NHS Booking and Referral Standard

Receive_Request
{
	initialise_variable "messageType" 
	initialise_variable "MessageReason" 
	initialise_variable "RequestType"
	
	//HTTP_Headers
	{
		if (HttpHeaders is null || HttpHeaders not Guid )
			OperationOutcome.issue.code = "invalid"
			throw exception with "REC_BAD_REQUEST"
			then return with HTTP.ResponseCode 400
		else if (HttpHeaders.RequestId == RequestId.AlreadyReceived)
			OperationOutcome.issue.code = "duplicate"
			throw exception with "REC_CONFLICT"
			then return with HTTP.ResponseCode 409
	}
	//Bundle
	{
		if(Bundle.meta.versionID is null)
			OperationOutcome.issue.code = "invariant"
			throw exception with "REC_BAD_REQUEST"
			then return with HTTP.ResponseCode 422
		else if!(Bundle.meta.versionID in versionID.supported)
			OperationOutcome.issue.code = "not-supported"
			throw exception with "REC_UNPROCESSABLE_ENTITY"
			then return with HTTP.ResponseCode 422
	}
	//Contents;
	{
		switch(MessageHeader.eventCoding)
		{
			case "servicerequest-request":
				if (MessageHeader.reason.code == "new" && ServiceRequest.status == "active")
					{
						switch(ServiceRequest.Category)
						{
							case "Validation":
								if (CarePlan.status != "active")
									{							
										RequestType = "unknown";
										OperationOutcome.issue.code = "invariant";//A content validation rule failed
										throw exception with "REC_BAD_REQUEST";
										then return  HTTP.ResponseCode 400;
									}
								else if(Encounter.Status.In("triaged","in-progress")
									{RequestType = "Im Receiving a new Validation Request";}
								else
									{
										RequestType = "unknown";
										OperationOutcome.issue.code = "invariant";//A content validation rule failed
										throw exception with "REC_BAD_REQUEST";
										then return  HTTP.ResponseCode 400;
									}
								break;
							case "Referral":
								if (Careplan.status != "completed")
								{
									RequestType = "unknown"
									OperationOutcome.issue.code = "invariant"//A content validation rule failed
									throw exception with "REC_BAD_REQUEST"
									then return  HTTP.ResponseCode 400
								}
								else if(Encounter.Status.In("triaged","finished"))
									RequestType = "Im Receiving a new Referral"
								else
									RequestType = "unknown"
									OperationOutcome.issue.code = "invariant"//A content validation rule failed
									throw exception with "REC_BAD_REQUEST"
									then return  HTTP.ResponseCode 400
								break;
							default:
								RequestType = "unknown"
								OperationOutcome.issue.code = "invariant"//A content validation rule failed
								throw exception with "REC_BAD_REQUEST"
								then return  HTTP.ResponseCode 400;
						}
					}
				else if (MessageHeader.reason.code == "update")
					{
						switch(ServiceRequest.category)
						{
							case "Validation":
								if(ServiceRequest.status.In("entered-in-error","revoked"))
									{RequestType = "im receiving a cancelled validation request";}
								else if(ServiceRequest.status.In("active","on-hold"))
									{RequestType = "im receiving an update to a validation request";} 
								else
								{
									RequestType = "unknown"
									OperationOutcome.issue.code = "invariant"//A content validation rule failed
									throw exception with "REC_BAD_REQUEST"
									then return  HTTP.ResponseCode 400								
								}
								break;
							case "Referral":
								if(ServiceRequest.status.In("entered-in-error","revoked"))
								{RequestType = "im receiving a cancelled referral"}
								else
								{
									RequestType = "unknown"
									OperationOutcome.issue.code = "invariant"//A content validation rule failed
									throw exception with "REC_BAD_REQUEST"
									then return  HTTP.ResponseCode 400								
								}
								break;
							default:
								RequestType = "unknown"
								OperationOutcome.issue.code = "invariant"//A content validation rule failed
								throw exception with "REC_BAD_REQUEST"
								then return  HTTP.ResponseCode 400;
						}

