#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#include <Servo.h>



LiquidCrystal_I2C lcd(0x27, 16, 2); // set the LCD address to 0x27 for a 16 chars and 2 line display

// Keypad Pins
const byte ROWS = 4;
const byte COLS = 4;
char hexaKeys[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {22, 24, 26, 28};
byte colPins[COLS] = {30, 32, 34, 36};
Keypad customKeypad = Keypad(makeKeymap(hexaKeys), rowPins, colPins, ROWS, COLS);

// Declare servo pins

int servoPin1 = 38;
int servoPin2 = 40;
int servoPin3 = 42;
int servoPin4 = 44;

// Create servo objects
Servo Servo1, Servo2, Servo3, Servo4;


// Global Variables
String selectedCode = "";
float selectedPrice = 0.0;
bool isServoRunning = false;

// Constants
const int numItems = 4;
struct Item {
  String code;
  float price;
};
Item items[numItems] = {
  {"A1", 100},
  {"A2", 200},
  {"B3", 300},
  {"B4", 500}
};

// Servo Positions
const int lockedPosition = 20;
const int unlockedPosition = 180;

// Servo Run Time (in milliseconds)
const unsigned long servoRunTime = 5000; // 5 seconds


void setup() {

  // Initialize LCD
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 1);
  lcd.print("Welcome to SuperVending");

 // Initialize Servo
  Servo1.attach(servoPin1);
  Servo2.attach(servoPin2);
  Servo3.attach(servoPin3);
  Servo4.attach(servoPin4);
  Servo1.write(lockedPosition);
  Servo2.write(lockedPosition);
  Servo3.write(lockedPosition);
  Servo4.write(lockedPosition);
  

  // Reset the machine
  resetMachine();
}

void loop() {
  // Handle keypad input
  char customKey = customKeypad.getKey();

  if (customKey) {
    if (customKey == '#') {
      selectedCode += customKey;
    } else if (customKey == '*') {
      resetMachine();
      lcd.clear();
      lcd.print("Canceled");
      delay(2000);
      lcd.clear();
      lcd.print("Make Your Choice");
      lcd.setCursor(0, 1);
      lcd.print("Item: ");
      return;
    } else {
      selectedCode += customKey;
      lcd.setCursor(7, 1);
      lcd.print(selectedCode);

      // Check if item selection is complete
      if (selectedCode.length() == 2) {
        selectedPrice = getItemPrice(selectedCode);
        if (selectedPrice != 0.0) {
          lcd.clear();
          lcd.print("Price: $");
          lcd.print(selectedPrice);
          lcd.setCursor(0, 1);
        } else {
          lcd.clear();
          lcd.print("Error");
          delay(2000);
          lcd.clear();
          lcd.print("Make Your Choice");
          lcd.setCursor(0, 1);
          lcd.print("Item: ");
          selectedCode = "";
        }
      }
    }
  }

}

float getItemPrice(String code) {
  for (int i = 0; i < numItems; i++) {
    if (items[i].code == code) {
      return items[i].price;
    }
  }
  return 0.0;
}

void processTransaction() {
  lcd.clear();
  lcd.print("Processing");
  lcd.setCursor(0, 1);
  delay(500);
  lcd.clear();
  lcd.print("Processing");
  lcd.setCursor(0, 1);
  delay(500);
  lcd.clear();
  lcd.print("Processing");
  lcd.setCursor(0, 1);
  delay(500);
  lcd.clear();
  lcd.print("Processing");
  lcd.setCursor(0, 1);
  delay(500);
  lcd.clear();
  lcd.print("Processing");
  lcd.setCursor(0, 1);
  
  // Check if the transaction was successful
  if (selectedCode == "A1") {
    lcd.clear();
    lcd.print("Transaction");
    lcd.setCursor(0, 1);
    lcd.print("Completed!");
  if (selectedCode == "A2")
    lcd.clear();
    lcd.print("Transaction");
    lcd.setCursor(0, 1);
    lcd.print("Completed!");
  if (selectedCode == "B3")  
    lcd.clear();
    lcd.print("Transaction");
    lcd.setCursor(0, 1);
    lcd.print("Completed!");
  if (selectedCode == "B4")  
    lcd.clear();
    lcd.print("Transaction");
    lcd.setCursor(0, 1);
    lcd.print("Completed!");


    if (selectedCode == "A1") {
      spinServo(38, 1);
    }   
    else if (selectedCode == "A2") {
      spinServo(40, 2);
    }
    else if (selectedCode == "B3") {
      spinServo(42, 1);
    }
    else if (selectedCode == "B4") {
      spinServo(44, 1);
    }
  
    lcd.clear();
    lcd.print("Enjoy!");
    delay(8000); // Wait for 8 seconds
    resetMachine();
    lcd.clear();
    lcd.print("Please Select");
    lcd.setCursor(0, 1);
    lcd.print("Item: ");

  }
}


void resetMachine() {
  selectedCode = "";
  selectedPrice = 0.0;
  isServoRunning = false;
  Servo1.write(lockedPosition);
  stopServo();
}


void spinServo(int servoPin, unsigned long duration) {
  digitalWrite(servoPin, HIGH);
  isServoRunning = true;
  delay(duration * 1000);
  digitalWrite(servoPin, LOW);
  isServoRunning = false;
}


void stopServo() {
  if (isServoRunning) {
    digitalWrite(servoPin1, LOW);
    digitalWrite(servoPin2, LOW);
    digitalWrite(servoPin3, LOW);
    digitalWrite(servoPin4, LOW);
    isServoRunning = false;
  }

}