import serial
import serial.tools.list_ports
import socket
import sys
import time
import traceback
from threading import Timer

class RepeatedTimer(object):
    def __init__(self, interval, function, *args, **kwargs):
        self._timer     = None
        self.interval   = interval
        self.function   = function
        self.args       = args
        self.kwargs     = kwargs
        self.is_running = False
        self.start()

    def _run(self):
        self.is_running = False
        self.start()
        self.function(*self.args, **self.kwargs)

    def start(self):
        if not self.is_running:
            self._timer = Timer(self.interval, self._run)
            self._timer.start()
            self.is_running = True

    def stop(self):
        self._timer.cancel()
        self.is_running = False

def feedWDT (s):
    sendSerChar (s, b'A')

def sendSerChar (s, c):
    print ('Sending ' + str (c))
    s.write(c)
       
def find_arduino_leonardo():
    # Scan for available COM ports
    ports = serial.tools.list_ports.comports()
    for port in ports:
	# Check if "LattePanda Leonardo" is in the description of any found port
        if "LattePanda Leonardo" in port.description:
            return port.device
    return None
 
def main():
    try:
        # Locate the Arduino Leonardo on the LattePanda board
        device = find_arduino_leonardo()
		
	# Exit if the device is not found
        if device is None:
            print("LattePanda Leonardo device not found. Please check if the device is connected and drivers are installed.")
            input("Press any key to exit...")
            sys.exit(1)
		
	# Open a Serial connection to the Arduino Leonardo
        ser = serial.Serial(device, 9600)
        
        # Start a repeating timer to feed the watchdog 
        rt  = RepeatedTimer (30, feedWDT, ser) # it auto-starts, no need of rt.start()
        
        # Setup a listening socket
        s = socket.socket (socket.AF_INET, socket.SOCK_STREAM)
        s.bind (('localhost', 9999))
        s.listen (5)
        print ('Server is listening')        
        
        while True:
            print ('Waiting for connection...')

            c, addr = s.accept ()

            print ('Got connection from', addr)
            
            data = c.recv (1).decode ('utf-8')
            if not data:
                continue

            print ('From online user: ' + data)

            if (data == 'T'):
                break

            b = bytes (data, 'utf-8')
            sendSerChar (ser, b)
            
            c.close()
            
            if (data == 'Q'):
                break

        RepeatedTimer.stop (rt)

    except Exception as e:
        # Handle exceptions and print the error message
        print("An error occurred:")
        print(str(e))
        print(traceback.format_exc())
        input("Press any key to exit...")
 
if __name__ == "__main__":
    main()