from abstract_instrument import abstract_instrument
  import serial
  
  #==============================================================================
  
  ALL_VAL_TYPE = ['PRE']
  ALL_CHANNELS = ['1']

  ADDRESS = "/dev/ttyS0"

  
  #==============================================================================
  
  class TPG261(abstract_instrument):

      def __init__(self, channels, vtypes, address):
          self.address = address

          self.channels = channels
          self.vtypes = vtypes

  
      def model(self):
          return "PfeifferTPG261"
  
      def connect(self):

          print('Connecting to device @%s...' %(self.address))
          self.TPG = MaxiGauge(self.address)

          print('  --> Ok')
          print(self.model())
          self.configure()
  
      def configure(self):

          pass

  
      def getValue(self):

          self.read()

          return "%s
  "%self.ps[0].pressure
  
      def read(self):

          self.ps = self.TPG.pressures()

  
      def disconnect(self):
          self.TPG.disconnect()
  
      def send(self, command):
          pass
  
  
  
  
  # from Philipp Klaus, philipp.l.klaus AT web.de PfeifferVacuum.py
  
  class MaxiGauge (object):
      def __init__(self, serialPort, baud=9600, debug=False):
          self.debug=debug
          try:
              self.connection = serial.Serial(serialPort, baudrate=baud, timeout=0.2)
          except serial.serialutil.SerialException as se:
              raise MaxiGaugeError(se)
          #self.send(C['ETX']) ### We might reset the connection first, but it doesn't really matter:
  
      def checkDevice(self):
          message = "The Display Contrast is currently set to %d (out of 20).
  " % self.displayContrast()
          message += "Keys since MaxiGauge was switched on: %s (out of 1,2,3,4,5).
  " % ", ".join( map (str, self.pressedKeys()) )
          return message
  
      def pressedKeys(self):
          keys = int(self.send('TKB',1)[0])
          pressedKeys = []
          for i in [4,3,2,1,0]: # It's got 5 keys
              if keys/2**i == 1:
                  pressedKeys.append(i+1)
                  keys = keys%2**i
          pressedKeys.reverse()
          return pressedKeys
  
      def displayContrast(self,newContrast=-1):
          if newContrast == -1: return int(self.send('DCC',1)[0])
          else: return int(self.send('DCC,%d' % (newContrast,) ,1)[0])
  
      def pressures(self):
          return [self.pressure(i+1) for i in range(1)]
  
      def pressure(self, sensor):
          if sensor < 1 or sensor >6: raise MaxiGaugeError('Sensor can only be between 1 and 6. You choose ' + str(sensor))
          reading = self.send('PR%d' % sensor, 1)  ## reading will have the form x,x.xxxEsx <CR><LF> (see p.88)
          try:
              r = reading[0].split(',')
              status = int(r[0])
              pressure = float(r[-1])
          except:
              raise MaxiGaugeError("Problem interpreting the returned line:
  %s" % reading)
          return PressureReading(sensor, status, pressure)
  
      def debugMessage(self, message):
          if self.debug: print(repr(message))
  
      def send(self, mnemonic, numEnquiries = 0):
          self.connection.flushInput()
          self.write(mnemonic+LINE_TERMINATION)
          #if mnemonic != C['ETX']: self.read()
          #self.read()
          self.getACQorNAK()
          response = []
          for i in range(numEnquiries):
              self.enquire()
              response.append(self.read())
          return response
  
      def write(self,what):
          self.debugMessage(what)
          self.connection.write(what)
  
      def enquire(self):
          self.write(C['ENQ'])
  
      def read(self):
          data = ""
          while True:
              x = self.connection.read()
              self.debugMessage(x)
              data += x
              if len(data)>1 and data[-2:]==LINE_TERMINATION:
                  break
          return data[:-len(LINE_TERMINATION)]
  
      def getACQorNAK(self):
          returncode = self.connection.readline()
          self.debugMessage(returncode)
          ## The following is usually expected but our MaxiGauge controller sometimes forgets this parameter... That seems to be a bug with the DCC command.
          #if len(returncode)<3: raise MaxiGaugeError('Only received a line termination from MaxiGauge. Was expecting ACQ or NAK.')
          if len(returncode)<3: self.debugMessage('Only received a line termination from MaxiGauge. Was expecting ACQ or NAK.')
          if len(returncode)>2 and returncode[-3] == C['NAK']:
              self.enquire()
              returnedError = self.read()
              error = str(returnedError).split(',' , 1)
              print repr(error)
              errmsg = { 'System Error': ERR_CODES[0][int(error[0])] , 'Gauge Error': ERR_CODES[1][int(error[1])] }
              raise MaxiGaugeNAK(errmsg)
          #if len(returncode)>2 and returncode[-3] != C['ACQ']: raise MaxiGaugeError('Expecting ACQ or NAK from MaxiGauge but neither were sent.')
          if len(returncode)>2 and returncode[-3] != C['ACQ']: self.debugMessage('Expecting ACQ or NAK from MaxiGauge but neither were sent.')
          # if no exception raised so far, the interface is just fine:
          return returncode[:-(len(LINE_TERMINATION)+1)]
  
      def disconnect(self):
          #self.send(C['ETX'])
          if hasattr(self, 'connection') and self.connection: self.connection.close()
  
      def __del__(self):
          self.disconnect()
  
  class PressureReading(object):
      def __init__(self, id, status, pressure):
          if int(id) not in range(1,7): raise MaxiGaugeError('Pressure Gauge ID must be between 1-6')
          self.id = int(id)
          if int(status) not in PRESSURE_READING_STATUS.keys(): raise MaxiGaugeError('The Pressure Status must be in the range %s' % PRESSURE_READING_STATUS.keys())
          self.status = int(status)
          self.pressure = float(pressure)
  
      def statusMsg(self):
          return PRESSURE_READING_STATUS[self.status]
  
      def __repr__(self):
          return "Gauge #%d: Status %d (%s), Pressure: %f mbar
  " % (self.id, self.status, self.statusMsg(), self.pressure)
  
