from machine import Pin, ADC
from utime import sleep
import math

from util import init_pins

sleep(0.1)

LED_START = 0
LED_COUNT = 2

NTC_ID = 27
PID_ID = 20
LIGHT_ID = 28

NTC = ADC(Pin(NTC_ID))
PID = Pin(PID_ID, Pin.IN, Pin.PULL_DOWN)
LIGHT = Pin(LIGHT_ID, Pin.IN, Pin.PULL_DOWN)


LEDS = init_pins(LED_START, LED_COUNT, Pin.OUT)

is_room_empty = True

def motion_interrupt(pin):
    global is_room_empty

    is_room_empty = False if is_room_empty else True


def read_temp(ntc):
    BETA = 3950
    R0 = 10000
    R_SERIES = 10000
    V_REF = 3.3
    T0 = 298.15

    analog_value = ntc.read_u16()
    voltage = (analog_value / 65535) * V_REF
    if voltage == V_REF:
        return None

    resistance = R_SERIES * voltage / (V_REF - voltage)
    celsius = 1 / (1 / T0 + (1 / BETA) * math.log(resistance / R0)) - 273.15

    return celsius

def main():
    PID.irq(handler=motion_interrupt, trigger=Pin.IRQ_RISING)
    print("Starting")

    is_fan = False
    
    while True:
        if read_temp(NTC) >= 30 and not is_room_empty and not is_fan:
            is_fan = True
            print("Too hot, turning fans on.")
            LEDS[1].on()
        elif is_fan and read_temp(NTC) < 30:
            is_fan = False
            print("Turning fans off.")
            LEDS[1].off()
        elif is_room_empty and is_fan:
            is_fan = False
            print("No one in the room, fans off.")
            LEDS[1].off()
        
        if not LIGHT.value() and not is_room_empty:
            LEDS[0].on()
        else:
            LEDS[0].off()
        
        sleep(0.2)

    

if __name__ == "__main__":
    main()