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

#define W 128
#define H 64
#define OLED_RESET -1
#define OLED_ADDR 0x3C

Adafruit_SSD1306 display(W, H, &Wire, OLED_RESET);

/* Text geometry */
#define TXT_X 22
#define TXT_Y 22
#define TXT_W 72
#define TXT_H 24

#define GROUND_Y 48

void setup() {
  display.begin(SSD1306_SWITCHCAPVCC, OLED_ADDR);
  randomSeed(analogRead(A0));
}

void loop() {
  show2025();
  manErase2025();
  airBombsWithWish();
  manReveal2026();
  finalWish();
}

/* ---------------- SHOW 2025 ---------------- */
void show2025() {
  display.clearDisplay();
  display.setTextSize(3);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(TXT_X, TXT_Y);
  display.print("2025");
  display.display();
  delay(1500);
}

/* ---------------- MAN ERASES 2025 ---------------- */
void manErase2025() {
  for (int x = -10; x <= W + 10; x++) {
    display.clearDisplay();

    display.setTextSize(3);
    display.setCursor(TXT_X, TXT_Y);
    display.print("2025");

    int maskW = constrain(x - TXT_X, 0, TXT_W);
    display.fillRect(TXT_X, TXT_Y, maskW, TXT_H, SSD1306_BLACK);

    drawMan(x, GROUND_Y, true);

    display.display();
    delay(18);
  }

  display.clearDisplay();
  display.display();
}

/* ---------------- AIR BOMBS + HAPPY NEW YEAR ---------------- */
void airBombsWithWish() {
  for (int i = 0; i < 4; i++) {
    int cx = random(20, W - 20);
    int cy = random(12, 30);

    for (int r = 2; r < 26; r++) {
      display.clearDisplay();

      /* Static Wish Text */
      display.setTextSize(1);
      display.setCursor(22, 0);
      display.print("HAPPY NEW YEAR");

      /* Firework */
      display.drawCircle(cx, cy, r, SSD1306_WHITE);
      for (int s = 0; s < 10; s++) {
        display.drawPixel(cx + random(-r, r),
                          cy + random(-r, r),
                          SSD1306_WHITE);
      }

      display.display();
      delay(30);
    }
  }
}

/* ---------------- MAN REVEALS 2026 ---------------- */
void manReveal2026() {
  for (int x = W + 10; x >= -10; x--) {
    display.clearDisplay();

    display.setTextSize(3);
    display.setCursor(TXT_X, TXT_Y);
    display.print("2026");

    int revealW = constrain((TXT_X + TXT_W) - x, 0, TXT_W);
    display.fillRect(TXT_X, TXT_Y,
                     TXT_W - revealW,
                     TXT_H,
                     SSD1306_BLACK);

    drawMan(x, GROUND_Y, false);

    display.display();
    delay(18);
  }
}

/* ---------------- DRAW WALKING MAN ---------------- */
void drawMan(int x, int y, bool leftToRight) {
  int dir = leftToRight ? 1 : -1;
  static bool step = false;
  step = !step;

  display.drawCircle(x, y - 14, 3, SSD1306_WHITE);          // head
  display.drawLine(x, y - 11, x, y - 2, SSD1306_WHITE);    // body

  display.drawLine(x, y - 9, x + dir * 4, y - 6, SSD1306_WHITE);
  display.drawLine(x, y - 9, x - dir * 4, y - 6, SSD1306_WHITE);

  if (step) {
    display.drawLine(x, y - 2, x + dir * 4, y + 4, SSD1306_WHITE);
    display.drawLine(x, y - 2, x - dir * 2, y + 4, SSD1306_WHITE);
  } else {
    display.drawLine(x, y - 2, x - dir * 4, y + 4, SSD1306_WHITE);
    display.drawLine(x, y - 2, x + dir * 2, y + 4, SSD1306_WHITE);
  }

  display.drawLine(0, y + 5, W, y + 5, SSD1306_WHITE); // ground
}

/* ---------------- FINAL WISH ---------------- */
void finalWish() {
  display.clearDisplay();

  display.setTextSize(1);
  display.setCursor(20, 2);
  display.print("HAPPY NEW YEAR");

  display.setTextSize(3);
  display.setCursor(TXT_X, TXT_Y);
  display.print("2026");

  display.display();
  delay(4000);
}