public MachineState Lock(MachineId machineId, string userName)
{
lock (_lock)
{
if (string.IsNullOrEmpty(userName))
{
throw new ArgumentException($"{nameof(userName)} is null or empty!");
}
if (!_stateDictionary.ContainsKey(machineId))
{
Add(machineId);
}
MachineState state = _stateDictionary[machineId];
if (state.IsLocked())
{
throw new InvalidOperationException($"machine {machineId} has already ben locked!");
}
MachineState newState = MachineState.ForLocked(machineId, userName);
_stateDictionary[machineId] = newState;
return(newState);
}
}
