import machine
import time
import urequests
import ujson
import network

# Define your Wi-Fi credentials
wifi_ssid = 'Wokwi-GUEST'
wifi_password = ''

# Connect to Wi-Fi
wifi = network.WLAN(network.STA_IF)
wifi.active(True)
wifi.connect(wifi_ssid, wifi_password)

# Wait for Wi-Fi connection
while not wifi.isconnected():
    pass

# Define GPIO pins for ultrasonic sensors
trig_pins = [2, 18, 22]  # Example pins, use the appropriate pins for your setup
echo_pins = [4, 19, 23]  # Example pins, use the appropriate pins for your setup

# Define GPIO pins for PIR sensors
pir_pins = [15, 5, 21]  # Example pins, use the appropriate pins for your setup
pir_sensors = [machine.Pin(pin, machine.Pin.IN) for pin in pir_pins]

# Threshold for PIR sensors (adjust as needed)
pir_threshold = 1  # This may vary based on the PIR sensor module

# Define the maximum distance to consider a parking space available (adjust as needed)
max_distance = 50  # in centimeters

# Firebase Realtime Database URL and secret
firebase_url = 'https://smart-parking-iot-387a4-default-rtdb.firebaseio.com/'
firebase_secret = 'hHfO7ikfdYRbyV9DsFW6KQywqJq90oAZNELNrc8L'

# Function to measure distance using ultrasonic sensor
def measure_distance(trig_pin, echo_pin):

    trig = machine.Pin(trig_pin, machine.Pin.OUT)
    echo = machine.Pin(echo_pin, machine.Pin.IN)
    
    # Ensure the trigger pin is low
    trig.off()
    time.sleep_us(2)
    
    # Generate a 10us pulse on the trigger pin
    trig.on()
    time.sleep_us(10)
    trig.off()
    
    # Measure the duration of the pulse on the echo pin
    while echo.value() == 0:
        pulse_start = time.ticks_us()
    while echo.value() == 1:
        pulse_end = time.ticks_us()
    
    # Calculate the duration of the pulse
    pulse_duration = time.ticks_diff(pulse_end, pulse_start)
    
    # Calculate the distance based on the speed of sound
    distance = (pulse_duration / 2) / 29.1  # Speed of sound in air is approximately 343 m/s
    
    return distance

def check_parking_availability():
    parking_status = []
    for i in range(len(trig_pins)):
        ultrasonic_distances = measure_distance(trig_pins[i], echo_pins[i])
        pir_value = pir_sensors[i].value()
        print(pir_value)
        # Check if a parking space is available
        if ultrasonic_distances > max_distance and pir_value <= pir_threshold:
            parking_status.append("Available")
        else:
            parking_status.append("Occupied")
    return parking_status

# Function to send parking availability to Firebase
def send_parking_to_firebase(parking_status):
    for i in range(len(parking_status)):
        slot_status = parking_status[i]
        data = {'ParkingSlot': i + 1, 'Status': slot_status}
        url = f'{firebase_url}/parking_slot_{i + 1}.json?auth={firebase_secret}'
        
        try:
            response = urequests.patch(url, json=data)  # Use 'patch' instead of 'put'
            if response.status_code == 200:
                print(f"Data for Parking Slot {i + 1} sent to Firebase")
            else:
                print(f"Failed to send data to Firebase. Status code: {response.status_code}")
        except Exception as e:
            print(f"Error sending data to Firebase: {str(e)}")

while True:
    parking_status = check_parking_availability()
    for i in range(len(parking_status)):
        print(f"Parking Slot {i + 1}: {parking_status[i]}")
    
    # Send data to Firebase
    send_parking_to_firebase(parking_status)
    
    time.sleep(1)  # Adjust the sleep duration as needed