"""
MicroPython IoT Weather Station Example for Wokwi.com

To view the data:

1. Go to http://www.hivemq.com/demos/websocket-client/
2. Click "Connect"
3. Under Subscriptions, click "Add New Topic Subscription"
4. In the Topic field, type "wokwi-weather" then click "Subscribe"

Now click on the DHT22 sensor in the simulation,
change the temperature/humidity, and you should see
the message appear on the MQTT Broker, in the "Messages" pane.

Copyright (C) 2022, Uri Shaked

https://wokwi.com/arduino/projects/322577683855704658
"""

import network
import time
import machine
from machine import Pin,I2C,Timer
import dht
import ujson
from umqtt.simple import MQTTClient
import ssd1306

# ESP32 Pin assignment 
i2c = I2C(0, scl=Pin(22), sda=Pin(21))

oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)

oled.text('Hello, Wokwi!', 10, 10)      
oled.show()

# MQTT Server Parameters
MQTT_CLIENT_ID = "jdfkldjfk6876gjgjg"
MQTT_BROKER    = "broker.emqx.io"
MQTT_USER      = ""
MQTT_PASSWORD  = ""
MQTT_TOPIC     = "ledxuzhinuo/2206055832"
TOPIC1 = b"ledxuzhinuo/2206055832" #灯控主题，为了避免主题和其他同学一样，末尾需要添加自己的学号
TOPIC2 = b"dataxuzhinuo/2206055832"
prev_weather=""

sensor = dht.DHT22(Pin(15))
led_blue = machine.PWM(machine.Pin(2), freq=1000)
led_blue.duty(0)

print("Connecting to WiFi", end="")
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect('Wokwi-GUEST', '')
while not sta_if.isconnected():
  print(".", end="")
  time.sleep(0.1)
print(" Connected!")

def is_valid_number(byte_string):
  """
  判断一个字节字符串是否表示一个有效的数字。

  参数：
    byte_string: 要判断的字节字符串。

  返回：
    如果字节字符串表示一个有效的数字，返回 True;否则，返回 False。
  """

  try:
    float(byte_string)
    return True
  except ValueError:
    return False

def sub_cb(topic, msg): #定义收到mqtt主题信息之后的回调函数
    global pwm_old, pwmval
    if topic == TOPIC1:
        print((topic, msg))
        if msg == b"on":
         pwmval = 1023
         led_blue.duty(pwmval)
        elif msg == b"off":
         pwmval = 0;
         led_blue.duty(pwmval)
        elif is_valid_number(msg):
          pwmval=int(msg)
          if pwmval>=0 and pwmval <=1023:
            led_blue.duty(pwmval)
    if topic == TOPIC2:
       pwmval = int(((100 - int(msg)) / 100) * 1023)
       if pwmval>1023 : pwmval=1023
       if pwmval<0: pwmval=0
       print((topic, pwmval))
       led_blue.duty(pwmval)

print("Connecting to MQTT server... ", end="")
client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD)
client.set_callback(sub_cb) 
client.connect()
client.subscribe(TOPIC1)
client.subscribe(TOPIC2) 
print("Connected!")

def sample_weather(V):
    global prev_weather
    print("Measuring weather conditions... ", end="")
    sensor.measure() 
    msg_data={
      "temp":sensor.temperature(),
      "humidity":sensor.humidity(),
    }
    message = ujson.dumps(msg_data)
    if message != prev_weather:
      print("Updated!")
      print("Reporting to MQTT topic {}: {}".format(MQTT_TOPIC, message))
      oled.fill(0)
      oled.scroll(0,15)
      oled.text('XZN-2206055832',0,0)
      oled.text('temp:%.1f dC'%(msg_data['temp']),0,25)
      oled.text('humidity:%.1f dC'%(msg_data['humidity']),0,40)
      oled.show()
      client.publish(MQTT_TOPIC, message)
      prev_weather = message
    else:
      print("No change")

tim = Timer(-1) #新建一个虚拟定时器
#此处执行时程序会等待5秒读取一次温湿度，period=5000 以毫秒为单位，mode=Timer.ONE_SHOT 表示只执行一次，Timer.PERIODIC表示循环执行，callback绑定回调函数
tim.init(period=5000, mode=Timer.PERIODIC, callback=sample_weather)    

while True:
  client.check_msg()
  time.sleep(1)