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

// OLED display size
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

// OLED reset pin
#define OLED_RESET -1
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// Button pins
#define BUTTON_LEFT D10
#define BUTTON_RIGHT D9
#define BUTTON_SHOOT D8
#define BUTTON_START D7

// Player properties
int playerX = 60;
const int playerY = 56;
bool bulletActive = false;
int bulletX, bulletY;

// Enemy properties
const int enemyRows = 3;
const int enemyCols = 5;
bool enemies[enemyRows][enemyCols];
int enemyX = 0;
int enemyDirection = 1; // 1: right, -1: left
int enemyY = 10;
int enemySpeed = 1; // Initial speed of enemies

// Game state
bool gameRunning = false;
int score = 0;
int roundNumber = 1;

void setup() {
  // Initialize display
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    while (true); // Stop if display fails
  }
  display.clearDisplay();
  display.display();

  // Initialize buttons
  pinMode(BUTTON_LEFT, INPUT_PULLUP);
  pinMode(BUTTON_RIGHT, INPUT_PULLUP);
  pinMode(BUTTON_SHOOT, INPUT_PULLUP);
  pinMode(BUTTON_START, INPUT_PULLUP);

  // Initialize enemies
  resetEnemies();
  introScreen();
}

void loop() {
  if (gameRunning) {
    playGame();
  } else {
    if (digitalRead(BUTTON_START) == LOW) {
      gameRunning = true;
      resetGame();
    }
  }
}

void resetGame() {
  playerX = 60;
  bulletActive = false;
  enemyX = 0;
  enemyDirection = 1;
  enemyY = 10;
  enemySpeed = 1 + roundNumber - 1; // Increase speed with each round
  resetEnemies();
}

void resetEnemies() {
  for (int row = 0; row < enemyRows; row++) {
    for (int col = 0; col < enemyCols; col++) {
      enemies[row][col] = true;
    }
  }
}

void introScreen() {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(10, 20);
  display.println("GALAGA-STYLE GAME");
  display.setCursor(15, 40);
  display.println("Press START to Play");
  display.display();
}

void playGame() {
  // Handle player movement
  if (digitalRead(BUTTON_LEFT) == LOW && playerX > 0) {
    playerX -= 2;
  }
  if (digitalRead(BUTTON_RIGHT) == LOW && playerX < (SCREEN_WIDTH - 12)) {
    playerX += 2;
  }

  // Handle shooting
  if (!bulletActive && digitalRead(BUTTON_SHOOT) == LOW) {
    bulletActive = true;
    bulletX = playerX + 5;
    bulletY = playerY - 2;
  }

  // Move bullet
  if (bulletActive) {
    bulletY -= 4;
    if (bulletY < 0) {
      bulletActive = false;
    }
  }

  // Move enemies
  static int enemyMoveCounter = 0;
  enemyMoveCounter++;
  if (enemyMoveCounter >= enemySpeed) {
    enemyX += enemyDirection;
    enemyMoveCounter = 0;
    if (enemyX <= 0 || enemyX + (enemyCols * 16) >= SCREEN_WIDTH) {
      enemyDirection *= -1;
      enemyY += 4;
    }
  }

  // Check for collisions
  for (int row = 0; row < enemyRows; row++) {
    for (int col = 0; col < enemyCols; col++) {
      if (enemies[row][col]) {
        int ex = enemyX + col * 16;
        int ey = enemyY + row * 8;
        if (bulletActive && bulletX >= ex && bulletX <= ex + 12 && bulletY >= ey && bulletY <= ey + 8) {
          enemies[row][col] = false;
          bulletActive = false;
          score++; // Increment score
        }
        if (ey + 8 >= playerY) {
          gameOver();
          return;
        }
      }
    }
  }

  // Check if all enemies are defeated
  if (areAllEnemiesDefeated()) {
    nextRound();
    return;
  }

  // Render the screen
  display.clearDisplay();
  renderPlayer();
  renderBullet();
  renderEnemies();
  renderScore();
  display.display();
}

void renderPlayer() {
  display.fillRect(playerX, playerY, 12, 4, SSD1306_WHITE); // Draw spaceship
}

void renderBullet() {
  if (bulletActive) {
    display.fillRect(bulletX, bulletY, 2, 4, SSD1306_WHITE); // Draw bullet
  }
}

void renderEnemies() {
  for (int row = 0; row < enemyRows; row++) {
    for (int col = 0; col < enemyCols; col++) {
      if (enemies[row][col]) {
        int ex = enemyX + col * 16;
        int ey = enemyY + row * 8;
        display.fillRect(ex, ey, 12, 8, SSD1306_WHITE); // Draw enemy
      }
    }
  }
}

void renderScore() {
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.print("Score: ");
  display.print(score);
  display.setCursor(80, 0);
  display.print("Round: ");
  display.print(roundNumber);
}

bool areAllEnemiesDefeated() {
  for (int row = 0; row < enemyRows; row++) {
    for (int col = 0; col < enemyCols; col++) {
      if (enemies[row][col]) {
        return false;
      }
    }
  }
  return true;
}

void nextRound() {
  roundNumber++;
  resetGame();
}

void gameOver() {
  gameRunning = false;
  roundNumber = 1; // Reset to first round
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(10, 20);
  display.println("GAME OVER");
  display.setCursor(15, 40);
  display.println("Press START to Retry");
  display.display();
}