#include <SPI.h>
#include <MFRC522.h>
#include <Keypad.h>
#include <Adafruit_GFX.h>
#include <Adafruit_PCD8544.h>

// Pin definitions for ESP32
#define SS_PIN    21   // SDA/SS pin
#define RST_PIN   22   // Reset pin
#define SCK_PIN   18   // SCK pin
#define MOSI_PIN  23   // MOSI pin
#define MISO_PIN  19   // MISO pin
#define OUTPUT_PIN 26  // Output pin to control

// Nokia 5110 LCD pin definitions
#define LCD_CLK    14 // SCK
#define LCD_DIN   25  // MOSI
#define LCD_DC    12  // Data/Command
#define LCD_CE    33  // Chip Enable
#define LCD_RST   32  // Reset

Adafruit_PCD8544 display = Adafruit_PCD8544(LCD_CLK, LCD_DIN, LCD_DC, LCD_CE, LCD_RST);

// Keypad configuration
const byte ROWS = 4;
const byte COLS = 3;

char keys[ROWS][COLS] = {
  {'1', '2', '3'},
  {'4', '5', '6'},
  {'7', '8', '9'},
  {'*', '0', '#'}
};

// Keypad pin connections
byte rowPins[ROWS] = {5, 17, 16, 4};   // R1, R2, R3, R4
byte colPins[COLS] = {2, 13, 15};      // C1, C2, C3

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, ROWS, COLS);

MFRC522 mfrc522(SS_PIN, RST_PIN);

// Variables for stable detection
bool cardPresent = false;
bool passwordEntered = false;
bool waitingForPassword = false;
unsigned long lastCardTime = 0;
const unsigned long CARD_TIMEOUT = 300; // 300ms timeout

// Password settings
String correctPassword = "1234";  // Change this to your desired password
String enteredPassword = "";
const int MAX_PASSWORD_LENGTH = 10;

// Display variables
unsigned long lastDisplayUpdate = 0;
const unsigned long DISPLAY_UPDATE_INTERVAL = 100; // Update display every 100ms

void setup() {
  Serial.begin(115200);
 
  // Initialize output pin
  pinMode(OUTPUT_PIN, OUTPUT);
  digitalWrite(OUTPUT_PIN, LOW); // Start with pin OFF
 
  // Initialize SPI with custom pins
  SPI.begin(SCK_PIN, MISO_PIN, MOSI_PIN, SS_PIN);
 
  // Initialize MFRC522
  mfrc522.PCD_Init();
  
  // Initialize Nokia 5110 display
  display.begin();
  display.setContrast(50);  // Adjust contrast (0-100)
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(BLACK);
  
  // Show startup screen
  display.setCursor(0, 0);
  display.println("RFID Security");
  display.println("System Ready");
  display.println("");
  display.println("Place card");
  display.println("near reader");
  display.display();
 
  Serial.println("RFID Reader with Keypad Password System");
  Serial.println("Place a card near the reader...");
  Serial.println("After card detection, enter password on keypad");
  Serial.println("GPIO 26 will turn ON when both card is detected AND correct password is entered");
  Serial.println();
}

void updateDisplay() {
  display.clearDisplay();
  display.setCursor(0, 0);
  display.setTextSize(1);
  
  if (!cardPresent) {
    // No card detected
    display.println("RFID Security");
    display.println("");
    display.println("Place card");
    display.println("near reader");
    display.println("");
    display.print("Status: LOCKED");
  } else if (waitingForPassword) {
    // Card detected, waiting for password
    display.println("Card Detected!");
    display.println("");
    display.println("Enter Password:");
    display.println("");
    
    // Show password as asterisks
    display.print("Pass: ");
    for (int i = 0; i < enteredPassword.length(); i++) {
      display.print("*");
    }
    display.println("");
    display.print("Press # to enter");
  } else if (passwordEntered) {
    // Both card and password correct
    display.println("ACCESS GRANTED");
    display.println("");
    display.println("System: UNLOCKED");
    display.println("");
    display.println("Machine: Running");
    display.println("");
    display.print("Remove card");
  }
  
  display.display();
}

void loop() {
  bool cardDetected = false;
 
  // Check if card is present
  if (mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial()) {
    cardDetected = true;
    lastCardTime = millis();
   
    // Print card info only when first detected
    if (!cardPresent) {
      Serial.println("Card detected!");
     
      Serial.print("Card UID: ");
      for (byte i = 0; i < mfrc522.uid.size; i++) {
        Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
        Serial.print(mfrc522.uid.uidByte[i], HEX);
      }
      Serial.println();
     
      // Print card type
      MFRC522::PICC_Type piccType = mfrc522.PICC_GetType(mfrc522.uid.sak);
      Serial.print("Card type: ");
      Serial.println(mfrc522.PICC_GetTypeName(piccType));
      
      // Start password entry process
      waitingForPassword = true;
      passwordEntered = false;
      enteredPassword = "";
      Serial.println("Please enter password on keypad:");
      Serial.println("---");
    }
  }
 
  // Update card presence with timeout for stability
  if (cardDetected) {
    cardPresent = true;
  } else if (millis() - lastCardTime > CARD_TIMEOUT) {
    if (cardPresent) {
      Serial.println("Card removed. GPIO 26 OFF");
      // Reset password states when card is removed
      waitingForPassword = false;
      passwordEntered = false;
      enteredPassword = "";
    }
    cardPresent = false;
  }
  
  // Handle keypad input when waiting for password
  if (waitingForPassword && cardPresent) {
    char key = keypad.getKey();
    
    if (key) {
      Serial.print("Key pressed: ");
      Serial.println(key);
      
      if (key == '#') {
        // Enter key - check password
        if (enteredPassword == correctPassword) {
          Serial.println("Password CORRECT! GPIO 26 ON");
          passwordEntered = true;
          waitingForPassword = false;
        } else {
          Serial.println("Password INCORRECT! Try again:");
          enteredPassword = "";
          
          // Show error on display briefly
          display.clearDisplay();
          display.setCursor(0, 0);
          display.println("WRONG PASSWORD");
          display.println("");
          display.println("Try Again...");
          display.display();
          delay(1500);
        }
      } else if (key == '*') {
        // Clear key - reset password entry
        Serial.println("Password cleared. Enter password:");
        enteredPassword = "";
      } else if (key >= '0' && key <= '9') {
        // Number key - add to password
        if (enteredPassword.length() < MAX_PASSWORD_LENGTH) {
          enteredPassword += key;
          Serial.print("Password: ");
          // Print asterisks for security
          for (int i = 0; i < enteredPassword.length(); i++) {
            Serial.print("*");
          }
          Serial.println();
        }
      }
      // Update display immediately after key press
      updateDisplay();
    }
  }
 
  // Set GPIO based on both card presence AND correct password
  bool shouldActivate = cardPresent && passwordEntered;
  digitalWrite(OUTPUT_PIN, shouldActivate ? HIGH : LOW);
  
  // Update display periodically
  if (millis() - lastDisplayUpdate > DISPLAY_UPDATE_INTERVAL) {
    updateDisplay();
    lastDisplayUpdate = millis();
  }
 
  delay(50); // Faster checking for better stability
}