#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x20, 16, 2);   // change to 0x7C if needed

const int buttonPin = D7;

bool lastButtonState = HIGH;
unsigned long lastDebounceTime = 0;
const unsigned long debounceDelay = 30;

int playerRow = 1;          // 1 = ground, 0 = jump
bool isJumping = false;
unsigned long jumpStartTime = 0;
const unsigned long jumpDuration = 500;

int obstacleCol = 15;
int score = 0;
bool gameOver = false;
unsigned long lastStepTime = 0;
int gameSpeed = 250;        // smaller = faster

void setup() {
  pinMode(buttonPin, INPUT_PULLUP);

  Wire.begin(D4, D5);
  lcd.init();
  lcd.backlight();

  showStartScreen();
}

void loop() {
  if (gameOver) {
    if (buttonPressed()) {
      resetGame();
    }
    return;
  }

  if (buttonPressed() && !isJumping) {
    isJumping = true;
    jumpStartTime = millis();
    playerRow = 0;
  }

  if (isJumping && millis() - jumpStartTime > jumpDuration) {
    isJumping = false;
    playerRow = 1;
  }

  if (millis() - lastStepTime > gameSpeed) {
    lastStepTime = millis();
    updateGame();
    drawGame();
  }
}

bool buttonPressed() {
  bool reading = digitalRead(buttonPin);

  if (reading != lastButtonState) {
    lastDebounceTime = millis();
    lastButtonState = reading;
  }

  if ((millis() - lastDebounceTime) > debounceDelay) {
    static bool stableState = HIGH;

    if (reading != stableState) {
      stableState = reading;
      if (stableState == LOW) {
        return true;
      }
    }
  }

  return false;
}

void showStartScreen() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Mini Jump Game");
  lcd.setCursor(0, 1);
  lcd.print("Press btn start");

  while (!buttonPressed()) {
    delay(10);
  }

  resetGame();
}

void resetGame() {
  playerRow = 1;
  isJumping = false;
  obstacleCol = 15;
  score = 0;
  gameOver = false;
  gameSpeed = 250;
  lcd.clear();
  drawGame();
}

void updateGame() {
  obstacleCol--;

  if (obstacleCol < 0) {
    obstacleCol = 15;
    score++;

    if (gameSpeed > 120) {
      gameSpeed -= 10;   // gradually increase difficulty
    }
  }

  if (obstacleCol == 1 && playerRow == 1) {
    gameOver = true;
    showGameOver();
  }
}

void drawGame() {
  lcd.clear();

  // player
  lcd.setCursor(1, playerRow);
  lcd.print("P");

  // obstacle
  lcd.setCursor(obstacleCol, 1);
  lcd.print("#");

  // score
  lcd.setCursor(10, 0);
  lcd.print("S:");
  lcd.print(score);
}

void showGameOver() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Game Over!");
  lcd.setCursor(0, 1);
  lcd.print("Score:");
  lcd.print(score);
  delay(1500);

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Press button");
  lcd.setCursor(0, 1);
  lcd.print("to restart");
}