//#include <SPI.h>
//#include <MFRC522.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>

#define SS_PIN 10
#define RST_PIN 9
//MFRC522 rfid(SS_PIN, RST_PIN);

LiquidCrystal_I2C lcd(0x27, 20, 4);
#define BUZZER_PIN 2

const int greenPins[4] = {A0, A3, 3, 6};
const int yellowPins[4] = {A1, 1, 4, 7};
const int redPins[4] = {A2, 0, 5, 8};

const byte emergencyUIDs[][4] = {
  {0x4, 0xF3, 0xEE, 0xA},
  {0x4, 0xF3, 0xE6, 0xA},
  {0x4, 0xF3, 0xED, 0xA},
};
const char* emergencyTypes[] = {
  ">>>--AMBULANCE--<<<",
  ">>>--FIRE TRUCK--<<<",
  ">>>---VIP TRIP---<<<SCOOTER"
};
const int numEmergencyUIDs = sizeof(emergencyUIDs) / sizeof(emergencyUIDs[0]);

bool emergencyDetected = false;
const char* detectedVehicle = "";
int N;

void setup()
{
    //for simulation only
      pinMode(9, INPUT) ;
      pinMode(10, INPUT) ;
      pinMode(11, INPUT) ;
     //Serial.begin(9600);
      lcd.init();
      lcd.backlight();
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Traffic System Init");

      //SPI.begin();
     // rfid.PCD_Init();

      pinMode(BUZZER_PIN, OUTPUT);
      digitalWrite(BUZZER_PIN, LOW);

      for (int i = 0; i < 4; i++) {
        pinMode(greenPins[i], OUTPUT);
        pinMode(yellowPins[i], OUTPUT);
        pinMode(redPins[i], OUTPUT);
        digitalWrite(greenPins[i], LOW);
        digitalWrite(yellowPins[i], LOW);
        digitalWrite(redPins[i], HIGH);
  }

  delay(2000);
  lcd.clear();
}

void loop() {
  for (int i = 0; i < 4; i++) {
    N=i;
    setTrafficLights(i);
    if (timedPhaseWithCheck("Green", 7000)) return;
    //lcd.setCursor(0, 0);
    //lcd.print("Road ");
    //lcd.print(i + 1);
    //lcd.print(" Yellow   ");
    digitalWrite(greenPins[i], LOW);
    digitalWrite(yellowPins[i], HIGH);
    if (timedPhaseWithCheck("Yellow", 3000)) return;

    digitalWrite(yellowPins[i], LOW);
    digitalWrite(redPins[i], HIGH);
  }
}

bool timedPhaseWithCheck(const char* phase, unsigned long duration) {
  unsigned long startTime = millis();
  unsigned long elapsed = 0;
  while (elapsed < duration) {
    checkRFID();
    if (emergencyDetected) {
      handleEmergency(detectedVehicle);
      emergencyDetected = false;
      return true;
    }
    lcd.setCursor(0, 0);
    lcd.print("--NORMAL RESTORED--");
    lcd.setCursor(0, 1);
    lcd.print("ROAD NO:");
    lcd.print(N + 1);
    lcd.print(" GRANTED");
    lcd.setCursor(0, 2);
    lcd.print("PHASE TYPE: ");
    lcd.print(phase);
    lcd.setCursor(0, 3);
    lcd.print("TIME LEFT: ");
    lcd.print((duration - elapsed) / 1000);
    lcd.print(" sec");
    delay(200); // small delay to reduce flicker
    elapsed = millis() - startTime;
  }
  lcd.clear();
  return false;
}

void checkRFID() {
  //real code
 /* if (rfid.PICC_IsNewCardPresent() && rfid.PICC_ReadCardSerial()) {
    for (int i = 0; i < numEmergencyUIDs; i++) {
      if (isMatchingUID(rfid.uid.uidByte, emergencyUIDs[i])) {
        detectedVehicle = emergencyTypes[i];
        emergencyDetected = true;
        rfid.PICC_HaltA();
        rfid.PCD_StopCrypto1();
        return;
      }
    }
    rfid.PICC_HaltA();
    rfid.PCD_StopCrypto1();
  }*/
  for (int i = 0; i < numEmergencyUIDs; i++) 
  {
    if(digitalRead(9+i)==LOW)
    {
      detectedVehicle = emergencyTypes[i];
      emergencyDetected = true;
      return;
    }
  }
}

bool isMatchingUID(byte* uid, const byte* targetUID) {
  for (byte i = 0; i < 4; i++) {
    if (uid[i] != targetUID[i]) {return false;}
    //Serial.print(uid[i],HEX);Serial.print(":");
  }
  return true;
}

void handleEmergency(const char* vehicleType) {
  for (int i = 0; i < 4; i++) {
    digitalWrite(greenPins[i], LOW);
    digitalWrite(yellowPins[i], LOW);
    digitalWrite(redPins[i], HIGH);
  }

  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("!EMERGENCY VEHICLE!");
  lcd.setCursor(0, 1);
  lcd.print(vehicleType);

  tone(BUZZER_PIN, 900);
  delay(7000);
  noTone(BUZZER_PIN);
  lcd.clear();
}

void setTrafficLights(int activeRoad) {
  for (int i = 0; i < 4; i++) {
    if (i == activeRoad) {
      digitalWrite(redPins[i], LOW);
      digitalWrite(greenPins[i], HIGH);
    } else {
      digitalWrite(greenPins[i], LOW);
      digitalWrite(redPins[i], HIGH);
    }
    digitalWrite(yellowPins[i], LOW);
  }
}