#include <Wire.h> 
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);

#define coinSlot 6
#define coinSlotRGBFrame 2
#define buzzer 13
#define incrementButton 9
#define decrementButton 10

// Relay pins array
const int relayPins[10] = {3, 4, 5, 7, 11, 12, A0, A1, A2, A3};

int coinSlotStatus;
int pulse;
int selectedRelay = 1; // Initial selected relay

boolean userBalance = false;
boolean noCoin = false;

char lcdBuffer[16];
int incrementButtonState, decrementButtonState;

void setup() {
  lcd.init();
  lcd.backlight();
  lcd.clear();

  pinMode(buzzer, OUTPUT);
  pinMode(coinSlot, INPUT_PULLUP);
  pinMode(coinSlotRGBFrame, OUTPUT);
  pinMode(incrementButton, INPUT_PULLUP);
  pinMode(decrementButton, INPUT_PULLUP);

  for (int i = 0; i < 10; i++) {
    pinMode(relayPins[i], OUTPUT);
    digitalWrite(relayPins[i], HIGH); // Ensure all relays are off initially
  }

  // Startup sound sequence
  tone(buzzer, 262);
  delay(150);
  tone(buzzer, 294);
  delay(150);
  tone(buzzer, 330);
  delay(150);
  tone(buzzer, 349);
  delay(150);
  tone(buzzer, 440);
  delay(150);
  tone(buzzer, 494);
  delay(150);
  tone(buzzer, 563);
  delay(500);
  noTone(buzzer);
  delay(1000);
} 

void loop() {
  // Display message for coin insertion if no coin has been inserted
  if (!noCoin) {
    noCoin = true;
    lcd.setCursor(0, 0);
    lcd.print("  INSERT COINS");
    digitalWrite(coinSlotRGBFrame, HIGH);
  }
  
  // Read button states
  incrementButtonState = digitalRead(incrementButton);
  decrementButtonState = digitalRead(decrementButton);

  // Increment selected relay if increment button is pressed
  if (incrementButtonState == LOW) {
    if (selectedRelay < 10) {
      selectedRelay++;
      updateRelaySelection();
      delay(200); // Debounce delay
    }
  }

  // Decrement selected relay if decrement button is pressed
  if (decrementButtonState == LOW) {
    if (selectedRelay > 1) {
      selectedRelay--;
      updateRelaySelection();
      delay(200); // Debounce delay
    }
  }

  // Activate selected relay if balance is available
  if (pulse > 0 && userBalance) { 
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("  ACTIVATING...");
    
    digitalWrite(relayPins[selectedRelay - 1], LOW); // Activate the selected relay

    for (int i = pulse; i > 0; i--) {
      lcd.setCursor(0, 1);
      lcd.print("  ");
      lcd.setCursor(0, 1);
      lcd.print(i);
      tone(buzzer, 523);
      delay(500);
      noTone(buzzer);
      delay(500);
    }

    digitalWrite(relayPins[selectedRelay - 1], HIGH); // Deactivate the relay
    pulse = 0;
    noCoin = false;
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Thank You Bye!");
    delay(2000);
    tone(buzzer, 3000);
    delay(200);
    noTone(buzzer);
    delay(50);
    tone(buzzer, 3000);
    delay(50);
    noTone(buzzer);
  }

  // Handle coin insertion
  coinSlotStatus = digitalRead(coinSlot);
  delay(30);
  if (coinSlotStatus == 0) {
    digitalWrite(coinSlotRGBFrame, LOW);
    tone(buzzer, 2000);
    userBalance = true;
    pulse += 1;
    
    lcd.setCursor(0, 0);
    lcd.print("Press a Button");
    sprintf(lcdBuffer, "Bal. Php %d.00", pulse);
    lcd.setCursor(0, 1);
    lcd.print(lcdBuffer);
    delay(30);
  }
  noTone(buzzer);
}

void updateRelaySelection() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Select Relay: ");
  lcd.print(selectedRelay);
}