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

# 硬件配置
TRIG_PIN = 14  # HC-SR04触发引脚
ECHO_PIN = 12  # HC-SR04回声引脚
BUZZER_PIN = 15  # 蜂鸣器引脚

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

# 系统状态
system_mode = "auto"  # 自动/手动模式
distance_threshold = 10.0  # 距离阈值(厘米)
buzzer_status = 0  # 蜂鸣器状态: 0-关闭, 1-开启

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

# 巴法云MQTT配置
MQTT_CLIENT_ID = "106786ca35a6454b871d685f23273ef9"  # 替换为你的Client ID
MQTT_BROKER = "bemfa.com" 
MQTT_PORT = 9501
MQTT_USER = "" 
MQTT_SECRET_KEY = "106786ca35a6454b871d685f23273ef9"  # 替换为你的巴法云密钥
TOPIC_DISTANCE = "SR04"  # 距离数据主题
TOPIC_CONTROL = "SR04CTRL"  # 控制命令主题

# 初始化硬件
i2c = I2C(0, sda=Pin(OLED_SDA), scl=Pin(OLED_SCL), freq=400000)
oled = ssd1306.SSD1306_I2C(OLED_WIDTH, OLED_HEIGHT, i2c)
buzzer = Pin(BUZZER_PIN, Pin.OUT)
buzzer.value(0)  # 初始关闭蜂鸣器

# 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
        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,
    keepalive=30
)

def mqtt_callback(topic, msg):
    """MQTT消息回调函数"""
    global system_mode, distance_threshold, buzzer_status
    
    topic = topic.decode('utf-8')
    msg = msg.decode('utf-8')
    print(f"收到命令: {topic} -> {msg}")
    
    # 在OLED上显示消息
    oled.fill(0)
    oled.text("MQTT Command", 0, 0)
    oled.text(f"{topic}:{msg}", 0, 20)
    oled.show()
    time.sleep(1)
    
    # 解析控制命令
    if topic == TOPIC_CONTROL:
        if msg.startswith("mode:"):
            mode = msg.split(":")[1]
            if mode in ["auto", "manual"]:
                system_mode = mode
                print(f"模式切换为: {system_mode}")
                if system_mode == "manual":
                    buzzer.value(0)  # 切换到手动模式时关闭蜂鸣器
        
        elif msg.startswith("threshold:"):
            try:
                distance_threshold = float(msg.split(":")[1])
                print(f"阈值设置为: {distance_threshold}cm")
            except ValueError:
                print("无效的阈值格式")
        
        elif msg.startswith("buzzer:") and system_mode == "manual":
            try:
                buzzer_status = int(msg.split(":")[1])
                buzzer.value(buzzer_status)
                print(f"蜂鸣器设置为: {'开启' if buzzer_status else '关闭'}")
            except ValueError:
                print("无效的蜂鸣器命令")

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")
        
        # 订阅控制主题
        mqtt_client.subscribe(TOPIC_CONTROL)
        print(f"已订阅控制主题: {TOPIC_CONTROL}")
        
        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)
        oled.show()
        raise

def read_sensor_data():
    """读取HC-SR04传感器数据"""
    try:
        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 handle_alarm(distance):
    """处理报警逻辑"""
    global buzzer_status
    
    if system_mode == "auto":
        if distance is not None and distance < distance_threshold:
            # 自动模式下距离低于阈值时蜂鸣器报警
            buzzer.value(1)
            buzzer_status = 1
        else:
            buzzer.value(0)
            buzzer_status = 0

def publish_data(distance):
    """通过MQTT发布数据到巴法云"""
    try:
        if distance is not None:
            data = f"distance:{distance:.1f},mode:{system_mode},threshold:{distance_threshold},buzzer:{buzzer_status}"
            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 display_data(distance):
    """在OLED和串口上显示数据"""
    oled.fill(0)
    oled.text("Distance Monitor", 0, 0)
    oled.hline(0, 12, OLED_WIDTH, 1)  # 分隔线
    
    if distance is not None:
        # 显示距离
        oled.text(f"Dist: {distance:.1f} cm", 0, 20)
        
        # 显示阈值
        oled.text(f"Thresh: {distance_threshold} cm", 0, 35)
        
        # 显示模式
        oled.text(f"Mode: {system_mode}", 0, 50)
        
        # 显示蜂鸣器状态
        buzzer_text = "Buzzer: ON" if buzzer_status else "Buzzer: OFF"
        oled.text(buzzer_text, 0, 58)
        
        print(f"距离: {distance:.1f}cm | 模式: {system_mode} | 蜂鸣器: {'开启' if buzzer_status else '关闭'}")
        publish_data(distance)
    else:
        oled.text("Sensor Error!", 0, 20)
        print("无法获取传感器数据")
    
    # 显示连接状态
    wifi_status = "WiFi: ON" if wifi.isconnected() else "WiFi: OFF"
    mqtt_status = "MQTT: ON" if mqtt_client.sock else "MQTT: OFF"
    oled.text(f"{wifi_status} {mqtt_status}", 0, 45)
    oled.show()

def main():
    """主函数，程序入口点"""
    print("HC-SR04距离监控系统启动...")
    
    # 初始连接
    connect_wifi()
    connect_mqtt()
    
    try:
        while True:
            # 检查MQTT消息
            try:
                mqtt_client.check_msg()
            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()
            handle_alarm(distance)
            display_data(distance)
            
            # 保持连接
            try:
                mqtt_client.ping()
            except:
                connect_mqtt()
                
            time.sleep(1)  # 每秒读取一次
            
    except KeyboardInterrupt:
        print("\n程序已停止")
        mqtt_client.disconnect()
    except Exception as e:
        print(f"发生错误：{e}")
        mqtt_client.disconnect()

if __name__ == "__main__":
    main()