import machine
import ssd1306
import time

# Constants for modes
MODE_NORMAL_CLOCK = 0
MODE_STOPWATCH = 1
MODE_TIMER = 2

# Constants for button pins
BUTTON_MODE_PIN = 5
BUTTON_SELECTOR_PIN = 4
BUTTON_INCREASE_PIN = 0
BUTTON_DECREASE_PIN = 2

# Constants for SSD1306 display
DISPLAY_WIDTH = 128
DISPLAY_HEIGHT = 64
DISPLAY_SCL_PIN = 22
DISPLAY_SDA_PIN = 21

# Global variables
mode = MODE_NORMAL_CLOCK
stopwatch_running = False
stopwatch_start_time = 1
timer_seconds = 60

# Initialize SSD1306 display
i2c = machine.SoftI2C(scl=machine.Pin(DISPLAY_SCL_PIN), sda=machine.Pin(DISPLAY_SDA_PIN))
oled = ssd1306.SSD1306_I2C(DISPLAY_WIDTH, DISPLAY_HEIGHT, i2c)

# Initialize buttons
button_mode = machine.Pin(BUTTON_MODE_PIN, machine.Pin.IN, machine.Pin.PULL_UP)
button_selector = machine.Pin(BUTTON_SELECTOR_PIN, machine.Pin.IN, machine.Pin.PULL_UP)
button_increase = machine.Pin(BUTTON_INCREASE_PIN, machine.Pin.IN, machine.Pin.PULL_UP)
button_decrease = machine.Pin(BUTTON_DECREASE_PIN, machine.Pin.IN, machine.Pin.PULL_UP)

# Helper functions
def update_display(value):
    oled.fill(0)
    oled.text(value, 0, 0)
    oled.show()

def change_mode(pin):
    global mode
    mode = (mode + 1) % 3

def select_action(pin):
    global mode, stopwatch_running, stopwatch_start_time, timer_seconds
    if mode == MODE_NORMAL_CLOCK:
        pass  
    elif mode == MODE_STOPWATCH:
        if stopwatch_running:
            stopwatch_running = False
        else:
            stopwatch_running = True
            stopwatch_start_time = time.ticks_ms()
    elif mode == MODE_TIMER:
        timer_seconds = 60  # Reset timer to 60 seconds

def increase_value(pin):
    global timer_seconds
    if mode == MODE_TIMER and timer_seconds < 3600: 
        timer_seconds += 1

def decrease_value(pin):
    global timer_seconds
    if mode == MODE_TIMER and timer_seconds > 0:
        timer_seconds -= 1


button_mode.irq(trigger=machine.Pin.IRQ_FALLING, handler=change_mode)
button_selector.irq(trigger=machine.Pin.IRQ_FALLING, handler=select_action)
button_increase.irq(trigger=machine.Pin.IRQ_FALLING, handler=increase_value)
button_decrease.irq(trigger=machine.Pin.IRQ_FALLING, handler=decrease_value)

# Main loop
while True:
    if mode == MODE_NORMAL_CLOCK:
        current_time = time.localtime()
        hours = current_time[3]
        minutes = current_time[4]
        seconds = current_time[5]
        update_display("CLOCK: {:02d}:{:02d}:{:02d}".format(hours, minutes, seconds))
        time.sleep_ms(500)
    elif mode == MODE_STOPWATCH:
        if stopwatch_running:
            elapsed_time = time.ticks_diff(time.ticks_ms(), stopwatch_start_time)
            update_display("{:02d}:{:02d}:{:02d}".format(elapsed_time // 3600000, (elapsed_time // 60000) % 60, (elapsed_time // 1000) % 60))
            time.sleep_ms(500)
    elif mode == MODE_TIMER:
        update_display("Timer: {:02d}:{:02d}".format(timer_seconds // 60, timer_seconds % 60))
        time.sleep_ms(1000)
        if timer_seconds > 0:
            timer_seconds -= 1