diff --git a/Telegram/SourceFiles/app.cpp b/Telegram/SourceFiles/app.cpp
index 3d4402b11..4eb3493f1 100644
--- a/Telegram/SourceFiles/app.cpp
+++ b/Telegram/SourceFiles/app.cpp
@@ -46,6 +46,8 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 #include "numbers.h"
 #include "observer_peer.h"
 #include "auth_session.h"
+#include "storage/storage_facade.h"
+#include "storage/storage_shared_media.h"
 #include "window/themes/window_theme.h"
 #include "window/notifications_manager.h"
 #include "platform/platform_notifications_manager.h"
@@ -1029,6 +1031,13 @@ namespace {
 			existing->setViewsCount(m.has_views() ? m.vviews.v : -1);
 			existing->addToOverview(AddToOverviewNew);
 
+			if (auto sharedMediaTypes = existing->sharedMediaTypes()) {
+				Auth().storage().add(Storage::SharedMediaAddNew(
+					peerId,
+					sharedMediaTypes,
+					existing->id));
+			}
+
 			if (!existing->detached()) {
 				App::checkSavedGif(existing);
 				return true;
diff --git a/Telegram/SourceFiles/history/history_shared_media.cpp b/Telegram/SourceFiles/history/history_shared_media.cpp
index 774fb9d83..2a70bb8b2 100644
--- a/Telegram/SourceFiles/history/history_shared_media.cpp
+++ b/Telegram/SourceFiles/history/history_shared_media.cpp
@@ -62,6 +62,42 @@ History *GetMigratedHistory(
 
 } // namespace
 
+base::optional<Storage::SharedMediaType> SharedMediaOverviewType(
+	Storage::SharedMediaType type) {
+	if (SharedMediaTypeToOverview(type) != OverviewCount) {
+		return type;
+	}
+	return base::none;
+}
+
+void SharedMediaShowOverview(
+	Storage::SharedMediaType type,
+	not_null<History*> history) {
+	if (SharedMediaOverviewType(type)) {
+		Ui::showPeerOverview(history, SharedMediaTypeToOverview(type));
+	}
+}
+
+QString SharedMediaSlice::debug() const {
+	auto before = _skippedBefore
+		? (*_skippedBefore
+			? ('(' + QString::number(*_skippedBefore) + ").. ")
+			: QString())
+		: QString(".. ");
+	auto after = _skippedAfter
+		? (*_skippedAfter
+			? (" ..(" + QString::number(*_skippedAfter) + ')')
+			: QString())
+		: QString(" ..");
+	auto middle = (size() > 2)
+		? QString::number((*this)[0]) + " .. " + QString::number((*this)[size() - 1])
+		: (size() > 1)
+		? QString::number((*this)[0]) + ' ' + QString::number((*this)[1])
+		: ((size() > 0) ? QString((*this)[0]) : QString());
+	return before + middle + after;
+}
+
+
 SharedMediaViewer::SharedMediaViewer(
 	Key key,
 	int limitBefore,
@@ -70,22 +106,8 @@ SharedMediaViewer::SharedMediaViewer(
 	, _limitBefore(limitBefore)
 	, _limitAfter(limitAfter)
 	, _data(_key) {
-}
-
-base::optional<Storage::SharedMediaType> SharedMediaOverviewType(
-		Storage::SharedMediaType type) {
-	if (SharedMediaTypeToOverview(type) != OverviewCount) {
-		return type;
-	}
-	return base::none;
-}
-
-void SharedMediaShowOverview(
-		Storage::SharedMediaType type,
-		not_null<History*> history) {
-	if (SharedMediaOverviewType(type)) {
-		Ui::showPeerOverview(history, SharedMediaTypeToOverview(type));
-	}
+	Expects(IsServerMsgId(key.messageId) || (key.messageId == 0));
+	Expects((key.messageId != 0) || (limitBefore == 0 && limitAfter == 0));
 }
 
 void SharedMediaViewer::start() {
@@ -125,10 +147,15 @@ void SharedMediaViewer::mergeSliceData(
 		base::optional<int> skippedBefore,
 		base::optional<int> skippedAfter) {
 	if (messageIds.empty()) {
-		if (count && *_data._fullCount != *count) {
+		if (count && _data._fullCount != count) {
 			_data._fullCount = count;
+			if (*_data._fullCount <= _data.size()) {
+				_data._fullCount = _data.size();
+				_data._skippedBefore = _data._skippedAfter = 0;
+			}
 			updated.notify(_data);
 		}
+		sliceToLimits();
 		return;
 	}
 	if (count) {
@@ -285,125 +312,71 @@ void SharedMediaViewer::requestMessages(RequestDirection direction) {
 		requestAroundData.second);
 }
 
