event: implement disappearing timer types (#399)

Co-authored-by: Tulir Asokan <tulir@maunium.net>

bridgev2/database/disappear.go

@@ -12,28 +12,41 @@ import (
 	"time"
 
 	"go.mau.fi/util/dbutil"
+	"go.mau.fi/util/jsontime"
 
 	"maunium.net/go/mautrix/bridgev2/networkid"
+	"maunium.net/go/mautrix/event"
 	"maunium.net/go/mautrix/id"
 )
 
-// DisappearingType represents the type of a disappearing message timer.
-type DisappearingType string
+// Deprecated: use [event.DisappearingType]
+type DisappearingType = event.DisappearingType
 
+// Deprecated: use constants in event package
 const (
-	DisappearingTypeNone      DisappearingType = ""
-	DisappearingTypeAfterRead DisappearingType = "after_read"
-	DisappearingTypeAfterSend DisappearingType = "after_send"
+	DisappearingTypeNone      = event.DisappearingTypeNone
+	DisappearingTypeAfterRead = event.DisappearingTypeAfterRead
+	DisappearingTypeAfterSend = event.DisappearingTypeAfterSend
 )
 
 // DisappearingSetting represents a disappearing message timer setting
 // by combining a type with a timer and an optional start timestamp.
 type DisappearingSetting struct {
-	Type        DisappearingType
+	Type        event.DisappearingType
 	Timer       time.Duration
 	DisappearAt time.Time
 }
 
+func (ds DisappearingSetting) ToEventContent() *event.BeeperDisappearingTimer {
+	if ds.Type == event.DisappearingTypeNone || ds.Timer == 0 {
+		return nil
+	}
+	return &event.BeeperDisappearingTimer{
+		Type:  ds.Type,
+		Timer: jsontime.MS(ds.Timer),
+	}
+}
+
 type DisappearingMessageQuery struct {
 	BridgeID networkid.BridgeID
 	*dbutil.QueryHelper[*DisappearingMessage]

bridgev2/database/portal.go

@@ -16,6 +16,7 @@ import (
 	"go.mau.fi/util/dbutil"
 
 	"maunium.net/go/mautrix/bridgev2/networkid"
+	"maunium.net/go/mautrix/event"
 	"maunium.net/go/mautrix/id"
 )
 
@@ -34,9 +35,20 @@ type PortalQuery struct {
 	*dbutil.QueryHelper[*Portal]
 }
 
+type CapStateFlags uint32
+
+func (csf CapStateFlags) Has(flag CapStateFlags) bool {
+	return csf&flag != 0
+}
+
+const (
+	CapStateFlagDisappearingTimerSet CapStateFlags = 1 << iota
+)
+
 type CapabilityState struct {
 	Source networkid.UserLoginID `json:"source"`
 	ID     string                `json:"id"`
+	Flags  CapStateFlags         `json:"flags"`
 }
 
 type Portal struct {
@@ -208,7 +220,7 @@ func (p *Portal) Scan(row dbutil.Scannable) (*Portal, error) {
 	}
 	if disappearType.Valid {
 		p.Disappear = DisappearingSetting{
-			Type:  DisappearingType(disappearType.String),
+			Type:  event.DisappearingType(disappearType.String),
 			Timer: time.Duration(disappearTimer.Int64),
 		}
 	}

