from machine import Pin
import time
import network
from umqtt.simple import MQTTClient
import gc  # 垃圾回收，优化内存使用

# ==================== 配置参数（需要你修改）====================
# WiFi配置
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASSWORD = ""

# 巴法云MQTT配置
BAFA_CLIENT_ID = "52ec0c74346341d49688088aedcfa4cb"  # 替换为你的巴法云私钥
BAFA_MQTT_SERVER = "bemfa.com"  # 固定
BAFA_MQTT_PORT = 9501  # 固定
SUB_TOPIC = "led001"  # 替换为你在巴法云创建的主题

# LED配置
LED_PIN = 2  # ESP32/ESP8266的GPIO2，通常有板载LED
led1 = Pin(LED_PIN, Pin.OUT)
led1.value(0)  # 默认关闭LED

# ==================== 核心功能函数 ====================
# 1. 连接WiFi（带重连机制）
def connect_wifi(max_retry=10):
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    
    # 如果已连接，直接返回
    if wlan.isconnected():
        print("WiFi已连接，IP:", wlan.ifconfig()[0])
        return wlan
    
    # 尝试连接WiFi
    print(f"正在连接WiFi: {WIFI_SSID}")
    wlan.connect(WIFI_SSID, WIFI_PASSWORD)
    
    retry_count = 0
    while not wlan.isconnected() and retry_count < max_retry:
        time.sleep(0.5)
        retry_count += 1
        print(f"连接中...({retry_count}/{max_retry})")
    
    if wlan.isconnected():
        print("WiFi连接成功！IP:", wlan.ifconfig()[0])
        return wlan
    else:
        print("WiFi连接失败！")
        wlan.active(False)
        return None

# 2. MQTT消息回调函数
def mqtt_callback(topic, msg):
    """
    收到MQTT消息后的处理逻辑
    topic: 订阅的主题（字节类型）
    msg: 收到的消息（字节类型）
    """
    try:
        topic_str = topic.decode('utf-8')
        msg_str = msg.decode('utf-8').strip()  # 去除首尾空格
        print(f"收到消息：主题={topic_str}，内容={msg_str}")
        
        # 控制LED逻辑
        if msg_str in ["on", "1"]:
            led1.value(1)
            print("✅ LED已点亮")
        elif msg_str in ["off", "0"]:
            led1.value(0)
            print("❌ LED已熄灭")
        else:
            print(f"⚠️ 未知指令：{msg_str}，支持：on/1（开灯）、off/0（关灯）")
    except Exception as e:
        print(f"消息处理失败：{e}")

# 3. 连接MQTT服务器
def connect_mqtt():
    # 垃圾回收，释放内存
    gc.collect()
    
    # 创建MQTT客户端
    client = MQTTClient(
        client_id=BAFA_CLIENT_ID,
        server=BAFA_MQTT_SERVER,
        port=BAFA_MQTT_PORT,
        keepalive=60,
        ssl=False  # 巴法云MQTT不使用SSL
    )
    
    # 设置回调函数
    client.set_callback(mqtt_callback)
    
    # 尝试连接
    try:
        client.connect()
        client.subscribe(SUB_TOPIC)
        print(f"✅ MQTT连接成功，已订阅主题：{SUB_TOPIC}")
        return client
    except Exception as e:
        print(f"❌ MQTT连接失败：{e}")
        # 关闭客户端连接（如果有）
        try:
            client.disconnect()
        except:
            pass
        return None

# 4. 检查并重建连接
def check_connections():
    global wlan, client
    
    # 检查WiFi连接
    if not wlan or not wlan.isconnected():
        wlan = connect_wifi()
        if not wlan:
            return False
    
    # 检查MQTT连接
    if not client:
        client = connect_mqtt()
    return True

# ==================== 主程序 ====================
if __name__ == "__main__":
    wlan = None
    client = None
    
    # 初始化连接
    print("========== 程序启动 ==========")
    check_connections()
    
    # 主循环
    print("等待接收控制指令...（按Ctrl+C退出）")
    try:
        while True:
            # 检查连接状态
            if not check_connections():
                print("⚠️ 连接异常，5秒后重试")
                time.sleep(5)
                continue
            
            # 非阻塞检查MQTT消息
            try:
                client.check_msg()
                # 定期发送心跳（每30秒）
                if time.time() % 30 == 0:
                    client.ping()
            except Exception as e:
                print(f"⚠️ MQTT通信异常：{e}")
                client = None  # 标记为断开，触发重连
            
            # 降低CPU占用
            time.sleep(0.1)
    
    # 捕获退出信号，优雅关闭
    except KeyboardInterrupt:
        print("\n========== 程序退出 ==========")
        led1.value(0)  # 关闭LED
        if client:
            try:
                client.disconnect()
            except:
                pass
        if wlan:
            wlan.active(False)
        print("资源已释放，程序正常退出")