#include <DFPlayerMini_Fast.h>
#include <SoftwareSerial.h>

// LDR pins (digital or analog depending on use)
const int ldrPins[5] = {A0, A1, A2, A3, A4};

// Answer button pins
const int buttonPins[6] = {23, 25, 27, 29, 31, 33}; 

// Indicator LEDs for buttons
const int buttonLEDs[6] = {35, 37, 39, 41, 43, 45}; 

// Feedback LEDs
const int greenLED = 47;
const int redLED = 49;

// Last pressed button
int lastButton = -1;

// LDR code to noun map
String nouns[32] = {
  "mother", "father", "children", "house", "bird", "tree", "hat", "scarf",
  "rabbit", "wardrobe", "butcher", "playground", "bin", "garland", "carpet", "fish",
  "fork", "snacks", "ship", "luggage", "traffic_lights", "hairdresser", "rug", "sofa",
  "socks", "trousers", "candle", "lamp", "eggs", "bread", "garlic", "bus"
};

// Setup DFPlayer on Serial1 (Mega: RX1 = pin 19, TX1 = pin 18)
DFPlayerMini_Fast MP3player;

int currentIndex = -1;

void setup() {
  Serial.begin(115200);
  Serial1.begin(9600); // MP3 module serial
  
  if (!MP3player.begin(Serial1)) {
   Serial.println("DFPlayer not found!");
   while (true); // Halt
  }
   MP3player.volume(27); // Set volume 0–30

  // Init button & LED pins
  for (int i = 0; i < 6; i++) {
    pinMode(buttonPins[i], INPUT_PULLUP);
    pinMode(buttonLEDs[i], OUTPUT);
  }
  pinMode(greenLED, OUTPUT);
  pinMode(redLED, OUTPUT);
}

void loop() {
  int pattern = readPattern();
  if (pattern != currentIndex) {
    currentIndex = pattern;
    resetLEDs();
    Serial.print("Detected: ");
    Serial.println(nouns[pattern]);
  }

  for (int i = 0; i < 6; i++) {
    if (digitalRead(buttonPins[i]) == LOW) {
      handleAnswer(i);
      delay(300); // debounce
    }
  }
}

int readPattern() {
  int value = 0;
  for (int i = 0; i < 5; i++) {
    int state = analogRead(ldrPins[i]) < 500 ? 1 : 0; // Adjust threshold
    value |= (state << (4 - i));
  }
  return value;
}

void handleAnswer(int index) {
  // Turn off last LED
  if (lastButton != -1 && lastButton != index) {
    digitalWrite(buttonLEDs[lastButton], LOW);
  }

  lastButton = index;
  digitalWrite(buttonLEDs[index], HIGH);

  if (index == 4) {
    digitalWrite(greenLED, HIGH);
    digitalWrite(redLED, LOW);
    MP3player.play(1); // correct.mp3 (0001.mp3)
  } else {
    digitalWrite(greenLED, LOW);
    digitalWrite(redLED, HIGH);
    MP3player.play(2 + currentIndex); // wrong sound: 0002.mp3 to 0033.mp3
  }
}

void resetLEDs() {
  for (int i = 0; i < 6; i++) {
    digitalWrite(buttonLEDs[i], LOW);
  }
  digitalWrite(greenLED, LOW);
  digitalWrite(redLED, LOW);
  lastButton = -1;
}