-//
-//base::optional<int> SharedMediaViewerMerged::Data::fullCount() const {
-//	if (_historyCount && _migratedCount) {
-//		return (*_historyCount + *_migratedCount);
-//	}
-//	return base::none;
-//}
-//base::optional<int> SharedMediaViewerMerged::Data::skippedBefore() const {
-//	if (_ids.empty()) {
-//		return base::none;
-//	} else if (!IsServerMsgId(_ids.front())) {
-//		return _migratedSkippedBefore;
-//	} else if (_historySkippedBefore && _migratedCount) {
-//		return *_historySkippedBefore + *_migratedCount;
-//	}
-//	return base::none;
-//}
-//
-//base::optional<int> SharedMediaViewerMerged::Data::skippedAfter() const {
-//	if (_ids.empty()) {
-//		return base::none;
-//	} else if (IsServerMsgId(_ids.back())) {
-//		return _historySkippedAfter;
-//	} else if (_migratedSkippedAfter && _historyCount) {
-//		return *_migratedSkippedAfter + *_historyCount;
-//	}
-//	return base::none;
-//}
-//
-//SharedMediaViewerMerged::SharedMediaViewerMerged(
-//	Type type,
-//	not_null<History*> history,
-//	MsgId aroundId,
-//	int limitBefore,
-//	int limitAfter)
-//: _type(type)
-//, _history(GetActualHistory(history))
-//, _migrated(GetMigratedHistory(history, _history))
-//, _universalAroundId((_history == _migrated) ? -aroundId : aroundId)
-//, _limitBefore(limitBefore)
-//, _limitAfter(limitAfter)
-//, _data(_history, _migrated) {
-//}
-//
-//bool SharedMediaViewerMerged::hasOverview() const {
-//	return SharedMediaTypeToOverview(_type) != OverviewCount;
-//}
-//
-//void SharedMediaViewerMerged::showOverview() const {
-//	if (hasOverview()) {
-//		Ui::showPeerOverview(_history, SharedMediaTypeToOverview(_type));
-//	}
-//}
-//
-//bool SharedMediaViewerMerged::moveTo(const SharedMediaViewerMerged &other) {
-//	if (_history != other._history || _type != other._type) {
-//		return false;
-//	}
-//	_universalAroundId = other._universalAroundId;
-//	if (!containsAroundId()) {
-//		clearAfterMove();
-//	}
-//	load();
-//	return true;
-//}
-//
-//bool SharedMediaViewerMerged::containsAroundId() const {
-//	if (_data._ids.empty()) {
-//		return false;
-//	}
-//	auto min = _data._ids.front();
-//	auto max = _data._ids.back();
-//	if (IsServerMsgId(_universalAroundId)) {
-//		return (!IsServerMsgId(min) || min <= aroundId())
-//			&& (IsServerMsgId(max) && max >= aroundId());
-//	}
-//	return (!IsServerMsgId(min) && -min <= aroundId())
-//		&& (IsServerMsgId(max) || -max >= aroundId());
-//}
-//
-//bool SharedMediaViewerMerged::amAroundMigrated() const {
-//	return !IsServerMsgId(_universalAroundId);
-//}
-//
-//not_null<History*> SharedMediaViewerMerged::aroundHistory() const {
-//	return amAroundMigrated() ? _migrated : _history;
-//}
-//
-//MsgId SharedMediaViewerMerged::aroundId() const {
-//	return amAroundMigrated() ? -_universalAroundId : _universalAroundId;
-//}
-//
-//void SharedMediaViewerMerged::clearAfterMove() {
-//	_data = Data(_history, _migrated, _data._historyCount, _data._migratedCount);
-//}
-//
-//void SharedMediaViewerMerged::load() {
-//	auto weak = base::make_weak_unique(this);
-//	auto peer = aroundHistory()->peer;
-//	Auth().storage().query(Storage::SharedMediaQuery(
-//			peer->id,
-//			_type,
-//			aroundId(),
-//			_limitBefore,
-//			_limitAfter), [weak, peer](Storage::SharedMediaResult &&result) {
-//		if (weak) {
-//			weak->applyStoredResult(peer, std::move(result));
-//		}
-//	});
-//}
-//
-//void SharedMediaViewerMerged::applyStoredResult(
-//		not_null<PeerData*> peer,
-//		Storage::SharedMediaResult &&result) {
-//	if (aroundHistory()->peer != peer) {
-//		return;
-//	}
-//	auto aroundMigrated = amAroundMigrated();
-//	if (result.count) {
-//		(aroundMigrated ? _data._migratedCount : _data._historyCount) = result.count;
-//	}
-//}
+SharedMediaViewerMerged::SharedMediaViewerMerged(
+	Key key,
+	int limitBefore,
+	int limitAfter)
+	: _key(key)
+	, _limitBefore(limitBefore)
+	, _limitAfter(limitAfter)
+	, _part(PartKey(_key), _limitBefore, _limitAfter)
+	, _migrated(MigratedViewer(_key, _limitBefore, _limitAfter))
+	, _data(_key, SharedMediaSlice(PartKey(_key)), MigratedSlice(_key)) {
+	Expects(IsServerMsgId(key.universalId)
+		|| (key.universalId == 0)
+		|| (IsServerMsgId(-key.universalId) && key.migratedPeerId != 0));
+	Expects((key.universalId != 0) || (limitBefore == 0 && limitAfter == 0));
+}
+
+SharedMediaSlice::Key SharedMediaViewerMerged::PartKey(const Key &key) {
+	return {
+		key.peerId,
+		key.type,
+		(key.universalId < 0) ? 1 : key.universalId
+	};
+}
+
+SharedMediaSlice::Key SharedMediaViewerMerged::MigratedKey(const Key &key) {
+	return {
+		key.migratedPeerId,
+		key.type,
+		(key.universalId <= 0) ? (-key.universalId) : (ServerMaxMsgId - 1)
+	};
+}
+
+std::unique_ptr<SharedMediaViewer> SharedMediaViewerMerged::MigratedViewer(
+		const Key &key,
+		int limitBefore,
+		int limitAfter) {
+	return key.migratedPeerId
+		? std::make_unique<SharedMediaViewer>(
+			MigratedKey(key),
+			limitBefore,
+			limitAfter)
+		: nullptr;
+}
+
+base::optional<SharedMediaSlice> SharedMediaViewerMerged::MigratedSlice(
+		const Key &key) {
+	if (!key.migratedPeerId) {
+		return base::none;
+	}
+	return SharedMediaSlice(MigratedKey(key));
+}
+
+void SharedMediaViewerMerged::start() {
+	subscribe(_part.updated, [this](const SharedMediaSlice &update) {
+		_data = SharedMediaSliceMerged(_key, update, _data._migrated);
+		updated.notify(_data);
+	});
+	if (_migrated) {
+		subscribe(_migrated->updated, [this](const SharedMediaSlice &update) {
+			_data = SharedMediaSliceMerged(_key, _data._part, update);
+			updated.notify(_data);
+		});
+	}
+	_part.start();
+	if (_migrated) {
+		_migrated->start();
+	}
+}
diff --git a/Telegram/SourceFiles/history/history_shared_media.h b/Telegram/SourceFiles/history/history_shared_media.h
index bc94d74ca..b9b8b62c0 100644
--- a/Telegram/SourceFiles/history/history_shared_media.h
+++ b/Telegram/SourceFiles/history/history_shared_media.h
@@ -42,6 +42,10 @@ public:
 		, _fullCount(fullCount) {
 	}
 
