feat: persist authenticated queue probe RTT

server/api/service.go

@@ -26,6 +26,9 @@ const maxBodyBytes = 8 << 10
 type CandidateProvider func(playerID, ticketID string) (domain.Candidate, error)
 type CandidateProviderV2 func(playerID, ticketID string, spec domain.QueueSpec) (domain.Candidate, error)
 type ProbeProvider func(playerID, region string, opaqueLocation, nonce []byte, receivedAt time.Time) (domain.ProbeEvidence, []byte, error)
+type ProbeRecorder interface {
+	RecordProbe(context.Context, string, string, time.Duration, time.Time) error
+}
 
 type QueueBackend interface {
 	Create(context.Context, string, string, string, domain.QueueSpec, time.Time) (domain.QueueTicket, error)
@@ -86,6 +89,7 @@ type Service struct {
 	QueueBackend    QueueBackend
 	CandidateIndex  CandidateIndex
 	Probe           ProbeProvider
+	ProbeRecorder   ProbeRecorder
 	Assignment      AssignmentProvider
 	Now             func() time.Time
 	Proposals       map[string]*domain.Proposal
@@ -653,6 +657,12 @@ func (s *Service) probe(w http.ResponseWriter, r *http.Request) {
 		writeError(w, http.StatusUnprocessableEntity, "invalid_probe")
 		return
 	}
+	if s.ProbeRecorder != nil {
+		if err := s.ProbeRecorder.RecordProbe(r.Context(), playerID, region, evidence.ServerRTT, receivedAt); err != nil {
+			writeError(w, http.StatusServiceUnavailable, "probe_persistence_failed")
+			return
+		}
+	}
 	writeJSON(w, http.StatusAccepted, map[string]any{"region": region, "server_rtt_ms": evidence.ServerRTT.Milliseconds(), "status": "accepted"})
 }
 

server/api/service_test.go

@@ -25,6 +25,21 @@ type candidateIndexSpy struct {
 	last                     domain.Candidate
 }
 
+type probeRecorderSpy struct {
+	calls int
+	err   error
+	last  struct {
+		player, region string
+		rtt            time.Duration
+	}
+}
+
+func (p *probeRecorderSpy) RecordProbe(_ context.Context, player, region string, rtt time.Duration, _ time.Time) error {
+	p.calls++
+	p.last.player, p.last.region, p.last.rtt = player, region, rtt
+	return p.err
+}
+
 func (i *candidateIndexSpy) Upsert(_ context.Context, candidate domain.Candidate) error {
 	i.upsertCalls++
 	i.last = candidate
@@ -936,6 +951,36 @@ func TestProbeAPIUsesServerEvidenceAndRejectsClientRTTField(t *testing.T) {
 	_ = response.Body.Close()
 }
 
+func TestProbeAPIRecordsOnlyValidatedServerEvidence(t *testing.T) {
+	now := time.Unix(1000, 0).UTC()
+	sessions := domain.NewSessionStore()
+	session, token, _ := sessions.Issue("player-a", time.Hour, now)
+	recorder := &probeRecorderSpy{}
+	service := &Service{Sessions: sessions, Now: func() time.Time { return now }, ProbeRecorder: recorder, Probe: func(_ string, region string, location, nonce []byte, _ time.Time) (domain.ProbeEvidence, []byte, error) {
+		return domain.ProbeEvidence{OpaqueLocation: location, Nonce: nonce, IssuedAt: now, Region: region, ServerRTT: 37 * time.Millisecond}, nonce, nil
+	}}
+	server := httptest.NewServer(service.Handler())
+	defer server.Close()
+	req, _ := http.NewRequest(http.MethodPost, server.URL+"/v1/probes/NA", strings.NewReader(`{"opaque_location":"b3BhcXVl","nonce":"bm9uY2U="}`))
+	req.Header.Set("Authorization", "Bearer "+session.SessionID+":"+token)
+	response, err := http.DefaultClient.Do(req)
+	if err != nil || response.StatusCode != http.StatusAccepted {
+		t.Fatalf("status=%v err=%v", response.StatusCode, err)
+	}
+	response.Body.Close()
+	if recorder.calls != 1 || recorder.last.player != "player-a" || recorder.last.region != "NA" || recorder.last.rtt != 37*time.Millisecond {
+		t.Fatalf("recorded probe=%+v calls=%d", recorder.last, recorder.calls)
+	}
+	recorder.err = errors.New("database unavailable")
+	req, _ = http.NewRequest(http.MethodPost, server.URL+"/v1/probes/NA", strings.NewReader(`{"opaque_location":"b3BhcXVl","nonce":"bm9uY2U="}`))
+	req.Header.Set("Authorization", "Bearer "+session.SessionID+":"+token)
+	response, err = http.DefaultClient.Do(req)
+	if err != nil || response.StatusCode != http.StatusServiceUnavailable {
+		t.Fatalf("persistence status=%v err=%v", response.StatusCode, err)
+	}
+	response.Body.Close()
+}
+
 func TestProposalRecoveryIsParticipantScopedAndExpiresAtReadBoundary(t *testing.T) {
 	now := time.Unix(1000, 0).UTC()
 	sessions := domain.NewSessionStore()