreviousMessage();
-				if (const auto item = App::histItemById(_history->channelId(), _replyToId)) {
-					if (const auto previous = item->previousItem()) {
-						Ui::showPeerHistory(_peer, previous->id);
-						replyToMessage(previous);
-					}
-				} else if (const auto previous = _history->lastMsg) {
-					Ui::showPeerHistory(_peer, previous->id);
-					replyToMessage(previous);
-				}
-			}
 		}
 	} else if (e->key() == Qt::Key_Return || e->key() == Qt::Key_Enter) {
 		onListEnterPressed();
@@ -5164,6 +5154,45 @@ void HistoryWidget::keyPressEvent(QKeyEvent *e) {
 	}
 }
 
+void HistoryWidget::replyToPreviousMessage() {
+	if (!_history || _editMsgId) {
+		return;
+	}
+	const auto fullId = FullMsgId(
+		_history->channelId(),
+		_replyToId);
+	if (const auto item = App::histItemById(fullId)) {
+		if (const auto view = item->mainView()) {
+			if (const auto previousView = view->previousInBlocks()) {
+				const auto previous = previousView->data();
+				Ui::showPeerHistoryAtItem(previous);
+				replyToMessage(previous);
+			}
+		}
+	} else if (const auto previous = _history->lastMessage()) {
+		Ui::showPeerHistoryAtItem(previous);
+		replyToMessage(previous);
+	}
+}
+
+void HistoryWidget::replyToNextMessage() {
+	if (!_history || _editMsgId) {
+		return;
+	}
+	const auto fullId = FullMsgId(
+		_history->channelId(),
+		_replyToId);
+	if (const auto item = App::histItemById(fullId)) {
+		if (const auto view = item->mainView()) {
+			if (const auto nextView = view->nextInBlocks()) {
+				const auto next = nextView->data();
+				Ui::showPeerHistoryAtItem(next);
+				replyToMessage(next);
+			}
+		}
+	}
+}
+
 void HistoryWidget::onFieldTabbed() {
 	if (!_fieldAutocomplete->isHidden()) {
 		_fieldAutocomplete->chooseSelected(FieldAutocomplete::ChooseMethod::ByTab);

Telegram/SourceFiles/history/history_widget.h

@@ -538,6 +538,8 @@ private:
 	void applyInlineBotQuery(UserData *bot, const QString &query);
 
 	void cancelReplyAfterMediaSend(bool lastKeyboardUsed);
+	void replyToPreviousMessage();
+	void replyToNextMessage();
 
 	void hideSelectorControlsAnimated();
 	int countMembersDropdownHeightMax() const;

Telegram/SourceFiles/history/view/history_view_element.cpp

@@ -611,6 +611,9 @@ void Element::clickHandlerPressedChanged(
 }
 
 Element::~Element() {
+	if (_data->mainView() == this) {
+		_data->clearMainView();
+	}
 	Auth().data().unregisterItemView(this);
 }
 

Telegram/SourceFiles/mainwidget.cpp

@@ -887,21 +887,27 @@ void MainWidget::deleteLayer(FullMsgId itemId) {
 void MainWidget::cancelUploadLayer(not_null<HistoryItem*> item) {
 	const auto itemId = item->fullId();
 	Auth().uploader().pause(itemId);
-	Ui::show(Box<ConfirmBox>(lang(lng_selected_cancel_sure_this), lang(lng_selected_upload_stop), lang(lng_continue), base::lambda_guarded(this, [=] {
+	const auto stopUpload = [=] {
 		Ui::hideLayer();
 		if (const auto item = App::histItemById(itemId)) {
 			const auto history = item->history();
-			const auto wasLast = (history->lastMsg == item);
 			item->destroy();
-			if (wasLast && !history->lastMsg) {
+			if (!history->lastMessageKnown()) {
-				checkPeerHistory(history->peer);
+				Auth().api().requestDialogEntry(history);
 			}
 			Auth().data().sendHistoryChangeNotifications();
 		}
 		Auth().uploader().unpause();
-	}), base::lambda_guarded(this, [] {
+	};
+	const auto continueUpload = [=] {
 		Auth().uploader().unpause();
-	})));
+	};
+	Ui::show(Box<ConfirmBox>(
+		lang(lng_selected_cancel_sure_this),
+		lang(lng_selected_upload_stop),
+		lang(lng_continue),
+		stopUpload,
+		continueUpload));
 }
 