+	const Key &key() const {
+		return _key;
+	}
+
 	base::optional<int> fullCount() const {
 		return _fullCount;
 	}
@@ -62,19 +66,10 @@ public:
 		return _ids.size();
 	}
 
-	using iterator = base::flat_set<MsgId>::const_iterator;
+	MsgId operator[](int index) const {
+		Expects(index >= 0 && index < size());
 
-	iterator begin() const {
-		return _ids.begin();
-	}
-	iterator end() const {
-		return _ids.end();
-	}
-	iterator cbegin() const {
-		return begin();
-	}
-	iterator cend() const {
-		return end();
+		return *(_ids.begin() + index);
 	}
 
 	base::optional<int> distance(const Key &a, const Key &b) const {
@@ -84,14 +79,16 @@ public:
 			|| b.peerId != _key.peerId) {
 			return base::none;
 		}
-		auto i = _ids.find(a.messageId);
-		auto j = _ids.find(b.messageId);
-		if (i == _ids.end() || j == _ids.end()) {
-			return base::none;
+		if (auto i = indexOf(a.messageId)) {
+			if (auto j = indexOf(b.messageId)) {
+				return *j - *i;
+			}
 		}
-		return j - i;
+		return base::none;
 	}
 
+	QString debug() const;
+
 private:
 	Key _key;
 	base::flat_set<MsgId> _ids;
@@ -115,6 +112,8 @@ public:
 		Key key,
 		int limitBefore,
 		int limitAfter);
+	SharedMediaViewer(const SharedMediaViewer &other) = delete;
+	SharedMediaViewer(SharedMediaViewer &&other) = default;
 
 	void start();
 
@@ -144,7 +143,6 @@ private:
 		base::optional<int> skippedBefore = base::none,
 		base::optional<int> skippedAfter = base::none);
 
-
 	Key _key;
 	int _limitBefore = 0;
 	int _limitAfter = 0;
@@ -153,164 +151,196 @@ private:
 	SharedMediaSlice _data;
 