  
  ### ------ now we define the exceptions that could occur ------
  
  class MaxiGaugeError(Exception):
      pass
  
  class MaxiGaugeNAK(MaxiGaugeError):
      pass
  
  ### ------- Control Symbols as defined on p. 81 of the english
  ###        manual for the Pfeiffer Vacuum TPG256A  -----------
  C = {
    'ETX': "\x03", # End of Text (Ctrl-C)   Reset the interface
    'CR':  "\x0D", # Carriage Return        Go to the beginning of line
    'LF':  "\x0A", # Line Feed              Advance by one line
    'ENQ': "\x05", # Enquiry                Request for data transmission
    'ACQ': "\x06", # Acknowledge            Positive report signal
    'NAK': "\x15", # Negative Acknowledge   Negative report signal
    'ESC': "\x1b", # Escape
  }
  
  LINE_TERMINATION=C['CR']+C['LF'] # CR, LF and CRLF are all possible (p.82)
  
  ### Mnemonics as defined on p. 85
  M = [
    'BAU', # Baud rate                           Baud rate                                    95
    'CAx', # Calibration factor Sensor x         Calibration factor sensor x (1 ... 6)        92
    'CID', # Measurement point names             Measurement point names                      88
    'DCB', # Display control Bargraph            Bargraph                                     89
    'DCC', # Display control Contrast            Display control contrast                     90
    'DCD', # Display control Digits              Display digits                               88
    'DCS', # Display control Screensave          Display control screensave                   90
    'DGS', # Degas                               Degas                                        93
    'ERR', # Error Status                        Error status                                 97
    'FIL', # Filter time constant                Filter time constant                         92
    'FSR', # Full scale range of linear sensors  Full scale range of linear sensors           93
    'LOC', # Parameter setup lock                Parameter setup lock                         91
    'NAD', # Node (device) address for RS485     Node (device) address for RS485              96
    'OFC', # Offset correction                   Offset correction                            93
    'OFC', # Offset correction                   Offset correction                            93
    'PNR', # Program number                      Program number                               98
    'PRx', # Status, Pressure sensor x (1 ... 6) Status, Pressure sensor x (1 ... 6)          88
    'PUC', # Underrange Ctrl                     Underrange control                           91
    'RSX', # Interface                           Interface                                    94
    'SAV', # Save default                        Save default                                 94
    'SCx', # Sensor control                      Sensor control                               87
    'SEN', # Sensor on/off                       Sensor on/off                                86
    'SPx', # Set Point Control Source for Relay xThreshold value setting, Allocation          90
    'SPS', # Set Point Status A,B,C,D,E,F        Set point status                             91
    'TAI', # Test program A/D Identify           Test A/D converter identification inputs    100
    'TAS', # Test program A/D Sensor             Test A/D converter measurement value inputs 100
    'TDI', # Display test                        Display test                                 98
    'TEE', # EEPROM test                         EEPROM test                                 100
    'TEP', # EPROM test                          EPROM test                                   99
    'TID', # Sensor identification               Sensor identification                       101
    'TKB', # Keyboard test                       Keyboard test                                99
    'TRA', # RAM test                            RAM test                                     99
    'UNI', # Unit of measurement (Display)       Unit of measurement (pressure)               89
    'WDT', # Watchdog and System Error Control   Watchdog and system error control           101
  ]
  
  
  ### Error codes as defined on p. 97
  ERR_CODES = [
    {
          0: 'No error',
          1: 'Watchdog has responded',
          2: 'Task fail error',
          4: 'IDCX idle error',
          8: 'Stack overflow error',
         16: 'EPROM error',
         32: 'RAM error',
         64: 'EEPROM error',
        128: 'Key error',
       4096: 'Syntax error',
       8192: 'Inadmissible parameter',
      16384: 'No hardware',
      32768: 'Fatal error'
    } ,
    {
          0: 'No error',
          1: 'Sensor 1: Measurement error',
          2: 'Sensor 2: Measurement error',
          4: 'Sensor 3: Measurement error',
          8: 'Sensor 4: Measurement error',
         16: 'Sensor 5: Measurement error',
         32: 'Sensor 6: Measurement error',
        512: 'Sensor 1: Identification error',
       1024: 'Sensor 2: Identification error',
       2048: 'Sensor 3: Identification error',
       4096: 'Sensor 4: Identification error',
       8192: 'Sensor 5: Identification error',
      16384: 'Sensor 6: Identification error',
    }
  ]
  
  ### pressure status as defined on p.88
  PRESSURE_READING_STATUS = {
    0: 'Measurement data okay',
    1: 'Underrange',
    2: 'Overrange',
    3: 'Sensor error',
    4: 'Sensor off',
    5: 'No sensor',
    6: 'Identification error'
  }