import os

import paho.mqtt.client as mqtt
import time

broker = '121.40.129.71'
port = 48835

# 回调函数，当客户端收到连接响应时被调用
def on_connect(client, userdata, flags, rc, properties=None):
    print("连接结果: " + str(rc))
    # 订阅响应主题
    client.subscribe("request/topic")

# 回调函数，当客户端收到消息时被调用
def on_message(client, userdata, msg):
    print("收到消息: " + msg.topic + " " + str(msg.payload))

    if not os.path.exists("user.txt"):
        with open("user.txt", "a") as f:
            f.write(msg.payload.decode("utf-8") + "\n")
    else:

        # 全局变量，用于标记是否收到响应
        global response_received
        response_received = True

# 创建客户端实例
client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION2,)

# 设置回调函数
client.on_connect = on_connect
client.on_message = on_message

# 连接到MQTT代理
client.connect(broker, port,  60)

# 启动一个后台线程来处理网络流量和回调
client.loop_start()

# 发布消息


# 等待响应
response_received = False
while not response_received:
    print("等待响应...")
    time.sleep(1)

client.publish("response/topic", "Set user.txt success!", qos=2)

# 停止网络循环并断开连接
client.loop_stop()
client.disconnect()

print("收到响应，客户端退出。")