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

// Pin definitions for 4 buttons
const int buttonPins[] = {2, 3, 4, 5};   // 4 push buttons on pins 2, 3, 4, 5
const int ledPin = 13;                    // LED pin

// LCD setup (Address, Columns, Rows)
LiquidCrystal_I2C lcd(0x27, 16, 2);  

// Game variables
unsigned long startTime;
unsigned long reactionTime;
bool gameStarted = false;
int correctButton = -1;  // Will hold the index of the correct button
bool buttonPressed = false;

void setup() {
  // Initialize button pins as input with internal pull-up resistors
  for (int i = 0; i < 4; i++) {
    pinMode(buttonPins[i], INPUT_PULLUP); 
  }
  
  // Initialize LED pin as output
  pinMode(ledPin, OUTPUT); 

  // Initialize LCD
  lcd.begin(16, 2);
  lcd.backlight();  // Turn on the backlight of the LCD
  lcd.clear();
  lcd.print("Fastest Finger First!");
  delay(2000);  // Wait for 2 seconds before starting the game
  
  // Seed random number generator
  randomSeed(analogRead(0));  
}

void loop() {
  if (!gameStarted) {
    // Random delay between 3 and 6 seconds before the game starts
    int delayTime = random(3000, 6000);  
    
    lcd.clear();
    lcd.print("Wait for GO!");
    
    delay(delayTime);  // Wait for the random time

    // Choose a random button to be the "correct" one
    correctButton = random(0, 4);  // Random index between 0 and 3 (for 4 buttons)
    
    // Start the game
    lcd.clear();
    lcd.print("GO!");
    digitalWrite(ledPin, HIGH);  // Turn on LED to indicate the game is on
    startTime = millis();  // Record the start time
    gameStarted = true;
  } else {
    // Check if any of the 4 buttons are pressed
    for (int i = 0; i < 4; i++) {
      if (digitalRead(buttonPins[i]) == LOW && !buttonPressed) {  // LOW means button pressed
        buttonPressed = true;
        unsigned long currentTime = millis();
        
        // Record the reaction time if the correct button was pressed
        reactionTime = currentTime - startTime;

        // Display the result on the LCD
        lcd.clear();
        lcd.print("Button ");
        lcd.print(i + 1);  // Display the button number (1-4)
        lcd.setCursor(0, 1);
        
        if (i == correctButton) {
          lcd.print("Correct! ");
          lcd.print(reactionTime);
          lcd.print(" ms");
        } else {
          lcd.print("Wrong!   ");
        }

        digitalWrite(ledPin, LOW);  // Turn off LED after a button press
        delay(3000);  // Wait for 3 seconds before resetting

        // Reset the game for the next round
        gameStarted = false;
        buttonPressed = false;
      }
    }
  }
}