Refactor: extract interfaces for a set of simple fabric classes

Change-Id: I4a23fb2277498f466ce20f82e38d5e9cb25dab6e
diff --git a/apps/simplefabric/api/src/main/java/org/onosproject/simplefabric/api/FabricRoute.java b/apps/simplefabric/api/src/main/java/org/onosproject/simplefabric/api/FabricRoute.java
new file mode 100644
index 0000000..f12260a
--- /dev/null
+++ b/apps/simplefabric/api/src/main/java/org/onosproject/simplefabric/api/FabricRoute.java
@@ -0,0 +1,124 @@
+/*
+ * 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 org.onosproject.simplefabric.api;
+
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.IpPrefix;
+import org.onosproject.cluster.NodeId;
+
+/**
+ * Interface of fabric route.
+ */
+public interface FabricRoute {
+
+    /**
+     * Source of the route.
+     */
+    enum Source {
+        /**
+         * Route came from the iBGP route source.
+         */
+        BGP,
+
+        /**
+         * Route came from the FPM route source.
+         */
+        FPM,
+
+        /**
+         * Route can from the static route source.
+         */
+        STATIC,
+
+        /**
+         * Route source was not defined.
+         */
+        UNDEFINED
+    }
+
+    /**
+     * Returns the route source.
+     *
+     * @return route source
+     */
+    Source source();
+
+    /**
+     * Returns the IP prefix of the route.
+     *
+     * @return IP prefix
+     */
+    IpPrefix prefix();
+
+    /**
+     * Returns the next hop IP address.
+     *
+     * @return next hop
+     */
+    IpAddress nextHop();
+
+    /**
+     * Returns the ONOS node the route was sourced from.
+     *
+     * @return ONOS node ID
+     */
+    NodeId sourceNode();
+
+    /**
+     * Builder of FabricRoute.
+     */
+    interface Builder {
+
+        /**
+         * Returns FabricRoute builder with supplied source.
+         *
+         * @param source source of route
+         * @return FabricRoute instance builder
+         */
+        Builder source(Source source);
+
+        /**
+         * Returns FabricRoute builder with supplied IP prefix.
+         *
+         * @param prefix IP prefix
+         * @return FabricRoute instance builder
+         */
+        Builder prefix(IpPrefix prefix);
+
+        /**
+         * Returns Fabric builder with supplied next hop.
+         *
+         * @param nextHop next hop
+         * @return FabricRoute instance builder
+         */
+        Builder nextHop(IpAddress nextHop);
+
+        /**
+         * Returns Fabric builder with supplied source node identifier.
+         *
+         * @param sourceNode source node identifier
+         * @return FabricRoute instance builder
+         */
+        Builder sourceNode(NodeId sourceNode);
+
+        /**
+         * Builds an immutable FabricRoute instance.
+         *
+         * @return FabricRoute instance
+         */
+        FabricRoute build();
+    }
+}