from test.helpers.syscmd import SysCommand
import unittest
import serial
import time

class Qamp(unittest.TestCase):

    def __init__(self, testname, testfunc, undercurrent=0.1, overcurrent=2):
        self._current = 0.0
        self._undercurrent=undercurrent
        self._overcurrent = overcurrent
        self._vshuntfactor=16384.0
        self._ser = serial.Serial()
        self._ser.port = '/dev/ttyUSB0'
        self._ser.baudrate = 115200
        self._ser.parity = serial.PARITY_NONE
        self._ser.timeout = 0
        self._ser.writeTimout = 0
        self._ser.xonxoff = False
        self._ser.rtscts = False
        self._ser.dsrdtr = False
        super(Qamp, self).__init__(testfunc)
        self._testMethodDoc = testname

    def __del__(self):
        self._ser.close()

    def execute(self):
        # Open Serial port ttyUSB0
        error=0
        try:
            self._ser.open()
        except:
            self.fail("failed: IMPOSSIBLE OPEN USB-SERIAL PORT ( {} )".format(self._ser.port))
            error=1
            return -1
        if error==0:
            # Clean input and output buffer of serial port
            self._ser.flushInput()
            self._ser.flushOutput()
            # Send command to read Voltage at Shunt resistor
            # Prepare cmd
            cmd = ('at\n\r')
            i=0
            while (i < len(cmd)):
                i = i + self._ser.write(cmd[i].encode('ascii'))
                time.sleep(0.05)
                self._ser.read(1)
            res0 = []
            while (self._ser.inWaiting() > 0):  # if incoming bytes are waiting to be read from the serial input buffer
                res0.append(self._ser.read(1).decode('ascii'))  # read the bytes and convert from binary array to ASCII
            print(res0)
            #CHECK COM FIRST
            cmd = ('at+in?\n\r')
            i = 0

            # Write, 1 by 1 byte at a time to avoid hanging of serial receiver code of listener, emphasis being made at sleep of 50 ms.
            while (i < len(cmd)):
                i = i + self._ser.write(cmd[i].encode('ascii'))
                time.sleep(0.05)
                self._ser.read(1)

            # Read, 1 by 1 byte
            res = []
            while (self._ser.inWaiting() > 0):  # if incoming bytes are waiting to be read from the serial input buffer
                res.append(self._ser.read(1).decode('ascii'))  # read the bytes and convert from binary array to ASCII

            string = ''.join(res)
            string = string.replace('\n', '')
            try:
                self._current = float(int(string, 0)) / self._vshuntfactor
            except:
                self.fail("failed: CAN'T READ CONSUMPTION (CURRENT=0?)")
                error=1
                return -1
            if error==0:
                print(self._current)
            # In order to give a valid result it is importarnt to define an under current value
                if (self._current > float(self._overcurrent)):
                    self.fail("failed: OVERCURRENT DETECTED ( {} )".format(self._current))
                    return -1

                if (self._current < float(self._undercurrent)):
                    self.fail("failed: UNDERCURRENT DETECTED ( {} )".format(self._current))
                    return -1