import network
import time
from umqtt.simple import MQTTClient

# WiFi credentials
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASS = ""

# MQTT Broker settings
MQTT_BROKER = "broker.emqx.io"
MQTT_PORT = 1883
MQTT_TOPIC = b"esp32/test"

# WiFi Connect
def wifi_connect():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(WIFI_SSID, WIFI_PASS)
    while not wlan.isconnected():
        print("Connecting to WiFi...")
        time.sleep(1)
    print("Connected to WiFi:", wlan.ifconfig())

# Callback function (must be defined before use!)
def sub_cb(topic, msg):
    print("Received message from topic:", topic.decode(), "->", msg.decode())

# Main
wifi_connect()

client = MQTTClient("esp32_sub", MQTT_BROKER, port=MQTT_PORT)
client.set_callback(sub_cb)      # set callback first
client.connect()
client.subscribe(MQTT_TOPIC)     # then subscribe
print("Subscribed to topic:", MQTT_TOPIC)

while True:
    client.wait_msg()   # blocking wait for new message