Add thread ID to read receipts

Author: tulir

bridge/bridge.go

@@ -59,7 +59,7 @@ type MembershipHandlingPortal interface {
 
 type ReadReceiptHandlingPortal interface {
 	Portal
-	HandleMatrixReadReceipt(sender User, eventID id.EventID, receiptTimestamp time.Time)
+	HandleMatrixReadReceipt(sender User, eventID id.EventID, receipt event.ReadReceipt)
 }
 
 type TypingPortal interface {

bridge/matrix.go

@@ -588,7 +588,7 @@ func (mx *MatrixHandler) HandleReceipt(evt *event.Event) {
 					dp.ScheduleDisappearing()
 				}
 			} else {
-				rrPortal.HandleMatrixReadReceipt(user, eventID, time.UnixMilli(receipt.Timestamp))
+				rrPortal.HandleMatrixReadReceipt(user, eventID, receipt)
 			}
 		}
 	}

event/ephemeral.go

@@ -8,6 +8,7 @@ package event
 
 import (
 	"encoding/json"
+	"time"
 
 	"maunium.net/go/mautrix/id"
 )
@@ -59,12 +60,19 @@ func (ur UserReceipts) Set(userID id.UserID, receipt ReadReceipt) {
 	ur[userID] = receipt
 }
 
+type ThreadID = id.EventID
+
+const ReadReceiptThreadMain ThreadID = "main"
+
 type ReadReceipt struct {
-	Timestamp int64 `json:"ts"`
+	Timestamp time.Time
+
+	// Thread ID for thread-specific read receipts from MSC3771
+	ThreadID ThreadID
 
 	// Extra contains any unknown fields in the read receipt event.
 	// Most servers don't allow clients to set them, so this will be empty in most cases.
-	Extra map[string]interface{} `json:"-"`
+	Extra map[string]interface{}
 }
 
 func (rr *ReadReceipt) UnmarshalJSON(data []byte) error {
@@ -84,15 +92,34 @@ func (rr *ReadReceipt) UnmarshalJSON(data []byte) error {
 	if err != nil {
 		return err
 	}
-	ts, _ := parsed["ts"].(float64)
+	threadID, _ := parsed["thread_id"].(string)
+	ts, tsOK := parsed["ts"].(float64)
+	delete(parsed, "thread_id")
 	delete(parsed, "ts")
 	*rr = ReadReceipt{
-		Timestamp: int64(ts),
-		Extra:     parsed,
+		ThreadID: ThreadID(threadID),
+		Extra:    parsed,
+	}
+	if tsOK {
+		rr.Timestamp = time.UnixMilli(int64(ts))
 	}
 	return nil
 }
 
+func (rr ReadReceipt) MarshalJSON() ([]byte, error) {
+	data := rr.Extra
+	if data == nil {
+		data = make(map[string]interface{})
+	}
+	if rr.ThreadID != "" {
+		data["thread_id"] = rr.ThreadID
+	}
+	if !rr.Timestamp.IsZero() {
+		data["ts"] = rr.Timestamp.UnixMilli()
+	}
+	return json.Marshal(data)
+}
+
 type Presence string
 
 const (