 void MainWidget::deletePhotoLayer(PhotoData *photo) {
@@ -1041,12 +1047,11 @@ void MainWidget::deleteConversation(
 	if (const auto history = App::historyLoaded(peer->id)) {
 		Auth().data().setPinnedDialog(history, false);
 		removeDialog(history);
-		if (peer->isMegagroup() && peer->asChannel()->mgInfo->migrateFromPtr) {
+		if (const auto channel = peer->asMegagroup()) {
-			if (auto migrated = App::historyLoaded(peer->asChannel()->mgInfo->migrateFromPtr->id)) {
+			channel->addFlags(MTPDchannel::Flag::f_left);
-				if (migrated->lastMsg) { // return initial dialog
+			if (const auto from = channel->mgInfo->migrateFromPtr) {
-					migrated->setLastMessage(migrated->lastMsg);
+				if (const auto migrated = App::historyLoaded(from)) {
-				} else {
+					migrated->updateChatListExistence();
-					checkPeerHistory(migrated->peer);
 				}
 			}
 		}
@@ -1059,7 +1064,12 @@ void MainWidget::deleteConversation(
 	}
 	if (deleteHistory) {
 		DeleteHistoryRequest request = { peer, false };
-		MTP::send(MTPmessages_DeleteHistory(MTP_flags(0), peer->input, MTP_int(0)), rpcDone(&MainWidget::deleteHistoryPart, request));
+		MTP::send(
+			MTPmessages_DeleteHistory(
+				MTP_flags(0),
+				peer->input,
+				MTP_int(0)),
+			rpcDone(&MainWidget::deleteHistoryPart, request));
 	}
 }
 
@@ -1068,47 +1078,6 @@ void MainWidget::deleteAndExit(ChatData *chat) {
 	MTP::send(MTPmessages_DeleteChatUser(chat->inputChat, App::self()->inputUser), rpcDone(&MainWidget::deleteHistoryAfterLeave, peer), rpcFail(&MainWidget::leaveChatFailed, peer));
 }
 
-void MainWidget::deleteAllFromUser(ChannelData *channel, UserData *from) {
-	Assert(channel != nullptr && from != nullptr);
-
-	QVector<MsgId> toDestroy;
-	if (auto history = App::historyLoaded(channel->id)) {
-		for (const auto &block : history->blocks) {
-			for (const auto &message : block->messages) {
-				const auto item = message->data();
-				if (item->from() == from && item->canDelete()) {
-					toDestroy.push_back(item->id);
-				}
-			}
-		}
-		for_const (auto &msgId, toDestroy) {
-			if (auto item = App::histItemById(peerToChannel(channel->id), msgId)) {
-				item->destroy();
-			}
-		}
-	}
-	MTP::send(
-		MTPchannels_DeleteUserHistory(
-			channel->inputChannel,
-			from->inputUser),
-		rpcDone(&MainWidget::deleteAllFromUserPart, { channel, from }));
-	Auth().data().sendHistoryChangeNotifications();
-}
-
-void MainWidget::deleteAllFromUserPart(DeleteAllFromUserParams params, const MTPmessages_AffectedHistory &result) {
-	auto &d = result.c_messages_affectedHistory();
-	params.channel->ptsUpdateAndApply(d.vpts.v, d.vpts_count.v);
-
-	auto offset = d.voffset.v;
-	if (offset > 0) {
-		MTP::send(MTPchannels_DeleteUserHistory(params.channel->inputChannel, params.from->inputUser), rpcDone(&MainWidget::deleteAllFromUserPart, params));
-	} else if (auto h = App::historyLoaded(params.channel)) {
-		if (!h->lastMsg) {
-			checkPeerHistory(params.channel);
-		}
-	}
-}
-
 void MainWidget::addParticipants(
 		not_null<PeerData*> chatOrChannel,
 		const std::vector<not_null<UserData*>> &users) {
@@ -1194,99 +1163,6 @@ bool MainWidget::addParticipantsFail(
 	return false;
 }
 