bridgev2/portal.go

@@ -1101,7 +1101,7 @@ func (portal *Portal) handleMatrixMessage(ctx context.Context, sender *UserLogin
 		}
 		portal.sendSuccessStatus(ctx, evt, resp.StreamOrder, message.MXID)
 	}
-	if portal.Disappear.Type != database.DisappearingTypeNone {
+	if portal.Disappear.Type != event.DisappearingTypeNone {
 		go portal.Bridge.DisappearLoop.Add(ctx, &database.DisappearingMessage{
 			RoomID:  portal.MXID,
 			EventID: message.MXID,
@@ -2281,6 +2281,7 @@ func (portal *Portal) sendConvertedMessage(
 	allSuccess := true
 	for i, part := range converted.Parts {
 		portal.applyRelationMeta(ctx, part.Content, replyTo, threadRoot, prevThreadEvent)
+		part.Content.BeeperDisappearingTimer = converted.Disappear.ToEventContent()
 		dbMessage := &database.Message{
 			ID:               id,
 			PartID:           part.ID,
@@ -2325,8 +2326,8 @@ func (portal *Portal) sendConvertedMessage(
 			logContext(log.Err(err)).Str("part_id", string(part.ID)).Msg("Failed to save message part to database")
 			allSuccess = false
 		}
-		if converted.Disappear.Type != database.DisappearingTypeNone && !dbMessage.HasFakeMXID() {
-			if converted.Disappear.Type == database.DisappearingTypeAfterSend && converted.Disappear.DisappearAt.IsZero() {
+		if converted.Disappear.Type != event.DisappearingTypeNone && !dbMessage.HasFakeMXID() {
+			if converted.Disappear.Type == event.DisappearingTypeAfterSend && converted.Disappear.DisappearAt.IsZero() {
 				converted.Disappear.DisappearAt = dbMessage.Timestamp.Add(converted.Disappear.Timer)
 			}
 			portal.Bridge.DisappearLoop.Add(ctx, &database.DisappearingMessage{
@@ -3648,6 +3649,15 @@ func (portal *Portal) UpdateCapabilities(ctx context.Context, source *UserLogin,
 	portal.CapState = database.CapabilityState{
 		Source: source.ID,
 		ID:     capID,
+		Flags:  portal.CapState.Flags,
+	}
+	if caps.DisappearingTimer != nil && !portal.CapState.Flags.Has(database.CapStateFlagDisappearingTimerSet) {
+		zerolog.Ctx(ctx).Debug().Msg("Disappearing timer capability was added, sending disappearing timer state event")
+		success = portal.sendRoomMeta(ctx, nil, time.Now(), event.StateBeeperDisappearingTimer, "", portal.Disappear.ToEventContent())
+		if !success {
+			return false
+		}
+		portal.CapState.Flags |= database.CapStateFlagDisappearingTimerSet
 	}
 	portal.lastCapUpdate = time.Now()
 	if implicit {
@@ -4030,7 +4040,7 @@ func DisappearingMessageNotice(expiration time.Duration, implicit bool) *event.M
 
 func (portal *Portal) UpdateDisappearingSetting(ctx context.Context, setting database.DisappearingSetting, sender MatrixAPI, ts time.Time, implicit, save bool) bool {
 	if setting.Timer == 0 {
-		setting.Type = ""
+		setting.Type = event.DisappearingTypeNone
 	}
 	if portal.Disappear.Timer == setting.Timer && portal.Disappear.Type == setting.Type {
 		return false
@@ -4046,6 +4056,9 @@ func (portal *Portal) UpdateDisappearingSetting(ctx context.Context, setting dat
 	if portal.MXID == "" {
 		return true
 	}
+
+	portal.sendRoomMeta(ctx, sender, ts, event.StateBeeperDisappearingTimer, "", setting.ToEventContent())
+
 	content := DisappearingMessageNotice(setting.Timer, implicit)
 	if sender == nil {
 		sender = portal.Bridge.Bot
@@ -4333,6 +4346,13 @@ func (portal *Portal) createMatrixRoomInLoop(ctx context.Context, source *UserLo
 		Type:     event.StateBeeperRoomFeatures,
 		Content:  event.Content{Parsed: roomFeatures},
 	})
+	if roomFeatures.DisappearingTimer != nil {
+		req.InitialState = append(req.InitialState, &event.Event{
+			Type:    event.StateBeeperDisappearingTimer,
+			Content: event.Content{Parsed: portal.Disappear.ToEventContent()},
+		})
+		portal.CapState.Flags |= database.CapStateFlagDisappearingTimerSet
+	}
 	if req.Topic == "" {
 		// Add explicit topic event if topic is empty to ensure the event is set.
 		// This ensures that there won't be an extra event later if PUT /state/... is called.

