Correct implementation of auto-translation.

Telegram/Resources/langs/lang.strings

@@ -4292,6 +4292,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 "lng_sensitive_toast" = "You can update the visibility of sensitive media in **Settings > Chat Settings > Sensitive content**";
 
 "lng_translate_show_original" = "Show Original";
+"lng_translate_return_original" = "View Original ({language})";
 "lng_translate_bar_to" = "Translate to {name}";
 "lng_translate_bar_to_other" = "Translate to {name}";
 "lng_translate_menu_to" = "Translate To";

Telegram/SourceFiles/boxes/peers/edit_peer_info_box.cpp

@@ -1116,29 +1116,37 @@ void Controller::fillAutoTranslateButton() {
 			[] {},
 			st::manageGroupTopicsButton,
 			{ &st::menuIconTranslate }));
-	const auto toggled = autotranslate->lifetime().make_state<
-		rpl::event_stream<bool>
-	>();
+	struct State {
+		rpl::event_stream<bool> toggled;
+		rpl::variable<bool> isLocked = false;
+	};
+	const auto state = autotranslate->lifetime().make_state<State>();
 	autotranslate->toggleOn(rpl::single(
 		channel->autoTranslation()
-	) | rpl::then(toggled->events()));
-	const auto isLocked = channel->levelHint() < requiredLevel;
+	) | rpl::then(state->toggled.events()));
+	state->isLocked = (channel->levelHint() < requiredLevel);
 	const auto reason = Ui::AskBoostReason{
 		.data = Ui::AskBoostAutotranslate{ .requiredLevel = requiredLevel },
 	};
 
-	autotranslate->setToggleLocked(isLocked);
+	state->isLocked.value() | rpl::start_with_next([=](bool locked) {
+		autotranslate->setToggleLocked(locked);
+	}, autotranslate->lifetime());
 
 	autotranslate->toggledChanges(
 	) | rpl::start_with_next([=](bool value) {
-		if (!isLocked) {
-			_autotranslateSavedValue = toggled;
+		if (!state->isLocked.current()) {
+			_autotranslateSavedValue = value;
 		} else if (value) {
-			toggled->fire(false);
+			state->toggled.fire(false);
+			auto weak = Ui::MakeWeak(autotranslate);
 			CheckBoostLevel(
 				_navigation->uiShow(),
 				_peer,
 				[=](int level) {
+					if (const auto strong = weak.data()) {
+						state->isLocked = (level < requiredLevel);
+					}
 					return (level < requiredLevel)
 						? std::make_optional(reason)
 						: std::nullopt;

Telegram/SourceFiles/history/history.cpp

@@ -3686,6 +3686,11 @@ void History::translateOfferFrom(LanguageId id) {
 		}
 	} else if (!_translation) {
 		_translation = std::make_unique<HistoryTranslation>(this, id);
+		using Flag = PeerData::TranslationFlag;
+		if (peer->autoTranslation()
+			&& (peer->translationFlag() == Flag::Enabled)) {
+			translateTo(Core::App().settings().translateTo());
+		}
 	} else {
 		_translation->offerFrom(id);
 	}

Telegram/SourceFiles/history/history_widget.cpp

@@ -7557,10 +7557,6 @@ void HistoryWidget::checkLastPinnedClickedIdReset(
 void HistoryWidget::setupTranslateBar() {
 	Expects(_history != nullptr);
 
-	if (_history->peer->autoTranslation()) {
-		_history->translateTo(Core::App().settings().translateTo());
-	}
-
 	_translateBar = std::make_unique<HistoryView::TranslateBar>(
 		this,
 		controller(),

Telegram/SourceFiles/history/view/history_view_translate_bar.cpp

@@ -372,11 +372,16 @@ void TranslateBar::setup(not_null<History*> history) {
 			const auto&,
 			const auto&) {
 		using Flag = PeerData::TranslationFlag;
-		//const auto autotranslation = history->peer->autoTranslation();
+		const auto automatic = history->peer->autoTranslation();
 		return (history->peer->translationFlag() != Flag::Enabled)
 			? rpl::single(QString())
 			: history->translatedTo()
-			? tr::lng_translate_show_original()
+			? (automatic
+				? tr::lng_translate_return_original(
+					lt_language,
+					rpl::single(Ui::LanguageName(
+						history->translateOfferedFrom())))
+				: tr::lng_translate_show_original())
 			: history->translateOfferedFrom()
 			? Ui::TranslateBarTo(to)
 			: rpl::single(QString());

Telegram/SourceFiles/history/view/history_view_translate_tracker.cpp

@@ -53,28 +53,23 @@ void TranslateTracker::setup() {
 	const auto peer = _history->peer;
 	peer->updateFull();
 
-	using namespace rpl::mappers;
-	_trackingLanguage = rpl::combine(
-		Data::AmPremiumValue(&_history->session()),
-		Core::App().settings().translateChatEnabledValue(),
-		_1 && _2);
-
 	const auto channel = peer->asChannel();
 	auto autoTranslationValue = (channel
 		? channel->flagsValue()
 		: rpl::single(Data::Flags<ChannelDataFlags>::Change({}, {}))
-	) | rpl::map([=](Data::Flags<ChannelDataFlags>::Change data) {
+		) | rpl::map([=](Data::Flags<ChannelDataFlags>::Change data) {
 		return (data.value & ChannelDataFlag::AutoTranslation);
 	}) | rpl::distinct_until_changed();
-	rpl::combine(
-		_trackingLanguage.value(),
-		std::move(autoTranslationValue)
-	) | rpl::start_with_next([=](bool tracking, bool autotranslation) {
+
+	using namespace rpl::mappers;
+	_trackingLanguage = rpl::combine(
+		Core::App().settings().translateChatEnabledValue(),
+		Data::AmPremiumValue(&_history->session()),
+		std::move(autoTranslationValue),
+		_1 && (_2 || _3));
+	_trackingLanguage.value() | rpl::start_with_next([=](bool tracking) {
 		_trackingLifetime.destroy();
-		if (autotranslation) {
-			_history->translateOfferFrom({ QLocale::French });
-			AssertIsDebug();
-		} else if (tracking) {
+		if (tracking) {
 			recognizeCollected();
 			trackSkipLanguages();
 		} else {
@@ -115,7 +110,7 @@ bool TranslateTracker::add(
 		bool skipDependencies) {
 	Expects(_addedInBunch >= 0);
 
-	if (item->out()
+	if ((item->out() && !item->history()->peer->autoTranslation())
 		|| item->isService()
 		|| !item->isRegular()
 		|| item->isOnlyEmojiAndSpaces()) {