					}
				else
				{
					RequestType = "unknown"
					OperationOutcome.issue.code = "invariant"//A content validation rule failed
					throw exception with "REC_BAD_REQUEST"
					then return  HTTP.ResponseCode 400}
				break;
			case "servicerequest-response":
				if (MessageHeader.Response is null )
				{
						RequestType = "Invalid servicerequest-response"
						OperationOutcome.issue.code = "invariant"//A content validation rule failed
						throw exception with "REC_BAD_REQUEST"
						then return  HTTP.ResponseCode 400;
				}
				else if ( !Message.Response.identifier.existsLocally())
				{
						RequestType = "none or invalid response ID"
						OperationOutcome.issue.code = "not-found"//A content validation rule failed
						throw exception with "REC_NOT_FOUND"
						then return  HTTP.ResponseCode 404;
				}
				switch (ServiceRequest.Category)
					{
						case "Referral":
							if (ServiceRequest.status == "revoked" && MessageHeader.reason.code == "new")
							{ RequestType = "im receiving a Safeguarding DNA response (noshow)" } 
							else
							{
								RequestType = "unknown"
								OperationOutcome.issue.code = "invariant"//A content validation rule failed
								throw exception with "REC_BAD_REQUEST"
								then return  HTTP.ResponseCode 400;
							}
							break;
						case "Validation":
							if(!AnyEncounter.Originates.Local && Encount.Count()<=3)
							{
								if (MessageHeader.Reason.code == "new" && ServiceRequest.status == "active" && MessageHeader.FocusEncounter.status=="in-progress")
								{Request Type = "im receiving a Validation Response interim update" }
								else if (MessageHeader.Reason.code.In ("new","update") && ServiceRequest.status == "completed" && MessageHeader.FocusEncounter.status.In("triaged","complete")
								{Request Type = "im receiving a final Validation Response" }
								else
								{
									RequestType = "unknown"
									OperationOutcome.issue.code = "invariant"//A content validation rule failed
									throw exception with "REC_BAD_REQUEST"
									then return  HTTP.ResponseCode 400;
								}
							}
							else if(MessageHeader.FocusEncounter.status = "triaged" && ServiceRequest.status == "revoked" && MessageHeader.Reason.code.In("new","update"))
							{ RequestType = "im receiving  a Rejected validation response" } // a new encounter here is an edge case.
							else
							{
								RequestType = "unknown"
								OperationOutcome.issue.code = "invariant"//A content validation rule failed
								throw exception with "REC_BAD_REQUEST"
								then return  HTTP.ResponseCode 400;
							}
						default:
							RequestType = "unknown"
							OperationOutcome.issue.code = "invariant"//A content validation rule failed
							throw exception with "REC_BAD_REQUEST"
							then return  HTTP.ResponseCode 400;
					}
			case "booking-request":
				if (MessageHeader.Reason.code== "new" && Appointment.Status == "booked")
					if(slot.IsFree())
					{RequestType = "Im Receiving a new booking.";}
					else
					{
						OperationOutcome.issue.code = "conflict"
						throw exception with "REC_CONFLICT"
						then return with HTTP.ResponseCode 409
					}
				else if (MessageHeader.Reason.code == "update")
					MessageHeaderIsUpdate = true;
					switch (Appointment.Status)
					{
						case "cancelled":
							RequestType = "Im Receiving a booking cancellation."
							break						
						case "entered-in-error":
							RequestType = "Im Receiving a booking cancellation."
							break
						case "booked":
							RequestType = "Im Receiving an update to a booking."
							break
						default:
							OperationOutcome.issue.code = "invariant"//A content validation rule failed
							throw exception with "REC_BAD_REQUEST"
							then return with HTTP.ResponseCode 400;
							break;
					}
				else
				{
					OperationOutcome.issue.code = "invariant"//A content validation rule failed
					throw exception with "REC_BAD_REQUEST"
					then return with HTTP.ResponseCode 400;
				}
				break;
			case "booking-response":
					OperationOutcome.issue.code = "invariant"//A content validation rule failed
					throw exception with 'REC_BAD_REQUEST'
					then return with HTTP.ResponseCode 400
					break;
			default:
				OperationOutcome.issue.code = "invariant"//A content validation rule failed
				throw exception with 'REC_BAD_REQUEST'
				then return with HTTP.ResponseCode 400
				break;
		}
		
	}
	//Submit //rework this
	{
		
		if (Message == "update")
		{
			if (currentLocalData.LastUpdated > originaRequest.ReceivedDate)
			{
				OperationOutcome.issue.code = "conflict"
				throw exception with 'REC_CONFLICT'
				then return with HTTP.ResponseCode 409
				break;
			}		
			foreach (Entry in Bundle)
			{
				if (currentLocalData.Item.exists)
				{
					if (currentLocalData.LastUpdated > originaRequest.Received)
					{
						OperationOutcome.issue.code = "conflict"
						throw exception with 'REC_CONFLICT'
						then return with HTTP.ResponseCode 409
						break;
					}
					if(Entry.LastUpdated > currentLocalData.Item.meta.LastUpdated && Entry.fullUrl = currentLocalData.Item.fullUrl)
						currentLocalData.Item = Entry.Item
						Entry.SubmitWith(currentLocalData.Item.meta.LastUpdated == Entry.LastUpdated )
					else
						ignore
				}
				else
					Entry.SubmitWith(currentLocalData.Item.meta.LastUpdated == Entry.LastUpdated )					
			}
			Submit(currentLocalData.Bundle.meta.LastUpdated = Bundle.Meta.LastUpdated)
			return HTTP.ResponseCode 200 'OK'
		}
		else
			{
				foreach(Entry in Bundle)
				{
					Entry.SubmitWith(currentLocalData.Item.meta.LastUpdated == Entry.LastUpdated )
					Submit(currentLocalData.Bundle.meta.LastUpdated = Bundle.Meta.LastUpdated)
					return HTTP.ResponseCode 200 'OK'
				}
			}
	}	
}