Add read status tracking to comments.

Telegram/SourceFiles/data/data_replies_list.cpp

@@ -165,7 +165,14 @@ bool RepliesList::buildFromData(not_null<Viewer*> viewer) {
 			= 0;
 		return true;
 	}
-	const auto around = viewer->around;
+	const auto around = [&] {
+		if (viewer->around != ShowAtUnreadMsgId) {
+			return viewer->around;
+		} else if (const auto item = lookupRoot()) {
+			return item->repliesReadTill();
+		}
+		return viewer->around;
+	}();
 	if (_list.empty()
 		|| (!around && _skippedAfter != 0)
 		|| (around > _list.front() && _skippedAfter != 0)
@@ -251,6 +258,10 @@ Histories &RepliesList::histories() {
 	return _history->owner().histories();
 }
 
+HistoryItem *RepliesList::lookupRoot() {
+	return _history->owner().message(_history->channelId(), _rootId);
+}
+
 void RepliesList::loadAround(MsgId id) {
 	if (_loadingAround && *_loadingAround == id) {
 		return;

Telegram/SourceFiles/data/data_replies_list.h

@@ -33,6 +33,7 @@ public:
 private:
 	struct Viewer;
 
+	HistoryItem *lookupRoot();
 	[[nodiscard]] Histories &histories();
 
 	[[nodiscard]] rpl::producer<MessagesSlice> sourceFromServer(

Telegram/SourceFiles/history/history_item.h

@@ -264,6 +264,11 @@ public:
 	}
 	virtual void changeRepliesCount(int delta, PeerId replier) {
 	}
+	virtual void setRepliesReadTill(MsgId readTillId) {
+	}
+	[[nodiscard]] virtual MsgId repliesReadTill() const {
+		return MsgId(0);
+	}
 	virtual void setReplyToTop(MsgId replyToTop) {
 	}
 	virtual void setRealId(MsgId newId);

Telegram/SourceFiles/history/history_item_components.h

@@ -46,6 +46,7 @@ struct HistoryMessageViews : public RuntimeComponent<HistoryMessageViews, Histor
 	Part replies;
 	ChannelId commentsChannelId = 0;
 	MsgId commentsRootId = 0;
+	MsgId repliesReadTillId = 0;
 };
 
 struct HistoryMessageSigned : public RuntimeComponent<HistoryMessageSigned, HistoryItem> {

Telegram/SourceFiles/history/history_message.cpp

@@ -1561,6 +1561,22 @@ void HistoryMessage::changeRepliesCount(int delta, PeerId replier) {
 	refreshRepliesText(views);
 }
 
+void HistoryMessage::setRepliesReadTill(MsgId readTillId) {
+	auto views = Get<HistoryMessageViews>();
+	if (!views) {
+		AddComponents(HistoryMessageViews::Bit());
+		views = Get<HistoryMessageViews>();
+	}
+	views->repliesReadTillId = std::max(readTillId, 1);
+}
+
+MsgId HistoryMessage::repliesReadTill() const {
+	if (const auto views = Get<HistoryMessageViews>()) {
+		return views->repliesReadTillId;
+	}
+	return 0;
+}
+
 void HistoryMessage::setReplyToTop(MsgId replyToTop) {
 	const auto reply = Get<HistoryMessageReply>();
 	if (!reply

Telegram/SourceFiles/history/history_message.h

@@ -136,6 +136,8 @@ public:
 	void setForwardsCount(int count) override;
 	void setReplies(const MTPMessageReplies &data) override;
 	void changeRepliesCount(int delta, PeerId replier) override;
+	void setRepliesReadTill(MsgId readTillId) override;
+	MsgId repliesReadTill() const override;
 	void setReplyToTop(MsgId replyToTop) override;
 	void setRealId(MsgId newId) override;
 	void incrementReplyToTopCounter() override;

Telegram/SourceFiles/history/view/history_view_list_widget.cpp

@@ -1265,8 +1265,8 @@ void ListWidget::restoreState(not_null<ListMemento*> memento) {
 	_aroundIndex = -1;
 	if (const auto limit = memento->idsLimit()) {
 		_idsLimit = limit;
-		_scrollTopState = memento->scrollTopState();
 	}
+	_scrollTopState = memento->scrollTopState();
 	refreshViewer();
 }
 