bridgev2/portalbackfill.go

@@ -339,6 +339,7 @@ func (portal *Portal) compileBatchMessage(ctx context.Context, source *UserLogin
 	for i, part := range msg.Parts {
 		partIDs = append(partIDs, part.ID)
 		portal.applyRelationMeta(ctx, part.Content, replyTo, threadRoot, prevThreadEvent)
+		part.Content.BeeperDisappearingTimer = msg.Disappear.ToEventContent()
 		evtID := portal.Bridge.Matrix.GenerateDeterministicEventID(portal.MXID, portal.PortalKey, msg.ID, part.ID)
 		dbMessage := &database.Message{
 			ID:               msg.ID,
@@ -379,8 +380,8 @@ func (portal *Portal) compileBatchMessage(ctx context.Context, source *UserLogin
 			prevThreadEvent.MXID = evtID
 			out.PrevThreadEvents[*msg.ThreadRoot] = evtID
 		}
-		if msg.Disappear.Type != database.DisappearingTypeNone {
-			if msg.Disappear.Type == database.DisappearingTypeAfterSend && msg.Disappear.DisappearAt.IsZero() {
+		if msg.Disappear.Type != event.DisappearingTypeNone {
+			if msg.Disappear.Type == event.DisappearingTypeAfterSend && msg.Disappear.DisappearAt.IsZero() {
 				msg.Disappear.DisappearAt = msg.Timestamp.Add(msg.Disappear.Timer)
 			}
 			out.Disappear = append(out.Disappear, &database.DisappearingMessage{

event/capabilities.d.ts

@@ -41,6 +41,8 @@ export interface RoomFeatures {
 	delete_max_age?: seconds
 	/** Whether deleting messages just for yourself is supported. No message age limit. */
 	delete_for_me?: boolean
+	/** Allowed configuration options for disappearing timers. */
+	disappearing_timer?: DisappearingTimerCapability
 
 	/** Whether reactions are supported. */
 	reaction?: CapabilitySupportLevel
@@ -57,6 +59,7 @@ export interface RoomFeatures {
 
 declare type integer = number
 declare type seconds = integer
+declare type milliseconds = integer
 declare type MIMEClass = "image" | "audio" | "video" | "text" | "font" | "model" | "application"
 declare type MIMETypeOrPattern =
 	"*/*"
@@ -106,6 +109,24 @@ export interface FileFeatures {
 	view_once?: boolean
 }
 
+export enum DisappearingType {
+	None = "",
+	AfterRead = "after_read",
+	AfterSend = "after_send",
+}
+
+export interface DisappearingTimerCapability {
+	types: DisappearingType[]
+	timers: milliseconds[]
+	/**
+	 * Whether clients should omit the empty disappearing_timer object in messages that they don't want to disappear
+	 *
+	 * Generally, bridged rooms will want the object to be always present, while native Matrix rooms don't,
+	 * so the hardcoded features for Matrix rooms should set this to true, while bridges will not.
+	 */
+	omit_empty_timer?: true
+}
+
 /**
  * The support level for a feature. These are integers rather than booleans
  * to accurately represent what the bridge is doing and hopefully make the

event/capabilities.go

@@ -44,6 +44,8 @@ type RoomFeatures struct {
 	DeleteForMe  bool                   `json:"delete_for_me,omitempty"`
 	DeleteMaxAge *jsontime.Seconds      `json:"delete_max_age,omitempty"`
 
+	DisappearingTimer *DisappearingTimerCapability `json:"disappearing_timer,omitempty"`
+
 	Reaction             CapabilitySupportLevel `json:"reaction,omitempty"`
 	ReactionCount        int                    `json:"reaction_count,omitempty"`
 	AllowedReactions     []string               `json:"allowed_reactions,omitempty"`
@@ -67,6 +69,13 @@ type FormattingFeatureMap map[FormattingFeature]CapabilitySupportLevel
 
 type FileFeatureMap map[CapabilityMsgType]*FileFeatures
 
+type DisappearingTimerCapability struct {
+	Types  []DisappearingType      `json:"types"`
+	Timers []jsontime.Milliseconds `json:"timers"`
+
+	OmitEmptyTimer bool `json:"omit_empty_timer,omitempty"`
+}
+
 type CapabilityMsgType = MessageType
 
 // Message types which are used for event capability signaling, but aren't real values for the msgtype field.
@@ -231,6 +240,7 @@ func (rf *RoomFeatures) Hash() []byte {
 	hashValue(hasher, "delete", rf.Delete)
 	hashBool(hasher, "delete_for_me", rf.DeleteForMe)
 	hashInt(hasher, "delete_max_age", rf.DeleteMaxAge.Get())
+	hashValue(hasher, "disappearing_timer", rf.DisappearingTimer)
 
 	hashValue(hasher, "reaction", rf.Reaction)
 	hashInt(hasher, "reaction_count", rf.ReactionCount)
@@ -249,6 +259,22 @@ func (rf *RoomFeatures) Hash() []byte {
 	return hasher.Sum(nil)
 }
 
