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'
  }