@@ -2663,6 +2663,10 @@ void ListWidget::replyToMessageRequestNotify(FullMsgId item) {
 	_requestedToReplyToMessage.fire(std::move(item));
 }
 
+rpl::producer<FullMsgId> ListWidget::readMessageRequested() const {
+	return _requestedToReadMessage.events();
+}
+
 ListWidget::~ListWidget() = default;
 
 } // namespace HistoryView

Telegram/SourceFiles/history/view/history_view_list_widget.h

@@ -188,10 +188,11 @@ public:
 	QPoint tooltipPos() const override;
 	bool tooltipWindowActive() const override;
 
-	rpl::producer<FullMsgId> editMessageRequested() const;
+	[[nodiscard]] rpl::producer<FullMsgId> editMessageRequested() const;
 	void editMessageRequestNotify(FullMsgId item);
-	rpl::producer<FullMsgId> replyToMessageRequested() const;
+	[[nodiscard]] rpl::producer<FullMsgId> replyToMessageRequested() const;
 	void replyToMessageRequestNotify(FullMsgId item);
+	[[nodiscard]] rpl::producer<FullMsgId> readMessageRequested() const;
 
 	// ElementDelegate interface.
 	Context elementContext() override;
@@ -529,6 +530,7 @@ private:
 
 	rpl::event_stream<FullMsgId> _requestedToEditMessage;
 	rpl::event_stream<FullMsgId> _requestedToReplyToMessage;
+	rpl::event_stream<FullMsgId> _requestedToReadMessage;
 
 	rpl::lifetime _viewerLifetime;
 

Telegram/SourceFiles/history/view/history_view_replies_section.cpp

@@ -59,6 +59,8 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 namespace HistoryView {
 namespace {
 
+constexpr auto kReadRequestTimeout = 3 * crl::time(1000);
+
 void ShowErrorToast(const QString &text) {
 	Ui::Toast::Show(Ui::Toast::Config{
 		.text = { text },
@@ -80,6 +82,16 @@ bool CanSendFiles(not_null<const QMimeData*> data) {
 
 } // namespace
 
+RepliesMemento::RepliesMemento(not_null<HistoryItem*> commentsItem)
+: RepliesMemento(commentsItem->history(), commentsItem->id) {
+	if (commentsItem->repliesReadTill() == MsgId(1)) {
+		_list.setAroundPosition(Data::MinMessagePosition);
+		_list.setScrollTopState(ListMemento::ScrollTopState{
+			Data::MinMessagePosition
+		});
+	}
+}
+
 object_ptr<Window::SectionWidget> RepliesMemento::createWidget(
 		QWidget *parent,
 		not_null<Window::SessionController*> controller,
@@ -106,6 +118,7 @@ RepliesWidget::RepliesWidget(
 , _history(history)
 , _rootId(rootId)
 , _root(lookupRoot())
+, _commentsRoot(lookupCommentsRoot())
 , _areComments(computeAreComments())
 , _scroll(this, st::historyScroll, false)
 , _topBar(this, controller)
@@ -115,7 +128,8 @@ RepliesWidget::RepliesWidget(
 	controller,
 	ComposeControls::Mode::Normal))
 , _rootShadow(this)
-, _scrollDown(_scroll, st::historyToDown) {
+, _scrollDown(_scroll, st::historyToDown)
+, _readRequestTimer([=] { sendReadTillRequest(); }) {
 	setupRoot();
 
 	_rootHeight = st::msgReplyPadding.top()
@@ -178,9 +192,13 @@ RepliesWidget::RepliesWidget(
 
