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

MQTT_CLIENT_ID = "DHT22"
MQTT_BROKER    = "8.137.152.225"
MQTT_USER      = "sensors"
MQTT_PASSWORD  = "Furutsuki1"
MQTT_TOPIC     = "wokwi-weather"

sensor = dht.DHT22(Pin(15))

def connect_wifi():
    wifi = network.WLAN(network.STA_IF)
    wifi.active(True)
    wifi.connect('Wokwi-GUEST', '')
    while not wifi.isconnected():
        time.sleep(0.1)
    print("WiFi Connected:", wifi.ifconfig()[0])

def connect_mqtt():
    client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD,keepalive=15)
    client.set_last_will(MQTT_TOPIC, "DHT22 offline", retain=True)#遗嘱要在写好，连接前发送
    client.connect()
    client.publish(MQTT_TOPIC, "DHT22 online", retain=True)  
    print("MQTT Connected!")
    return client

connect_wifi()
client = connect_mqtt()

while True:
    try:
        sensor.measure()
        message = ujson.dumps({
            "temp": sensor.temperature(),
            "humidity": sensor.humidity(),
        })
        client.publish(MQTT_TOPIC, message, qos=1)
        print(message)
    except Exception as e:
        print("Error:", e, "- Reconnecting...")
        time.sleep(2)
        try:
            client = connect_mqtt()
        except:
            pass
    time.sleep(1)