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

// LCD and Stepper Motor
LiquidCrystal_I2C lcd(0x27, 16, 2);
const int steps = 200;
Stepper myStepper(steps, 4, 5, 6, 7);

// RGB LED Pins
const int redd = 3;
const int greenn = 2;
const int bluee = 1;

// Button Pins for True/False
const int t = A2; 
const int f = A3;

// Ultrasonic Sensor Pins
const int trigPin = 8;
const int echoPin = A0;

// Servo (Eyelid) Pin
Servo eyelidServo;
const int servoPin = 9;

// Quiz Variables
String questions[] = {"Pogi si butlig?", "Mabait si butlig?"};
int index[2] = {0, 1};
int ques = 0;
int points = 0;
bool quizz = false;

// Blink Timing
unsigned long lastBlinkTime = 0;

void setup() {
  // Initialize LCD and Backlight
  lcd.begin(16, 2);
  lcd.noBacklight();
  lcd.clear();

  // Set Pin Modes
  pinMode(redd, OUTPUT);
  pinMode(greenn, OUTPUT);
  pinMode(bluee, OUTPUT);
  pinMode(t, INPUT);
  pinMode(f, INPUT); 
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  // Initialize RGB LED and Servo
  setRGB(0, 0, 0);
  eyelidServo.attach(servoPin);
  eyelidServo.write(0); // Start with eyelid "closed"

  // Randomize Question Order and Stepper Motor Speed
  randomizeQuestions();
  myStepper.setSpeed(60);
}

void loop() {
  bool isClose = ultrasonicCheck();

  if (isClose && !quizz) {
    startQuiz();
  } else if (!isClose && quizz) {
    endQuiz();
  }

  if (quizz) {
    eyelidBlink(); // Blink eyelid every 2 seconds during quiz
    checkAnswer();
  }
}

/* --- Ultrasonic Sensor Functions --- */
bool ultrasonicCheck() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  long duration = pulseIn(echoPin, HIGH);
  float distance = (duration * 0.034) / 2;
  return distance < 50;
}

/* --- Quiz Management Functions --- */
void startQuiz() {
  quizz = true;
  lcd.backlight();
  displayQuestion();
}

void endQuiz() {
  quizz = false;
  lcd.noBacklight();
  lcd.clear();
  setRGB(0, 0, 0); 
}

void randomizeQuestions() {
  for (int i = 0; i < 2; i++) {
    int r = random(i, 2);
    int temp = index[i];
    index[i] = index[r];
    index[r] = temp;
  }
}

/* --- Question Display and Answer Checking --- */
void displayQuestion() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(questions[index[ques]]);
  setRGB(0, 0, 255); // Blue light for new question
}

void checkAnswer() {
  if (digitalRead(t) == LOW || digitalRead(f) == LOW) {
    if (digitalRead(t) == LOW) {
      processAnswer(true);
    } else {
      processAnswer(false);
    }
    delay(1000);
    ques++;
    if (ques >= 2) {
      displayPoints();
    } else {
      displayQuestion();
    }
  }
}

void processAnswer(bool answer) {
  bool correctAnswer = (index[ques] == 0) ? !answer : answer;
  if (correctAnswer) {
    points++;
    setRGB(0, 255, 0); // Green for correct answer
    displayResult("Correct");
  } else {
    setRGB(255, 0, 0); // Red for incorrect answer
    displayResult("Incorrect");
    moveStepper();
  }
}

/* --- Display Functions --- */
void displayResult(const char* result) {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(result);
}

void displayPoints() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("My Points:");
  lcd.setCursor(0, 1);
  lcd.print(points);
  setRGB(255, 255, 255); // White light for points display
}

/* --- Stepper Motor Action on Incorrect Answer --- */
void moveStepper() {
  myStepper.step(steps);
  delay(500);
  myStepper.step(-steps);
}

/* --- Servo (Eyelid) Blink Function --- */
void eyelidBlink() {
  unsigned long currentMillis = millis();
  if (currentMillis - lastBlinkTime >= 2000) { // Blink every 2 seconds
    eyelidServo.write(0);  // Close eyelid
    delay(200);            // Short delay for closing
    eyelidServo.write(90); // Open eyelid
    lastBlinkTime = currentMillis;
  }
}

/* --- RGB LED Control Function --- */
void setRGB(int red, int green, int blue) {
  analogWrite(redd, red);
  analogWrite(greenn, green);
  analogWrite(bluee, blue);
}