import dht
from machine import Pin, I2C
import ssd1306
import time
import network
from umqtt.simple import MQTTClient

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

# 巴法云MQTT配置
MQTT_SERVER = "bemfa.com"
MQTT_PORT = 9501
MQTT_CLIENT_ID = "b2e3961e73fe4064b831d9b4b821d965"  # 必须唯一
MQTT_USER = ""
MQTT_PASSWORD = ""
MQTT_TOPIC = "mydht"  # 主题名称
MQTT_CONTROL_TOPIC = "light002"  # 控制主题

# 硬件配置
dht_pin = Pin(4)
sensor = dht.DHT22(dht_pin)

led_pin = Pin(15, Pin.OUT)
led_pin.value(0)  # 初始关闭LED

i2c = I2C(0, scl=Pin(18), sda=Pin(23), freq=400000)
oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)

# 系统状态
system_mode = "auto"  # 初始为自动模式
temp_threshold = 30.0  # 默认温度阈值
hum_threshold = 70.0   # 默认湿度阈值
last_alert_time = 0
alert_interval = 1     # 报警闪烁间隔(秒)
led_status = 0         # LED当前状态
last_sensor_time = 0   # 上次读取传感器时间
sensor_interval = 2    # 传感器读取间隔(秒)

# 连接WiFi
def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    if not wlan.isconnected():
        print('Connecting to network...')
        wlan.connect(WIFI_SSID, WIFI_PASSWORD)
        while not wlan.isconnected():
            time.sleep(0.1)
    print('Network config:', wlan.ifconfig())
    return wlan

# 订阅消息回调函数
def sub_cb(topic, msg):
    global system_mode, temp_threshold, hum_threshold
    topic = topic.decode('utf-8')
    msg = msg.decode('utf-8')
    print(f"Received message on topic {topic}: {msg}")
    
    try:
        # 解析控制命令
        if topic == MQTT_CONTROL_TOPIC:
            if msg.startswith("mode:"):
                mode = msg.split(":")[1]
                if mode in ["auto", "manual"]:
                    system_mode = mode
                    print(f"Changed to {system_mode} mode")
                    log_event(f"System mode changed to {system_mode}")
                else:
                    print(f"Invalid mode: {mode}")
            elif msg.startswith("temp_threshold:"):
                temp_threshold = float(msg.split(":")[1])
                print(f"Temperature threshold set to: {temp_threshold}°C")
                log_event(f"Temperature threshold set to {temp_threshold}°C")
            elif msg.startswith("hum_threshold:"):
                hum_threshold = float(msg.split(":")[1])
                print(f"Humidity threshold set to: {hum_threshold}%")
                log_event(f"Humidity threshold set to {hum_threshold}%")
            elif msg.startswith("led:"):
                if system_mode == "manual":
                    led_state = int(msg.split(":")[1])
                    led_pin.value(led_state)
                    led_status = led_state  # 更新LED状态
                    print(f"LED set to: {led_state}")
                    log_event(f"LED manually set to {led_state}")
                else:
                    print("Cannot manually control LED in auto mode")
    except Exception as e:
        print(f"Error processing message: {e}")

# 连接MQTT服务器
def connect_mqtt():
    client = MQTTClient(MQTT_CLIENT_ID, MQTT_SERVER, MQTT_PORT)
    # 设置订阅回调函数
    client.set_callback(sub_cb)  
    try:
        client.connect()
        print(f"Connected to MQTT Broker: {MQTT_SERVER}")
        # 订阅控制主题以接收命令
        client.subscribe(MQTT_CONTROL_TOPIC)
        print(f"Subscribed to control topic: {MQTT_CONTROL_TOPIC}")
        return client
    except Exception as e:
        print(f"MQTT connection failed: {e}")
        return None

# 读取DHT22传感器数据
def read_sensor():
    try:
        sensor.measure()
        temp = sensor.temperature()
        hum = sensor.humidity()
        return temp, hum
    except OSError as e:
        print(f"Sensor read error: {e}")
        return None, None

# 更新控制台显示
def update_console(temp, hum):
    if temp is not None and hum is not None:
        print(f"Temperature: {temp:.1f}°C | Humidity: {hum:.1f}% | Mode: {system_mode}")
        print(f"Thresholds: Temp={temp_threshold}°C, Hum={hum_threshold}%")
    else:
        print("Sensor read failed")

# 更新OLED屏幕显示 - 增强报警显示效果
def update_oled(temp, hum, mqtt_connected=False):
    oled.fill(0)  # 清屏
    
    # 显示标题
    oled.text("DHT22 Monitoring", 0, 0)
    
    # 检查是否有报警情况
    has_alarm = False
    if temp is not None and temp > temp_threshold:
        has_alarm = True
    if hum is not None and hum > hum_threshold:
        has_alarm = True
    
