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

WIFI_SSID = 'Wokwi-GUEST'
WIFI_PASSWORD = ''

MQTT_Broker = "mqtt3.thingspeak.com"
MQTT_Client = "FgY0DwInJzQqKzchGiEtKjM"
MQTT_Username = "FgY0DwInJzQqKzchGiEtKjM"
MQTT_Password = "AI/s/7747+Y4PbAnL9XLKx+g"
MQTT_Topic = "channels/2491429/publish"
Write_Key = "4XJ64X5FBTY3NP0G"

trigger_pin = Pin(14, Pin.OUT)
echo_pin = Pin(5, Pin.IN)
pir_sensor = Pin(16, Pin.IN, Pin.PULL_UP)

def connect_to_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    if not wlan.isconnected():
        print('Connecting to network...')
        wlan.connect(WIFI_SSID, WIFI_PASSWORD)
        while not wlan.isconnected():
            pass
    print('Network config:', wlan.ifconfig())


connect_to_wifi()

client = MQTTClient(MQTT_Client, MQTT_Broker, port=1883, user=MQTT_Username, password=MQTT_Password)
client.connect()

def send_thingspeak_mqtt(client, distance):
    payload = 'field1={}&api_key={}'.format(distance, Write_Key)
    client.publish(MQTT_Topic, payload)

def measure_distance():
    trigger_pin.off()
    time.sleep_us(2)
    trigger_pin.on()
    time.sleep_us(10)
    trigger_pin.off()
    duration = time_pulse_us(echo_pin,1,1000000)
    if duration < 0:
        duration = 1000000
    distance = (duration / 2) / 29.1
    return distance

def check_motion():
    motion = pir_sensor.value()
    return motion


while True:
    distance = measure_distance()
    motion = check_motion()

    if distance < 200:
        print('Parking spot is occupied')
    
    else:
        print('Parking spot is vaccant')
    
    if motion:
        print('Motion Detected')
    send_thingspeak_mqtt(client, distance)
    time.sleep(15)