# 作业27-DHT22-阈值
# 在shell控制台、OLED屏、网页或小程序中上同时显示DHT22的信息
# 当温度或湿度高于某一特定值（阈值）时，连接ESP32引脚15的led闪烁，实现报警。
# 通过light002主题控制LED灯

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 = "e9043ebda15dd81b945cc88cccbcb3c6"  # 必须唯一
MQTT_USER = ""
MQTT_PASSWORD = ""
MQTT_TOPIC = "DHT22"      # 数据发布主题
MQTT_LIGHT_TOPIC = "light002"  # 灯光控制主题

# 阈值配置
TEMP_THRESHOLD = 28  # 温度阈值(°C)
HUMI_THRESHOLD = 70  # 湿度阈值(%)

# 初始化硬件
dht_pin = Pin(4)
sensor = dht.DHT22(dht_pin)

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)

# LED控制引脚
led_pin = Pin(15, Pin.OUT)  # 控制LED灯的引脚
led_state = False           # 当前LED状态
alarm_state = False         # 报警状态

# 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():
            pass
    print('Network config:', wlan.ifconfig())
    return wlan

# 订阅消息回调函数 - 处理接收到的MQTT消息
def sub_cb(topic, msg):
    global led_state
    topic = topic.decode()
    msg = msg.decode()
    print(f"Received message on topic {topic}: {msg}")
    
    # 处理温度/湿度数据主题
    if topic == MQTT_TOPIC:
        pass  # 确保空代码块有pass语句
    
    # 处理灯光控制主题
    elif topic == MQTT_LIGHT_TOPIC:
        if msg == 'on':
            led_state = True
            led_pin.on()
            print("LED turned ON")
        elif msg == 'off':
            led_state = False
            led_pin.off()
            print("LED turned OFF")
        elif msg == 'toggle':
            led_state = not led_state
            led_pin.value(led_state)
            print(f"LED toggled to {'ON' if led_state else 'OFF'}")

# 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}")
        # 订阅数据主题和灯光控制主题
        client.subscribe(MQTT_TOPIC)
        client.subscribe(MQTT_LIGHT_TOPIC)
        print(f"Subscribed to topics: {MQTT_TOPIC}, {MQTT_LIGHT_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

# 检查是否触发报警条件
def check_alarm(temp, hum):
    global alarm_state
    if temp is not None and hum is not None:
        alarm_state = (temp > TEMP_THRESHOLD) or (hum > HUMI_THRESHOLD)
        return alarm_state
    return False

# 处理报警状态
def handle_alarm():
    if alarm_state:
        # 闪烁LED实现报警
        for _ in range(3):
            led_pin.on()
            time.sleep(0.3)
            led_pin.off()
            time.sleep(0.3)
        # 恢复LED到之前的状态
        led_pin.value(led_state)

# 更新控制台显示
def update_console(temp, hum):
    if temp is not None and hum is not None:
        alarm_text = " (ALARM!)" if check_alarm(temp, hum) else ""
        print(f"Temperature: {temp:.1f}°C | Humidity: {hum:.1f}% | LED: {'ON' if led_state else 'OFF'}{alarm_text}")
    else:
        print("Sensor read failed")

# 更新OLED屏幕显示
def update_oled(temp, hum, mqtt_connected=False):
    oled.fill(0)  # 清屏
    
    if temp is not None and hum is not None:
        # 显示标题
        oled.text("DHT22 Monitoring", 0, 0)
        
        # 显示温度
        oled.text(f"Temp: {temp:.1f}°C", 10, 20)
        
        # 显示湿度
        oled.text(f"Hum:  {hum:.1f}%", 10, 40)
        
        # 显示LED状态
        led_text = f"LED: {'ON' if led_state else 'OFF'}"
        if alarm_state:
            led_text += " (ALARM!)"
        oled.text(led_text, 0, 50)
        
        # 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

# 主函数
def main():
    print("Starting DHT22 Monitoring System...")
    oled.text("Initializing...", 10, 30)
    oled.show()
    
    # 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
    
    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()  # 尝试重新连接
            
            # 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)
                    
                    # 检查是否触发报警
                    if check_alarm(temperature, humidity):
                        handle_alarm()
                    
                    # 更新OLED显示
                    update_oled(temperature, humidity, mqtt_client is not None)
                    
                    # 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},led:{led_state},alarm:{alarm_state}"
                        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()
        oled.fill(0)
        oled.show()  # 清屏

if __name__ == "__main__":
    main()