#include <LiquidCrystal.h>
#include <Keypad.h>

// LCD: RS, E, D4, D5, D6, D7 (D7 = A3)
LiquidCrystal lcd(7, 8, 9, 10, 11, A3);

// Shift register pins
const int dataPin = 6;
const int latchPin = 13;
const int clockPin = 12;

// Keypad setup (4x3 including A, B, 9)
const byte ROWS = 3;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', ' '} // last column = A4 (connected to A, B, 9)
};
byte rowPins[ROWS] = {2, 3, 4};
byte colPins[COLS] = {A0, A1, A2, A4};  // A4 is column for A/B/9

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// Game state
String pattern = "";
String userInput = "";
int level = 1;
bool gameRunning = true;

void setup() {
  lcd.begin(16, 2);
  pinMode(dataPin, OUTPUT);
  pinMode(latchPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  randomSeed(analogRead(A5));

  showStartupInstructions();
}

void loop() {
  if (!gameRunning) return;

  generatePattern(level);
  showPattern();

  if (!getUserInput()) {
    return;
  }

  lcd.clear();
  lcd.print("Correct!");
  level++;
  delayWithExit(1500);
  lcd.clear();
}

void showStartupInstructions() {
  lcd.print("Memory Game!");
  delayWithExit(1500);
  lcd.clear();
  lcd.print("Press keys:");
  delayWithExit(1000);

  lcd.clear();
  lcd.print("9=Exit");
  delayWithExit(1200);

  lcd.clear();
  lcd.print("A=Delete");
  delayWithExit(1200);

  lcd.clear();
  lcd.print("B=Reset");
  delayWithExit(1200);

  lcd.clear();
  lcd.print("Repeat Pattern!");
  delayWithExit(1500);
  lcd.clear();
}

void generatePattern(int len) {
  pattern = "";
  for (int i = 0; i < len; i++) {
    char c = '1' + random(0, 8);  // only 1–8
    pattern += c;
  }
}

void showPattern() {
  for (char c : pattern) {
    checkForImmediateExit();
    int index = c - '1';
    lcd.clear();
    lcd.print("Watch: ");
    lcd.print(c);
    lightLED(index);
    delayWithExit(700);
    lightLED(-1);
    delayWithExit(200);
  }
  lcd.clear();
  lcd.print("Your turn:");
}

bool getUserInput() {
  userInput = "";
  lcd.setCursor(0, 1); // bottom line

  while (userInput.length() < pattern.length()) {
    char key = keypad.getKey();
    if (key) {
      if (key == '9') {
        endGame();
        return false;
      } else if (key == 'A') {
        // Delete last character
        if (userInput.length() > 0) {
          userInput.remove(userInput.length() - 1);
          lcd.setCursor(userInput.length(), 1);
          lcd.print(" ");
          lcd.setCursor(userInput.length(), 1);
        }
      } else if (key == 'B') {
        // Reset game
        level = 1;
        gameRunning = true;
        lcd.clear();
        lcd.print("Resetting...");
        delay(1000);
        lcd.clear();
        return true;
      } else if (key >= '1' && key <= '8') {
        userInput += key;
        lcd.print("*");
        int index = key - '1';
        lightLED(index);
        delay(200);
        lightLED(-1);
      }
    }
  }

  return userInput == pattern;
}

void endGame() {
  lcd.clear();
  lcd.print("Game Over!");
  lcd.setCursor(0, 1);
  lcd.print("Score: ");
  lcd.print(level - 1);
  delay(2000);

  lcd.clear();
  lcd.print(getFeedback(level - 1));
  gameRunning = false;
  while (true); // freeze
}

String getFeedback(int score) {
  if (score >= 10) return "Amazing Memory!";
  if (score >= 5) return "Good Job!";
  return "Try Again!";
}

void lightLED(int index) {
  byte leds = 0;
  if (index >= 0 && index < 8) {
    leds = 1 << index;
  }
  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, MSBFIRST, leds);
  digitalWrite(latchPin, HIGH);
}

// Delay but allow exit check
void delayWithExit(unsigned long ms) {
  unsigned long start = millis();
  while (millis() - start < ms) {
    checkForImmediateExit();
  }
}

void checkForImmediateExit() {
  char key = keypad.getKey();
  if (key == '9') {
    endGame();
  }
}