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

# 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 = "tjy2306022237"
MQTT_BROKER    = "broker.emqx.io"
MQTT_USER      = ""
MQTT_PASSWORD  = ""
MQTT_TOPIC     = "weather2306022237"
TOPIC1 = b"ledctl2013206032"  #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"pwmled2013206032"
TOPIC3 = b"ledstatus2013206032"
prev_weather = ""
sensor = dht.DHT22(Pin(15))
# 选择gpio2引脚
led_blue = machine.PWM(machine.Pin(2), freq=1000)  # 设置 GPIO2 为输出
led_blue.duty(1023)

#连接wifi配置
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!")

#配置定义回调函数
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 = 0
            led_blue.duty(pwmval)
        elif msg == b"off":
            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)    #定义好client参数之后，就需要在connect之前
client.connect()
client.subscribe(TOPIC1)     #connect之后就需要马上订阅主题，才能收到mqtt服务器送过来的信息
client.subscribe(TOPIC2)     
print("Connected!")
#定义采集温湿度的函数，方便后面定时器定时调用
def sample_weather(V):
    global prev_weather
    while True:
        print("Measuring weather conditions... ", end="")
        sensor.measure() 
        message = ujson.dumps({
            "temp": sensor.temperature(),
            "humidity": sensor.humidity(),
        })
        if message != prev_weather:
            print("Updated!")
            print("Reporting to MQTT topic {}: {}".format(MQTT_TOPIC, message))
            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.wait_msg()
    time.sleep(1)