 };
-//
-//class SharedMediaSliceMerged :
-//	private MTP::Sender,
-//	private base::Subscriber,
-//	public base::enable_weak_from_this {
-//public:
-//	class Data;
-//
-//private:
-//	friend class Data;
-//	using UniversalMsgId = MsgId;
-//
-//public:
-//	using Type = Storage::SharedMediaType;
-//
-//	SharedMediaSliceMerged(
-//		Type type,
-//		not_null<History*> history,
-//		MsgId aroundId,
-//		int limitBefore,
-//		int limitAfter);
-//
-//	bool hasOverview() const;
-//	void showOverview() const;
-//	bool moveTo(const SharedMediaSliceMerged &other);
-//
-//	void load();
-//
-//	class Data {
-//	public:
-//		base::optional<int> fullCount() const;
-//		base::optional<int> skippedBefore() const;
-//		base::optional<int> skippedAfter() const;
-//		int size() const {
-//			return _ids.size();
-//		}
-//
-//		class iterator {
-//		public:
-//			FullMsgId operator*() const {
-//				auto id = _data->_ids[_index];
-//				Assert(IsServerMsgId(id)
-//					|| (_data->_migrated != nullptr && IsServerMsgId(-id)));
-//				return IsServerMsgId(id)
-//					? FullMsgId(_data->_history->channelId(), id)
-//					: FullMsgId(_data->_migrated->channelId(), -id);
-//			}
-//			iterator &operator--() {
-//				--_index;
-//				return *this;
-//			}
-//			iterator operator--(int) {
-//				auto result = *this;
-//				--*this;
-//				return result;
-//			}
-//			iterator &operator++() {
-//				++_index;
-//				return *this;
-//			}
-//			iterator operator++(int) {
-//				auto result = *this;
-//				++*this;
-//				return result;
-//			}
-//			iterator &operator+=(int offset) {
-//				_index += offset;
-//				return *this;
-//			}
-//			iterator operator+(int offset) const {
-//				auto result = *this;
-//				return result += offset;
-//			}
-//			bool operator==(iterator other) const {
-//				return (_data == other._data) && (_index == other._index);
-//			}
-//			bool operator!=(iterator other) const {
-//				return !(*this == other);
-//			}
-//			bool operator<(iterator other) const {
-//				return (_data < other._data)
-//					|| (_data == other._data && _index < other._index);
-//			}
-//
-//		private:
-//			friend class Data;
-//
-//			iterator(not_null<const Data*> data, int index)
-//				: _data(data)
-//				, _index(index) {
-//			}
-//
-//			not_null<const Data*> _data;
-//			int _index = 0;
-//
-//		};
-//
-//		iterator begin() const {
-//			return iterator(this, 0);
-//		}
-//		iterator end() const {
-//			iterator(this, _ids.size());
-//		}
-//		iterator cbegin() const {
-//			return begin();
-//		}
-//		iterator cend() const {
-//			return end();
-//		}
-//
-//	private:
-//		friend class iterator;
-//		friend class SharedMediaSliceMerged;
-//
-//		Data(
-//			not_null<History*> history,
-//			History *migrated,
-//			base::optional<int> historyCount = base::none,
-//			base::optional<int> migratedCount = base::none)
-//			: _history(history)
-//			, _migrated(migrated)
-//			, _historyCount(historyCount)
-//			, _migratedCount(migratedCount) {
-//			if (!_migrated) {
-//				_migratedCount = 0;
-//			}
-//		}
-//
-//		not_null<History*> _history;
-//		History *_migrated = nullptr;
-//		std::vector<UniversalMsgId> _ids;
-//		base::optional<int> _historyCount;
-//		base::optional<int> _historySkippedBefore;
-//		base::optional<int> _historySkippedAfter;
-//		base::optional<int> _migratedCount;
-//		base::optional<int> _migratedSkippedBefore;
-//		base::optional<int> _migratedSkippedAfter;
-//
-//	};
-//	base::Observable<Data> updated;
-//
-//private:
-//	bool amAroundMigrated() const;
-//	not_null<History*> aroundHistory() const;
-//	MsgId aroundId() const;
-//
-//	void applyStoredResult(
-//		not_null<PeerData*> peer,
-//		Storage::SharedMediaResult &&result);
-//	bool containsAroundId() const;
-//	void clearAfterMove();
-//
-//	Type _type = Type::kCount;
-//	not_null<History*> _history;
-//	History *_migrated = nullptr;
-//	UniversalMsgId _universalAroundId = 0;
-//	int _limitBefore = 0;
-//	int _limitAfter = 0;
-//	Data _data;
-//
-//};
+
+class SharedMediaViewerMerged;
+class SharedMediaSliceMerged {
+public:
+	using Type = Storage::SharedMediaType;
+	using UniversalMsgId = MsgId;
+	struct Key {
+		Key(
+			PeerId peerId,
+			PeerId migratedPeerId,
+			Type type,
+			UniversalMsgId universalId)
+			: peerId(peerId)
+			, migratedPeerId(migratedPeerId)
+			, type(type)
+			, universalId(universalId) {
+		}
+
+		bool operator==(const Key &other) const {
+			return (peerId == other.peerId)
+				&& (migratedPeerId == other.migratedPeerId)
+				&& (type == other.type)
+				&& (universalId == other.universalId);
+		}
+
+		PeerId peerId = 0;
+		PeerId migratedPeerId = 0;
+		Type type = Type::kCount;
+		UniversalMsgId universalId = 0;
+
+	};
+	SharedMediaSliceMerged(
+		Key key,
+		SharedMediaSlice part,
+		base::optional<SharedMediaSlice> migrated)
+		: _key(key)
+		, _part(part)
+		, _migrated(migrated) {
+	}
+
+	base::optional<int> fullCount() const {
+		return Add(
+			_part.fullCount(),
+			_migrated ? _migrated->fullCount() : 0);
+	}
+	base::optional<int> skippedBefore() const {
+		return Add(
+			isolatedInMigrated() ? 0 : _part.skippedBefore(),
+			_migrated
+				? (isolatedInPart()
+					? _migrated->fullCount()
+					: _migrated->skippedBefore())
+				: 0
+		);
+	}
+	base::optional<int> skippedAfter() const {
+		return Add(
+			isolatedInMigrated() ? _part.fullCount() : _part.skippedAfter(),
+			isolatedInPart() ? 0 : _migrated->skippedAfter()
+		);
+	}
+	base::optional<int> indexOf(FullMsgId fullId) const {
+		return isFromPart(fullId)
+			? (_part.indexOf(fullId.msg) | func::add(migratedSize()))
+			: isolatedInPart()
+				? base::none
+				: isFromMigrated(fullId)
+					? _migrated->indexOf(fullId.msg)
+					: base::none;
+	}
+	int size() const {
+		return (isolatedInPart() ? 0 : migratedSize())
+			+ (isolatedInMigrated() ? 0 : _part.size());
+	}
+
+	FullMsgId operator[](int index) const {
+		Expects(index >= 0 && index < size());
+
+		if (auto size = migratedSize()) {
+			if (index < size) {
+				return ComputeId(*_migrated, index);
+			}
+			index -= size;
+		}
+		return ComputeId(_part, index);
+	}
+
+	base::optional<int> distance(const Key &a, const Key &b) const {
+		if (a.type != _key.type
+			|| b.type != _key.type
+			|| a.peerId != _key.peerId
+			|| b.peerId != _key.peerId
+			|| a.migratedPeerId != _key.migratedPeerId
+			|| b.migratedPeerId != _key.migratedPeerId) {
+			return base::none;
+		}
+		if (auto i = indexOf(ComputeId(a))) {
+			if (auto j = indexOf(ComputeId(b))) {
+				return *j - *i;
+			}
+		}
+		return base::none;
+	}
+
+	QString debug() const {
+		return (_migrated ? (_migrated->debug() + '|') : QString()) + _part.debug();
+	}
+
+private:
+	static bool IsFromSlice(const SharedMediaSlice &slice, FullMsgId fullId) {
+		auto peer = slice.key().peerId;
+		return peerIsChannel(peer)
+			? (peer == peerFromChannel(fullId.channel))
+			: !fullId.channel;
+	}
+	static FullMsgId ComputeId(PeerId peerId, MsgId msgId) {
+		return FullMsgId(
+			peerIsChannel(peerId) ? peerToBareInt(peerId) : 0,
+			msgId);
+	}
+	static FullMsgId ComputeId(const SharedMediaSlice &slice, int index) {
+		return ComputeId(slice.key().peerId, slice[index]);
+	};
+	static FullMsgId ComputeId(const Key &key) {
+		return (key.universalId > 0)
+			? ComputeId(key.peerId, key.universalId)
+			: ComputeId(key.migratedPeerId, -key.universalId);
+	}
+	static base::optional<int> Add(
+			const base::optional<int> &a,
+			const base::optional<int> &b) {
+		return (a && b) ? base::make_optional(*a + *b) : base::none;
+	}
+
+	bool isFromPart(FullMsgId fullId) const {
+		return IsFromSlice(_part, fullId);
+	}
+	bool isFromMigrated(FullMsgId fullId) const {
+		return _migrated ? IsFromSlice(*_migrated, fullId) : false;
+	}
+	int migratedSize() const {
+		return isolatedInPart() ? 0 : _migrated->size();
+	}
+	bool isolatedInPart() const {
+		return IsServerMsgId(_key.universalId)
+			&& (!_migrated || _part.skippedBefore() != 0);
+	}
+	bool isolatedInMigrated() const {
+		return IsServerMsgId(-_key.universalId)
+			&& (_migrated->skippedAfter() != 0);
+	}
+
+	Key _key;
+	SharedMediaSlice _part;
+	base::optional<SharedMediaSlice> _migrated;
+
+	friend class SharedMediaViewerMerged;
+
+};
+
+class SharedMediaViewerMerged : private base::Subscriber {
+public:
+	using Type = SharedMediaSliceMerged::Type;
+	using Key = SharedMediaSliceMerged::Key;
+
+	SharedMediaViewerMerged(
+		Key key,
+		int limitBefore,
+		int limitAfter);
+	SharedMediaViewerMerged(const SharedMediaViewerMerged &other) = delete;
+	SharedMediaViewerMerged(SharedMediaViewerMerged &&other) = default;
+
+	void start();
+
+	base::Observable<SharedMediaSliceMerged> updated;
+
+private:
+	static SharedMediaSlice::Key PartKey(const Key &key);
+	static SharedMediaSlice::Key MigratedKey(const Key &key);
+	static std::unique_ptr<SharedMediaViewer> MigratedViewer(
+		const Key &key,
+		int limitBefore,
+		int limitAfter);
+	static base::optional<SharedMediaSlice> MigratedSlice(const Key &key);
+
+	Key _key;
+	int _limitBefore = 0;
+	int _limitAfter = 0;
+	SharedMediaViewer _part;
+	std::unique_ptr<SharedMediaViewer> _migrated;
+	SharedMediaSliceMerged _data;
+
+};
diff --git a/Telegram/SourceFiles/mediaview.cpp b/Telegram/SourceFiles/mediaview.cpp
index 97457cfdd..aacc02591 100644
--- a/Telegram/SourceFiles/mediaview.cpp
+++ b/Telegram/SourceFiles/mediaview.cpp
@@ -68,13 +68,13 @@ constexpr auto kIdsPreloadAfter = 28;
 } // namespace
 
