#include <MD_Parola.h>
#include <MD_MAX72xx.h>
#include <SPI.h>

#define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW
#define MAX_DEVICES 4
#define CS_PIN 10

#define BUTTON_PIN 2  // Button simulates wave

MD_Parola P = MD_Parola(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);

enum QuizState { SHOW_QUESTION, SHOW_ANIM, SHOW_ANSWER, WAIT_ANSWER };
QuizState state = SHOW_QUESTION;

unsigned long stateTimer = 0;
unsigned long blinkTimer = 0;
bool blinkOn = true;

int num1, num2, result;

const char* animFrames[] = { " * ", " ** ", " *** ", " ** ", " * " };
const int animCount = sizeof(animFrames)/sizeof(animFrames[0]);
int animIndex = 0;

const unsigned long BLINK_INTERVAL = 500;
const unsigned long ANIM_DELAY = 200;
const unsigned long ANSWER_DELAY = 4000;

void setup() {
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  randomSeed(analogRead(0));

  P.begin();
  P.setIntensity(3);
  P.displayClear();

  generateQuestion();
}

void loop() {
  P.displayAnimate();
  unsigned long now = millis();

  switch(state) {

    case SHOW_QUESTION:
      // Blink ?
      if(now - blinkTimer >= BLINK_INTERVAL){
        blinkTimer = now;
        blinkOn = !blinkOn;
        displayQuestion();
      }

      // Button pressed → show animation
      if(digitalRead(BUTTON_PIN) == LOW){
        delay(50); // debounce
        if(digitalRead(BUTTON_PIN) == LOW){
          state = SHOW_ANIM;
          animIndex = 0;
          stateTimer = now;
        }
      }
      break;

    case SHOW_ANIM:
      if(now - stateTimer >= ANIM_DELAY){
        stateTimer = now;
        P.displayClear();
        P.displayText((char*)animFrames[animIndex], PA_CENTER, 50, 0, PA_PRINT, PA_NO_EFFECT);
        animIndex++;
        if(animIndex >= animCount){
          state = SHOW_ANSWER;
          stateTimer = now;
        }
      }
      break;

    case SHOW_ANSWER:
      displayAnswer();
      state = WAIT_ANSWER;
      stateTimer = now;
      break;

    case WAIT_ANSWER:
      if(now - stateTimer >= ANSWER_DELAY){
        generateQuestion();
      }
      break;
  }
}

// -------- Functions --------
void generateQuestion(){
  num1 = random(1,10);
  num2 = random(1,10);
  result = num1 + num2;
  blinkOn = true;
  state = SHOW_QUESTION;
  stateTimer = millis();
  blinkTimer = millis();
  displayQuestion();
}

void displayQuestion(){
  char q[10];
  if(blinkOn) sprintf(q, "%d+%d=?", num1, num2);
  else sprintf(q, "%d+%d= ", num1, num2);

  // Clear display only for blinking zone (simulate static + blinking)
  P.displayClear();
  P.displayText(q, PA_CENTER, 50, 0, PA_PRINT, PA_NO_EFFECT);
  P.displayAnimate();
}

void displayAnswer(){
  char a[10];
  sprintf(a, "%d+%d=%d", num1, num2, result);
  P.displayClear();
  P.displayText(a, PA_CENTER, 50, 0, PA_PRINT, PA_NO_EFFECT);
  P.displayAnimate();
}