import machine
import time
import dht
import onewire
import ds18x20
import random
import network
import ujson
from umqtt.simple import MQTTClient
from machine import Pin, ADC

# ================= 配置区域 =================
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASS = ""
BROKER = "broker.hivemq.com"
CLIENT_ID = "qin08_esp32_client" # 确保你的电脑端 Client ID 与这里不同
TOPIC_PREFIX = "assessment/qin08/qin225"
TOPIC_TELEMETRY = f"{TOPIC_PREFIX}/telemetry"
TOPIC_STATUS = f"{TOPIC_PREFIX}/status"
TOPIC_COMMAND = f"{TOPIC_PREFIX}/command"
TOPIC_STATE = f"{TOPIC_PREFIX}/state"
DEVICE_ID = "qin08_wokwi_esp32"

# ⚠️ 测试阶段用 10000(10秒)，最终提交/验收前请改回 300000(5分钟)
REPORT_INTERVAL = 10000  
HEARTBEAT_INTERVAL = 30000
# ============================================

# ================= 硬件初始化 =================
ow = onewire.OneWire(Pin(4))
ds = ds18x20.DS18X20(ow)
devices = ds.scan()
d = dht.DHT22(machine.Pin(15))
ldr = ADC(Pin(34))
ldr.atten(ADC.ATTN_11DB)
pot = ADC(Pin(32))
pot.atten(ADC.ATTN_11DB)

# 继电器初始化 (根据实际接线，假设高电平触发)
relay = Pin(5, Pin.OUT)
relay.value(0) # 初始化为关闭状态

state_data = {"soil_temp": 23.0, "soil_moisture": 50.0, "air_temp": 25.0, "air_hum": 60.0, "illuminance": 400.0}

def clamp(val, min_v, max_v): return max(min_v, min(val, max_v))

def smooth_random(prev, step, min_v, max_v, target=None, pull=0.1):
    if target is not None:
        change = (target - prev) * pull + random.uniform(-step, step)
    else:
        change = random.uniform(-step, step)
    change = clamp(change, -step, step)
    return clamp(prev + change, min_v, max_v)

# ================= MQTT 回调 =================
def sub_cb(topic, msg):
    if topic.decode() == TOPIC_COMMAND:
        try:
            data = ujson.loads(msg)
            cmd_id = data.get("command_id")
            target_state = data.get("pump_on")
            
            # 安全校验：必须是 0 或 1 才执行
            if target_state in (0, 1):
                relay.value(target_state)
                print(f"收到指令 {cmd_id}: 设置水泵为 {target_state}")
                
                # 回传实际执行的状态 (必须是 relay.value())
                ack = ujson.dumps({"command_id": cmd_id, "pump_on": relay.value()})
                mqtt_client.publish(TOPIC_STATE, ack)
            else:
                print(f"无效的指令状态: {target_state}")
        except Exception as e:
            print("指令解析失败:", e)

def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(WIFI_SSID, WIFI_PASS)
    print("正在连接 Wi-Fi...")
    while not wlan.isconnected(): 
        time.sleep(0.5)
    print("Wi-Fi 连接成功!")

def connect_mqtt():
    print("连接 MQTT...")
    try:
        # 增加遗嘱消息 (Last Will) - 掉线时自动通知电脑端
        will_msg = ujson.dumps({"device_id": DEVICE_ID, "status": "offline"})
        client = MQTTClient(
            CLIENT_ID, BROKER, keepalive=60,
            will_topic=TOPIC_STATUS.encode(), 
            will_msg=will_msg
        )
        client.set_callback(sub_cb)
        client.connect()
        client.publish(TOPIC_STATUS, ujson.dumps({"device_id": DEVICE_ID, "status": "online"}))
        client.subscribe(TOPIC_COMMAND)
        print("MQTT 连接成功并订阅了 command 主题!")
        return client
    except Exception as e:
        print("MQTT 连接失败，错误:", e)
        return None

# ================= 主流程 =================
connect_wifi()

mqtt_client = None
while mqtt_client is None:
    mqtt_client = connect_mqtt()
    if mqtt_client is None:
        print("3秒后重试...")
        time.sleep(3)

last_report = time.ticks_ms()
last_heartbeat = time.ticks_ms()

while True:
    current_ms = time.ticks_ms()

    # 1. 检查 MQTT 消息 (非阻塞，接收指令必加)
    try:
        mqtt_client.check_msg()
    except Exception as e:
        print("接收指令异常，尝试重连", e)
        mqtt_client = None
        while mqtt_client is None:
            mqtt_client = connect_mqtt()
            time.sleep(3)

    # 2. 发送心跳和在线状态 (30秒一次)
    if time.ticks_diff(current_ms, last_heartbeat) >= HEARTBEAT_INTERVAL:
        try:
            mqtt_client.publish(TOPIC_STATUS, ujson.dumps({"device_id": DEVICE_ID, "status": "online"}))
            last_heartbeat = current_ms
        except Exception:
            pass # 断线交由 check_msg 捕获

    # 3. 采集数据并上报 (定时)
    if time.ticks_diff(current_ms, last_report) >= REPORT_INTERVAL:
        try:
            # 采集空气温湿度
            d.measure()
            base_air_temp = d.temperature()
            base_air_hum = d.humidity()
        except OSError:
            base_air_temp, base_air_hum = state_data["air_temp"], state_data["air_hum"]

        # 采集土壤湿度(电位器)和光照
        base_moisture = (pot.read() / 4095.0) * 100
        base_illuminance = 50 + (ldr.read() / 4095.0) * 1150

        # 采集土壤温度(DS18B20)
        base_soil_temp = state_data["soil_temp"]
        if devices:
            ds.convert_temp()
            time.sleep_ms(750) # 等待转换
            base_soil_temp = ds.read_temp(devices[0])

        # 平滑随机变化
        # ⚠️ 注意：这里以 10 秒(测试) 为基础步长，5分钟上报时步长要调小(如除以30)
        state_data["soil_temp"] = smooth_random(state_data["soil_temp"], 0.01, 18.0, 30.0, target=base_soil_temp)
        state_data["soil_moisture"] = smooth_random(state_data["soil_moisture"], 0.1, 25.0, 80.0, target=base_moisture)
        state_data["air_temp"] = smooth_random(state_data["air_temp"], 0.02, 18.0, 35.0, target=base_air_temp)
        state_data["air_hum"] = smooth_random(state_data["air_hum"], 0.1, 35.0, 85.0, target=base_air_hum)
        state_data["illuminance"] = smooth_random(state_data["illuminance"], 5, 50, 1200, target=base_illuminance)

        # 构造上报数据
        payload = {
            "device_id": DEVICE_ID, "source": "wokwi_simulated",
            "soil_temperature_c": round(state_data["soil_temp"], 2),
            "soil_moisture_pct": round(state_data["soil_moisture"], 2),
            "air_temperature_c": round(state_data["air_temp"], 2),
            "air_humidity_pct": round(state_data["air_hum"], 2),
            "illuminance_lx": round(state_data["illuminance"], 1),
            "pump_on": relay.value()
        }

        try:
            mqtt_client.publish(TOPIC_TELEMETRY, ujson.dumps(payload))
            print("已发送数据:", payload)
            last_report = current_ms
        except Exception:
            print("发送遥测数据失败...")

    # 必须要有小休眠，防止死循环卡死 CPU
    time.sleep(0.1)