#include <Arduino.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET    -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Pins
#define BUTTON_PIN 34
#define BUZZER_PIN 15

// Button timing
#define DEBOUNCE_MS 40
#define LONG_PRESS_MS 2000

// State
unsigned long lastChange = 0;
bool btnLast = false;
bool btnStable = false;
unsigned long pressedAt = 0;
bool isPressed = false;

void beep(int ms = 80) {
  tone(BUZZER_PIN, 1200);
  delay(ms);
  noTone(BUZZER_PIN);
}

void drawDiceFace(int value) {
  display.clearDisplay();
  int x=28, y=4, s=64;
  display.drawRoundRect(x, y, s, s, 6, WHITE);
  auto dot = [&](int cx, int cy) { display.fillCircle(cx, cy, 4, WHITE); };
  int cx = x + s/2; int cy = y + s/2;
  int left = x + s*2/7;  int right = x + s*5/7;
  int top  = y + s*2/7;  int bottom= y + s*5/7;
  switch (value) {
    case 1: dot(cx, cy); break;
    case 2: dot(left, top); dot(right, bottom); break;
    case 3: dot(left, top); dot(cx, cy); dot(right, bottom); break;
    case 4: dot(left, top); dot(right, top); dot(left, bottom); dot(right, bottom); break;
    case 5: dot(left, top); dot(right, top); dot(cx, cy); dot(left, bottom); dot(right, bottom); break;
    case 6: dot(left, top); dot(right, top); dot(left, cy); dot(right, cy); dot(left, bottom); dot(right, bottom); break;
  }
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(6, 54);
  display.print("Value: ");
  display.print(value);
  display.display();
}

void showSplash() {
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(WHITE);
  display.setCursor(8, 10);
  display.print("DICE");
  display.setCursor(8, 34);
  display.print("GAME");
  display.display();
  delay(700);
  display.clearDisplay();
  display.setTextSize(1);
  display.setCursor(8, 22);
  display.print("Press button to roll");
  display.setCursor(8, 38);
  display.print("Long press to reset");
  display.display();
}

bool readButtonRaw() { return digitalRead(BUTTON_PIN) == HIGH; }

void updateButton() {
  bool now = readButtonRaw();
  if (now != btnLast) {
    lastChange = millis();
    btnLast = now;
  }
  if (millis() - lastChange > DEBOUNCE_MS) {
    if (btnStable != now) {
      btnStable = now;
      if (btnStable) { pressedAt = millis(); isPressed = true; }
      else { isPressed = false; }
    }
  }
}

bool shortPressTriggered() {
  if (!btnStable && pressedAt > 0) {
    unsigned long dur = millis() - pressedAt;
    if (dur >= 60 && dur < LONG_PRESS_MS) { pressedAt = 0; return true; }
  }
  return false;
}

bool longPressDetected() {
  if (btnStable && isPressed && (millis() - pressedAt >= LONG_PRESS_MS)) {
    isPressed = false; pressedAt = 0; return true;
  }
  return false;
}

void rollAnimation() {
  for (int i=0;i<10;i++) {
    int v = random(1,7);
    drawDiceFace(v);
    delay(60 + i*15);
  }
}

void setup() {
  pinMode(BUTTON_PIN, INPUT);
  pinMode(BUZZER_PIN, OUTPUT);
  noTone(BUZZER_PIN);
  Wire.begin(21,22);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.clearDisplay();
  display.display();
  randomSeed(analogRead(32) ^ millis());
  showSplash();
}

void loop() {
  updateButton();
  if (longPressDetected()) {
    display.clearDisplay();
    display.setTextSize(2);
    display.setTextColor(WHITE);
    display.setCursor(20, 20);
    display.print("RESET");
    display.display();
    beep(120);
    delay(400);
    showSplash();
  }
  if (shortPressTriggered()) {
    beep(60);
    rollAnimation();
    int value = random(1,7);
    drawDiceFace(value);
  }
}