1 files changed, 93 insertions, 0 deletions
diff --git a/app-c/appc/appc-dispatcher/appc-dispatcher-common/state-machine-lib/src/main/java/org/openecomp/appc/statemachine/impl/StateMachineImpl.java b/app-c/appc/appc-dispatcher/appc-dispatcher-common/state-machine-lib/src/main/java/org/openecomp/appc/statemachine/impl/StateMachineImpl.java
new file mode 100644
index 000000000..f4f6612f8
--- /dev/null
+++ b/app-c/appc/appc-dispatcher/appc-dispatcher-common/state-machine-lib/src/main/java/org/openecomp/appc/statemachine/impl/StateMachineImpl.java
@@ -0,0 +1,93 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * openECOMP : APP-C
+ * ================================================================================
+ * Copyright (C) 2017 AT&T Intellectual Property. All rights
+ * 						reserved.
+ * ================================================================================
+ * 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.openecomp.appc.statemachine.impl;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import org.openecomp.appc.statemachine.StateMachine;
+import org.openecomp.appc.statemachine.objects.*;
+
+
+public class StateMachineImpl implements StateMachine {
+
+	private final Set<State> states;
+
+	private final Set<Event> events;
+
+	StateMachineImpl(StateMachineMetadata metadata){
+		this.states = new HashSet<State>();
+		this.states.addAll(metadata.getStates());
+		this.events = new HashSet<Event>();
+		this.events.addAll(metadata.getEvents());
+	}
+
+	public StateMachineResponse handleEvent(State inputState, Event event) throws InvalidInputException{
+
+		if(!validateInputs(inputState,event)){
+			throw new InvalidInputException("VNF State or incoming event is invalid. State = " +inputState + " event = " + event );
+		}
+
+		StateMachineResponse response = new StateMachineResponse();
+		State currentState = null,nextState = null;
+		for(State stateInSet:states){
+			if(stateInSet.equals(inputState)){
+				currentState = stateInSet;
+				break;
+			}
+		}
+		for(Transition transition : currentState.getTransitions()){
+			if(event.equals(transition.getEvent())){
+				nextState = transition.getNextState();
+			}
+		}
+		if(nextState == null){
+			response.setResponse(Response.NO_TRANSITION_DEFINED);
+		}
+		else if(inputState.equals(nextState)){
+			response.setResponse(Response.NO_STATE_CHANGE);
+		}
+		else{
+			response.setResponse(Response.VALID_TRANSITION);
+		}
+		response.setNextState(nextState);
+		return response;
+	}
+
+	private boolean validateInputs(State state,Event event){
+		if(state ==null || event == null){
+			return false;
+		}
+		if(!(this.states.contains(state) && this.events.contains(event))){
+			return false;
+		}
+		return true;
+	}
+
+	@Override
+	public String toString() {
+		return "StateMachineImpl{" +
+				"states=" + states +
+				", events=" + events +
+				'}';
+	}
+}