from machine import UART, Pin, Timer
import time
import network
from umqtt.simple import MQTTClient

# 串口配置
UART_PORT = 1
UART_BAUDRATE = 115200
UART_TX_PIN = 1
UART_RX_PIN = 3

# LED 引脚
LED_PIN = 15  

# 网络配置
WIFI_SSID = "Wokwi-GUEST"  
WIFI_PASSWORD = ""  

# 巴法云 MQTT 配置
MQTT_BROKER = "bemfa.com"  
MQTT_PORT = 9501  
MQTT_CLIENT_ID = "f72ebbb051666a315cbae015845649f1"  
MQTT_LIGHT_TOPIC = "light002"  
MQTT_STATUS_TOPIC = "status"
ONLINE_STATUS = "on"

# 全局变量
light_status = False
mqtt_client = None
timer = None
uart = None
led = None
wifi_connected = False
connection_attempts = 0  # 连接尝试计数
max_connection_attempts = 3  # 最大连接尝试次数

def connect_wifi():
    """连接 WiFi 网络"""
    global wifi_connected
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    if not wlan.isconnected():
        print("正在连接 WiFi...")
        wlan.connect(WIFI_SSID, WIFI_PASSWORD)
        max_wait = 15  # 增加等待时间
        while max_wait > 0:
            if wlan.isconnected():
                break
            max_wait -= 1
            time.sleep(1)
        if wlan.isconnected():
            print(f"WiFi 连接成功，网络配置: {wlan.ifconfig()}")
            wifi_connected = True
            return True
        else:
            print("WiFi 连接失败")
            wifi_connected = False
            return False
    else:
        print(f"已连接 WiFi，网络配置: {wlan.ifconfig()}")
        wifi_connected = True
        return True

def setup_hardware():
    """初始化硬件组件：串口、LED"""
    global uart, led
    # 初始化串口
    uart = UART(UART_PORT, baudrate=UART_BAUDRATE, tx=Pin(UART_TX_PIN), rx=Pin(UART_RX_PIN))
    # 初始化 LED
    led = Pin(LED_PIN, Pin.OUT)
    return uart, led

def connect_mqtt():
    """连接巴法云 MQTT 服务器"""
    global mqtt_client, connection_attempts
    
    # 限制连接尝试频率
    connection_attempts += 1
    if connection_attempts > max_connection_attempts:
        print("连接尝试次数过多，等待30秒后重试...")
        time.sleep(30)
        connection_attempts = 0
    
    try:
        # 确保之前的客户端已关闭
        if mqtt_client:
            try:
                mqtt_client.disconnect()
            except:
                pass
            mqtt_client = None
        
        # 创建新的MQTT客户端连接
        mqtt_client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, MQTT_PORT, keepalive=60)
        mqtt_client.set_callback(mqtt_message_callback)
        mqtt_client.connect()
        print("已连接到巴法云 MQTT 服务器")
        # 订阅控制主题
        mqtt_client.subscribe(MQTT_LIGHT_TOPIC)
        print(f"已订阅主题: {MQTT_LIGHT_TOPIC}")
        
        # 立即发布一次在线状态
        publish_online_status(None)
        connection_attempts = 0  # 重置连接尝试计数
        return True
    except Exception as e:
        print(f"连接 MQTT 服务器失败: {e}")
        mqtt_client = None
        return False

def publish_light_status(status):
    """发布灯状态到巴法云指定 MQTT 主题"""
    global mqtt_client
    if mqtt_client:
        try:
            mqtt_client.publish(MQTT_LIGHT_TOPIC, status)
            print(f"已发布灯状态到 {MQTT_LIGHT_TOPIC}: {status}")
        except Exception as e:
            print(f"发布灯状态失败: {e}")

def publish_online_status(timer):
    """定期发布在线状态到巴法云平台"""
    global mqtt_client
    if mqtt_client:
        try:
            status_topic = f"{MQTT_CLIENT_ID}/{MQTT_STATUS_TOPIC}"
            mqtt_client.publish(status_topic, ONLINE_STATUS, retain=True)
            print(f"已发布在线状态到 {status_topic}")
        except Exception as e:
            print(f"发布在线状态失败: {e}")

def mqtt_message_callback(topic, msg):
    """处理接收到的 MQTT 消息"""
    global light_status, led, uart
    topic_str = topic.decode('utf-8')
    msg_str = msg.decode('utf-8')
    print(f"收到消息: 主题={topic_str}, 内容={msg_str}")
    
    # 检查是否是我们订阅的主题
    if topic_str == MQTT_LIGHT_TOPIC:
        if msg_str == 'ON':
            led.value(1)
            light_status = True
            uart.write(b"\rMQTT: LED is ON.\n")
            print("LED 已打开")
        elif msg_str == 'OFF':
            led.value(0)
            light_status = False
            uart.write(b"\rMQTT: LED is OFF.\n")
            print("LED 已关闭")

def check_mqtt_connection():
    """检查 MQTT 连接状态，如果断开则重新连接"""
    global mqtt_client, wifi_connected
    
    # 首先确保WiFi已连接
    if not wifi_connected:
        wifi_connected = connect_wifi()
        if not wifi_connected:
            return False
    
    # 检查MQTT连接状态
    if mqtt_client:
        try:
            # 使用ping检查连接是否活跃
            mqtt_client.ping()
            return True
        except:
            print("MQTT ping失败，连接已断开")
            mqtt_client = None
    
    # 连接断开，尝试重新连接
    print("MQTT 连接已断开，尝试重新连接...")
    return connect_mqtt()

def main():
    """主程序逻辑：串口控制 LED、MQTT 上传状态"""
    global light_status, mqtt_client, timer
    
    # 连接 WiFi
    wifi_connected = connect_wifi()
    if not wifi_connected:
        print("WiFi 连接失败，程序退出")
        return
    
    # 初始化硬件
    uart, led = setup_hardware()
    
    # 连接 MQTT 服务器
    if not connect_mqtt():
        print("MQTT 连接失败，程序退出")
        return
    
    # 设置定时器定期发送在线状态，增加间隔时间减少网络负担
    timer = Timer(0)
    timer.init(period=120000, mode=Timer.PERIODIC, callback=publish_online_status)
    
    # 运行前提示信息
    uart.write(b"\rPlease enter 1 or 0,1 is open led,0 is close led:\n")
    
    while True:
        # 检查 MQTT 连接
        if not check_mqtt_connection():
            time.sleep(10)  # 连接失败后增加等待时间
            continue
        
        # 处理 MQTT 消息
        try:
            mqtt_client.check_msg()
        except Exception as e:
            print(f"处理 MQTT 消息时出错: {e}")
            mqtt_client = None
            time.sleep(5)  # 出错后短暂等待
        
        # 处理串口数据
        if uart.any():
            data = uart.read()
            print("Received:", data)
            if data == b'1':
                led.value(1)
                light_status = True
                uart.write(b"\rinput 1, LED is ON.\n")
                publish_light_status("ON")
            elif data == b'0':
                led.value(0)
                light_status = False
                uart.write(b"\rinput 0, LED is OFF.\n")
                publish_light_status("OFF")
            else:
                uart.write(b"\rInvalid input! Please enter 1 or 0.\n")
        
        time.sleep(0.1)  # 适当延时，减少 CPU 使用率

if __name__ == "__main__":
    main()