+func (dtc *DisappearingTimerCapability) Hash() []byte {
+	if dtc == nil {
+		return nil
+	}
+	hasher := sha256.New()
+	hasher.Write([]byte("types"))
+	for _, t := range dtc.Types {
+		hasher.Write([]byte(t))
+	}
+	hasher.Write([]byte("timers"))
+	for _, timer := range dtc.Timers {
+		hashInt(hasher, "", timer.Milliseconds())
+	}
+	return hasher.Sum(nil)
+}
+
 func (ff *FileFeatures) Hash() []byte {
 	hasher := sha256.New()
 	hashMap(hasher, "mime_types", ff.MimeTypes)

event/content.go

@@ -48,6 +48,7 @@ var TypeMap = map[Type]reflect.Type{
 
 	StateElementFunctionalMembers: reflect.TypeOf(ElementFunctionalMembersContent{}),
 	StateBeeperRoomFeatures:       reflect.TypeOf(RoomFeatures{}),
+	StateBeeperDisappearingTimer:  reflect.TypeOf(BeeperDisappearingTimer{}),
 
 	EventMessage:   reflect.TypeOf(MessageEventContent{}),
 	EventSticker:   reflect.TypeOf(MessageEventContent{}),

event/message.go

@@ -138,6 +138,8 @@ type MessageEventContent struct {
 
 	BeeperLinkPreviews []*BeeperLinkPreview `json:"com.beeper.linkpreviews,omitempty"`
 
+	BeeperDisappearingTimer *BeeperDisappearingTimer `json:"com.beeper.disappearing_timer,omitempty"`
+
 	MSC1767Audio *MSC1767Audio `json:"org.matrix.msc1767.audio,omitempty"`
 	MSC3245Voice *MSC3245Voice `json:"org.matrix.msc3245.voice,omitempty"`
 }

event/state.go

@@ -10,6 +10,8 @@ import (
 	"encoding/base64"
 	"slices"
 
+	"go.mau.fi/util/jsontime"
+
 	"maunium.net/go/mautrix/id"
 )
 
@@ -207,6 +209,20 @@ type BridgeEventContent struct {
 	BeeperRoomTypeV2 string `json:"com.beeper.room_type.v2,omitempty"`
 }
 
+// DisappearingType represents the type of a disappearing message timer.
+type DisappearingType string
+
+const (
+	DisappearingTypeNone      DisappearingType = ""
+	DisappearingTypeAfterRead DisappearingType = "after_read"
+	DisappearingTypeAfterSend DisappearingType = "after_send"
+)
+
+type BeeperDisappearingTimer struct {
+	Type  DisappearingType      `json:"type"`
+	Timer jsontime.Milliseconds `json:"timer"`
+}
+
 type SpaceChildEventContent struct {
 	Via       []string `json:"via,omitempty"`
 	Order     string   `json:"order,omitempty"`

event/type.go

@@ -112,7 +112,7 @@ func (et *Type) GuessClass() TypeClass {
 		StatePowerLevels.Type, StateRoomName.Type, StateRoomAvatar.Type, StateServerACL.Type, StateTopic.Type,
 		StatePinnedEvents.Type, StateTombstone.Type, StateEncryption.Type, StateBridge.Type, StateHalfShotBridge.Type,
 		StateSpaceParent.Type, StateSpaceChild.Type, StatePolicyRoom.Type, StatePolicyServer.Type, StatePolicyUser.Type,
-		StateElementFunctionalMembers.Type, StateBeeperRoomFeatures.Type:
+		StateElementFunctionalMembers.Type, StateBeeperRoomFeatures.Type, StateBeeperDisappearingTimer.Type:
 		return StateEventType
 	case EphemeralEventReceipt.Type, EphemeralEventTyping.Type, EphemeralEventPresence.Type:
 		return EphemeralEventType
@@ -202,6 +202,7 @@ var (
 
 	StateElementFunctionalMembers = Type{"io.element.functional_members", StateEventType}
 	StateBeeperRoomFeatures       = Type{"com.beeper.room_features", StateEventType}
+	StateBeeperDisappearingTimer  = Type{"com.beeper.disappearing_timer", StateEventType}
 )
 
 // Message events