#include <SPI.h>
#include <Adafruit_PN532.h>
#include <MFRC522.h>

// Define pins
#define RST_PIN 1       // Reset pin for RC522
#define SS_RC522 13     // Chip select for RC522
#define SS_PN532 13      // Chip select for PN532
#define BUZZER_PIN 2    // Buzzer pin

// RFID readers
Adafruit_PN532 nfc(SS_PN532);
MFRC522 mfrc522(SS_RC522, RST_PIN);

// Function prototypes
void playTone(int frequency, int duration, int times);
bool detectRC522();
bool detectPN532();
void printUID(uint8_t *uid, uint8_t uidLength);

//set the booleans for the readers so it only has to set once during setup and can use these later on
bool rc522Connected = false;
bool pn532Connected = false; 

void setup() {
    Serial.begin(115200);
    pinMode(BUZZER_PIN, OUTPUT);

    // Initialize SPI bus
    SPI.begin();

    // Detect which reader is connected
    rc522Connected = detectRC522(); 
    if(rc522Connected){
        playTone(1000, 100, 3);  // Three beeps for RC522
        Serial.println("RC522 detected.");
    }
    else{ //no rc522 :(
        pn532Connected = detectPN532(); 
        if(pn532Connected){
            Serial.println("RC522 detected.");

            playTone(1000, 100, 2);  // Two beeps for PN532
        }
        else{
            //no reader detected at all, long beep repeatedly every 3 seconds
            while (true){
                
                playTone(1000, 500, 1);  // Long beep if no reader is found
                Serial.println("No RFID reader detected.");
                delay(3000); //wait 3 seconds and do the beep/serial log again, in case it was missed the first time? might be too annoying so move outside the loop otherwise. 
            };  // Halt execution if no reader is found
        }
    }
}

void loop() {
    // Check if PN532 is connected and try to read
    if (pn532Connected) {
        uint8_t uid[] = { 0, 0, 0, 0, 0, 0, 0 };  // Buffer to store the returned UID
        uint8_t uidLength;

        if (nfc.readPassiveTargetID(PN532_MIFARE_ISO14443A, uid, &uidLength)) {
            Serial.print("PN532 UID: ");
            printUID(uid, uidLength);
            playTone(1000, 100, 1);  // Single beep for a successful read
        }
    }
    // Check if RC522 is connected and try to read
    else if (rc522Connected) {
        mfrc522.PCD_Init();  // Ensure RC522 is initialized for every cycle

        if (mfrc522.PICC_IsNewCardPresent() && mfrc522.PICC_ReadCardSerial()) {
            Serial.print("RC522 UID: ");
            printUID(mfrc522.uid.uidByte, mfrc522.uid.size);
            playTone(1000, 100, 1);  // Single beep for a successful read
            mfrc522.PICC_HaltA();  // Halt PICC (Tag)
        }
    }
    delay(500);  // Small delay to avoid continuous reading
}

// Function to detect RC522
bool detectRC522() {
    mfrc522.PCD_Init();  // Initialize the RC522
    delay(100);
    // Check if the VersionReg is readable
    byte version = mfrc522.PCD_ReadRegister(MFRC522::VersionReg);
    return (version != 0 && version != 0xFF);  // Return true if detected
}

// Function to detect PN532
bool detectPN532() {
    nfc.begin();
    delay(100);
    // Try to get the firmware version
    uint32_t version = nfc.getFirmwareVersion();
    return (version);  // Return true if detected
}

// Function to print UID
void printUID(uint8_t *uid, uint8_t uidLength) {
    for (uint8_t i = 0; i < uidLength; i++) {
        Serial.print(uid[i] < 0x10 ? " 0" : " ");
        Serial.print(uid[i], HEX);
    }
    Serial.println();
}

// Function to make a tone sound with custom frequency, duration, and repeat count
void playTone(int frequency, int duration, int times) {
    for (int i = 0; i < times; i++) {
        tone(BUZZER_PIN, frequency);  // Play tone on buzzer
        delay(duration);               // Tone duration
        noTone(BUZZER_PIN);            // Stop tone
        delay(100);                    // Delay between tones
    }
}