fix(channels): sync preserve locally cleared dialogs

internal/domain/channel.go

@@ -485,23 +485,29 @@ func (c Channel) MembersListAdminOnly() bool {
 
 // ChannelMember is one user's channel membership and read state.
 type ChannelMember struct {
-	ChannelID            int64
-	UserID               int64
-	InviterUserID        int64
-	Role                 ChannelMemberRole
-	Status               ChannelMemberStatus
-	JoinedAt             int
-	LeftAt               int
-	AdminRights          ChannelAdminRights
-	BannedRights         ChannelBannedRights
-	Rank                 string
-	AvailableMinID       int
-	AvailableMinPts      int
-	ReadInboxMaxID       int
-	ReadInboxDate        int
-	ReadOutboxMaxID      int
-	UnreadMark           bool
-	SlowmodeLastSendDate int
+	ChannelID       int64
+	UserID          int64
+	InviterUserID   int64
+	Role            ChannelMemberRole
+	Status          ChannelMemberStatus
+	JoinedAt        int
+	LeftAt          int
+	AdminRights     ChannelAdminRights
+	BannedRights    ChannelBannedRights
+	Rank            string
+	AvailableMinID  int
+	AvailableMinPts int
+	// HistoryClearAnchorID/Date identify an owner-local channels.deleteHistory
+	// boundary. They are deliberately separate from AvailableMinID: joining a
+	// hidden-prehistory channel also advances AvailableMinID but must not
+	// manufacture a "History cleared" service message.
+	HistoryClearAnchorID   int
+	HistoryClearAnchorDate int
+	ReadInboxMaxID         int
+	ReadInboxDate          int
+	ReadOutboxMaxID        int
+	UnreadMark             bool
+	SlowmodeLastSendDate   int
 	// Guest is a computed, non-persisted view used for subscribers accessing a
 	// private linked discussion group without joining it. Guest must never be
 	// written to channel_members and is still projected to clients as left.
@@ -545,22 +551,24 @@ func (m ChannelMember) CanPostChannelMessages() bool {
 
 // ChannelDialog is the current user's owner-view dialog state for a channel.
 type ChannelDialog struct {
-	UserID              int64
-	ChannelID           int64
-	FolderID            int
-	TopMessageID        int
-	TopMessageDate      int
-	ReadInboxMaxID      int
-	ReadOutboxMaxID     int
-	UnreadCount         int
-	UnreadMentions      int
-	UnreadReactions     int
-	Pinned              bool
-	PinnedOrder         int
-	UnreadMark          bool
-	ViewForumAsMessages bool
-	HasScheduled        bool
-	DefaultSendAs       *Peer
+	UserID                 int64
+	ChannelID              int64
+	FolderID               int
+	TopMessageID           int
+	TopMessageDate         int
+	HistoryClearAnchorID   int
+	HistoryClearAnchorDate int
+	ReadInboxMaxID         int
+	ReadOutboxMaxID        int
+	UnreadCount            int
+	UnreadMentions         int
+	UnreadReactions        int
+	Pinned                 bool
+	PinnedOrder            int
+	UnreadMark             bool
+	ViewForumAsMessages    bool
+	HasScheduled           bool
+	DefaultSendAs          *Peer
 }
 
 // ChannelMessageActionType identifies service messages generated by channel operations.
@@ -573,7 +581,11 @@ const (
 	ChannelActionChatDelete      ChannelMessageActionType = "chat_delete_user"
 	ChannelActionChatEditPhoto   ChannelMessageActionType = "chat_edit_photo"
 	ChannelActionChatDeletePhoto ChannelMessageActionType = "chat_delete_photo"
-	ChannelActionChatJoined      ChannelMessageActionType = "chat_joined"
+	// ChannelActionHistoryClear is an owner-local projection at the member's
+	// channels.deleteHistory boundary. It is never persisted into the shared
+	// channel_messages row and never produces channel PTS.
+	ChannelActionHistoryClear ChannelMessageActionType = "history_clear"
+	ChannelActionChatJoined   ChannelMessageActionType = "chat_joined"
 	// ChannelActionChatJoinedByLink 是经邀请链接加入的服务消息，
 	// 渲染为 "X joined the group via invite link"。
 	ChannelActionChatJoinedByLink ChannelMessageActionType = "chat_joined_by_link"
@@ -710,6 +722,39 @@ type ChannelMessage struct {
 	Deleted    bool
 }
 
