from machine import Pin, I2C, UART
from i2c_lcd import I2cLcd
import time

# ---------- UART Setup ----------
uart_connection = UART(1, baudrate=9600, tx=Pin(17), rx=Pin(16))
print("UART START")

# ---------- Hardware Setup ----------
i2c_bus = I2C(0, scl=Pin(22), sda=Pin(21))
found_devices = i2c_bus.scan()

if not found_devices:
    raise RuntimeError("No LCD!")

lcd_display = I2cLcd(i2c_bus, found_devices[0], 2, 16)

# ---------- Display Function ----------
def show_reading(temperature, humidity, door_state, gas_value):

    lcd_display.clear()

    # Gas Alert
    if gas_value == 0:
        lcd_display.move_to(0, 0)
        lcd_display.putstr("GAS ALERT!")
        lcd_display.move_to(0, 1)
        lcd_display.putstr("Ventilate NOW")
        return

    # Normal Display
    lcd_display.move_to(0, 0)
    lcd_display.putstr("T:{:.1f} H:{:.1f}".format(temperature, humidity))

    lcd_display.move_to(0, 1)
    lcd_display.putstr(("Door:" + door_state)[:16])


# ---------- Startup ----------
def show_waiting():
    lcd_display.clear()
    lcd_display.move_to(1, 0)
    lcd_display.putstr("Wait for data")
    lcd_display.move_to(5, 1)
    lcd_display.putstr("......")


show_waiting()
time.sleep(2)

# ---------- Previous Values ----------
last_payload = None
last_gas = None

# ---------- Main Loop ----------
while True:

    if uart_connection.any():

        raw_uart_data = uart_connection.readline()

        if raw_uart_data:

            decoded_string = raw_uart_data.decode().strip()
            print("RECEIVED:", decoded_string)

            data_fields = decoded_string.split(",")

            if len(data_fields) != 5:
                continue

            try:
                temperature = float(data_fields[0])
                humidity = float(data_fields[1])
                near_flag = int(data_fields[2])
                door_state = data_fields[3]
                gas_value = int(data_fields[4])

            except:
                continue

            payload = (temperature, humidity, door_state)

            # Only update LCD if something changed
            if payload == last_payload and gas_value == last_gas:
                continue

            print(temperature, humidity, near_flag, door_state, gas_value)

            show_reading(
                temperature,
                humidity,
                door_state,
                gas_value
            )

            last_payload = payload
            last_gas = gas_value

    time.sleep(0.2)