import dht
import machine
import time
import ssd1306
from umqtt.simple import MQTTClient

# 全局配置
DHT_PIN = 14  # DHT22数据引脚连接到GPIO14
I2C_SCL = 5   # I2C时钟线连接到GPIO5
I2C_SDA = 4   # I2C数据线连接到GPIO4
OLED_WIDTH = 128  # OLED宽度
OLED_HEIGHT = 64  # OLED高度

# 需要修改的地方
wifiName = "Wokwi-GUEST"  # wifi名称，不支持5G wifi
wifiPassword = ""  # wifi密码
clientID = "d2bc31d11dbd41a08255a2d5a60a1dee"  # Client ID，密钥，巴法云控制台获取
tempTopic = "mytemp"  # 温度主题，巴法MQTT控制台创建
humiTopic = "humi"    # 湿度主题，巴法MQTT控制台创建

# 默认设置
serverIP = "bemfa.com"  # mqtt服务器地址
port = 9501

# WIFI连接函数
def do_connect():
    import network
    sta_if = network.WLAN(network.STA_IF)
    if not sta_if.isconnected():
        print('connecting to network...')
        sta_if.active(True)
        sta_if.connect(wifiName, wifiPassword)
        max_retries = 10
        retry_count = 0
        while not sta_if.isconnected() and retry_count < max_retries:
            time.sleep(1)
            retry_count += 1
        if not sta_if.isconnected():
            print("Failed to connect to WiFi after multiple retries.")
            raise OSError("WiFi connection failed")
    print('connect WiFi ok')

# 初始化mqtt连接配置
def connect_and_subscribe():
    max_retries = 5
    retry_count = 0
    while retry_count < max_retries:
        try:
            client = MQTTClient(clientID, serverIP, port)
            client.connect()
            print("Connected to %s" % serverIP)
            return client
        except OSError as e:
            print(f"MQTT connection error (attempt {retry_count + 1}): {e}")
            retry_count += 1
            time.sleep(2)
    print("Failed to connect to MQTT broker after multiple retries.")
    raise OSError("MQTT connection failed")

def init_display():
    """初始化OLED显示屏"""
    i2c = machine.I2C(scl=machine.Pin(I2C_SCL), sda=machine.Pin(I2C_SDA))
    display = ssd1306.SSD1306_I2C(OLED_WIDTH, OLED_HEIGHT, i2c)
    return display

def read_sensor_data():
    """读取DHT22传感器数据"""
    sensor = dht.DHT22(machine.Pin(DHT_PIN))
    
    try:
        sensor.measure()
        temperature = sensor.temperature()
        humidity = sensor.humidity()
        return temperature, humidity
    except OSError as e:
        print(f"传感器读取错误: {e}")
        return None, None

def display_data(temperature, humidity, display):
    """格式化并显示温湿度数据到终端和OLED屏幕"""
    if temperature is not None and humidity is not None:
        # 显示到终端
        print(f"温度: {temperature}°C | 湿度: {humidity}%")
        
        # 显示到OLED屏幕
        display.fill(0)  # 清屏
        display.text("Temp & Humidity", 0, 0)
        display.text(f"Temp: {temperature} C", 0, 20)
        display.text(f"Humi: {humidity} %", 0, 40)
        display.show()  # 更新显示
    else:
        print("无法读取传感器数据")
        display.fill(0)
        display.text("Sensor Error", 0, 0)
        display.show()

def publish_to_mqtt(client, temperature, humidity):
    """发布温湿度数据到MQTT主题"""
    if temperature is not None and humidity is not None:
        try:
            # 发布温度数据到mytemp主题
            client.publish(tempTopic, str(temperature))
            # 发布湿度数据到humi主题
            client.publish(humiTopic, str(humidity))
            print("Data published to MQTT Broker!")
        except Exception as e:
            print(f"Error publishing data to MQTT: {e}")
            raise  # 重新抛出异常以便上层处理

def main():
    """主函数，程序入口点"""
    print("DHT22温湿度监控系统启动...")
    
    # 连接WiFi
    try:
        do_connect()
    except OSError as e:
        print(f"WiFi连接错误: {e}")
        time.sleep(10)
        machine.reset()
    
    # 连接MQTT
    try:
        client = connect_and_subscribe()
    except OSError as e:
        print(f"MQTT连接错误: {e}")
        time.sleep(10)
        machine.reset()
    
    # 初始化显示屏
    display = init_display()
    display.text("System Starting...", 0, 0)
    display.show()
    time.sleep(2)
    
    try:
        while True:
            # 读取传感器数据
            temperature, humidity = read_sensor_data()
            
            # 显示数据
            display_data(temperature, humidity, display)
            
            # 发布数据到MQTT
            try:
                publish_to_mqtt(client, temperature, humidity)
            except Exception as e:
                print(f"MQTT发布失败，尝试重连: {e}")
                client = connect_and_subscribe()
                # 重连成功后再次尝试发布
                publish_to_mqtt(client, temperature, humidity)
            
            # 等待2秒（DHT22最小采样间隔）
            time.sleep(2)
            
    except KeyboardInterrupt:
        print("\n程序已停止")
        display.fill(0)
        display.text("Program Stopped", 0, 0)
        display.show()
    except Exception as e:
        print(f"发生错误: {e}")
        display.fill(0)
        display.text("System Error", 0, 0)
        display.show()
    finally:
        # 断开MQTT连接
        try:
            client.disconnect()
            print("Disconnected from MQTT Broker")
        except Exception:
            pass

# 程序入口
if __name__ == "__main__":
    main()