# -*- coding: utf-8 -*-
  
  """
  author  Benoit Dubois
  brief   Subclass of SerialCom: add specific decoding message capability
          for servo application.
  """
  import serial_com
  
  
  MNEMO_LIST = ["kp", "ki", "sp", "osp", "imax", "omax", "oscale", "fs"]
  
  
  class ServoSerialCom(serial_com.SerialCom):
  
      @staticmethod
      def decode_message(msg):
          """Message can be of type request or command.
          Request message are made of a mnemonique followed by '?'.
          Command message are made of 3 parts:
          - a mnemonique,
          - the controller number,
          - the value to be applied.
          Each parts are separated with a space.
          """
          if msg[:-1] == '?': # Request
              return
          else:
              cmd = msg.split()
              if len(cmd) != 3:
                  print("Decode error: bad command format")
                  return
              mnemo = str(cmd[0])
              if mnemo not in MNEMO_LIST:
                  print("Decode error: bad mnemonique")
                  return
              num = cmd[1]
              if num != '0' and num != '1':
                  print("Decode error: bad controller number")
                  return
              try:
                  val = int(cmd[2])
              except ValueError:
                  print("Decode error: bad command value")
                  return
              return (mnemo, num, val)