Destroy messages by ttl_period dates.

Telegram/Resources/langs/lang.strings

@@ -975,6 +975,13 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 "lng_manage_history_visibility_hidden_about" = "New members won't see earlier messages.";
 "lng_manage_history_visibility_hidden_legacy" = "New members won't see more than 100 previous messages.";
 
+"lng_manage_messages_ttl_title" = "Auto-delete messages";
+"lng_manage_messages_ttl_never" = "Never";
+"lng_manage_messages_ttl_after1" = "After 24 hours";
+"lng_manage_messages_ttl_after2" = "After 7 days";
+"lng_manage_messages_ttl_about" = "Turning on this setting will make auto-delete messages from this group after the selected period.";
+"lng_manage_messages_ttl_about_channel" = "Turning on this setting will make auto-delete messages from this channel after the selected period.";
+
 "lng_report_title" = "Report channel";
 "lng_report_group_title" = "Report group";
 "lng_report_bot_title" = "Report bot";

Telegram/SourceFiles/data/data_session.cpp

@@ -220,6 +220,7 @@ Session::Session(not_null<Main::Session*> session)
 	session->serverConfig().pinnedDialogsCountMax.value())
 , _contactsList(Dialogs::SortMode::Name)
 , _contactsNoChatsList(Dialogs::SortMode::Name)
+, _ttlCheckTimer([=] { checkTTLs(); })
 , _selfDestructTimer([=] { checkSelfDestructItems(); })
 , _sendActionsAnimation([=](crl::time now) {
 	return sendActionsAnimationCallback(now);
@@ -1959,6 +1960,54 @@ void Session::registerMessage(not_null<HistoryItem*> item) {
 	list->emplace(itemId, item);
 }
 
+void Session::registerMessageTTL(TimeId when, not_null<HistoryItem*> item) {
+	Expects(when > 0);
+
+	auto &list = _ttlMessages[when];
+	list.emplace(item);
+
+	const auto nearest = _ttlMessages.begin()->first;
+	if (nearest < when && _ttlCheckTimer.isActive()) {
+		return;
+	}
+	scheduleNextTTLs();
+}
+
+void Session::scheduleNextTTLs() {
+	if (_ttlMessages.empty()) {
+		return;
+	}
+	const auto nearest = _ttlMessages.begin()->first;
+	const auto now = base::unixtime::now();
+	const auto timeout = (std::max(now, nearest) - now) * crl::time(1000);
+	_ttlCheckTimer.callOnce(timeout);
+}
+
+void Session::unregisterMessageTTL(
+		TimeId when,
+		not_null<HistoryItem*> item) {
+	Expects(when > 0);
+
+	const auto i = _ttlMessages.find(when);
+	if (i == end(_ttlMessages)) {
+		return;
+	}
+	auto &list = i->second;
+	list.erase(item);
+	if (list.empty()) {
+		_ttlMessages.erase(i);
+	}
+}
+
+void Session::checkTTLs() {
+	_ttlCheckTimer.cancel();
+	const auto now = base::unixtime::now();
+	while (!_ttlMessages.empty() && _ttlMessages.begin()->first <= now) {
+		_ttlMessages.begin()->second.front()->destroy();
+	}
+	scheduleNextTTLs();
+}
+
 void Session::processMessagesDeleted(
 		ChannelId channelId,
 		const QVector<MTPint> &data) {

Telegram/SourceFiles/data/data_session.h

@@ -328,6 +328,9 @@ public:
 	void registerMessage(not_null<HistoryItem*> item);
 	void unregisterMessage(not_null<HistoryItem*> item);
 
+	void registerMessageTTL(TimeId when, not_null<HistoryItem*> item);
+	void unregisterMessageTTL(TimeId when, not_null<HistoryItem*> item);
+
 	// Returns true if item found and it is not detached.
 	bool checkEntitiesAndViewsUpdate(const MTPDmessage &data);
 	void updateEditedMessage(const MTPMessage &data);
@@ -686,6 +689,9 @@ private:
 
 	void checkSelfDestructItems();
 
+	void scheduleNextTTLs();
+	void checkTTLs();
+
 	int computeUnreadBadge(const Dialogs::UnreadState &state) const;
 	bool computeUnreadBadgeMuted(const Dialogs::UnreadState &state) const;
 
