from machine import Pin
import time
from utime import sleep
import network
import ujson
from umqtt.simple import MQTTClient


led = Pin(2, Pin.OUT)
trig = Pin(4, Pin.OUT)
echo = Pin(15, Pin.IN)

# MQTT Server Parameters
MQTT_CLIENT_ID = "uni123"
MQTT_BROKER    = "broker.emqx.io"
MQTT_USER      = ""
MQTT_PASSWORD  = ""
MQTT_TOPIC     = "UNI123/algorithmavengers"

print("Hello, ESP32!")

# WIFI Connection
print("Connecting to 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(" Connected!")

# MQTT Server connection
print("Connecting to MQTT server... ", end="")
client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD)
client.connect()
print("Connected!")


def pulseIn(pin, level, timeout):
    start_time = time.ticks_us()
    while pin.value() != level:
        if time.ticks_diff(time.ticks_us(), start_time) > timeout * 1_000_000:
            return 0
    
    start_pulse = time.ticks_us()
    while pin.value() == level:
        if time.ticks_diff(time.ticks_us(), start_pulse) > timeout * 1_000_000:
            return 0
    
    return time.ticks_diff(time.ticks_us(), start_pulse)

prevState = 0
while True:
    trig.value(1)
    time.sleep(0.1)
    trig.value(0)
    
    duration = pulseIn(echo, 1, 1)
    distanceInCm = duration / 58
    if distanceInCm <= 50:
        led.value(1)
        if prevState == 0:
            print("Terbuka")
            prevState = 1
            message = ujson.dumps({
                "Tempat sampah": "Terbuka"
                
            })
            client.publish(MQTT_TOPIC, message)
    else:
        led.value(0)
        if prevState == 1:
            print("Tertutup")
            prevState = 0
            message = ujson.dumps({
                "Tempat sampah": "Tertutup"   

            })
            client.publish(MQTT_TOPIC, message)
    
    sleep(0.5)