WIP [VOL-2811] - Incorporate preliminary onu-adapter-go code into opencord repo

- functionality: reason "initial-mib-downloaded" reached
- omciAgent removed, object relation restructured
- adapter code restructuring + internal lib interface update

Change-Id: Ie53450a5e2c093aaaf68fe652f95e7b4c4a014c7
Signed-off-by: Holger Hildebrandt <holger.hildebrandt@adtran.com>
diff --git a/internal/pkg/onuadaptercore/messageTypes.go b/internal/pkg/onuadaptercore/messageTypes.go
new file mode 100644
index 0000000..05c5fff
--- /dev/null
+++ b/internal/pkg/onuadaptercore/messageTypes.go
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+//Package adaptercoreonu provides the utility for onu devices, flows and statistics
+package adaptercoreonu
+
+import (
+	gp "github.com/google/gopacket"
+	"github.com/opencord/omci-lib-go"
+)
+
+type MessageType int
+
+const (
+	TestMsg MessageType = 0
+	OMCI    MessageType = 1
+)
+
+func (m MessageType) String() string {
+	names := [...]string{
+		"TestMsg",
+		"OMCI",
+	}
+	return names[m]
+}
+
+type Message struct {
+	Type MessageType
+	Data interface{}
+}
+
+const (
+	AnyTriggerForMibSyncUploadMib = 0
+)
+
+//TODO: place holder to have a second interface variant - to be replaced by real variant later on
+type TestMessage struct {
+	TestMessageVal uint32
+}
+
+type OmciMessage struct {
+	//OnuSN   *openolt.SerialNumber
+	//OnuID   uint32
+	OmciMsg    *omci.OMCI
+	OmciPacket *gp.Packet
+}