"""
MicroPython MQTT LED light control Example for Wokwi.com

To control the led:

1. Open MQTTX application, New connection
2. Name: test, Server Address: broker.emqx.io
3. Click "Connect"
4. Add subscription, set the topic to "wokwi-message"
5. Under "JSON" option, set the Topic to "wokwi-light"
6. Turn on the light: In the Message field type (json format): {"setValue": true}
7. click "Publish"
8. Turn off the light: In the Message field type (json format): {"setValue": false}
9. click "Publish"

Copyright (C) 2022, Uri Shaked

Reference:
https://wokwi.com/arduino/projects/315787266233467457

umqtt.simple参考：
https://mpython.readthedocs.io/en/master/library/mPython/umqtt.simple.html
https://pypi.org/project/micropython-umqtt.simple/
"""

import network
import machine
from machine import Pin
from time import sleep
import ujson
from umqtt.simple import MQTTClient

# WiFi Hotspot Parameters
WIFI_AP = "Wokwi-GUEST"
WIFI_PASS = ""

# MQTT Server Parameters
MQTT_CLIENT_ID = "mqtt-explorer-8ef67865"
MQTT_BROKER    = "broker.emqx.io"
MQTT_USER      = ""
MQTT_PASSWORD  = ""
MQTT_SUB_TOPIC     = "wokwi-light"
MQTT_PUB_TOPIC     = "wokwi-message"


# LED灯连接在ESP32的IO13引脚
led = Pin(13, Pin.OUT)

# mqtt回调函数，当收到订阅主体的MQTT消息时执行
def mqtt_message(topic, msg):
  print("Incoming message:", msg)
  try:
    msg = ujson.loads(msg)
    print(msg)
    if(msg['method']=='setValue'):
        if(msg['params']): led.on()
        elif(not msg['params']): led.off()
        else: print('Unknow command')
  except Exception as e:
    print("Error:", e)

def blink(num, period):
    for i in range(num):
        led.on()
        sleep(period)
        led.off()
        sleep(period)

def reset():
    print("Resetting...")
    sleep(1)
    machine.reset()

def mainroutine():
    blink(3,0.25)
    # 延时次数计数变量，每次延时0.2秒，10次延时是2秒钟
    counter=0
    # 连接WiFi
    print("Connecting to WiFi...", end="")
    wifi = network.WLAN(network.STA_IF)
    wifi.active(True)
    wifi.connect(WIFI_AP, WIFI_PASS)
    while not wifi.isconnected():
      sleep(0.5)
      print(".", end="")
    print("Wifi Connection Done")
    blink(2, 0.5)

    # 连接 MQTT服务器
    print("Connecting to MQTT...")
    client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, port=1883, ssl=False, user=MQTT_USER, password=MQTT_PASSWORD)
    client.set_callback(mqtt_message)
    client.connect()
    #sleep(2)
    client.subscribe(MQTT_SUB_TOPIC)
    #sleep(2)
    print("MQTT Connected!")
    blink(2, 1)

    # 如下循环执行两个周期性事务
    # 1. 调用mqtt的check_msg()方法检查是否有来自MQTT服务器的消息
    # 2. 每2秒钟，上报一个数据
    while True:
      if (counter<10000): counter=counter+1  
      elif (counter>=10000):
        counter=0
        message = ujson.dumps({
            "msg":"hello from esp32"
        })
        client.publish(MQTT_PUB_TOPIC,message)
        # client.publish(MQTT_PUB_TOPIC,"hello from esp32") //umqtt error: OS Error. Succeed after changing to json format.
      sleep(0.001)
      client.check_msg()

def main():
	try:
		mainroutine()
	except Exception as e:
		print("Error: " + str(e))
		reset()

main()