+// ProjectChannelHistoryClearMessage returns the owner-local service-message
+// projection for one channel history boundary. Identity fields from the shared
+// source are retained when available, while all user payload, media, reply,
+// reaction, pin, TTL and edit state is removed. A zero source is valid for a
+// retained anchor whose shared row has already been physically pruned.
+func ProjectChannelHistoryClearMessage(source ChannelMessage, channelID int64, messageID, messageDate int) ChannelMessage {
+	if source.ChannelID == 0 {
+		source.ChannelID = channelID
+	}
+	if source.ID == 0 {
+		source.ID = messageID
+	}
+	if source.Date == 0 {
+		source.Date = messageDate
+	}
+	return ChannelMessage{
+		ChannelID:    source.ChannelID,
+		ID:           source.ID,
+		SenderUserID: source.SenderUserID,
+		From:         source.From,
+		Date:         source.Date,
+		Post:         source.Post,
+		Silent:       source.Silent,
+		Action:       &ChannelMessageAction{Type: ChannelActionHistoryClear},
+	}
+}
+
+// IsChannelHistoryClearMessage reports whether msg is an owner-local history
+// clear projection rather than a shared channel service message.
+func IsChannelHistoryClearMessage(msg ChannelMessage) bool {
+	return msg.Action != nil && msg.Action.Type == ChannelActionHistoryClear
+}
+
 // MessageReactionType identifies one stored reaction constructor without depending on TL types.
 type MessageReactionType string
 
@@ -1290,19 +1335,27 @@ type ChannelDifference struct {
 	Events       []ChannelUpdateEvent
 	NewMessages  []ChannelMessage
 	OtherUpdates []ChannelUpdateEvent
-	Users        []User
-	Channels     []Channel
-	Pts          int
-	Final        bool
-	TooLong      bool
-	Dialog       ChannelDialog
-	Timeout      int
+	// AvailableMinID is an owner-local, absolute no-PTS boundary appended to a
+	// normal channel difference. It must never be represented as a synthetic
+	// ChannelUpdateEvent because updateChannelAvailableMessages has no pts.
+	AvailableMinID int
+	Users          []User
+	Channels       []Channel
+	Pts            int
+	Final          bool
+	TooLong        bool
+	Dialog         ChannelDialog
+	Timeout        int
 }
 
-// DirtyChannel identifies an active channel with channel-scoped updates after an account difference date.
+// DirtyChannel identifies an active channel with shared channel updates and/or
+// an owner-local no-PTS history-clear boundary after an account difference date.
 type DirtyChannel struct {
-	ChannelID int64
-	Pts       int
+	ChannelID           int64
+	Pts                 int
+	ChannelUpdatesDirty bool
+	AvailableMinID      int
+	HistoryClearDate    int
 }
 
 // ChannelUpdateRetentionCheckpoint is the durable recovery boundary for one channel.
@@ -1980,6 +2033,9 @@ type DeleteChannelHistoryResult struct {
 	Recipients     []int64
 	Offset         int
 	AvailableMinID int
+	// AvailableMinChanged is true only when this owner-local request advanced
+	// the member boundary and installed a new history-clear anchor.
+	AvailableMinChanged bool
 }
 
