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

# 全局配置
TRIG_PIN = 14  # HC-SR04触发引脚连接到GPIO14
ECHO_PIN = 12  # HC-SR04回声引脚连接到GPIO12
BUZZER_PIN = 15  # 蜂鸣器连接到GPIO15

# 报警阈值配置（单位：厘米）
DISTANCE_THRESHOLD = 30.0  # 距离小于此值时触发报警

# SSD1306 OLED配置
OLED_WIDTH = 128
OLED_HEIGHT = 64
OLED_SDA = 4  # GPIO4
OLED_SCL = 5  # GPIO5

# Wokwi WiFi配置
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASSWORD = ""

# 巴法云MQTT配置
MQTT_CLIENT_ID = "c34f996c831c59799e2b0b5ef4c0aac9"  # 替换为你的Client ID
MQTT_BROKER = "bemfa.com" 
MQTT_PORT = 9501
MQTT_USER = ""  # 如果不需要用户名，可以留空
MQTT_SECRET_KEY = "c34f996c831c59799e2b0b5ef4c0aac9"  # 替换为你的巴法云密钥
TOPIC_DISTANCE = "Distance"  # 距离主题

# 初始化I2C和OLED
i2c = I2C(0, sda=Pin(OLED_SDA), scl=Pin(OLED_SCL), freq=400000)
oled = ssd1306.SSD1306_I2C(OLED_WIDTH, OLED_HEIGHT, i2c)

# 初始化蜂鸣器
buzzer = Pin(BUZZER_PIN, Pin.OUT)
buzzer.value(0)  # 初始状态关闭蜂鸣器

# 初始化WiFi
wifi = network.WLAN(network.STA_IF)
wifi.active(True)

def connect_wifi():
    """连接WiFi网络"""
    if not wifi.isconnected():
        print("正在连接WiFi...")
        oled.fill(0)
        oled.text("Connecting WiFi", 0, 20)
        oled.show()
        
        wifi.connect(WIFI_SSID, WIFI_PASSWORD)
        max_attempts = 20  # 增加尝试次数
        while not wifi.isconnected() and max_attempts > 0:
            max_attempts -= 1
            print(f"等待WiFi连接...剩余尝试 {max_attempts}次")
            time.sleep(1)
    
    if wifi.isconnected():
        print("WiFi连接成功:", wifi.ifconfig())
        oled.fill(0)
        oled.text("WiFi Connected", 0, 20)
        oled.text(wifi.ifconfig()[0], 0, 35)
        oled.show()
        time.sleep(1)
    else:
        print("WiFi连接失败")
        oled.fill(0)
        oled.text("WiFi Failed", 0, 20)
        oled.show()
        raise RuntimeError("无法连接WiFi")

# 初始化MQTT客户端
mqtt_client = MQTTClient(
    client_id=MQTT_CLIENT_ID,
    server=MQTT_BROKER,
    port=MQTT_PORT,
    user=MQTT_USER,
    password=MQTT_SECRET_KEY,  # 使用密钥而不是密码
    keepalive=30  # 缩短心跳间隔
)

def mqtt_callback(topic, msg):
    """MQTT消息回调函数"""
    print(f"收到消息: {topic.decode()} -> {msg.decode()}")
    # 可以在OLED上显示收到的消息
    oled.fill(0)
    oled.text("MQTT Msg:", 0, 0)
    oled.text(f"{topic.decode()}:{msg.decode()}", 0, 20)
    oled.show()
    time.sleep(2)

def connect_mqtt():
    """连接MQTT服务器并订阅主题"""
    try:
        mqtt_client.set_callback(mqtt_callback)
        mqtt_client.connect()
        print("MQTT连接成功")
        
        # 订阅主题（使状态显示为在线）
        mqtt_client.subscribe(TOPIC_DISTANCE)
        print(f"已订阅主题: {TOPIC_DISTANCE}")
        
        oled.fill(0)
        oled.text("MQTT Connected", 0, 20)
        oled.text("Subscribed!", 0, 35)
        oled.show()
        time.sleep(1)
    except Exception as e:
        print(f"MQTT连接失败: {e}")
        oled.fill(0)
        oled.text("MQTT Failed", 0, 20)
        oled.text(str(e)[:20], 0, 35)  # 显示部分错误信息
        oled.show()
        raise

def read_sensor_data():
    """读取HC-SR04传感器数据"""
    try:
        # 触发HC-SR04传感器
        trigger = Pin(TRIG_PIN, Pin.OUT)
        echo = Pin(ECHO_PIN, Pin.IN)
        
        trigger.value(0)
        time.sleep_us(2)
        trigger.value(1)
        time.sleep_us(10)
        trigger.value(0)
        