@@ -857,6 +863,8 @@ private:
 	std::map<
 		not_null<HistoryItem*>,
 		base::flat_set<not_null<HistoryItem*>>> _dependentMessages;
+	std::map<TimeId, base::flat_set<not_null<HistoryItem*>>> _ttlMessages;
+	base::Timer _ttlCheckTimer;
 
 	base::flat_map<uint64, FullMsgId> _messageByRandomId;
 	base::flat_map<uint64, SentData> _sentMessagesData;

Telegram/SourceFiles/history/history_item.h

@@ -79,6 +79,9 @@ public:
 	[[nodiscard]] virtual bool notificationReady() const {
 		return true;
 	}
+	[[nodiscard]] virtual TimeId ttlDestroyAt() const {
+		return 0;
+	}
 	[[nodiscard]] PeerData *specialNotificationPeer() const;
 
 	[[nodiscard]] UserData *viaBot() const;

Telegram/SourceFiles/history/history_message.cpp

@@ -50,6 +50,9 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "styles/style_chat.h"
 #include "styles/style_window.h"
 
+#include "base/call_delayed.h" // #TODO ttl
+#include "base/unixtime.h"
+
 #include <QtGui/QGuiApplication>
 #include <QtGui/QClipboard>
 
@@ -523,6 +526,12 @@ HistoryMessage::HistoryMessage(
 		setGroupId(
 			MessageGroupId::FromRaw(history->peer->id, groupedId->v));
 	}
+
+	if (const auto period = data.vttl_period()) {
+		if (period->v > 0) {
+			applyTTL(data.vdate().v + period->v);
+		}
+	}
 }
 
 HistoryMessage::HistoryMessage(
@@ -1352,6 +1361,12 @@ void HistoryMessage::applyEdition(const MTPDmessage &message) {
 		clearReplies();
 	}
 
+	if (const auto period = message.vttl_period(); period && period->v > 0) {
+		applyTTL(message.vdate().v + period->v);
+	} else {
+		applyTTL(0);
+	}
+
 	finishEdition(keyboardTop);
 }
 
@@ -1367,6 +1382,25 @@ void HistoryMessage::applyEdition(const MTPDmessageService &message) {
 	}
 }
 
+void HistoryMessage::applyTTL(TimeId destroyAt) {
+	const auto previousDestroyAt = std::exchange(_ttlDestroyAt, destroyAt);
+	if (previousDestroyAt) {
+		history()->owner().unregisterMessageTTL(previousDestroyAt, this);
+	}
+	if (!_ttlDestroyAt) {
+		return;
+	} else if (base::unixtime::now() >= _ttlDestroyAt) {
+		const auto session = &history()->session();
+		crl::on_main(session, [session, id = fullId()]{
+			if (const auto item = session->data().message(id)) {
+				item->destroy();
+			}
+		});
+	} else {
+		history()->owner().registerMessageTTL(_ttlDestroyAt, this);
+	}
+}
+
 void HistoryMessage::updateSentContent(
 		const TextWithEntities &textWithEntities,
 		const MTPMessageMedia *media) {
@@ -1872,6 +1906,7 @@ std::unique_ptr<HistoryView::Element> HistoryMessage::createView(
 }
 
 HistoryMessage::~HistoryMessage() {
+	applyTTL(0);
 	_media.reset();
 	clearSavedMedia();
 	if (auto reply = Get<HistoryMessageReply>()) {

Telegram/SourceFiles/history/history_message.h

@@ -188,6 +188,10 @@ public:
 		return replyToId();
 	}
 
+	[[nodiscard]] TimeId ttlDestroyAt() const override {
+		return _ttlDestroyAt;
+	}
+
 	// dynamic_cast optimization.
 	[[nodiscard]] HistoryMessage *toHistoryMessage() override {
 		return this;
@@ -240,6 +244,8 @@ private:
 		const TextWithEntities &textWithEntities) const;
 	void reapplyText();
 
+	void applyTTL(TimeId destroyAt);
+
 	[[nodiscard]] bool checkRepliesPts(const MTPMessageReplies &data) const;
 
 	QString _timeText;
@@ -247,6 +253,8 @@ private:
 
 	mutable int32 _fromNameVersion = 0;
 
+	TimeId _ttlDestroyAt = 0;
+
 	friend class HistoryView::Element;
 	friend class HistoryView::Message;