 	_history->session().changes().messageUpdates(
 		Data::MessageUpdate::Flag::Destroyed
-	) | rpl::filter([=](const Data::MessageUpdate &update) {
+	) | rpl::start_with_next([=](const Data::MessageUpdate &update) {
-		return (update.item == _replyReturn);
+		if (update.item == _root) {
-	}) | rpl::start_with_next([=](const Data::MessageUpdate &update) {
+			_root = nullptr;
+		}
+		if (update.item == _commentsRoot) {
+			_commentsRoot = nullptr;
+		}
 		while (update.item == _replyReturn) {
 			calculateNextReplyReturn();
 		}
@@ -190,10 +208,33 @@ RepliesWidget::RepliesWidget(
 	setupComposeControls();
 }
 
-RepliesWidget::~RepliesWidget() = default;
+RepliesWidget::~RepliesWidget() {
+	if (_readRequestTimer.isActive()) {
+		sendReadTillRequest();
+	}
+}
+
+void RepliesWidget::sendReadTillRequest() {
+	if (!_commentsRoot || !_root) {
+		return;
+	}
+	if (_readRequestTimer.isActive()) {
+		_readRequestTimer.cancel();
+	}
+	const auto api = &_history->session().api();
+	api->request(base::take(_readRequestId)).cancel();
+	_readRequestId = api->request(MTPmessages_ReadDiscussion(
+		_commentsRoot->history()->peer->input,
+		MTP_int(_commentsRoot->id),
+		MTP_int(_root->repliesReadTill())
+	)).done([=](const MTPBool &) {
+
+	}).send();
+}
 
 void RepliesWidget::setupRoot() {
 	if (_root) {
+		setupCommentsRoot();
 		refreshRootView();
 	} else {
 		const auto channel = _history->peer->asChannel();
@@ -201,6 +242,7 @@ void RepliesWidget::setupRoot() {
 			_root = lookupRoot();
 			if (_root) {
 				_areComments = computeAreComments();
+				setupCommentsRoot();
 			}
 			refreshRootView();
 		});
@@ -208,6 +250,30 @@ void RepliesWidget::setupRoot() {
 	}
 }
 
+void RepliesWidget::setupCommentsRoot() {
+	Expects(_root != nullptr);
+
+	const auto postChannel = _root->discussionPostOriginalSender();
+	if (!postChannel) {
+		return;
+	} else if (_commentsRoot) {
+		sendReadTillRequest();
+	} else {
+		const auto forwarded = _root->Get<HistoryMessageForwarded>();
+		const auto messageId = forwarded->savedFromMsgId;
+		const auto done = crl::guard(this, [=](ChannelData*, MsgId) {
+			_commentsRoot = lookupCommentsRoot();
+			if (_commentsRoot) {
+				sendReadTillRequest();
+			}
+		});
+		_history->session().api().requestMessageData(
+			postChannel,
+			messageId,
+			done);
+	}
+}
+
 void RepliesWidget::refreshRootView() {
 	const auto sender = (_root && _root->discussionPostOriginalSender())
 		? _root->discussionPostOriginalSender()
@@ -240,6 +306,17 @@ HistoryItem *RepliesWidget::lookupRoot() const {
 	return _history->owner().message(_history->channelId(), _rootId);
 }
 
+HistoryItem *RepliesWidget::lookupCommentsRoot() const {
+	if (!computeAreComments()) {
+		return nullptr;
+	}
+	const auto forwarded = _root->Get<HistoryMessageForwarded>();
+	Assert(forwarded != nullptr);
+	return _history->owner().message(
+		forwarded->savedFromPeer->asChannel(),
+		forwarded->savedFromMsgId);
+}
+
 bool RepliesWidget::computeAreComments() const {
 	return _root && _root->isDiscussionPost();
 }
@@ -1364,11 +1441,49 @@ void RepliesWidget::listSelectionChanged(SelectedItems &&items) {
 	_topBar->showSelected(state);
 }
 
