# Contador regresivo con displays de ánodo común y 4 botones
from machine import Pin
import time

# CONFIG 
DEBUG = False  

# Pines de segmentos A-G
ledPins = [
    Pin(26, Pin.OUT),  # A
    Pin(27, Pin.OUT),  # B
    Pin(14, Pin.OUT),  # C
    Pin(12, Pin.OUT),  # D
    Pin(13, Pin.OUT),  # E
    Pin(25, Pin.OUT),  # F
    Pin(33, Pin.OUT)   # G
]

# Pines de control de displays
unidades = Pin(4, Pin.OUT)
decenas  = Pin(5, Pin.OUT)

# LED indicador de fin
ledFin = Pin(32, Pin.OUT)
ledFin.value(0)

# Botones con resistencia pull-up interna
# Conectar: GPIO Pulsador GND
BTN_MODE  = Pin(15, Pin.IN, Pin.PULL_UP)  # Alterna programar/contar
BTN_INC   = Pin(2,  Pin.IN, Pin.PULL_UP)  # Incrementar
BTN_DEC   = Pin(18, Pin.IN, Pin.PULL_UP)  # Decrementar
BTN_RESET = Pin(21, Pin.IN, Pin.PULL_UP)  # Resetear a 00 y detener

# ESTADO
DEBOUNCE_MS = 80
_last_raw = {
    "mode": BTN_MODE.value(),
    "inc":  BTN_INC.value(),
    "dec":  BTN_DEC.value(),
    "rst":  BTN_RESET.value()
}
_last_change = {
    "mode": time.ticks_ms(),
    "inc":  time.ticks_ms(),
    "dec":  time.ticks_ms(),
    "rst":  time.ticks_ms()
}
_stable_state = dict(_last_raw)

set_time = 0     # Empieza en 00
i = set_time
counting = False
_last_second = time.ticks_ms()

# Tabla de dígitos (0 = encendido, 1 = apagado -> para ánodo común)
digits = [
    0b0000001,  # 0
    0b1001111,  # 1
    0b0010010,  # 2
    0b0000110,  # 3
    0b1001100,  # 4
    0b0100100,  # 5
    0b0100000,  # 6
    0b0001111,  # 7
    0b0000000,  # 8
    0b0000100   # 9
]

# FUNCIONES DISPLAY 
def clear_segments_off():
    for p in ledPins:
        p.value(1)
    unidades.value(0)
    decenas.value(0)

def showDigit(digit):
    for j in range(7):
        bit = (digit >> (6 - j)) & 1
        ledPins[j].value(bit)

def displayNumber(num):
    d = (num // 10) % 10
    u = num % 10

    # Decenas
    clear_segments_off()
    showDigit(digits[d])
    decenas.value(1)
    time.sleep_ms(4)
    decenas.value(0)

    # Unidades
    clear_segments_off()
    showDigit(digits[u])
    unidades.value(1)
    time.sleep_ms(4)
    unidades.value(0)

def blink_with_display(number, times=12, period_ms=100):
    half = period_ms // 2
    for _ in range(times):
        ledFin.value(1)
        t0 = time.ticks_ms()
        while time.ticks_diff(time.ticks_ms(), t0) < half:
            displayNumber(number)
        ledFin.value(0)
        t1 = time.ticks_ms()
        while time.ticks_diff(time.ticks_ms(), t1) < half:
            displayNumber(number)

# FUNCIONES BOTONES 
def update_button(name, pin):
    """
    Manejo de debounce.
    Devuelve True solo cuando hay flanco 1->0 (pulsación).
    """
    now = time.ticks_ms()
    raw = pin.value()

    if raw != _last_raw[name]:
        _last_raw[name] = raw
        _last_change[name] = now
        return False

    if time.ticks_diff(now, _last_change[name]) >= DEBOUNCE_MS:
        if raw != _stable_state[name]:
            prev = _stable_state[name]
            _stable_state[name] = raw
            if prev == 1 and raw == 0:  # flanco descendente
                if DEBUG:
                    print("[BTN]", name, "pressed")
                return True
    return False

#  INIT VISUAL 
for _ in range(60):
    displayNumber(0)

#  LOOP PRINCIPAL 
while True:
    # Mostrar en display
    displayNumber(i if counting else set_time)

    # Botón MODE -> alterna programar/contar
    if update_button("mode", BTN_MODE):
        counting = not counting
        if counting:
            i = set_time
            _last_second = time.ticks_ms()
        if DEBUG:
            print("MODE -> counting =", counting)

    # Incrementar (solo programando)
    if not counting and update_button("inc", BTN_INC):
        if set_time < 99:
            set_time += 1
        if DEBUG:
            print("INC -> set_time =", set_time)

    # Decrementar (solo programando)
    if not counting and update_button("dec", BTN_DEC):
        if set_time > 0:
            set_time -= 1
        if DEBUG:
            print("DEC -> set_time =", set_time)

    # Reset -> fuerza a 00 y detiene
    if update_button("rst", BTN_RESET):
        i = 0
        set_time = 0   # CORRECCIÓN: también reinicia el valor programado
        counting = False
        if DEBUG:
            print("RST -> reset to 00")

    # Conteo por segundo
    if counting and time.ticks_diff(time.ticks_ms(), _last_second) >= 1000:
        _last_second = time.ticks_ms()
        if i > 0:
            i -= 1
            if DEBUG:
                print("counting:", i)
        else:
            # Al terminar: parpadea LED y queda en 00
            blink_with_display(0, times=12, period_ms=100)
            i = set_time + 1
            counting = True
            if DEBUG:
                print("FIN -> back to 00")