#include <WiFi.h>
#include <HTTPClient.h>
#include <ArduinoJson.h>
#include <ESP32Servo.h>
#include <LiquidCrystal.h>
#include <SPI.h>
#include <MFRC522.h>

// ========= WiFi =========
const char* ssid = "Wokwi-GUEST";
const char* password = "";
String SERVER_URL = "http://eugenie-confabulatory-undespotically.ngrok-free.dev/api/update";

// ========= Ultrasonic Pins =========
const int TRIG1 = 32;  const int ECHO1 = 34;
const int TRIG2 = 33;  const int ECHO2 = 35;
const int TRIG3 = 25;  const int ECHO3 = 36;
const int TRIG_ENTRY = 26;  const int ECHO_ENTRY = 39;
const int TRIG_EXIT  = 27;  const int ECHO_EXIT  = 4;

// ========= Servo =========
const int SERVO_ENTRY_PIN = 13;
const int SERVO_EXIT_PIN  = 12;

// ========= LEDs =========
const int LED_GREEN = 16;

// ========= LCD =========
LiquidCrystal lcd(23, 22, 21, 19, 18, 5);

// ========= RFID =========
#define RFID_SS   14
#define RFID_RST  2
MFRC522 rfid(RFID_SS, RFID_RST);

// ========= Allowed Cards =========
String allowedCards[] = {
  "DE AD BE EF",
  "12 34 56 78"
};
const int allowedCount = 2;

// ========= States =========
bool spot1=false, spot2=false, spot3=false;
bool entryGateOpen=false, exitGateOpen=false;

// ========= Objects =========
Servo entryServo;
Servo exitServo;

// ========= Helpers =========
void setGate(Servo &s, bool openNow) {
  s.write(openNow ? 90 : 0);
}

bool hasFreeSpot() {
  return (!spot1 || !spot2 || !spot3);
}

long readDistanceCM(int trigPin, int echoPin) {
  digitalWrite(trigPin, LOW); delayMicroseconds(2);
  digitalWrite(trigPin, HIGH); delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  long d = pulseIn(echoPin, HIGH, 25000);
  if (d == 0) return 999;
  return d * 0.034 / 2;
}

bool isOccupied(int trig, int echo) {
  return readDistanceCM(trig, echo) <= 10;
}

bool isCarAtGate(int trig, int echo) {
  return readDistanceCM(trig, echo) <= 15;
}

// ========= RFID Check =========
bool isCardAllowed() {
  if (!rfid.PICC_IsNewCardPresent()) return false;
  if (!rfid.PICC_ReadCardSerial()) return false;

  String uid="";
  for (byte i=0;i<rfid.uid.size;i++) {
    if (rfid.uid.uidByte[i]<0x10) uid+="0";
    uid+=String(rfid.uid.uidByte[i],HEX);
    if (i<rfid.uid.size-1) uid+=" ";
  }
  uid.toUpperCase();
  Serial.println(uid);

  rfid.PICC_HaltA();
  rfid.PCD_StopCrypto1();

  for (int i=0;i<allowedCount;i++) {
    if (uid==allowedCards[i]) return true;
  }
  return false;
}

// ========= LCD =========
void showSlots() {
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("S1:");
  lcd.print(spot1?"F":"E");
  lcd.print("  S2:");
  lcd.print(spot2?"F":"E");

  lcd.setCursor(0,1);
  lcd.print("S3:");
  lcd.print(spot3?"F":"E");
}

// ========= Setup =========
void setup() {
  Serial.begin(115200);

  pinMode(TRIG1,OUTPUT); pinMode(ECHO1,INPUT);
  pinMode(TRIG2,OUTPUT); pinMode(ECHO2,INPUT);
  pinMode(TRIG3,OUTPUT); pinMode(ECHO3,INPUT);
  pinMode(TRIG_ENTRY,OUTPUT); pinMode(ECHO_ENTRY,INPUT);
  pinMode(TRIG_EXIT,OUTPUT);  pinMode(ECHO_EXIT,INPUT);

  pinMode(LED_GREEN,OUTPUT);

  entryServo.attach(SERVO_ENTRY_PIN);
  exitServo.attach(SERVO_EXIT_PIN);
  setGate(entryServo,false);
  setGate(exitServo,false);

  lcd.begin(16,2);
  lcd.setCursor(0,0); lcd.print("Welcome in our");
  lcd.setCursor(0,1); lcd.print("Parking");
  delay(3000);
  lcd.clear();

  WiFi.begin(ssid,password);
  while(WiFi.status()!=WL_CONNECTED) delay(200);

  rfid.PCD_Init(); // ✅ استخدم SPI الافتراضي

  spot1=isOccupied(TRIG1,ECHO1);
  spot2=isOccupied(TRIG2,ECHO2);
  spot3=isOccupied(TRIG3,ECHO3);

  showSlots();
}

// ========= Main Loop =========
void loop() {

  // Update slots
  spot1=isOccupied(TRIG1,ECHO1);
  spot2=isOccupied(TRIG2,ECHO2);
  spot3=isOccupied(TRIG3,ECHO3);

  digitalWrite(LED_GREEN, hasFreeSpot());

  // ENTRY GATE
  if (!entryGateOpen && isCarAtGate(TRIG_ENTRY,ECHO_ENTRY)) {

    if (!isCardAllowed()) {
      lcd.clear();
      lcd.print("ACCESS DENIED");
      delay(1500);
      showSlots();
      return;
    }

    if (!hasFreeSpot()) {
      lcd.clear();
      
      showSlots();
      return;
    }

    entryGateOpen=true;
    setGate(entryServo,true);
    delay(1500);
    entryGateOpen=false;
    setGate(entryServo,false);
  }
// ========= EXIT GATE =========
  if (!exitGateOpen && isCarAtGate(TRIG_EXIT,ECHO_EXIT)) {
    exitGateOpen = true;
    setGate(exitServo,true);
    delay(3000);
  }

  if (exitGateOpen && !isCarAtGate(TRIG_EXIT,ECHO_EXIT)) {
    setGate(exitServo,false);
    exitGateOpen = false;
    delay(1000);
  }
  showSlots();
  delay(300);
}