from machine import Pin, I2C, time_pulse_us
import ssd1306
import time
from blynk_lib import Blynk

try:
    IOError
except NameError:
    IOError = OSError

# Define pins
TRIG_PIN = 32
ECHO_PIN = 33
BUZZER_PIN = 4
GREEN_LED_PIN = 27
YELLOW_LED_PIN = 26
RED_LED_PIN = 25

# Initialize pins
trig = Pin(TRIG_PIN, Pin.OUT)
echo = Pin(ECHO_PIN, Pin.IN)
buzzer = Pin(BUZZER_PIN, Pin.OUT)
green_led = Pin(GREEN_LED_PIN, Pin.OUT)
yellow_led = Pin(YELLOW_LED_PIN, Pin.OUT)
red_led = Pin(RED_LED_PIN, Pin.OUT)

# Initialize I2C for OLED display
i2c = I2C(0, scl=Pin(22), sda=Pin(21), freq=400000)
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

# Blynk Auth Token (your own)
BLYNK_AUTH_TOKEN = '5MLW9RMNk8-KytxzhedXEqoboKaK780l'
blynk = Blynk(BLYNK_AUTH_TOKEN)

def measure_distance():
    trig.value(0) # Ensure TRIG is low
    time.sleep_us(2)
    trig.value(1) # Send a pulse
    time.sleep_us(10)
    trig.value(0) # Stop pulse
    
    duration = time_pulse_us(echo, 1) # Read echo pin duration
    distance = (duration * 0.0343) / 2 # Calculate distance in cm
    
    return distance

def update_display(distance):
    oled.fill(0) # Clear display
    oled.text("Distance: {} cm".format(distance), 0, 0)
    oled.show()

def control_alerts(distance):
    # Control the LEDs and buzzer based on the distance
    if distance > 200:
        # Green LED: Distance > 200
        green_led.on()
        yellow_led.off()
        red_led.off()
        buzzer.off()
        # Update Blynk LEDs
        try:
            blynk.virtual_write(2, 255)  # Green LED on (V2)
            blynk.virtual_write(1, 0)    # Yellow LED off (V1)
            blynk.virtual_write(0, 0)    # Red LED off (V0)
        except Exception as e:
            print("Error updating Blynk LED V2:", e)
    elif distance > 100:
        # Yellow LED: 101 < Distance <= 200
        green_led.off()
        yellow_led.on()
        red_led.off()
        buzzer.off()
        # Update Blynk LEDs
        try:
            blynk.virtual_write(2, 0)    # Green LED off (V2)
            blynk.virtual_write(1, 255)  # Yellow LED on (V1)
            blynk.virtual_write(0, 0)    # Red LED off (V0)
        except Exception as e:
            print("Error updating Blynk LED V1:", e)
    else:
        # Red LED: Distance <= 100
        green_led.off()
        yellow_led.off()
        red_led.on()
        buzzer.on()  # Sound alarm when too close
        # Update Blynk LEDs
        try:
            blynk.virtual_write(2, 0)    # Green LED off (V2)
            blynk.virtual_write(1, 0)    # Yellow LED off (V1)
            blynk.virtual_write(0, 255)  # Red LED on (V0)
        except Exception as e:
            print("Error updating Blynk LED V0:", e)

# Blynk event for V3 gauge widget
@blynk.handle_event('write V3')
def handle_v3(pin, value):
    # Send the ultrasonic sensor's distance value to V3 gauge
    distance = measure_distance()
    try:
        blynk.virtual_write(3, distance)  # Send to V3 (gauge)
    except Exception as e:
        print("Error updating Blynk gauge V3:", e)
    update_display(distance)
    control_alerts(distance)

# Main loop
while True:
    distance = measure_distance()
    update_display(distance)
    control_alerts(distance)
    
    time.sleep(0.5) # Delay before next measurement
    blynk.run()  # Keep Blynk connection alive