from re       import compile
from serial   import Serial
from datetime import datetime

class State:
	acc   = [None]*3
	mag   = [None]*3
	touch = [None]*2
	light = [None]*1
	a2d   = [None]*6
	time  = None

	def __init__(self):
		self.time = datetime.utcnow()

class Device:
	# Attributes
	port = "/dev/ttyACM0"

	# Constructors
	def __init__(self, config):
		self.config = config
		self.serial = None

	# Methods
	def connect(self):
		try:
			self.inbuf  = []
			self.serial = Serial(self.port,          \
				baudrate = self.config.baudrate, \
				parity   = self.config.parity,   \
				bytesize = self.config.databits, \
				stopbits = self.config.stopbits, \
				timeout  = 0)
			self.serial.flushInput()
		except Exception as ex:
			return str(ex)

	def disconnect(self):
		if self.serial and self.serial.isOpen():
			self.serial.close()

	def running(self):
		if self.serial == None:
			return False
		if self.serial.isOpen() == False:
			return False
		return True

	def control(self):
		pass

	def process(self):
		items = []
		count = 0
		limit = 1000
		if not self.running():
			return items
		while self.serial.readable():
			try:
				char = self.serial.read().decode()
			except Exception as ex:
				char = ''
			if len(char) == 0:
				break
			if char == '\r' or char == '\n':
				if len(self.inbuf) == 0:
					continue
				line = "".join(self.inbuf)
				item = self._parse_ascii(line)
				items.append(item)
				self.inbuf = []
			else:
				self.inbuf.append(char)
			if count > limit:
				print("Error: exceeded read limit")
				break
			count += 1
		return items

	# Private methods
	def _parse_ascii(self, line):
		acc_re = compile("\[ACC\] accX=(.*) accY=(.*) accZ=(.*)")
		mag_re = compile("\[MAG\] magX=(.*) magY=(.*) magZ=(.*)")
		lgt_re = compile("\[LGT\] Light Intensity=(.*)")
		tch_re = compile("\[TCH\] Force=(.*) Distance=(.*)")
		a2d_re = compile("\[A2D\] ...")

		acc_m = acc_re.match(line)
		mag_m = mag_re.match(line)
		lgt_m = lgt_re.match(line)
		tch_m = tch_re.match(line)
		a2d_m = a2d_re.match(line)

		state = State()
		if acc_m:
			state.acc[0]   = float(acc_m.group(1))
			state.acc[1]   = float(acc_m.group(2))
			state.acc[2]   = float(acc_m.group(3))
		if mag_m:              
			state.mag[0]   = float(mag_m.group(1))
			state.mag[1]   = float(mag_m.group(2))
			state.mag[2]   = float(mag_m.group(3))
		if lgt_m:
			state.light[0] = float(lgt_m.group(1))
		if tch_m:
			state.touch[0] = float(tch_m.group(1))
		if a2d_m:
			state.a2d[0]   = float(tch_m.group(1))
			state.a2d[1]   = float(tch_m.group(2))
			state.a2d[2]   = float(tch_m.group(3))
			state.a2d[3]   = float(tch_m.group(4))
			state.a2d[4]   = float(tch_m.group(5))
			state.a2d[5]   = float(tch_m.group(6))

		return state