from machine import Pin, ADC, time_pulse_us, I2C
from ssd1306 import SSD1306_I2C
from time import sleep, sleep_us

# Important Variables
system_status = "ENERGY SAVE"
w = 128
h = 64

i2c = I2C(0, scl=Pin(22), sda=Pin(21), freq=400000)
oled = SSD1306_I2C(w, h, i2c)


# Initializing sensors
trig = Pin(12, Pin.OUT)
echo = Pin(14, Pin.OUT)

gas = ADC(Pin(34))
gas.atten(ADC.ATTN_11DB) # Give me the maximum range in microcontroller for this sensor in ESP32 (0 - 4095)

ldr = ADC(Pin(35))
ldr.atten(ADC.ATTN_11DB) # Give me the maximum range in microcontroller for this sensor in ESP32 (0 - 4095)

# Initializing LEDs
tunnel = Pin(4, Pin.OUT)
red = Pin(15, Pin.OUT)

# Thresholds
v_dist = 30
d_dist = 15

gas_limit = 2000
light_limit = 1000

# Functions
# Distance function
def get_distance():
    trig.value(0)
    sleep_us(2)
    trig.value(1)
    sleep_us(10)
    trig.value(0)

    duration = time_pulse_us(echo, 1, 30000) # This nly accepts the duration from 1 to 30000 us
    if duration < 0:
        return None
    else:
        return (duration * 0.0343) / 2 # Distance return

def distance_state(d):
    # Distance checker
    if d is None:
        return "NO SIGNAL!"
    elif d < d_dist:
        return "TOO CLOSE!!"
    elif d < v_dist:
        return "VEHICLE"
    else:
        return "CLEAR"

def gas_state(g):
    # Gas checker
    if g > gas_limit:
        return "DANGER!"
    else:
        return "SAFE"

def light_threshold(l):
    # Light checker
    if l < light_limit:
        return "BRIGHT"
    else:
        return "DARK"

# Main loop
while True:
    distance = get_distance()
    gas_value = gas.read()
    light_value = ldr.read()

    dist_status = distance_state(distance)
    gas_status = gas_state(gas_value)
    light_status = light_threshold(light_value)

    # Detecting possible threats or vehicle entries
    if gas_status == "DANGER!":
        red.value(1)
        system_status = "GAS DANGER"    
    elif dist_status == "TOO CLOSE!!":
        red.value(1)
        system_status = "OBJECT DANGER"
    elif dist_status == "VEHICLE":
        tunnel.value(1)
        system_status = "VEHICLE PRESENT"
    elif light_status == "DARK":
        tunnel.value(1)
        system_status = "DARK AREA"
    else:
        system_status = "POWER SAVING :)"
        tunnel.value(0)
        red.value(0)

    oled.fill(0)
    oled.text(f"Distance: {dist_status}", 0, 0)
    oled.text(f"Gas: {gas_status}", 0, 10)
    oled.text(f"Light: {light_status}", 0, 20)
    oled.text(f"System: {system_status}", 0, 30)
    sleep(0.5)
    oled.show()

    sleep(1)