 struct MediaView::SharedMedia {
-	SharedMedia(SharedMediaViewer::Key key)
+	SharedMedia(SharedMediaViewerMerged::Key key)
 		: key(key)
 		, slice(key, kIdsLimit, kIdsLimit) {
 	}
 
-	SharedMediaViewer::Key key;
-	SharedMediaViewer slice;
+	SharedMediaViewerMerged::Key key;
+	SharedMediaViewerMerged slice;
 };
 
 MediaView::MediaView() : TWidget(nullptr)
@@ -192,7 +192,7 @@ void MediaView::moveToScreen() {
 	_saveMsg.moveTo((width() - _saveMsg.width()) / 2, (height() - _saveMsg.height()) / 2);
 }
 
-void MediaView::handleSharedMediaUpdate(const SharedMediaSlice &update) {
+void MediaView::handleSharedMediaUpdate(const SharedMediaSliceMerged &update) {
 	if (isHidden() || (!_photo && !_doc) || !_sharedMedia) {
 		_index = _fullIndex = _fullCount = base::none;
 		return;
@@ -275,9 +275,9 @@ void MediaView::documentUpdated(DocumentData *doc) {
 }
 
 void MediaView::changingMsgId(not_null<HistoryItem*> row, MsgId newId) {
-	if (row->id == _msgid) {
-		_msgid = newId;
-		validateSharedMedia();
+	if (row->fullId() == _msgid) {
+		_msgid = FullMsgId(_msgid.channel, newId);
+		refreshSharedMedia();
 	}
 }
 
@@ -367,7 +367,7 @@ void MediaView::updateControls() {
 		d = date(_photo->date);
 	} else if (_doc) {
 		d = date(_doc->date);
-	} else if (HistoryItem *item = App::histItemById(_msgmigrated ? 0 : _channel, _msgid)) {
+	} else if (auto item = App::histItemById(_msgid)) {
 		d = item->date;
 	}
 	if (d.date() == dNow.date()) {
@@ -409,7 +409,7 @@ void MediaView::updateActions() {
 	if (_doc && _doc->loading()) {
 		_actions.push_back({ lang(lng_cancel), SLOT(onSaveCancel()) });
 	}
-	if (_msgid > 0 && _msgid < ServerMaxMsgId) {
+	if (IsServerMsgId(_msgid.msg)) {
 		_actions.push_back({ lang(lng_context_to_msg), SLOT(onToMessage()) });
 	}
 	if (_doc && !_doc->filepath(DocumentData::FilePathResolveChecked).isEmpty()) {
@@ -535,12 +535,12 @@ void MediaView::step_radial(TimeMs ms, bool timer) {
 			_autoplayVideoDocument = _doc;
 		}
 		if (!_doc->data().isEmpty() && (_doc->isAnimation() || _doc->isVideo())) {
-			displayDocument(_doc, App::histItemById(_msgmigrated ? 0 : _channel, _msgid));
+			displayDocument(_doc, App::histItemById(_msgid));
 		} else {
 			auto &location = _doc->location(true);
 			if (location.accessEnable()) {
 				if (_doc->isAnimation() || _doc->isVideo() || _doc->isTheme() || QImageReader(location.name()).canRead()) {
-					displayDocument(_doc, App::histItemById(_msgmigrated ? 0 : _channel, _msgid));
+					displayDocument(_doc, App::histItemById(_msgid));
 				}
 				location.accessDisable();
 			}
@@ -731,7 +731,7 @@ void MediaView::onScreenResized(int screen) {
 	}
 	if (!ignore) {
 		moveToScreen();
-		auto item = (_msgid ? App::histItemById(_msgmigrated ? 0 : _channel, _msgid) : nullptr);
+		auto item = (_msgid ? App::histItemById(_msgid) : nullptr);
 		if (_photo) {
 			displayPhoto(_photo, item);
 		} else if (_doc) {
@@ -741,7 +741,7 @@ void MediaView::onScreenResized(int screen) {
 }
 
