from machine import Pin, I2C, ADC
from ssd1306 import SSD1306_I2C
import time

BUTTON_PIN = 3
LED_PIN = 28
POT_PIN = 26
I2C_SCL_PIN = 1
I2C_SDA_PIN = 0

button = Pin(BUTTON_PIN, Pin.IN, Pin.PULL_UP)
led = Pin(LED_PIN, Pin.OUT)
pot = ADC(POT_PIN)

i2c = I2C(0, scl=Pin(I2C_SCL_PIN), sda=Pin(I2C_SDA_PIN), freq=400000)
oled = SSD1306_I2C(128, 64, i2c)

running = False
start_ticks = 0
elapsed_ms = 0
last_button_state = 1
reset_latched = False
last_reset_msg_time = 0
show_reset_msg_ms = 1000

def format_time(ms):
    minutes = ms // 60000
    remaining = ms % 60000
    seconds = remaining // 1000
    millis = remaining % 1000
    return "{:02d}:{:02d}.{:03d}".format(minutes, seconds, millis)

def update_display(show_reset=False):
    oled.fill(0)
    oled.text("Chronometre", 0, 0)
    state_text = "EN COURS" if running else "ARRETE"
    oled.text("Etat: " + state_text, 0, 12)
    time_text = format_time(elapsed_ms)
    oled.text("Temps: " + time_text, 0, 24)
    if show_reset:
        oled.text("REMIS A ZERO", 0, 52)
    oled.show()

led.value(0)
update_display()

while True:
    now = time.ticks_ms()
    
    current_button_state = button.value()
    if current_button_state == 0 and last_button_state == 1:
        if not running:
            start_ticks = now
            running = True
        else:
            elapsed_ms = elapsed_ms + time.ticks_diff(now, start_ticks)
            running = False
    
    last_button_state = current_button_state
    
    if running:
        current_elapsed = time.ticks_diff(now, start_ticks)
        elapsed_ms_display = elapsed_ms + current_elapsed
    else:
        elapsed_ms_display = elapsed_ms
    
    led.value(1 if running else 0)
    
    pot_value = pot.read_u16()
    if pot_value > 65000 and not reset_latched:
        running = False
        elapsed_ms = 0
        reset_latched = True
        last_reset_msg_time = now
        update_display(show_reset=True)
        time.sleep_ms(100)
    elif pot_value < 65000:
        reset_latched = False
    
    if last_reset_msg_time != 0 and time.ticks_diff(now, last_reset_msg_time) < show_reset_msg_ms:
        update_display(show_reset=True)
    else:
        update_display(show_reset=False)
    
    time.sleep_ms(20)