from machine import Pin
import time

# 初始化 3 個 LED 和 3 個按鈕
leds = [Pin(2, Pin.OUT), Pin(12, Pin.OUT), Pin(16, Pin.OUT)]  # 綠燈、紅燈、黃燈分別連接到 GPIO 2, 12, 16
buttons = [Pin(4, Pin.IN, Pin.PULL_UP), Pin(13, Pin.IN, Pin.PULL_UP), Pin(18, Pin.IN, Pin.PULL_UP)]  # 按鈕連接到 GPIO 4, 13, 18

# 每個燈的亮燈時間：綠燈 3 秒，紅燈 2 秒，黃燈 1 秒
durations = [3, 2, 1]

# 用於記錄當前的燈索引和是否開始循環
current_index = 0
start_cycle = False
interrupt_triggered = False

def button_handler(pin):
    global current_index, start_cycle, interrupt_triggered
    # 根據哪個按鈕被按下設置起始的燈
    if pin == buttons[0]:  # 綠燈按鈕
        current_index = 0
    elif pin == buttons[1]:  # 紅燈按鈕
        current_index = 1
    elif pin == buttons[2]:  # 黃燈按鈕
        current_index = 2
    start_cycle = True  # 開始燈循環
    interrupt_triggered = True  # 中斷燈循環，從新開始

# 設置中斷處理程序
buttons[0].irq(trigger=Pin.IRQ_FALLING, handler=button_handler)
buttons[1].irq(trigger=Pin.IRQ_FALLING, handler=button_handler)
buttons[2].irq(trigger=Pin.IRQ_FALLING, handler=button_handler)

def cycle_lights():
    global current_index, interrupt_triggered
    while start_cycle:
        # 若有中斷觸發，跳出循環重新開始
        if interrupt_triggered:
            interrupt_triggered = False
            continue  # 重新開始循環

        # 熄滅所有燈
        for led in leds:
            led.off()
        # 亮起當前燈
        leds[current_index].on()
        time.sleep(durations[current_index])
        leds[current_index].off()
        # 移動到下一個燈
        current_index = (current_index + 1) % 3

while True:
    if start_cycle:
        cycle_lights()