-void MainWidget::checkPeerHistory(PeerData *peer) {
-	auto offsetId = 0;
-	auto offsetDate = 0;
-	auto addOffset = 0;
-	auto limit = 1;
-	auto maxId = 0;
-	auto minId = 0;
-	auto historyHash = 0;
-	MTP::send(
-		MTPmessages_GetHistory(
-			peer->input,
-			MTP_int(offsetId),
-			MTP_int(offsetDate),
-			MTP_int(addOffset),
-			MTP_int(limit),
-			MTP_int(maxId),
-			MTP_int(minId),
-			MTP_int(historyHash)),
-		rpcDone(&MainWidget::checkedHistory, peer));
-}
-
-void MainWidget::checkedHistory(PeerData *peer, const MTPmessages_Messages &result) {
-	const QVector<MTPMessage> *v = 0;
-	switch (result.type()) {
-	case mtpc_messages_messages: {
-		auto &d(result.c_messages_messages());
-		App::feedUsers(d.vusers);
-		App::feedChats(d.vchats);
-		v = &d.vmessages.v;
-	} break;
-
-	case mtpc_messages_messagesSlice: {
-		auto &d(result.c_messages_messagesSlice());
-		App::feedUsers(d.vusers);
-		App::feedChats(d.vchats);
-		v = &d.vmessages.v;
-	} break;
-
-	case mtpc_messages_channelMessages: {
-		auto &d(result.c_messages_channelMessages());
-		if (peer && peer->isChannel()) {
-			peer->asChannel()->ptsReceived(d.vpts.v);
-		} else {
-			LOG(("API Error: received messages.channelMessages when no channel was passed! (MainWidget::checkedHistory)"));
-		}
-		App::feedUsers(d.vusers);
-		App::feedChats(d.vchats);
-		v = &d.vmessages.v;
-	} break;
-
-	case mtpc_messages_messagesNotModified: {
-		LOG(("API Error: received messages.messagesNotModified! (MainWidget::checkedHistory)"));
-	} break;
-	}
-
-	if (!v || v->isEmpty()) {
-		if (peer->isChat() && !peer->asChat()->haveLeft()) {
-			if (const auto history = App::historyLoaded(peer->id)) {
-				Local::addSavedPeer(peer, history->chatsListDate());
-			}
-		} else if (const auto channel = peer->asChannel()) {
-			if (channel->inviter > 0 && channel->amIn()) {
-				if (const auto from = App::userLoaded(channel->inviter)) {
-					const auto history = App::history(peer->id);
-					history->clear(true);
-					history->addNewerSlice(QVector<MTPMessage>());
-					history->asChannelHistory()->insertJoinedMessage(true);
-				}
-			}
-		} else if (const auto history = App::historyLoaded(peer->id)) {
-			deleteConversation(history->peer, false);
-		}
-	} else {
-		const auto history = App::history(peer->id);
-		if (!history->lastMsg) {
-			history->addNewMessage((*v)[0], NewMessageLast);
-		}
-		if (!history->chatsListDate().isNull() && history->loadedAtBottom()) {
-			if (const auto channel = peer->asChannel()) {
-				if (channel->inviter > 0
-					&& history->chatsListDate() <= channel->inviteDate
-					&& channel->amIn()) {
-					if (const auto from = App::userLoaded(channel->inviter)) {
-						history->asChannelHistory()->insertJoinedMessage(true);
-					}
-				}
-			}
-		}
-		history->updateChatListExistence();
-	}
-	Auth().data().sendHistoryChangeNotifications();
-}
-
 bool MainWidget::sendMessageFail(const RPCError &error) {
 	if (MTP::isDefaultHandledError(error)) return false;
 
@@ -1562,9 +1438,9 @@ void MainWidget::messagesAffected(
 		ptsUpdateAndApply(data.vpts.v, data.vpts_count.v);
 	}
 
-	if (auto h = App::historyLoaded(peer ? peer->id : 0)) {
+	if (const auto history = App::historyLoaded(peer)) {
-		if (!h->lastMsg) {
+		if (!history->lastMessageKnown()) {
-			checkPeerHistory(peer);
+			Auth().api().requestDialogEntry(history);
 		}
 	}
 }
@@ -3473,7 +3349,9 @@ void MainWidget::updSetState(int32 pts, int32 date, int32 qts, int32 seq) {
 	}
 }
 
-void MainWidget::gotChannelDifference(ChannelData *channel, const MTPupdates_ChannelDifference &diff) {
+void MainWidget::gotChannelDifference(
+		ChannelData *channel,
+		const MTPupdates_ChannelDifference &diff) {
 	_channelFailDifferenceTimeout.remove(channel);
 
 	int32 timeout = 0;
@@ -3491,28 +3369,28 @@ void MainWidget::gotChannelDifference(ChannelData *channel, const MTPupdates_Cha
 