 void MediaView::onToMessage() {
-	if (auto item = _msgid ? App::histItemById(_msgmigrated ? 0 : _channel, _msgid) : 0) {
+	if (auto item = _msgid ? App::histItemById(_msgid) : 0) {
 		close();
 		Ui::showPeerHistoryAtItem(item);
 	}
@@ -830,7 +830,7 @@ void MediaView::clipCallback(Media::Clip::Notification notification) {
 
 	switch (notification) {
 	case NotificationReinit: {
-		if (auto item = App::histItemById(_msgmigrated ? 0 : _channel, _msgid)) {
+		if (auto item = App::histItemById(_msgid)) {
 			if (_gif->state() == State::Error) {
 				stopGif();
 				updateControls();
@@ -944,8 +944,10 @@ void MediaView::onShowInFolder() {
 }
 
 void MediaView::onForward() {
-	auto item = App::histItemById(_msgmigrated ? 0 : _channel, _msgid);
-	if (!_msgid || !item || item->id < 0 || item->serviceMsg()) return;
+	auto item = App::histItemById(_msgid);
+	if (!item || !IsServerMsgId(item->id) || item->serviceMsg()) {
+		return;
+	}
 
 	close();
 	if (auto main = App::main()) {
@@ -970,7 +972,7 @@ void MediaView::onDelete() {
 
 	if (deletingPeerPhoto()) {
 		App::main()->deletePhotoLayer(_photo);
-	} else if (auto item = App::histItemById(_msgmigrated ? 0 : _channel, _msgid)) {
+	} else if (auto item = App::histItemById(_msgid)) {
 		App::contextItem(item);
 		App::main()->deleteLayer();
 	}
@@ -1004,8 +1006,7 @@ void MediaView::onCopy() {
 
 base::optional<MediaView::SharedMediaType> MediaView::sharedMediaType() const {
 	using Type = SharedMediaType;
-	auto channelId = _msgmigrated ? NoChannel : _channel;
-	if (auto item = App::histItemById(channelId, _msgid)) {
+	if (auto item = App::histItemById(_msgid)) {
 		if (_photo) {
 			if (item->toHistoryMessage()) {
 				return Type::Photo;
@@ -1024,8 +1025,15 @@ base::optional<MediaView::SharedMediaType> MediaView::sharedMediaType() const {
 }
 
 base::optional<MediaView::SharedMediaKey> MediaView::sharedMediaKey() const {
+	if (!IsServerMsgId(_msgid.msg)) {
+		return base::none;
+	}
 	auto keyForType = [this](SharedMediaType type) -> SharedMediaKey {
-		return { (_msgmigrated ? _migrated : _history)->peer->id, type, _msgid };
+		return {
+			_history->peer->id,
+			_migrated ? _migrated->peer->id : 0,
+			type,
+			(_msgid.channel == _history->channelId()) ? _msgid.msg : -_msgid.msg };
 	};
 	return
 		sharedMediaType()
@@ -1038,7 +1046,7 @@ bool MediaView::validSharedMedia() const {
 			return false;
 		}
 		auto countDistanceInData = [](const auto &a, const auto &b) {
-			return [&](const SharedMediaSlice &data) {
+			return [&](const SharedMediaSliceMerged &data) {
 				return data.distance(a, b);
 			};
 		};
@@ -1046,7 +1054,7 @@ bool MediaView::validSharedMedia() const {
 		auto distance = (key == _sharedMedia->key) ? 0 :
 			_sharedMediaData
 			| countDistanceInData(*key, _sharedMedia->key)
-			| base::abs;
+			| func::abs;
 		if (distance) {
 			return (*distance < kIdsPreloadAfter);
 		}
@@ -1057,7 +1065,7 @@ bool MediaView::validSharedMedia() const {
 void MediaView::validateSharedMedia() {
 	if (auto key = sharedMediaKey()) {
 		_sharedMedia = std::make_unique<SharedMedia>(*key);
-		subscribe(_sharedMedia->slice.updated, [this](const SharedMediaSlice &data) {
+		subscribe(_sharedMedia->slice.updated, [this](const SharedMediaSliceMerged &data) {
 			handleSharedMediaUpdate(data);
 		});
 		_sharedMedia->slice.start();
@@ -1103,14 +1111,12 @@ void MediaView::showPhoto(not_null<PhotoData*> photo, HistoryItem *context) {
 	}
 	if (!_animOpacities.isEmpty()) _animOpacities.clear();
 
-	_msgid = context ? context->id : 0;
-	_msgmigrated = context ? (context->history() == _migrated) : false;
-	_channel = _history ? _history->channelId() : NoChannel;
+	_msgid = context ? context->fullId() : FullMsgId();
 	_canForward = context ? context->canForward() : false;
 	_canDelete = context ? context->canDelete() : false;
 	_photo = photo;
 
-	validateSharedMedia();
+	refreshSharedMedia();
 	if (_history) {
 		if (context && !context->toHistoryMessage()) {
 			if (!_history->peer->isUser()) {
@@ -1140,13 +1146,11 @@ void MediaView::showPhoto(not_null<PhotoData*> photo, PeerData *context) {
 	}
 	if (!_animOpacities.isEmpty()) _animOpacities.clear();
 
-	_msgid = 0;
-	_msgmigrated = false;
-	_channel = NoChannel;
+	_msgid = {};
 	_canForward = _canDelete = false;
 	_photo = photo;
 
-	validateSharedMedia();
+	refreshSharedMedia();
 	if (_user) {
 		//if (_user->photos.isEmpty() && _user->photosCount < 0 && _user->photoId && _user->photoId != UnknownPeerPhotoId) {
 		//	_fullIndex = 0;
@@ -1217,9 +1221,7 @@ void MediaView::showDocument(not_null<DocumentData*> document, HistoryItem *cont
 	}
 	if (!_animOpacities.isEmpty()) _animOpacities.clear();
 