+void RepliesWidget::readTill(MsgId tillId) {
+	if (!_root) {
+		return;
+	}
+	const auto now = _root->repliesReadTill();
+	if (now < tillId) {
+		_root->setRepliesReadTill(tillId);
+		if (!_readRequestTimer.isActive()) {
+			_readRequestTimer.callOnce(kReadRequestTimeout);
+		}
+	}
+}
+
 void RepliesWidget::listVisibleItemsChanged(HistoryItemsList &&items) {
+	const auto reversed = ranges::view::reverse(items);
+	const auto good = ranges::find_if(reversed, [](auto item) {
+		return IsServerMsgId(item->id);
+	});
+	if (good != end(reversed)) {
+		readTill((*good)->id);
+	}
 }
 
 std::optional<int> RepliesWidget::listUnreadBarView(
 		const std::vector<not_null<Element*>> &elements) {
+	if (!_root) {
+		return std::nullopt;
+	}
+	const auto till = _root->repliesReadTill();
+	if (till < 2) {
+		return std::nullopt;
+	}
+	for (auto i = 0, count = int(elements.size()); i != count; ++i) {
+		const auto item = elements[i]->data();
+		if (item->id > till) {
+			if (item->out()) {
+				_root->setRepliesReadTill(item->id);
+				_readRequestTimer.callOnce(kReadRequestTimeout);
+			} else {
+				return i;
+			}
+		}
+	}
 	return std::nullopt;
 }
 

Telegram/SourceFiles/history/view/history_view_replies_section.h

@@ -11,6 +11,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "window/section_memento.h"
 #include "history/view/history_view_list_widget.h"
 #include "data/data_messages.h"
+#include "base/timer.h"
 
 class History;
 enum class CompressConfirm;
@@ -148,8 +149,11 @@ private:
 	void setupComposeControls();
 
 	void setupRoot();
+	void setupCommentsRoot();
 	void refreshRootView();
 	void setupDragArea();
+	void sendReadTillRequest();
+	void readTill(MsgId id);
 
 	void setupScrollDownButton();
 	void scrollDownClicked();
@@ -172,6 +176,7 @@ private:
 	[[nodiscard]] SendMenu::Type sendMenuType() const;
 	[[nodiscard]] MsgId replyToId() const;
 	[[nodiscard]] HistoryItem *lookupRoot() const;
+	[[nodiscard]] HistoryItem *lookupCommentsRoot() const;
 	[[nodiscard]] bool computeAreComments() const;
 
 	void pushReplyReturn(not_null<HistoryItem*> item);
@@ -224,6 +229,7 @@ private:
 	const not_null<History*> _history;
 	const MsgId _rootId = 0;
 	HistoryItem *_root = nullptr;
+	HistoryItem *_commentsRoot = nullptr;
 	std::shared_ptr<Data::RepliesList> _replies;
 	rpl::variable<bool> _areComments = false;
 	object_ptr<Ui::ScrollArea> _scroll;
@@ -248,14 +254,19 @@ private:
 	Data::MessagesSlice _lastSlice;
 	bool _choosingAttach = false;
 
+	base::Timer _readRequestTimer;
+	mtpRequestId _readRequestId = 0;
+
 };
 
+
 class RepliesMemento : public Window::SectionMemento {
 public:
 	RepliesMemento(not_null<History*> history, MsgId rootId)
 	: _history(history)
 	, _rootId(rootId) {
 	}
+	explicit RepliesMemento(not_null<HistoryItem*> commentsItem);
 
 	object_ptr<Window::SectionWidget> createWidget(
 		QWidget *parent,

Telegram/SourceFiles/window/window_session_controller.cpp

@@ -110,7 +110,7 @@ void SessionNavigation::showRepliesForMessage(
 	} else if (const auto id = item->commentsItemId()) {
 		if (const auto item = _session->data().message(id)) {
 			showSection(
-				HistoryView::RepliesMemento(item->history(), item->id));
+				HistoryView::RepliesMemento(item));
 			return;
 		}
 	}
@@ -148,8 +148,11 @@ void SessionNavigation::showRepliesForMessage(
 				if (post) {
 					post->setCommentsItemId(item->fullId());
 				}
+				if (const auto readTill = data.vread_max_id()) {
+					item->setRepliesReadTill(readTill->v);
+				}
 				showSection(
-					HistoryView::RepliesMemento(item->history(), item->id));
+					HistoryView::RepliesMemento(item));
 			}
 		});
 	}).fail([=](const RPCError &error) {