 		App::feedUsers(d.vusers);
 		App::feedChats(d.vchats);
-		auto h = App::historyLoaded(channel->id);
+		auto history = App::historyLoaded(channel->id);
-		if (h) {
+		if (history) {
-			h->setNotLoadedAtBottom();
+			history->setNotLoadedAtBottom();
 		}
 		App::feedMsgs(d.vmessages, NewMessageLast);
-		if (h) {
+		if (history) {
-			if (auto item = App::histItemById(peerToChannel(channel->id), d.vtop_message.v)) {
+			history->applyDialogFields(
-				h->setLastMessage(item);
+				d.vunread_count.v,
-			}
+				d.vread_inbox_max_id.v,
-			if (d.vunread_count.v >= h->unreadCount()) {
+				d.vread_outbox_max_id.v);
-				h->setUnreadCount(d.vunread_count.v);
+			history->applyDialogTopMessage(d.vtop_message.v);
-				h->inboxReadBefore = d.vread_inbox_max_id.v + 1;
+			history->setUnreadMentionsCount(d.vunread_mentions_count.v);
-			}
-			h->setUnreadMentionsCount(d.vunread_mentions_count.v);
 			if (_history->peer() == channel) {
 				_history->updateHistoryDownVisibility();
 				_history->preloadHistoryIfNeeded();
 			}
-			h->asChannelHistory()->getRangeDifference();
+			Auth().api().requestChannelRangeDifference(history);
 		}
 
-		if (d.has_timeout()) timeout = d.vtimeout.v;
+		if (d.has_timeout()) {
+			timeout = d.vtimeout.v;
+		}
 		isFinal = d.is_final();
 		channel->ptsInit(d.vpts.v);
 	} break;
@@ -3520,39 +3398,7 @@ void MainWidget::gotChannelDifference(ChannelData *channel, const MTPupdates_Cha
 	case mtpc_updates_channelDifference: {
 		auto &d = diff.c_updates_channelDifference();
 
-		App::feedUsers(d.vusers);
+		feedChannelDifference(d);
-		App::feedChats(d.vchats);
-
-		_handlingChannelDifference = true;
-		feedMessageIds(d.vother_updates);
-
-		// feed messages and groups, copy from App::feedMsgs
-		auto h = App::history(channel->id);
-		auto &vmsgs = d.vnew_messages.v;
-		auto indices = base::flat_map<uint64, int>();
-		for (auto i = 0, l = vmsgs.size(); i != l; ++i) {
-			const auto &msg = vmsgs[i];
-			if (msg.type() == mtpc_message) {
-				const auto &data = msg.c_message();
-				if (App::checkEntitiesAndViewsUpdate(data)) { // new message, index my forwarded messages to links _overview, already in blocks
-					LOG(("Skipping message, because it is already in blocks!"));
-					continue;
-				}
-			}
-			const auto msgId = idFromMessage(msg);
-			indices.emplace((uint64(uint32(msgId)) << 32) | uint64(i), i);
-		}
-		for (const auto [position, index] : indices) {
-			const auto &msg = vmsgs[index];
-			if (channel->id != peerFromMessage(msg)) {
-				LOG(("API Error: message with invalid peer returned in channelDifference, channelId: %1, peer: %2").arg(peerToChannel(channel->id)).arg(peerFromMessage(msg)));
-				continue; // wtf
-			}
-			h->addNewMessage(msg, NewMessageUnread);
-		}
-
-		feedUpdateVector(d.vother_updates, true);
-		_handlingChannelDifference = false;
 
 		if (d.has_timeout()) timeout = d.vtimeout.v;
 		isFinal = d.is_final();
@@ -3570,55 +3416,16 @@ void MainWidget::gotChannelDifference(ChannelData *channel, const MTPupdates_Cha
 	}
 }
 
-void MainWidget::gotRangeDifference(
+void MainWidget::feedChannelDifference(
-		ChannelData *channel,
+		const MTPDupdates_channelDifference &data) {
-		const MTPupdates_ChannelDifference &diff) {
+	App::feedUsers(data.vusers);
-	int32 nextRequestPts = 0;
+	App::feedChats(data.vchats);
-	bool isFinal = true;
-	switch (diff.type()) {
-	case mtpc_updates_channelDifferenceEmpty: {
-		auto &d = diff.c_updates_channelDifferenceEmpty();
-		nextRequestPts = d.vpts.v;
-		isFinal = d.is_final();
-	} break;
-
-	case mtpc_updates_channelDifferenceTooLong: {
-		auto &d = diff.c_updates_channelDifferenceTooLong();
-
-		App::feedUsers(d.vusers);
-		App::feedChats(d.vchats);
-
-		nextRequestPts = d.vpts.v;
-		isFinal = d.is_final();
-	} break;
-
-	case mtpc_updates_channelDifference: {
-		auto &d = diff.c_updates_channelDifference();
-
-		App::feedUsers(d.vusers);
-		App::feedChats(d.vchats);
 
