/// <summary>
/// The state moves from 'From' to 'To' if:
/// 1. Code is valid, or
/// 2. In the definition of transition, the guard condition of the Code validation is False
/// Of course that the seonnd one is not usually considered in a secure system
/// </summary>
/// <param name="obj"></param>
private void ChangeMachineState(List <JToken> obj)
{
if ((string)obj[0][MachineDefinition.GuardCodeValidation] == MachineDefinition.False || CodeValid == true)
{
EnvParameter.ChangeCurrentState((string)obj[0][MachineDefinition.To]);
}
}
/// <summary>
/// obj is the current transition
/// </summary>
/// <param name="obj"></param>
private void ActionCodeValidation(List <JToken> obj)
{
if ((string)obj[0][MachineDefinition.GuardCodeValidation] == MachineDefinition.True)
{
CodeValid = EnvParameter.ValidateCode((string)objectTrigger[MachineDefinition.Code]);
}
}
/// <summary>
/// jsonTrigger is a json string, IoT event request, the message body of lambda function
/// </summary>
/// <param name="jsonTrigger"></param>
public JsonMachine(string jsonTrigger)
{
/// <summary>
/// CurrentClass and Code are stored in three ways: AWS Parameter Storing, file, and as AWS Lambda Function Environment Variables
/// MachineDefinition is just a static class of global strings, in ApiBody.cs
/// </summary>
ApiResponse.State = EnvParameter.CurrentState();
ApiResponse.Response = MachineDefinition.Http200;
try
{
objectTrigger = JObject.Parse(jsonTrigger);
if (objectTrigger == null)
{
return;
}
// Reset is needed in development stage, CurrentState=Disarmed and Code=1111
if ((string)objectTrigger[MachineDefinition.Reset] == MachineDefinition.True)
{
EnvParameter.SetDefault();
ApiResponse.State = EnvParameter.CurrentState();
return;
}
// Connect is just for read the state of the machine before request
if ((string)objectTrigger[MachineDefinition.Connect] == MachineDefinition.True)
{
return;
}
MachineString = File.ReadAllText(MachineDefinition.MachineFile);
MachineObject = JObject.Parse(MachineString);
string[] actions = MachineObject.SelectToken(MachineDefinition.actions).Select(s1 => (string)s1).ToArray();
// Search the state machine for the proper transition, the same with trigger
var objectCurrent = (from s2 in MachineObject[MachineDefinition.transitions]
where (string)s2[MachineDefinition.Event] == (string)objectTrigger[MachineDefinition.Event] &&
(string)s2[MachineDefinition.From] == (string)objectTrigger[MachineDefinition.State]
select s2).ToList();
// What action must be run(or initialized) first? the action the same as entryAction in the transitition definition.
TransiantAction(Array.FindAll(actions, s4 => s4.Equals((string)objectCurrent[0][MachineDefinition.EntryAction])), objectCurrent);
/// As a constraint if the transiant has a code validation action, it must be put in entryAction
/// because the state transfers after entryAction
if (CodeValid == true)
{
ChangeMachineState(objectCurrent);
}
// and the second action is the insideAction, finally the last one is exitAction
TransiantAction(Array.FindAll(actions, s4 => s4.Equals((string)objectCurrent[0][MachineDefinition.InsideAction])), objectCurrent);
TransiantAction(Array.FindAll(actions, s5 => s5.Equals((string)objectCurrent[0][MachineDefinition.ExitAction])), objectCurrent);
// Init the Api response, current state plus Ok/Error/Http 200. (all the strings and names are defined in MachineDefinition class)
ApiResponse.State = EnvParameter.CurrentState();
ApiResponse.Response = (Response == "" && Http200 != "" ? Http200 : Response);
}
catch (Exception ex)
{
ApiResponse.State = EnvParameter.CurrentState();
ApiResponse.Response = "InnerMessage: " + ex.InnerException.Message + " ;Message: " + ex.Message;
}
}