        # 等待回声信号
        while echo.value() == 0:
            pulse_start = time.ticks_us()
        
        while echo.value() == 1:
            pulse_end = time.ticks_us()
        
        # 计算脉冲持续时间
        pulse_duration = pulse_end - pulse_start
        
        # 计算距离 (声音速度 = 34300厘米/秒)
        distance = pulse_duration * 0.0343 / 2
        return distance
    except Exception as e:
        print(f"传感器读取错误: {e}")
        return None

def publish_data(distance, alarm_status=False):
    """通过MQTT发布数据到巴法云"""
    try:
        if distance is not None:
            # 包含距离和报警状态
            data = f"dist:{distance:.1f},alarm:{1 if alarm_status else 0}"
            mqtt_client.publish(TOPIC_DISTANCE, data)
            print(f"已发布数据: {data}")
    except Exception as e:
        print(f"MQTT发布失败: {e}")
        # 尝试重新连接
        connect_mqtt()

def control_buzzer(alarm_active):
    """控制蜂鸣器"""
    if alarm_active:
        # 距离小于阈值，触发报警 - 蜂鸣器发出警报声
        buzzer.value(1)
        time.sleep(0.2)  # 蜂鸣器响200ms
        buzzer.value(0)
        time.sleep(0.1)  # 暂停100ms
    else:
        # 距离正常，关闭蜂鸣器
        buzzer.value(0)

def display_data(distance):
    """在OLED和串口上显示数据"""
    oled.fill(0)
    oled.text("Distance Monitor", 0, 0)
    for x in range(OLED_WIDTH):
        oled.pixel(x, 12, 1)
    
    alarm_status = False
    
    if distance is not None:
        oled.text(f"Dist: {distance:.1f} cm", 0, 20)
        
        # 根据距离显示状态和控制报警
        if distance < 10:
            oled.text("Very Close!", 0, 35)
            alarm_status = True
        elif distance < 30:
            oled.text("Close", 0, 35)
            alarm_status = True
        elif distance < 100:
            oled.text("Medium", 0, 35)
        else:
            oled.text("Far", 0, 35)
            
        print(f"距离: {distance}厘米 - 报警状态: {'开启' if alarm_status else '关闭'}")
        
        # 控制蜂鸣器
        control_buzzer(alarm_status)
        
        # 发布数据
        publish_data(distance, alarm_status)
    else:
        oled.text("Sensor Error!", 0, 20)
        print("无法获取传感器数据")
    
    # 显示连接状态
    status = f"WiFi:{'On' if wifi.isconnected() else 'Off'}"
    status += f" MQTT:{'On' if mqtt_client.sock else 'Off'}"
    oled.text(status, 0, 50)
    
    # 显示报警状态
    if alarm_status:
        oled.text("ALARM!", 90, 50)
    
    oled.show()

def main():
    """主函数，程序入口点"""
    print("HC-SR04距离监控系统启动...")
    print(f"距离报警阈值: {DISTANCE_THRESHOLD}厘米")
    
    # 初始连接
    connect_wifi()
    connect_mqtt()
    
    try:
        while True:
            # 检查MQTT消息
            try:
                mqtt_client.check_msg()  # 检查新消息
            except Exception as e:
                print(f"检查消息错误: {e}")
                connect_mqtt()  # 出错时重新连接
            
            # 读取和显示数据
            distance = read_sensor_data()
            display_data(distance)
            
            # 保持连接
            try:
                mqtt_client.ping()
            except:
                connect_mqtt()
                
            # 短暂延迟
            time.sleep(0.1)
            
    except KeyboardInterrupt:
        print("\n程序已停止")
        buzzer.value(0)  # 确保关闭蜂鸣器
        mqtt_client.disconnect()
    except Exception as e:
        print(f"发生错误：{e}")
        buzzer.value(0)  # 确保关闭蜂鸣器
        mqtt_client.disconnect()

if __name__ == "__main__":
    main()