# Module to choose and open a serial port
# Written as a telemetry tool by:
# The UoN Robot Wars Project, 2018

def selectserial():
    import platform
    import serial
    import os
    
    devpatterns = ['ttyACM', 'ttyUSB', 'rfcomm']
    targetdevs = []
    if platform.system()=='Windows':
        com_ports = ['COM%s' % (i + 1) for i in range(256)]
        for port in com_ports:
            try:
                s = serial.Serial(port)
                s.close()
                targetdevs.append(port)
            except (OSError, serial.SerialException):
                pass
        os='Windows'    #may be useful
    else:
        alldevs = os.listdir("/dev/")
        targetdevs = []
        for dev in alldevs:
            for pattern in devpatterns:
                if pattern in dev:
                    targetdevs.append("/dev/" + dev)
        os='Other'     #may be useful

    if len(targetdevs) == 0:
        return "Sorry, no serial devices found."
    elif len(targetdevs) > 1:
        print("Found multiple serial devices: ")
        for i, dev in enumerate(targetdevs):
            print("  " + str(i) + ": " + dev)
        while True:
            try:
                selection = int(input("Please enter your selection (as a digit):\n > "))
                if selection >= 0 and selection < len(targetdevs):
                    break
            except KeyboardInterrupt:
                sys.exit()
            except:
                print("Choice unrecognised: please try again:")
    else:
        if os=='Windows':
            print("Only found one likely serial device: " + targetdevs[0])
        else:
            print("Only found one likely serial device: " + targetdevs[0])
        selection = 0

    serialport=targetdevs[selection]


    try:
        datafeed = serial.Serial(
        port=serialport,
        baudrate = 9600,
        parity=serial.PARITY_NONE,
        stopbits=serial.STOPBITS_ONE,
        bytesize=serial.EIGHTBITS,
        timeout=1
        )

        print("Sucessfully opened " + serialport + " as data source!")
        return datafeed
    except Exception as e:
        return str(e)