from machine import Timer
from umqtt.simple import MQTTClient
import utime
import os
import sys
PUBLISH_PERIOD   = 20
Led = True
timeSave = 0
CHANNEL_TOKEN = 'token_gRaBLbUJe4zo30dO'
CHANNEL_NAME  = 'teachersChannel'
RESOURCE_NAME = 'led'
MQTT_SERVER = 'mqtt.beebotte.com'
MQTT_USER = 'token:' + CHANNEL_TOKEN
MQTT_TOPIC = CHANNEL_NAME + '/' + RESOURCE_NAME
def handleTimerInt(timer):
    global Led
    global timeSave
    msg1 = b'{"data":true,"ispublic":true}'
    msg2 = b'{"data":false,"ispublic":true}'
    if Led:
        client.publish(MQTT_TOPIC,msg1, qos=0)
        print("Publish:",msg1)
    else:
        client.publish(MQTT_TOPIC,msg2, qos=0)
        print("Publish:",msg2)
    Led = not Led
    timeSave = 0 
# create a random MQTT clientID
random_num = int.from_bytes(os.urandom(3), 'little')
mqtt_client_id = bytes('client_'+str(random_num), 'utf-8')
client=MQTTClient(mqtt_client_id,MQTT_SERVER,user=MQTT_USER,password='',keepalive=PUBLISH_PERIOD*2)
myTimer = Timer(0)
try:      
    client.connect()
    myTimer.init(period=PUBLISH_PERIOD*1000, mode=Timer.PERIODIC, callback=handleTimerInt)
except Exception as e:
    print('could not connect to MQTT server {}{}'.format(type(e).__name__, e))
    sys.exit()
while True:
    try:
        print('Publish new data in', (PUBLISH_PERIOD-timeSave) , "second. ", end="\r")
        utime.sleep(1)
        timeSave+=1
    except KeyboardInterrupt:
        print('Ctrl-C pressed...exiting')
        client.disconnect()
        sys.exit()