import sys
from machine import Pin, PWM
import dht
import ujson
from umqtt.simple import MQTTClient
from _thread import start_new_thread
import ntptime
import utime
print("starting...")
# Global variables
is_mqtt_connected = False

def localtime():
    # UTC+8 时区偏移量（单位为秒）
    UTC_OFFSET = 8 * 3600
    # 获取UTC时间戳
    utc_time = utime.time()
    # 计算本地时间戳（加上时区偏移量）
    local_timestamp = utc_time + UTC_OFFSET
    # 转换为本地时间元组
    local_time = utime.localtime(local_timestamp)
    return local_time

def measure_and_publish(client, sensor, topic):
    global is_mqtt_connected
    print("Measuring weather conditions... ")
    sensor.measure()
    # 获取中国时间
    china_time = localtime()
    current_time = china_time
    time_string = "{:04}-{:02}-{:02}_{:02}:{:02}:{:02}".format(current_time[0], current_time[1], current_time[2], current_time[3], current_time[4], current_time[5])

    message = ujson.dumps({
        "time": time_string,
        "temp": sensor.temperature(),
        "humidity": sensor.humidity(),
    })

    try:
        client.publish(topic, message)
        print("Reporting to MQTT topic {}: {}".format(topic, message))
        is_mqtt_connected = True  # MQTT 发布成功，设置为连接状态
    except OSError as e:
        print("Failed to publish message:", e)
        is_mqtt_connected = False  # MQTT 发布失败，设置为断开状态
        try:
            client.connect()
        except OSError as e:
            print("Failed to reconnect to MQTT server:", e)

    return message

def breathing_lights():
    led2 = PWM(Pin(2))
    led2.freq(1000)
    while True:
        if is_mqtt_connected:
            # 呼吸灯效果
            for i in range(0, 1024):
                led2.duty(i)
                utime.sleep_ms(1)

            for i in range(1023, -1, -1):
                led2.duty(i)
                utime.sleep_ms(1)
        else:
            # 信号不能传输时常亮
            led2.duty(1023)  # 设置为最大亮度，即常亮状态
            utime.sleep(1)   # 等待1秒后重新检查

def connect_to_mqtt(client_id, broker, user, password):
    global is_mqtt_connected
    print("Connecting to MQTT server... ", end="")
    client = MQTTClient(client_id, broker, user=user, password=password)

    try:
        client.connect()
        print("Connected!")
        is_mqtt_connected = True
    except OSError as e:
        print("Failed to connect to MQTT server:", e)
        is_mqtt_connected = False
        sys.exit()

    return client

def main(sta_if, mqtt_client_id, mqtt_broker, mqtt_user, mqtt_password, mqtt_topic):
    # Synchronize with NTP server
    ntptime.settime()

    # Create DHT22 sensor object
    sensor = dht.DHT22(Pin(15))

    # Connect to MQTT broker
    client = connect_to_mqtt(mqtt_client_id, mqtt_broker, mqtt_user, mqtt_password)

    # Start a new thread for breathing lights
    start_new_thread(breathing_lights, ())

    # Main loop: measure and publish data
    while True:
        measure_and_publish(client, sensor, mqtt_topic)
        utime.sleep(10)