// ==============================
// PINES
// ==============================
const int btnStart1 = 2;
const int btnStart2 = 3;
const int btnStop   = 4;

const int bomba1 = 8;
const int bomba2 = 9;

// ==============================
// TIEMPO ANTIRREBOTE (ms)
// ==============================
const unsigned long debounceTime = 50;

// ==============================
// ESTADOS DE BOTONES
// ==============================
bool estadoStart1 = HIGH;
bool estadoStart2 = HIGH;
bool estadoStop   = HIGH;

bool lastStart1 = HIGH;
bool lastStart2 = HIGH;
bool lastStop   = HIGH;

unsigned long tStart1 = 0;
unsigned long tStart2 = 0;
unsigned long tStop   = 0;

// ==============================
// MEMORIA TIPO PLC
// ==============================
bool estadoBomba1 = false;
bool estadoBomba2 = false;

// ==============================
void setup() {
  pinMode(btnStart1, INPUT_PULLUP);
  pinMode(btnStart2, INPUT_PULLUP);
  pinMode(btnStop,   INPUT_PULLUP);

  pinMode(bomba1, OUTPUT);
  pinMode(bomba2, OUTPUT);

  digitalWrite(bomba1, LOW);
  digitalWrite(bomba2, LOW);
}

// ==============================
void loop() {
  leerBotones();
  logicaControl();
  actualizarSalidas();
}

// ==============================
// ANTIRREBOTE
// ==============================
void leerBotones() {
  unsigned long ahora = millis();

  // --- START 1 ---
  bool lectura1 = digitalRead(btnStart1);
  if (lectura1 != lastStart1) {
    tStart1 = ahora;
  }
  if ((ahora - tStart1) > debounceTime) {
    estadoStart1 = lectura1;
  }
  lastStart1 = lectura1;

  // --- START 2 ---
  bool lectura2 = digitalRead(btnStart2);
  if (lectura2 != lastStart2) {
    tStart2 = ahora;
  }
  if ((ahora - tStart2) > debounceTime) {
    estadoStart2 = lectura2;
  }
  lastStart2 = lectura2;

  // --- STOP ---
  bool lecturaS = digitalRead(btnStop);
  if (lecturaS != lastStop) {
    tStop = ahora;
  }
  if ((ahora - tStop) > debounceTime) {
    estadoStop = lecturaS;
  }
  lastStop = lecturaS;
}

// ==============================
// LÓGICA DE CONTROL
// ==============================
void logicaControl() {

  bool start1 = (estadoStart1 == LOW);
  bool start2 = (estadoStart2 == LOW);
  bool stop   = (estadoStop   == LOW);

  // STOP GENERAL (PRIORIDAD)
  if (stop) {
    estadoBomba1 = false;
    estadoBomba2 = false;
    return;
  }

  // START BOMBA 1 (interlock)
  if (start1 && !estadoBomba2) {
    estadoBomba1 = true;
    estadoBomba2 = false;
  }

  // START BOMBA 2 (interlock)
  if (start2 && !estadoBomba1) {
    estadoBomba2 = true;
    estadoBomba1 = false;
  }
}

// ==============================
void actualizarSalidas() {
  digitalWrite(bomba1, estadoBomba1);
  digitalWrite(bomba2, estadoBomba2);
}