-	_msgid = context ? context->id : 0;
-	_msgmigrated = context ? (context->history() == _migrated) : false;
-	_channel = _history ? _history->channelId() : NoChannel;
+	_msgid = context ? context->fullId() : FullMsgId();
 	_canForward = context ? context->canForward() : false;
 	_canDelete = context ? context->canDelete() : false;
 
@@ -1239,7 +1241,7 @@ void MediaView::displayPhoto(not_null<PhotoData*> photo, HistoryItem *item) {
 	_photo = photo;
 	_radial.stop();
 
-	validateSharedMedia();
+	refreshSharedMedia();
 
 	_photoRadialRect = QRect(QPoint((width() - st::radialSize.width()) / 2, (height() - st::radialSize.height()) / 2), st::radialSize);
 
@@ -1299,7 +1301,7 @@ void MediaView::destroyThemePreview() {
 }
 
 void MediaView::displayDocument(DocumentData *doc, HistoryItem *item) { // empty messages shown as docs: doc can be NULL
-	auto documentChanged = (!doc || doc != _doc || (item && (item->id != _msgid || (item->history() != (_msgmigrated ? _migrated : _history)))));
+	auto documentChanged = (!doc || doc != _doc || (item && item->fullId() != _msgid));
 	if (documentChanged || (!doc->isAnimation() && !doc->isVideo())) {
 		_fullScreenVideo = false;
 		_current = QPixmap();
@@ -1314,7 +1316,7 @@ void MediaView::displayDocument(DocumentData *doc, HistoryItem *item) { // empty
 	_photo = nullptr;
 	_radial.stop();
 
-	validateSharedMedia();
+	refreshSharedMedia();
 
 	if (_autoplayVideoDocument && _doc != _autoplayVideoDocument) {
 		_autoplayVideoDocument = nullptr;
@@ -1521,7 +1523,7 @@ void MediaView::createClipReader() {
 		_current = _doc->thumb->pixNoCache(_doc->thumb->width(), _doc->thumb->height(), videoThumbOptions(), st::mediaviewFileIconSize, st::mediaviewFileIconSize);
 	}
 	auto mode = (_doc->isVideo() || _doc->isRoundVideo()) ? Media::Clip::Reader::Mode::Video : Media::Clip::Reader::Mode::Gif;
-	_gif = Media::Clip::MakeReader(_doc, FullMsgId(_channel, _msgid), [this](Media::Clip::Notification notification) {
+	_gif = Media::Clip::MakeReader(_doc, _msgid, [this](Media::Clip::Notification notification) {
 		clipCallback(notification);
 	}, mode);
 
@@ -1611,7 +1613,7 @@ void MediaView::setClipControllerGeometry() {
 void MediaView::onVideoPauseResume() {
 	if (!_gif) return;
 
-	if (auto item = App::histItemById(_msgmigrated ? 0 : _channel, _msgid)) {
+	if (auto item = App::histItemById(_msgid)) {
 		if (_gif->state() == Media::Clip::State::Error) {
 			displayDocument(_doc, item);
 		} else if (_gif->state() == Media::Clip::State::Finished) {
@@ -1637,7 +1639,7 @@ void MediaView::restartVideoAtSeekPosition(TimeMs positionMs) {
 		auto rounding = (_doc && _doc->isRoundVideo()) ? ImageRoundRadius::Ellipse : ImageRoundRadius::None;
 		_current = _gif->current(_gif->width() / cIntRetinaFactor(), _gif->height() / cIntRetinaFactor(), _gif->width() / cIntRetinaFactor(), _gif->height() / cIntRetinaFactor(), rounding, ImageRoundCorner::All, getms());
 	}
-	_gif = Media::Clip::MakeReader(_doc, FullMsgId(_channel, _msgid), [this](Media::Clip::Notification notification) {
+	_gif = Media::Clip::MakeReader(_doc, _msgid, [this](Media::Clip::Notification notification) {
 		clipCallback(notification);
 	}, Media::Clip::Reader::Mode::Video, positionMs);
 
@@ -2215,11 +2217,9 @@ bool MediaView::moveToNext(int32 delta) {
 	if (newIndex < 0 || newIndex >= _sharedMediaData->size()) {
 		return false;
 	}
-	if (auto item = App::histItemById(_history->channelId(), *(_sharedMediaData->begin() + newIndex))) {
+	if (auto item = App::histItemById((*_sharedMediaData)[newIndex])) {
 		_index = newIndex;
-		_msgid = item->id;
-		_msgmigrated = (item->history() == _migrated);
-		_channel = _history ? _history->channelId() : NoChannel;
+		_msgid = item->fullId();
 		_canForward = item->canForward();
 		_canDelete = item->canDelete();
 		stopGif();
@@ -2338,7 +2338,7 @@ void MediaView::preloadData(int32 delta) {
 
 	auto forgetIndex = *_index - delta * 2;
 	if (forgetIndex >= 0 && forgetIndex < _sharedMediaData->size()) {
-		if (auto item = App::histItemById(_history->channelId(), *(_sharedMediaData->begin() + forgetIndex))) {
+		if (auto item = App::histItemById((*_sharedMediaData)[forgetIndex])) {
 			if (auto media = item->getMedia()) {
 				switch (media->type()) {
 				case MediaTypePhoto: static_cast<HistoryPhoto*>(media)->photo()->forget(); break;
@@ -2353,7 +2353,7 @@ void MediaView::preloadData(int32 delta) {
 
