client: support TG -> Matrix disappearing messages

Signed-off-by: Sumner Evans <sumner.evans@automattic.com>

pkg/connector/config.go

@@ -154,6 +154,7 @@ type GhostMetadata struct {
 type PortalMetadata struct {
 	IsSuperGroup bool `json:"is_supergroup,omitempty"`
 	ReadUpTo     int  `json:"read_up_to,omitempty"`
+	MessagesTTL  int  `json:"messages_ttl,omitempty"`
 }
 
 type MessageMetadata struct {

pkg/connector/telegram.go

@@ -262,7 +262,18 @@ func (t *TelegramClient) onUpdateNewMessage(ctx context.Context, channels map[in
 		// case *tg.MessageActionGeoProximityReached:
 		// case *tg.MessageActionGroupCall:
 		// case *tg.MessageActionInviteToGroupCall:
-		// case *tg.MessageActionSetMessagesTTL:
+		case *tg.MessageActionSetMessagesTTL:
+			eventMeta.Type = bridgev2.RemoteEventChatResync
+			t.main.Bridge.QueueRemoteEvent(t.userLogin, &simplevent.ChatResync{
+				EventMeta: eventMeta,
+				ChatInfo: &bridgev2.ChatInfo{
+					ExtraUpdates: func(ctx context.Context, p *bridgev2.Portal) bool {
+						updated := p.Portal.Metadata.(*PortalMetadata).MessagesTTL != action.Period
+						p.Portal.Metadata.(*PortalMetadata).MessagesTTL = action.Period
+						return updated
+					},
+				},
+			})
 		// case *tg.MessageActionGroupCallScheduled:
 		// case *tg.MessageActionSetChatTheme:
 		// case *tg.MessageActionChatJoinedByRequest:

pkg/connector/tomatrix.go

@@ -166,6 +166,22 @@ func (c *TelegramClient) convertToMatrix(ctx context.Context, portal *bridgev2.P
 		}
 	}
 
+	if disappearingSetting == nil {
+		// The TTL is either included in the message, or it's on the portal's
+		// metadata.
+		if ttl, ok := msg.GetTTLPeriod(); ok {
+			cm.Disappear = database.DisappearingSetting{
+				Type:  database.DisappearingTypeAfterSend,
+				Timer: time.Duration(ttl) * time.Second,
+			}
+		} else if portal.Metadata.(*PortalMetadata).MessagesTTL > 0 {
+			cm.Disappear = database.DisappearingSetting{
+				Type:  database.DisappearingTypeAfterSend,
+				Timer: time.Duration(ttl) * time.Second,
+			}
+		}
+	}
+
 	return
 }