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

// -------- Display Setup --------
#define HARDWARE_TYPE MD_MAX72XX::PAROLA_HW
#define MAX_DEVICES 4
#define CS_PIN   10
#define DATA_PIN 11
#define CLK_PIN  13

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

// -------- Quiz State --------
enum QuizState { SHOW_QUESTION, WAIT_QUESTION, SHOW_ANIM, SHOW_ANSWER, WAIT_ANSWER };
QuizState state = SHOW_QUESTION;

unsigned long stateTimer = 0;
int num1, num2, result;

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

// -------- Timing --------
const unsigned long QUESTION_DELAY = 3000;
const unsigned long ANSWER_DELAY   = 3000;
const unsigned long ANIM_DELAY     = 200;

// -------- Setup --------
void setup() {
  randomSeed(analogRead(0));
  P.begin();
  P.setIntensity(3);
  P.displayClear();
  generateQuestion();
}

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

  switch (state) {
    case SHOW_QUESTION:
      // Display question immediately, then move to WAIT_QUESTION
      displayQuestion();
      state = WAIT_QUESTION;
      stateTimer = now;
      break;

    case WAIT_QUESTION:
      if (now - stateTimer >= QUESTION_DELAY) {
        state = SHOW_ANIM;
        animIndex = 0;
        stateTimer = now;
      }
      break;

    case SHOW_ANIM:
      if (now - stateTimer >= ANIM_DELAY) {
        stateTimer = now;
        displayAnimation();
        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 --------

// Generate a new random question
void generateQuestion() {
  num1 = random(1, 10);
  num2 = random(1, 10);
  result = num1 + num2;
  state = SHOW_QUESTION;
}

// Display the question
void displayQuestion() {
  char q[10];
  sprintf(q, "%d+%d=?", num1, num2);
  P.displayClear();
  P.displayText(q, PA_CENTER, 50, 0, PA_PRINT, PA_NO_EFFECT);
  P.displayReset();
}

// Display animation
void displayAnimation() {
  P.displayClear();
  P.displayText((char*)animFrames[animIndex], PA_CENTER, 50, 0, PA_PRINT, PA_NO_EFFECT);
  P.displayReset();
}

// Display the answer
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.displayReset();
}