 	for (auto index = from; index != till; ++index) {
 		if (index >= 0 && index < _sharedMediaData->size()) {
-			if (auto item = App::histItemById(_history->channelId(), *(_sharedMediaData->begin() + index))) {
+			if (auto item = App::histItemById((*_sharedMediaData)[index])) {
 				if (auto media = item->getMedia()) {
 					switch (media->type()) {
 					case MediaTypePhoto: static_cast<HistoryPhoto*>(media)->photo()->download(); break;
@@ -2568,7 +2568,7 @@ void MediaView::updateOver(QPoint pos) {
 		updateOverState(OverRightNav);
 	} else if (_nameNav.contains(pos)) {
 		updateOverState(OverName);
-	} else if ((_msgid > 0 && _msgid < ServerMaxMsgId) && _dateNav.contains(pos)) {
+	} else if (IsServerMsgId(_msgid.msg) && _dateNav.contains(pos)) {
 		updateOverState(OverDate);
 	} else if (_headerHasLink && _headerNav.contains(pos)) {
 		updateOverState(OverHeader);
@@ -2985,7 +2985,8 @@ void MediaView::updateHeader() {
 			_headerText = _doc->name.isEmpty() ? lang(lng_mediaview_doc_image) : _doc->name;
 		} else if (_user) {
 			_headerText = lang(lng_mediaview_profile_photo);
-		} else if ((_channel && !_history->isMegagroup()) || (_peer && _peer->isChannel() && !_peer->isMegagroup())) {
+		} else if ((_history && _history->channelId() && !_history->isMegagroup())
+			|| (_peer && _peer->isChannel() && !_peer->isMegagroup())) {
 			_headerText = lang(lng_mediaview_channel_photo);
 		} else if (_peer) {
 			_headerText = lang(lng_mediaview_group_photo);
diff --git a/Telegram/SourceFiles/mediaview.h b/Telegram/SourceFiles/mediaview.h
index c17df973d..bc5c7c53c 100644
--- a/Telegram/SourceFiles/mediaview.h
+++ b/Telegram/SourceFiles/mediaview.h
@@ -156,15 +156,15 @@ private:
 	void updateMixerVideoVolume() const;
 
 	struct SharedMedia;
-	using SharedMediaType = SharedMediaViewer::Type;
-	using SharedMediaKey = SharedMediaViewer::Key;
+	using SharedMediaType = SharedMediaViewerMerged::Type;
+	using SharedMediaKey = SharedMediaViewerMerged::Key;
 	base::optional<SharedMediaType> sharedMediaType() const;
 	base::optional<SharedMediaKey> sharedMediaKey() const;
 	void validateSharedMedia();
 	bool validSharedMedia() const;
 	std::unique_ptr<SharedMedia> createSharedMedia() const;
 	void refreshSharedMedia();
-	void handleSharedMediaUpdate(const SharedMediaSlice &update);
+	void handleSharedMediaUpdate(const SharedMediaSliceMerged &update);
 	void refreshNavVisibility();
 
 	void dropdownHidden();
@@ -244,7 +244,7 @@ private:
 	PhotoData *_photo = nullptr;
 	DocumentData *_doc = nullptr;
 	std::unique_ptr<SharedMedia> _sharedMedia;
-	base::optional<SharedMediaSlice> _sharedMediaData;
+	base::optional<SharedMediaSliceMerged> _sharedMediaData;
 
 	QRect _closeNav, _closeNavIcon;
 	QRect _leftNav, _leftNavIcon, _rightNav, _rightNavIcon;
@@ -326,9 +326,7 @@ private:
 	base::optional<int> _index; // Index in current _sharedMedia data.
 	base::optional<int> _fullIndex; // Index in full shared media.
 	base::optional<int> _fullCount;
-	MsgId _msgid = 0; // msgId of current photo or file
-	bool _msgmigrated = false; // msgId is from _migrated history
-	ChannelId _channel = NoChannel;
+	FullMsgId _msgid;
 	bool _canForward = false;
 	bool _canDelete = false;
 
diff --git a/Telegram/SourceFiles/stdafx.h b/Telegram/SourceFiles/stdafx.h
index d4e504eab..b33aa3e77 100644
--- a/Telegram/SourceFiles/stdafx.h
+++ b/Telegram/SourceFiles/stdafx.h
@@ -74,6 +74,9 @@ Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
 #include "base/variant.h"
 #include "base/optional.h"
 #include "base/algorithm.h"
+#include "base/functors.h"
+
+namespace func = base::functors;
 
 #include "base/flat_set.h"
 #include "base/flat_map.h"
diff --git a/Telegram/SourceFiles/storage/storage_shared_media.cpp b/Telegram/SourceFiles/storage/storage_shared_media.cpp
index abfe86eb2..da68ecdc9 100644
--- a/Telegram/SourceFiles/storage/storage_shared_media.cpp
+++ b/Telegram/SourceFiles/storage/storage_shared_media.cpp
@@ -316,6 +316,13 @@ void SharedMedia::query(
 	if (peerIt != _lists.end()) {
 		auto index = static_cast<int>(query.key.type);
 		peerIt->second[index].query(query, std::move(callback));
+	} else {
+		base::TaskQueue::Main().Put(
+			[
+				callback = std::move(callback)
+			]() mutable {
+			callback(SharedMediaResult());
+		});
 	}
 }
 
diff --git a/Telegram/SourceFiles/structs.h b/Telegram/SourceFiles/structs.h
index e8d2b0254..dd1708aef 100644
--- a/Telegram/SourceFiles/structs.h
+++ b/Telegram/SourceFiles/structs.h
@@ -89,6 +89,9 @@ struct FullMsgId {
 	FullMsgId() = default;
 	FullMsgId(ChannelId channel, MsgId msg) : channel(channel), msg(msg) {
 	}
+	explicit operator bool() const {
+		return msg != 0;
+	}
 	ChannelId channel = NoChannel;
 	MsgId msg = 0;
 };
diff --git a/Telegram/gyp/telegram_sources.txt b/Telegram/gyp/telegram_sources.txt
index a16df536d..724847c8f 100644
--- a/Telegram/gyp/telegram_sources.txt
+++ b/Telegram/gyp/telegram_sources.txt
@@ -5,6 +5,7 @@
 <(src_loc)/base/enum_mask.h
 <(src_loc)/base/flat_map.h
 <(src_loc)/base/flat_set.h
+<(src_loc)/base/functors.h
 <(src_loc)/base/lambda.h
 <(src_loc)/base/lambda_guard.h
 <(src_loc)/base/index_based_iterator.h