from machine import Pin, I2C, ADC
import ssd1306
import time

print("=== LAB 9 DEMO VERSION (NO ASYNC) ===")

# ================= OLED =================
i2c = I2C(1, sda=Pin(6), scl=Pin(7), freq=400000)
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

# ================= POTENTIOMETER (VOC SIMULATION) =================
adc = ADC(28)

# ================= BUTTON =================
button = Pin(3, Pin.IN, Pin.PULL_UP)

running = True
btn_flag = False
last_press = 0

def button_irq(pin):
    global btn_flag, last_press
    now = time.ticks_ms()
    if time.ticks_diff(now, last_press) > 300:
        btn_flag = True
        last_press = now

button.irq(trigger=Pin.IRQ_FALLING, handler=button_irq)

# ================= MAIN LOOP =================
while True:

    # обробка кнопки
    if btn_flag:
        btn_flag = False
        running = not running

    if not running:
        oled.fill(0)
        oled.text("PROGRAM OFF", 20, 28)
        oled.show()
        time.sleep(0.3)
        continue

    raw = adc.read_u16()

    # 0..65535 -> 0..500
    voc_index = int((raw / 65535) * 500)

    oled.fill(0)
    oled.text("VOC Index:", 0, 0)
    oled.text(str(voc_index), 0, 12)

    # 5 секторів
    sector_width = 20
    start_x = 10
    start_y = 30
    height = 20

    for i in range(5):
        x = start_x + i * (sector_width + 2)
        oled.rect(x, start_y, sector_width, height, 1)

    # визначення активного сектору
    sector = voc_index // 100
    if sector > 4:
        sector = 4

    for i in range(sector + 1):
        x = start_x + i * (sector_width + 2)
        oled.fill_rect(x+1, start_y+1, sector_width-2, height-2, 1)

    # текстова інтерпретація
    if voc_index <= 100:
        quality = "Excellent"
    elif voc_index <= 200:
        quality = "Good"
    elif voc_index <= 300:
        quality = "Light"
    elif voc_index <= 400:
        quality = "Moderate"
    else:
        quality = "Bad"

    oled.text(quality, 0, 55)

    oled.show()
    time.sleep(0.2)