 	_handlingChannelDifference = true;
-		feedMessageIds(d.vother_updates);
+	feedMessageIds(data.vother_updates);
-		App::feedMsgs(d.vnew_messages, NewMessageUnread);
+	App::feedMsgs(data.vnew_messages, NewMessageUnread);
-		feedUpdateVector(d.vother_updates, true);
+	feedUpdateVector(data.vother_updates, true);
 	_handlingChannelDifference = false;
-
-		nextRequestPts = d.vpts.v;
-		isFinal = d.is_final();
-	} break;
-	}
-
-	if (!isFinal) {
-		if (const auto history = App::historyLoaded(channel->id)) {
-			MTP_LOG(0, ("getChannelDifference { "
-				"good - after not final channelDifference was received, "
-				"validating history part }%1"
-				).arg(cTestMode() ? " TESTMODE" : ""));
-			history->asChannelHistory()->getRangeDifferenceNext(
-				nextRequestPts);
-		}
-	}
 }
 
 bool MainWidget::failChannelDifference(ChannelData *channel, const RPCError &error) {
@@ -3985,12 +3792,12 @@ void MainWidget::onSelfParticipantUpdated(ChannelData *channel) {
 			history = App::history(channel);
 		}
 		if (history->isEmpty()) {
-			checkPeerHistory(channel);
+			Auth().api().requestDialogEntry(history);
 		} else {
-			history->asChannelHistory()->checkJoinedMessage(true);
+			history->checkJoinedMessage(true);
 		}
 	} else if (history) {
-		history->asChannelHistory()->checkJoinedMessage();
+		history->checkJoinedMessage();
 	}
 	Auth().data().sendHistoryChangeNotifications();
 }
@@ -4768,10 +4575,9 @@ void MainWidget::feedUpdate(const MTPUpdate &update) {
 				const auto existing = App::histItemById(channel, newId);
 				if (existing && !local->mainView()) {
 					const auto history = local->history();
-					const auto wasLast = (history->lastMsg == local);
 					local->destroy();
-					if (wasLast && !history->lastMsg) {
+					if (!history->lastMessageKnown()) {
-						checkPeerHistory(history->peer);
+						Auth().api().requestDialogEntry(history);
 					}
 				} else {
 					if (existing) {
@@ -5211,7 +5017,7 @@ void MainWidget::feedUpdate(const MTPUpdate &update) {
 
 	case mtpc_updateChannel: {
 		auto &d = update.c_updateChannel();
-		if (auto channel = App::channelLoaded(d.vchannel_id.v)) {
+		if (const auto channel = App::channelLoaded(d.vchannel_id.v)) {
 			channel->inviter = 0;
 			if (!channel->amIn()) {
 				if (const auto history = App::historyLoaded(channel->id)) {

Telegram/SourceFiles/mainwidget.h

@@ -215,9 +215,6 @@ public:
 		not_null<ChannelData*> channel,
 		const RPCError &e); // for multi invite in channels
 
-	void checkPeerHistory(PeerData *peer);
-	void checkedHistory(PeerData *peer, const MTPmessages_Messages &result);
-
 	bool sendMessageFail(const RPCError &error);
 
 	Dialogs::IndexedList *contactsList();
@@ -288,8 +285,8 @@ public:
 
 	void scheduleViewIncrement(HistoryItem *item);
 
-	void gotRangeDifference(ChannelData *channel, const MTPupdates_ChannelDifference &diff);
 	void onSelfParticipantUpdated(ChannelData *channel);
+	void feedChannelDifference(const MTPDupdates_channelDifference &data);
 
 	// Mayde public for ApiWrap, while it is still here.
 	// Better would be for this to be moved to ApiWrap.
@@ -478,7 +475,6 @@ private:
 	void feedUpdate(const MTPUpdate &update);
 
 	void deleteHistoryPart(DeleteHistoryRequest request, const MTPmessages_AffectedHistory &result);
-	void deleteAllFromUserPart(DeleteAllFromUserParams params, const MTPmessages_AffectedHistory &result);
 
 	void updateReceived(const mtpPrime *from, const mtpPrime *end);
 	bool updateFail(const RPCError &e);

Telegram/SourceFiles/window/window_peer_menu.cpp

@@ -593,7 +593,15 @@ void PeerMenuAddChannelMembers(not_null<ChannelData*> channel) {
 }
 
 void ToggleChannelGrouping(not_null<ChannelData*> channel, bool group) {
-	Auth().api().toggleChannelGrouping(channel, group);
+	const auto callback = [=] {
+		Ui::Toast::Show(lang(group
+			? lng_feed_channel_added
+			: lng_feed_channel_removed));
+	};
+	Auth().api().toggleChannelGrouping(
+		channel,
+		group,
+		callback);
 }
 
 base::lambda<void()> ClearHistoryHandler(not_null<PeerData*> peer) {