import machine
import time
import network
from hcsr04 import HCSR04
from umqtt.simple import MQTTClient
import ssd1306
import ubinascii
import sys

# ====================== 配置参数 ======================
CONFIG = {
    # 巴法云MQTT配置
    "mqtt": {
        "server": "mqtt.bemfa.com",
        "port": 9501,
        "user": "a019001c4fee4049a0e55087d01bfc91",
        "password": "",
        "topic_distance": "mydistance",
        "topic_status": "mystatus"
    },
    
    # WiFi配置
    "wifi": {
        "ssid": "Wokwi-GUEST",
        "password": ""
    },
    
    # 硬件配置
    "hardware": {
        "ultrasonic": {
            "trigger_pin": 4,
            "echo_pin": 27
        },
        "oled": {
            "scl_pin": 18,
            "sda_pin": 19,
            "width": 128,
            "height": 64
        },
        "led_pin": 2
    },
    
    # 系统参数
    "system": {
        "publish_interval": 3,
        "max_retries": 5,
        "retry_delay": 5
    }
}

# ====================== 系统初始化 ======================
class DistanceMonitor:
    def __init__(self, config):
        self.config = config
        self.distance = 0
        self.mqtt_client = None
        self.initialize_hardware()
        
    def initialize_hardware(self):
        """初始化硬件设备"""
        # 超声波传感器
        self.sensor = HCSR04(
            trigger_pin=self.config["hardware"]["ultrasonic"]["trigger_pin"],
            echo_pin=self.config["hardware"]["ultrasonic"]["echo_pin"]
        )
        
        # OLED显示屏
        self.i2c = machine.SoftI2C(
            scl=machine.Pin(self.config["hardware"]["oled"]["scl_pin"]),
            sda=machine.Pin(self.config["hardware"]["oled"]["sda_pin"])
        )
        self.oled = ssd1306.SSD1306_I2C(
            self.config["hardware"]["oled"]["width"],
            self.config["hardware"]["oled"]["height"],
            self.i2c
        )
        
        # LED指示灯
        self.led = machine.Pin(self.config["hardware"]["led_pin"], machine.Pin.OUT)
        self.led.off()
    
    def connect_wifi(self):
        """连接WiFi网络"""
        wlan = network.WLAN(network.STA_IF)
        wlan.active(True)
        
        if not wlan.isconnected():
            print(f"Connecting to WiFi: {self.config['wifi']['ssid']}")
            wlan.connect(self.config["wifi"]["ssid"], self.config["wifi"]["password"])
            
            for _ in range(10):  # 等待10秒
                if wlan.isconnected():
                    break
                time.sleep(1)
                print(".", end="")
        
        if wlan.isconnected():
            print("\nWiFi connected:", wlan.ifconfig())
            return True
        print("\nWiFi connection failed")
        return False
    
    def connect_mqtt(self):
        """连接MQTT服务器"""
        try:
            # 生成唯一客户端ID
            client_id = f"{self.config['mqtt']['user']}_{ubinascii.hexlify(machine.unique_id()).decode()}"
            
            # 创建MQTT客户端
            self.mqtt_client = MQTTClient(
                client_id=client_id,
                server=self.config["mqtt"]["server"],
                port=self.config["mqtt"]["port"],
                user=self.config["mqtt"]["user"],
                password=self.config["mqtt"]["password"],
                keepalive=60
            )
            
            # 设置最后遗嘱
            self.mqtt_client.set_last_will(
                f"{client_id}/{self.config['mqtt']['topic_status']}",
                "offline",
                retain=True
            )
            
            # 建立连接
            self.mqtt_client.connect()
            print(f"MQTT connected as {client_id}")
            
            # 发布在线状态
            self.mqtt_client.publish(
                f"{client_id}/{self.config['mqtt']['topic_status']}",
                "online",
                retain=True
            )
            
            return True
        except Exception as e:
            print("MQTT connection failed:", e)
            self.mqtt_client = None
            return False
    
    def measure_distance(self):
        """测量距离并返回厘米值"""
        try:
            dist = self.sensor.distance_cm()
            return max(2, min(500, dist))  # 限制在2-500cm范围内
        except Exception as e:
            print("Distance measurement error:", e)
            return -1
    
    def publish_data(self, distance):
        """发布数据到MQTT"""
        if not self.mqtt_client or distance < 0:
            return False
        
        try:
            payload = str(distance)
            self.mqtt_client.publish(
                self.config["mqtt"]["topic_distance"],
                payload
            )
            print(f"Published: {payload}cm")
            
            # LED闪烁指示
            self.led.on()
            time.sleep(0.1)
            self.led.off()
            
            return True
        except Exception as e:
            print("Publish failed:", e)
            self.mqtt_client = None
            return False
    
    def display_status(self, distance, wifi_ok, mqtt_ok):
        """在OLED上显示系统状态"""
        self.oled.fill(0)
        self.oled.text("Distance Monitor", 0, 0)
        self.oled.text(f"Dist: {distance:.1f}cm", 0, 20)
        self.oled.text(f"WiFi: {'OK' if wifi_ok else 'NO'}", 0, 35)
        self.oled.text(f"MQTT: {'OK' if mqtt_ok else 'NO'}", 0, 50)
        self.oled.show()
    
    def run(self):
        """主运行循环"""
        # 初始连接
        wifi_ok = self.connect_wifi()
        mqtt_ok = wifi_ok and self.connect_mqtt()
        last_publish = 0
        
        while True:
            try:
                # 测量距离
                self.distance = self.measure_distance()
                print(f"Distance: {self.distance:.1f}cm")
                
                # 更新显示
                self.display_status(
                    self.distance,
                    network.WLAN(network.STA_IF).isconnected(),
                    mqtt_ok and self.mqtt_client is not None
                )
                
                # 发布数据
                current_time = time.time()
                if (mqtt_ok and 
                    current_time - last_publish >= self.config["system"]["publish_interval"]):
                    if self.publish_data(self.distance):
                        last_publish = current_time
                    else:
                        mqtt_ok = False
                
                # 检查并恢复连接
                if not network.WLAN(network.STA_IF).isconnected():
                    wifi_ok = self.connect_wifi()
                    mqtt_ok = False
                
                if not mqtt_ok and wifi_ok:
                    mqtt_ok = self.connect_mqtt()
                
                time.sleep(1)
                
            except Exception as e:
                print("System error:", e)
                time.sleep(5)

# ====================== 主程序 ======================
if __name__ == "__main__":
    monitor = DistanceMonitor(CONFIG)
    monitor.run()