from machine import Pin, SoftI2C
import time
from dht import DHT22  # 导入DHT22模块
from ssd1306 import SSD1306_I2C  # I2C的oled驱动
import network
from umqtt.simple import MQTTClient

# 硬件配置
DHT_PIN = 2       # DHT22数据引脚
OLED_SDA_PIN = 23  # OLED SDA引脚
OLED_SCL_PIN = 18  # OLED SCL引脚

# 网络配置 - 请修改为你的网络信息
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASSWORD = ""

# 巴法云MQTT配置
MQTT_PROFILE_NAME = "yanqi-巴法云平台MQTT"
MQTT_BROKER = "bemfa.com"
MQTT_PORT = 9501
MQTT_CLIENT_ID = "eac294c0d54f24e87948fe5831d0d4f6"
MQTT_TOPIC = "mydht"  # 要订阅和发布的主题

# 全局变量，用于保存 MQTT 客户端
mqtt_client = None  

def connect_wifi():
    """连接WiFi网络"""
    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)

        # 等待连接
        max_wait = 10
        while max_wait > 0:
            if wlan.isconnected():
                break
            max_wait -= 1
            print("等待连接...")
            time.sleep(1)

        if wlan.isconnected():
            print(f"WiFi连接成功，网络配置: {wlan.ifconfig()}")
            return True
        else:
            print("WiFi连接失败")
            return False
    else:
        print(f"已连接WiFi，网络配置: {wlan.ifconfig()}")
        return True

def setup_hardware():
    """初始化硬件组件"""
    # 创建软件I2C对象
    i2c = SoftI2C(sda=Pin(OLED_SDA_PIN), scl=Pin(OLED_SCL_PIN))
    # 创建OLED对象
    oled = SSD1306_I2C(128, 64, i2c)
    # 初始化DHT22传感器
    dht_sensor = DHT22(Pin(DHT_PIN))

    return oled, dht_sensor

def display_sensor_data(oled, temperature, humidity, wifi_connected):
    """在OLED上显示传感器数据"""
    oled.fill(0)  # 清空屏幕

    # 显示标题
    oled.text("DHT22 senor", 0, 0, 1)

    # 显示温度数据
    temp_text = f"temp: {temperature:.1f} °C"
    oled.text(temp_text, 10, 20, 1)

    # 显示湿度数据
    hum_text = f"humi: {humidity:.1f} %"
    oled.text(hum_text, 10, 40, 1)

    # 显示WiFi状态
    wifi_text = "WiFi: success" if wifi_connected else "WiFi: 未连接"
    oled.text(wifi_text, 0, 56, 1)

    oled.show()  # 刷新屏幕显示

def read_sensor_data(dht_sensor):
    """读取DHT22传感器数据"""
    try:
        dht_sensor.measure()
        temperature = dht_sensor.temperature()
        humidity = dht_sensor.humidity()
        return temperature, humidity
    except Exception as e:
        raise RuntimeError(f"读取传感器失败: {e}")

def connect_mqtt():
    """连接MQTT服务器并订阅主题"""
    global mqtt_client
    try:
        mqtt_client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, MQTT_PORT)
        # 定义回调函数，用于处理订阅主题收到的消息
        mqtt_client.set_callback(sub_callback)  
        mqtt_client.connect()
        # 订阅主题
        mqtt_client.subscribe(MQTT_TOPIC)  
        print(f"已连接到MQTT服务器并订阅主题: {MQTT_TOPIC}")
        return mqtt_client
    except Exception as e:
        print(f"连接MQTT服务器或订阅失败: {e}")
        return None

def sub_callback(topic, msg):
    """订阅主题的回调函数，当收到消息时会被调用"""
    print(f"收到订阅消息，主题: {topic.decode()}, 内容: {msg.decode()}")
    # 这里可以根据收到的消息进行相应处理，比如控制硬件、修改显示等
    # 示例：如果收到特定指令，可在此处扩展逻辑

def publish_data(client, temperature, humidity):
    """发布温湿度数据到MQTT主题"""
    try:
        data = f"temp={temperature:.1f}&hum={humidity:.1f}"
        client.publish(MQTT_TOPIC, data)
        print(f"已发布数据: {data}")
    except Exception as e:
        print(f"发布数据失败: {e}")

def main():
    """主程序入口"""
    try:
        # 连接WiFi
        wifi_connected = connect_wifi()

        # 初始化硬件
        oled, dht_sensor = setup_hardware()

        # 显示初始化信息
        oled.fill(0)
        oled.text("系统初始化中...", 15, 20, 1)
        oled.text(f"WiFi: {'已连接' if wifi_connected else '未连接'}", 15, 40, 1)
        oled.show()
        time.sleep(3)  # 等待传感器稳定

        print("DHT22温湿度监测系统已启动")
        print("-" * 30)

        # 连接MQTT服务器并订阅主题
        client = connect_mqtt()
        if client is None:
            return

        while True:
            try:
                # 读取传感器数据
                temperature, humidity = read_sensor_data(dht_sensor)

                # 显示数据
                display_sensor_data(oled, temperature, humidity, wifi_connected)

                # 发布数据到MQTT主题
                publish_data(client, temperature, humidity)

                # 检查是否有订阅消息（非阻塞方式，需定期调用）
                if client is not None:
                    client.check_msg()  

                # 等待5秒再进行下一次读取（DHT22建议采样间隔至少2秒，这里设置为5秒更保险）
                time.sleep(5)

            except RuntimeError as e:
                # 处理传感器读取错误
                oled.fill(0)
                oled.text("传感器错误!", 20, 20, 1)
                oled.text(str(e), 10, 40, 1)
                oled.show()
                print(f"运行时错误: {e}")
                time.sleep(5)  # 错误发生后等待更长时间

    except KeyboardInterrupt:
        # 清理资源
        oled.fill(0)
        oled.text("程序已停止", 25, 30, 1)
        oled.show()
        time.sleep(1)
        oled.fill(0)
        oled.show()
        print("\n程序已停止")
        if mqtt_client is not None:
            mqtt_client.disconnect()
    except Exception as e:
        print(f"发生未知错误: {e}")
        if 'oled' in locals():
            oled.fill(0)
            oled.text("致命错误!", 20, 20, 1)
            oled.text(str(e), 10, 40, 1)
            oled.show()
            if mqtt_client is not None:
                mqtt_client.disconnect()

if __name__ == "__main__":
    main()