import paho.mqtt.client as mqtt
import time

# MQTT 服务器地址
MQTT_SERVER = "127.0.0.1"
MQTT_PORT = 1883
MQTT_TOPIC = "test/topic"

# 当客户端从服务器成功接收 CONNACK 响应时调用的回调函数
def on_connect(client, userdata, flags, rc):
    print(f"Connected with result code {rc}")
    # 订阅主题
    client.subscribe(MQTT_TOPIC)

# 当接收到订阅主题的消息时调用的回调函数
def on_message(client, userdata, msg):
    print(f"Received message: {msg.payload.decode()} on topic {msg.topic}")

# 创建 MQTT 客户端实例
client = mqtt.Client()

# 绑定回调函数
client.on_connect = on_connect
client.on_message = on_message

# 连接到 MQTT 服务器
client.connect(MQTT_SERVER, MQTT_PORT, 60)

# 开始循环处理网络事件
client.loop_start()

# 让客户端运行一段时间，以便接收消息
try:
    while True:
        time.sleep(1)
except KeyboardInterrupt:
    pass

# 停止循环
client.loop_stop()
client.disconnect()