import random
from machine import Pin, I2C, PWM, time_pulse_us
from ssd1306 import SSD1306_I2C
import dht
import time

count = 0

# US Pin
trigger = Pin(20, Pin.OUT)
echo = Pin(21, Pin.IN)
SOUND_SPEED = 340
TRIG_PULSE_DURATION_US = 10

# DHT22 Pin
data_pin = Pin(13, Pin.IN, Pin.PULL_UP)
sensor = dht.DHT22(data_pin)

# Buzzer Pin
buzzer_pin = Pin(12, Pin.OUT)
buzzer = PWM(buzzer_pin)

# RGB LED Pins
red_pin = Pin(2, Pin.OUT)
green_pin = Pin(1, Pin.OUT)
blue_pin = Pin(0, Pin.OUT)

# Display
WIDTH = 128
HEIGHT = 64

i2c = I2C(0, scl=Pin(17), sda=Pin(16), freq=200000)
oled = SSD1306_I2C(WIDTH, HEIGHT, i2c)

CRITICAL_DISTANCE = 10
MAJOR_DISTANCE = 20
MINOR_DISTANCE = 30

def generate_random_distance():
    return random.uniform(0, 100)

def ultra(test_mode=False):
    if test_mode:
        distance_cm = generate_random_distance()
    else:
        trigger.value(0)
        time.sleep_us(5)

        trigger.value(1)
        time.sleep_us(TRIG_PULSE_DURATION_US)
        trigger.value(0)

        ultrason_duration = time_pulse_us(echo, 1, 30000)
        distance_cm = SOUND_SPEED * ultrason_duration / 20000

    print(f"Distance : {distance_cm} cm")
    oled.fill_rect(0, 55, 128, 10, 0)
    oled.text("{:.2f} cm".format(distance_cm), 4, 56)
    oled.show()
    
    if distance_cm < CRITICAL_DISTANCE:
        print('critical buzzing')
        buzzer.duty_u16(65535)  # 100%
        red_pin.value(1)
        green_pin.value(0)
        blue_pin.value(0)
    elif distance_cm < MAJOR_DISTANCE:
        print('major buzzing')

        buzzer.duty_u16(49151)  #~75%
        red_pin.value(0)
        green_pin.value(0)
        blue_pin.value(1)
    elif distance_cm < MINOR_DISTANCE:
        print('minor buzzing')
        buzzer.duty_u16(32768)  # ~50%
        red_pin.value(0)
        green_pin.value(1)
        blue_pin.value(0)
    else:
        red_pin.value(0)
        green_pin.value(0)
        blue_pin.value(0)

    time.sleep_ms(500)


def read_DHT22sensor():
    try:
        sensor.measure()
        temperature = sensor.temperature()
        humidity = sensor.humidity()
        print_dht22_data(temperature, humidity)
    except OSError as e:
        print("Error reading data from the sensor")


def print_dht22_data(temperature, humidity):
    print("Temperature:{}, Humidity:{}".format(temperature, humidity))
    oled.fill_rect(0, 0, 128, 55, 0)
    oled.text("Temp.", 4, 8)
    oled.text("Humid.", 4, 20)
    oled.text(str(temperature), 65, 8)
    oled.text(str(humidity), 65, 20)
    oled.show()


while True:
    ultra(test_mode=True)
    count += 1

    if count == 25:
        read_DHT22sensor()
        count = 0