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

// ------------------ LCD ------------------
LiquidCrystal_I2C lcd(0x27, 16, 2);  // Change address to 0x3F if 0x27 doesn’t work

// ------------------ Keypad ------------------
const byte ROWS = 4;
const byte COLS = 4;
char keys[ROWS][COLS] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};

byte rowPins[ROWS] = {2, 3, 4, 5};
byte colPins[COLS] = {6, 7, 8, 9};
Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

// ------------------ Servo ------------------
Servo dispenserServo;
int servoPin = 15;

// ------------------ UART Devices ------------------
SoftwareSerial sim800(10, 11);    // RX, TX (to SIM800L)
SoftwareSerial rfid(12, 13);      // RX, TX (from EM18 RFID)
SoftwareSerial fingerprint(14, 16); // RX, TX (fingerprint sensor)

// ------------------ Constants ------------------
String rationItems = "Wheat=3kg Rice=5kg Dal=1kg";
String phoneNumber = "+91XXXXXXXXXX"; // replace with your number

// ------------------ Helper Functions ------------------
void lcdPrint(String line1, String line2 = "") {
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print(line1);
  lcd.setCursor(0,1);
  lcd.print(line2);
}

bool verifyFingerprint() {
  // Placeholder function - adapt for your sensor
  // Simulate fingerprint success for now
  lcdPrint("Place Finger...");
  delay(2000);
  // If real module connected, use serial commands here
  return true;  // Assume fingerprint matched
}

void sendSMS(String msg) {
  sim800.println("AT");
  delay(500);
  sim800.println("AT+CMGF=1");
  delay(500);
  sim800.print("AT+CMGS=\"");
  sim800.print(phoneNumber);
  sim800.println("\"");
  delay(500);
  sim800.print(msg);
  sim800.write(26); // Ctrl+Z to send
  delay(3000);
}

void releaseRation() {
  lcdPrint("Dispensing...", "");
  dispenserServo.write(90);
  delay(2000);
  dispenserServo.write(0);
  delay(500);
  lcdPrint("Ration Released", "");
  delay(2000);
}

// ------------------ Setup ------------------
void setup() {
  Wire.begin();
  lcd.init();
  lcd.backlight();
  dispenserServo.attach(servoPin);
  dispenserServo.write(0);

  sim800.begin(9600);
  rfid.begin(9600);
  fingerprint.begin(57600);

  lcdPrint("Ration Card", "Vending Machine");
  delay(1000);
}

// ------------------ Loop ------------------
void loop() {
  String enteredID = "";
  char key;
  
  lcdPrint("Enter Ration", "Card ID:");
  
  while (true) {
    key = keypad.getKey();
    if (key) {
      if (key == '#') {
        if (enteredID.length() > 0) break;
      } 
      else if (key == '*') {
        if (enteredID.length() > 0) enteredID.remove(enteredID.length() - 1);
      } 
      else {
        if (enteredID.length() < 12) enteredID += key;
      }
      lcdPrint("ID:", enteredID);
    }

    // Optional: Read RFID tag if available
    if (rfid.available()) {
      String tag = rfid.readStringUntil('\n');
      tag.trim();
      if (tag.length() > 0) {
        enteredID = tag;
        lcdPrint("RFID:", tag);
        delay(1000);
        break;
      }
    }
  }

  lcdPrint("Card ID Saved", enteredID);
  delay(1000);

  lcdPrint("Scan Fingerprint", "");
  bool verified = verifyFingerprint();

  if (verified) {
    lcdPrint("Fingerprint", "Matched");
    delay(1000);
    releaseRation();
    sendSMS("Ration dispensed to ID: " + enteredID);
    lcdPrint("Wheat=3kg", "Rice=5kg Dal=1kg");
    delay(3000);
  } else {
    lcdPrint("Fingerprint", "Failed!");
    delay(2000);
  }

  lcdPrint("Thank You", "Next Customer");
  delay(2000);
}