Stage 11: account linking & merge (email + Telegram Login Widget) (#12)

gateway/internal/transcode/encode.go

@@ -61,6 +61,40 @@ func encodeProfile(p backendclient.ProfileResp) []byte {
 	return b.FinishedBytes()
 }
 
+// encodeLinkResult builds a LinkResult payload (Stage 11). A switched-session token
+// (a guest initiator whose durable counterpart won) is carried as a nested Session
+// for the client to adopt; it is omitted otherwise.
+func encodeLinkResult(r backendclient.LinkResultResp) []byte {
+	b := flatbuffers.NewBuilder(256)
+	status := b.CreateString(r.Status)
+	secID := b.CreateString(r.SecondaryUserID)
+	secName := b.CreateString(r.SecondaryName)
+	hasSession := r.Token != "" && r.Profile != nil
+	var sess flatbuffers.UOffsetT
+	if hasSession {
+		token := b.CreateString(r.Token)
+		uid := b.CreateString(r.Profile.UserID)
+		name := b.CreateString(r.Profile.DisplayName)
+		fb.SessionStart(b)
+		fb.SessionAddToken(b, token)
+		fb.SessionAddUserId(b, uid)
+		fb.SessionAddIsGuest(b, r.Profile.IsGuest)
+		fb.SessionAddDisplayName(b, name)
+		sess = fb.SessionEnd(b)
+	}
+	fb.LinkResultStart(b)
+	fb.LinkResultAddStatus(b, status)
+	fb.LinkResultAddSecondaryUserId(b, secID)
+	fb.LinkResultAddSecondaryDisplayName(b, secName)
+	fb.LinkResultAddSecondaryGames(b, int32(r.SecondaryGames))
+	fb.LinkResultAddSecondaryFriends(b, int32(r.SecondaryFriends))
+	if hasSession {
+		fb.LinkResultAddSession(b, sess)
+	}
+	b.Finish(fb.LinkResultEnd(b))
+	return b.FinishedBytes()
+}
+
 // encodeMoveResult builds a MoveResult payload.
 func encodeMoveResult(r backendclient.MoveResultResp) []byte {
 	b := flatbuffers.NewBuilder(512)