import network
import time
from machine import Pin, time_pulse_us
import neopixel
import ujson
from umqtt.simple import MQTTClient

MQTT_CLIENT_ID = "micropython-distance-demo"
MQTT_BROKER    = "broker.mqttdashboard.com"
MQTT_USER      = ""
MQTT_PASSWORD  = ""
MQTT_TOPIC = "wokwi-distancia"
MQTT_TOPIC_SUB = "wokwi-leds"

trigger = Pin(32, Pin.OUT)
echo = Pin(33, Pin.IN)
strip = neopixel.NeoPixel(Pin(21), 8)

def sub(topic, msg):
  try:
    colors = ujson.loads(msg)
    for i in range(8):
        strip[i] = colors
    strip.write()
  except:
    print("Cores são inválidas.")

def distancia_cm():
  trigger.value(0)
  time.sleep_us(5)
  trigger.value(1)
  time.sleep_us(10)
  trigger.value(0)
  pulse_duracao = time_pulse_us(echo, 1, 30000)
  if pulse_duracao < 0:
    return None
  return int(pulse_duracao / 58.0)

print("Conectando ao WiFi", end="")
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect('Wokwi-GUEST', '')
while not sta_if.isconnected():
  print(".", end="")
  time.sleep(0.1)
print(" Conectado!")

print("Connecting to MQTT server... ", end="")
client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD)
client.set_callback(sub)
client.connect()
client.subscribe(MQTT_TOPIC_SUB)

print("Conectado!")

prev_distance = ""
while True:
  print("Medindo distancia.. ", end="")
  distance = distancia_cm()
  message = ujson.dumps({
    "distance": distance,
  })
  if message != prev_distance:
    print("Atualizado!")
    print(f"Reporting to MQTT topic {MQTT_TOPIC}: {message}")
    client.publish(MQTT_TOPIC, message)
    prev_distance = message
  else:
    print("Sem alterações nos dados")
  client.check_msg()
  time.sleep(1)