    # 报警状态下的特殊显示
    if has_alarm and (time.time() % 2 < 1):  # 每秒切换一次
        oled.fill(1)  # 全屏反色
        oled.text("ALARM!", 40, 25, 0)  # 黑色文字
    
    if temp is not None and hum is not None:
        # 显示温度和阈值
        temp_text = f"Temp: {temp:.1f}°C"
        temp_color = 0 if (temp > temp_threshold and has_alarm) else 1
        oled.text(temp_text, 10, 20, temp_color)
        
        # 显示湿度和阈值
        hum_text = f"Hum:  {hum:.1f}%"
        hum_color = 0 if (hum > hum_threshold and has_alarm) else 1
        oled.text(hum_text, 10, 40, hum_color)
        
        # 显示模式
        oled.text(f"Mode: {system_mode}", 0, 52)
        
        # 显示MQTT连接状态
        status_text = "MQTT: Connected" if mqtt_connected else "MQTT: Disconnected"
        oled.text(status_text, 0, 56)
    else:
        oled.text("Sensor Error", 20, 30)
    
    oled.show()  # 更新显示

# 处理报警逻辑 - 增强LED闪烁效果
def handle_alarm(temp, hum):
    global last_alert_time, led_status, led_pin
    
    # 检查是否需要报警
    need_alarm = False
    if temp is not None and temp > temp_threshold:
        need_alarm = True
    if hum is not None and hum > hum_threshold:
        need_alarm = True
    
    # 处理报警状态
    current_time = time.time()
    if need_alarm:
        # 闪烁LED - 不同报警级别不同频率
        flash_interval = alert_interval
        if (temp is not None and temp > temp_threshold + 5) or (hum is not None and hum > hum_threshold + 10):
            flash_interval = alert_interval / 2  # 紧急情况加快闪烁频率
            
        if current_time - last_alert_time >= flash_interval:
            led_status = 1 - led_status  # 切换LED状态
            led_pin.value(led_status)
            last_alert_time = current_time
    else:
        # 关闭报警
        if led_status != 0:
            led_status = 0
            led_pin.value(led_status)

# 记录事件日志
def log_event(message):
    timestamp = time.localtime()
    log_msg = f"{timestamp[0]}-{timestamp[1]:02d}-{timestamp[2]:02d} {timestamp[3]:02d}:{timestamp[4]:02d}:{timestamp[5]:02d} - {message}"
    print(f"LOG: {log_msg}")
    # 可以扩展将日志发布到MQTT
    # mqtt_client.publish("DHT22_LOG", log_msg)

# 主函数
def main():
    print("Starting DHT22 Monitoring System...")
    oled.text("Initializing...", 10, 30)
    oled.show()
    
    mqtt_client = None  # 初始化 MQTT 客户端变量
    # 连接 WiFi
    wlan = connect_wifi()
    
    # 连接 MQTT
    mqtt_client = connect_mqtt()
    
    # 记录上次发布时间
    last_publish_time = 0
    publish_interval = 5  # 每 5 秒发布一次数据
    
    # 记录启动事件
    log_event("System started")
    
    try:
        while True:
            # 检查 MQTT 连接状态，若连接则处理可能收到的订阅消息
            if mqtt_client:
                try:
                    mqtt_client.check_msg()
                except Exception as e:
                    print(f"Error checking MQTT messages: {e}")
                    mqtt_client = connect_mqtt()  # 重新连接并更新变量
            
            # 检查是否到发布数据时间
            if mqtt_client and (time.time() - last_publish_time) >= publish_interval:
                try:
                    # 读取传感器数据
                    temperature, humidity = read_sensor()
                    
                    # 更新控制台显示
                    update_console(temperature, humidity)
                    
                    # 更新 OLED 显示
                    update_oled(temperature, humidity, mqtt_client is not None)
                    
                    # 处理报警逻辑
                    handle_alarm(temperature, humidity)
                    
                    # 发布数据到 MQTT 主题
                    if temperature is not None and humidity is not None:
                        data = f"temp:{temperature:.1f},hum:{humidity:.1f},mode:{system_mode},temp_threshold:{temp_threshold},hum_threshold:{hum_threshold},led:{led_status}"
                        mqtt_client.publish(MQTT_TOPIC, data)
                        print(f"Published: {data}")
                    
                    # 更新发布时间
                    last_publish_time = time.time()
                    
                except Exception as e:
                    print(f"Error in main loop: {e}")
                    # 尝试重新连接 MQTT
                    mqtt_client = connect_mqtt()
                    update_oled(None, None, False)
            
            # 短暂休眠，避免 CPU 占用过高
            time.sleep(0.1)
            
    except KeyboardInterrupt:
        print("\nProgram stopped by user")
        if mqtt_client:
            mqtt_client.disconnect()
        led_pin.value(0)  # 关闭 LED
        oled.fill(0)
        oled.show()  # 清屏

if __name__ == "__main__":
    main()