from machine import Pin, I2C, PWM
from utime import sleep, sleep_us, time  
import network
import urequests
from i2c_lcd import I2cLcd

# LCD Setup
I2C_ADDR = 0x27
i2c = I2C(0, scl=Pin(21), sda=Pin(20), freq=400000)
lcd = I2cLcd(i2c, I2C_ADDR, 4, 20)
print("LCD initialized.")

# Ultrasonic Sensor Setup (HC-SR04)
trigger = Pin(12, Pin.OUT)
echo = Pin(13, Pin.IN)
print("Ultrasonic Sensor initialized.")

# Servo Setup
servo = PWM(Pin(15))
servo.freq(50)
print("Servo initialized.")

# Keypad Setup
rows = [Pin(pin, Pin.OUT) for pin in [18, 19, 20, 21]]
cols = [Pin(pin, Pin.IN, Pin.PULL_UP) for pin in [22, 26, 27, 28]]
keys = [
    ['1', '2', '3', 'A'],
    ['4', '5', '6', 'B'],
    ['7', '8', '9', 'C'],
    ['*', '0', '#', 'D']
]
print("Keypad initialized.")

# Wi-Fi Setup
SSID = "Wokwi-GUEST"
PASSWORD = ""
ADAFRUIT_AIO_USERNAME = "tharunnv"
ADAFRUIT_AIO_KEY      = "aio_uqnk18hiIB1r16iUxRXq24U49BcL"
AIO_FEED = f"{ADAFRUIT_AIO_USERNAME}/feeds/"

def connect_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    print("Attempting to connect to Wi-Fi...")
    wlan.connect(SSID, PASSWORD)
    timeout = 20  # Increased timeout
    start_time = time()
    while not wlan.isconnected():
        if time() - start_time > timeout:
            print("Wi-Fi connection timed out.")
            return False
        print("Connecting to Wi-Fi...")  # Debug message
        sleep(1)
    print("Connected to Wi-Fi")
    return True


def update_adafruit(status):
    headers = {'X-AIO-Key': ADAFRUIT_AIO_KEY, 'Content-Type': 'application/json'}
    data = {"value": status}
    try:
        response = urequests.post(AIO_FEED, json=data, headers=headers)
        response.close()
        print("Updated Adafruit IO:", status)
    except Exception as e:
        print("Failed to update Adafruit IO:", e)

# Read Keypad
def read_key():
    for row in range(4):
        rows[row].value(0)
        for col in range(4):
            if cols[col].value() == 0:
                sleep(0.1)  # Debounce
                while cols[col].value() == 0:
                    pass
                rows[row].value(1)
                return keys[row][col]
        rows[row].value(1)
    return None

# Get OTP from Keypad
def get_otp():
    lcd.clear()
    lcd.putstr("Enter OTP: ")
    otp = ""
    while len(otp) < 4:
        key = read_key()
        if key:
            otp += key
            lcd.move_to(10 + len(otp), 1)
            lcd.putstr("*")
    return otp

# Function to measure distance using the ultrasonic sensor
def get_distance():
    trigger.low()
    sleep_us(2)
    trigger.high()
    sleep_us(10)
    trigger.low()

    pulse_start = 0
    pulse_end = 0
    timeout = time() + 0.1  # 100ms timeout

    while not echo.value():
        if time() > timeout:
            print("Timeout: No pulse start detected.")
            return -1  # Timeout if no pulse received
        pulse_start = time()
    
    while echo.value():
        if time() > timeout:
            print("Timeout: No pulse end detected.")
            return -1  # Timeout if no pulse end received
        pulse_end = time()

    pulse_duration = pulse_end - pulse_start
    distance = (pulse_duration * 34300) / 2  # Distance in cm
    return distance

def main():
    print("Starting main loop...")
    
    if not connect_wifi():
        print("Proceeding without Wi-Fi connection.")
        return

    while True:
        distance = get_distance()  # Get distance from ultrasonic sensor
        if distance == -1:
            lcd.clear()
            lcd.putstr("Sensor Timeout!")
            print("Sensor Timeout!")
            continue
        
        lcd.clear()
        lcd.putstr(f"Distance: {distance:.2f} cm")
        print(f"Distance: {distance:.2f} cm")

        if distance < 100:  # Threshold for vehicle detection (if the vehicle is within 1 meter)
            lcd.clear()
            lcd.putstr("No Parking Available!")
            update_adafruit("Occupied")
            print("Parking Status: Occupied")
            
            # Ask for OTP to open the gate
            lcd.putstr("\nEnter OTP: ")
            otp = get_otp()  # Get OTP from keypad
            if otp == "1234":  # Correct OTP
                lcd.clear()
                lcd.putstr("Access Granted!")
                servo.duty_u16(7500)  # Open gate
                sleep(5)
                servo.duty_u16(2500)  # Close gate
            else:
                lcd.clear()
                lcd.putstr("Wrong OTP!")
                sleep(2)
        else:
            lcd.clear()
            lcd.putstr("Parking Available!")
            update_adafruit("Available")
            print("Parking Status: Available")
            sleep(1)

# Run the System
print("Starting system...")
main()