 // UpdateChannelPinnedMessageRequest pins or unpins one channel/supergroup message.
@@ -2192,6 +2248,10 @@ type ChannelHistoryFilter struct {
 	SenderUserID int64
 	PinnedOnly   bool
 	MusicOnly    bool
+	// IncludeHistoryClearAnchor is set only by messages.getHistory. Search,
+	// media and topic projections must not count the owner-local service marker
+	// as shared channel content.
+	IncludeHistoryClearAnchor bool
 	// NeedTotalCount requests the exact number of messages matching the static
 	// filters before offset/add_offset pagination. Ordinary history pages leave
 	// this false and keep the bounded len(page)+has-more hint.

internal/domain/dialog.go

@@ -69,24 +69,29 @@ func (p Peer) IsSelfUser(userID int64) bool {
 
 // Dialog 是账号的一条会话摘要。
 type Dialog struct {
-	Peer                  Peer
-	ChannelLeft           bool
-	FolderID              int
-	TopMessage            int
-	TopMessageDate        int
-	ReadInboxMaxID        int
-	ReadOutboxMaxID       int
-	UnreadCount           int
-	UnreadMentions        int
-	UnreadReactions       int
-	TTLPeriod             int
-	ThemeEmoticon         string
-	HasScheduled          bool
-	Pinned                bool
-	PinnedOrder           int
-	UnreadMark            bool
-	ViewForumAsMessages   bool
-	PeerSettingsBarHidden bool
+	Peer           Peer
+	ChannelLeft    bool
+	FolderID       int
+	TopMessage     int
+	TopMessageDate int
+	// HistoryClearAnchorID/Date are internal owner-view projection metadata.
+	// They are not TL dialog fields; dialog response assembly uses them to
+	// materialize the matching messageActionHistoryClear top payload.
+	HistoryClearAnchorID   int
+	HistoryClearAnchorDate int
+	ReadInboxMaxID         int
+	ReadOutboxMaxID        int
+	UnreadCount            int
+	UnreadMentions         int
+	UnreadReactions        int
+	TTLPeriod              int
+	ThemeEmoticon          string
+	HasScheduled           bool
+	Pinned                 bool
+	PinnedOrder            int
+	UnreadMark             bool
+	ViewForumAsMessages    bool
+	PeerSettingsBarHidden  bool
 	// Pts 是 channel peer 当前 channel pts；客户端用 dialog.pts 初始化本地
 	// channel 序列并决定 getChannelDifference 起点，channel dialog 必填。
 	Pts   int

internal/domain/update_event.go

@@ -44,7 +44,6 @@ const (
 	UpdateEventDialogFilterOrder        UpdateEventType = "dialog_filter_order"
 	UpdateEventDialogFilters            UpdateEventType = "dialog_filters"
 	UpdateEventFolderPeers              UpdateEventType = "folder_peers"
-	UpdateEventChannelAvailable         UpdateEventType = "channel_available_messages"
 	UpdateEventChannelViewForum         UpdateEventType = "channel_view_forum_as_messages"
 	UpdateEventStory                    UpdateEventType = "story"
 	UpdateEventReadStories              UpdateEventType = "read_stories"
@@ -141,7 +140,6 @@ func (e UpdateEvent) LacksWirePts() bool {
 		UpdateEventDialogFilter,
 		UpdateEventDialogFilterOrder,
 		UpdateEventDialogFilters,
-		UpdateEventChannelAvailable,
 		UpdateEventChannelViewForum,
 		UpdateEventStory,
 		UpdateEventReadStories,
@@ -178,7 +176,10 @@ type UpdateDifference struct {
 
 // ChannelDifferenceNudge is a computed account-level hint that a channel diff is dirty.
 type ChannelDifferenceNudge struct {
-	ChannelID int64
-	Pts       int
-	Channel   *ChannelView
+	ChannelID           int64
+	Pts                 int
+	ChannelUpdatesDirty bool
+	AvailableMinID      int
+	HistoryClearDate    int
+	Channel             *ChannelView
 }