from machine import Pin
import utime
from neopixel import Neopixel

# Constants for Pins
TRIGGER_PIN = 0
ECHO_PIN = 1

# Constants for LED Gauge
MIN_DISTANCE = 50
MAX_DISTANCE = 200
MIN_LEDS = 0
MAX_LEDS = 16

# Constants for LED Colors
GREEN_COLOR = (0, 255, 0)
RED_COLOR = (255, 0, 0)
OFF_COLOR = (0, 0, 0)  # Black, for turning off LEDs

# Brightness factor (between 0.0 and 1.0)
BRIGHTNESS = 0.5  # Adjust this value to set the desired brightness

# Constants for Flashing
FLASH_INTERVALS = {0: 0.2, 1: 0.3, 2: 0.4, 3: 0.5}

# Initialize Ultrasonic Sensor
trigger = Pin(TRIGGER_PIN, Pin.OUT)
echo = Pin(ECHO_PIN, Pin.IN)

def get_distance():
    trigger.low()
    utime.sleep_us(2)
    trigger.high()
    utime.sleep_us(5)
    trigger.low()
    
    signaloff = utime.ticks_us()  # Initialize with default values
    while echo.value() == 0:
        signaloff = utime.ticks_us()
    
    signalon = utime.ticks_us()  # Initialize with default values
    while echo.value() == 1:
        signalon = utime.ticks_us()
    
    timepassed = signalon - signaloff
    distance = (timepassed * 0.0343) / 2
    return distance

# Initialize Neopixel
pixels = Neopixel(16, 0, 6, "GRB")

# Toggle variable for the direction of LED calculation
reverse_leds = True

while True:
    raw_distance = get_distance()
    
    # Ensure distance is within the specified range
    distance = max(MIN_DISTANCE, min(MAX_DISTANCE, raw_distance))
    
    if reverse_leds:
        # Calculate the number of LEDs to turn green inversely proportional to distance
        leds_to_turn_green = MAX_LEDS - int((distance - MIN_DISTANCE) / (MAX_DISTANCE - MIN_DISTANCE) * (MAX_LEDS - MIN_LEDS))
    else:
        # Calculate the number of LEDs to turn green proportional to distance
        leds_to_turn_green = int((distance - MIN_DISTANCE) / (MAX_DISTANCE - MIN_DISTANCE) * (MAX_LEDS - MIN_LEDS)) + MIN_LEDS
    
    # Determine the flashing interval based on the number of green LEDs
    flash_interval = FLASH_INTERVALS.get(leds_to_turn_green, 0.2)
    
    # LED Gauge Display
    if leds_to_turn_green <= 3:

        for i in range(16):
            if reverse_leds:
                led_index = (16 - i - 1)  # Anticlockwise direction
            else:
                led_index = i  # Clockwise direction

            if led_index < leds_to_turn_green:
                pixels.set_pixel(led_index, tuple(int(c * BRIGHTNESS) for c in GREEN_COLOR))
            else:
                pixels.set_pixel(led_index, tuple(int(c * BRIGHTNESS) for c in RED_COLOR))
        pixels.show()
        utime.sleep(flash_interval)
        for i in range(16):
            if reverse_leds:
                led_index = (16 - i - 1)  # Anticlockwise direction
            else:
                led_index = i  # Clockwise direction

            if led_index < leds_to_turn_green:
                pixels.set_pixel(led_index, tuple(int(c * BRIGHTNESS) for c in GREEN_COLOR))
            else:
                pixels.set_pixel(led_index, tuple(int(c * BRIGHTNESS) for c in OFF_COLOR))
        pixels.show()
        utime.sleep(flash_interval)
    
    else:
        # All LEDs are green, and distance is outside the range
        if leds_to_turn_green == 16 and (raw_distance < MIN_DISTANCE or raw_distance > MAX_DISTANCE):
            #print("overfill")
            for i in range(16):
                pixels.set_pixel(i, tuple(int(c * BRIGHTNESS) for c in GREEN_COLOR))
            pixels.show()
            utime.sleep(0.2)
            for i in range(16):
                pixels.set_pixel(i, tuple(int(c * BRIGHTNESS) for c in OFF_COLOR))
            pixels.show()
            utime.sleep(0.2)
        else:
            # Delay for the normal display
            for i in range(16):
                if reverse_leds:
                    led_index = (16 - i - 1)  # Anticlockwise direction
                else:
                    led_index = i  # Clockwise direction

                if led_index < leds_to_turn_green:
                    pixels.set_pixel(led_index, tuple(int(c * BRIGHTNESS) for c in GREEN_COLOR))
                else:
                    pixels.set_pixel(led_index, tuple(int(c * BRIGHTNESS) for c in RED_COLOR))
            pixels.show()
            utime.sleep(0.1)  # Adjust this value to change the duration of the normal display