feat: write protocol acknowledgements from go gateway

go/vehicle-gateway/internal/protocol/jt808/parser_test.go

@@ -332,6 +332,86 @@ func TestParseFrameParsesAuthenticationToken(t *testing.T) {
 	}
 }
 
+func TestAutoResponderBuildsRegisterAck(t *testing.T) {
+	body := make([]byte, 0, 46)
+	body = binary.BigEndian.AppendUint16(body, 16)
+	body = binary.BigEndian.AppendUint16(body, 32)
+	body = appendFixedASCII(body, "YUTNG", 5)
+	body = appendFixedASCII(body, "ZK6105CHEVNPG4", 20)
+	body = appendFixedASCII(body, "DEV0001", 7)
+	body = append(body, 2)
+	body = append(body, []byte("TEST123")...)
+	request := buildFrame(0x0100, "013079963379", 9, body)
+	env, err := ParseFrame(request, 1782918600000, "115.231.168.135:43625")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	response, ok, err := NewAutoResponder("g7gps").Respond(request, env)
+	if err != nil {
+		t.Fatalf("Respond() error = %v", err)
+	}
+	if !ok {
+		t.Fatal("expected response")
+	}
+	frames, remainder, err := ExtractFrames(response)
+	if err != nil {
+		t.Fatalf("ExtractFrames() error = %v", err)
+	}
+	if len(frames) != 1 || len(remainder) != 0 {
+		t.Fatalf("unexpected response split frames=%d remainder=%s", len(frames), hex.EncodeToString(remainder))
+	}
+	payload := frames[0]
+	if binary.BigEndian.Uint16(payload[0:2]) != 0x8100 {
+		t.Fatalf("message id = %04x", binary.BigEndian.Uint16(payload[0:2]))
+	}
+	if hex.EncodeToString(payload[4:10]) != "013079963379" {
+		t.Fatalf("phone bcd = %x", payload[4:10])
+	}
+	if binary.BigEndian.Uint16(payload[12:14]) != 9 || payload[14] != 0 || string(payload[15:20]) != "g7gps" {
+		t.Fatalf("unexpected register ack body: %x", payload[12:len(payload)-1])
+	}
+}
+
+func TestAutoResponderBuildsVersionedGeneralAck(t *testing.T) {
+	request := buildVersionedFrame(0x0200, "14894135060", 12, make([]byte, 28))
+	env, err := ParseFrame(request, 1782918600000, "115.231.168.135:43625")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	response, ok, err := NewAutoResponder("").Respond(request, env)
+	if err != nil {
+		t.Fatalf("Respond() error = %v", err)
+	}
+	if !ok {
+		t.Fatal("expected response")
+	}
+	frames, remainder, err := ExtractFrames(response)
+	if err != nil {
+		t.Fatalf("ExtractFrames() error = %v", err)
+	}
+	if len(frames) != 1 || len(remainder) != 0 {
+		t.Fatalf("unexpected response split frames=%d remainder=%s", len(frames), hex.EncodeToString(remainder))
+	}
+	payload := frames[0]
+	if binary.BigEndian.Uint16(payload[0:2]) != 0x8001 {
+		t.Fatalf("message id = %04x", binary.BigEndian.Uint16(payload[0:2]))
+	}
+	if binary.BigEndian.Uint16(payload[2:4])&0x4000 == 0 || payload[4] != 1 {
+		t.Fatalf("versioned header not preserved: %x", payload[:5])
+	}
+	if hex.EncodeToString(payload[5:15]) != "00000000014894135060" {
+		t.Fatalf("phone bcd = %x", payload[5:15])
+	}
+	bodyStart := 17
+	if binary.BigEndian.Uint16(payload[bodyStart:bodyStart+2]) != 12 ||
+		binary.BigEndian.Uint16(payload[bodyStart+2:bodyStart+4]) != 0x0200 ||
+		payload[bodyStart+4] != 0 {
+		t.Fatalf("unexpected general ack body: %x", payload[bodyStart:len(payload)-1])
+	}
+}
+
 func TestExtractFramesHandlesEscapedPayload(t *testing.T) {
 	payload := []byte{0x02, 0x00, 0x00, 0x02, 0x01, 0x33, 0x07, 0x79, 0x54, 0x25, 0x00, 0x01, 0x7e, 0x7d}
 	frame := append([]byte{0x7e}, escape(append(payload, checksum(payload)))...)