#include <WiFi.h>
#include <MFRC522.h>
#include <HTTPClient.h>
#include <DHT.h>

// Define pins for RFID
#define SS_PIN 21
#define RST_PIN 22

// Define pins for sensors and actuators
#define QR_BUTTON_PIN 32
#define QR_LED_PIN 33
#define TRIG_PIN 5
#define ECHO_PIN 18
#define TRAFFIC_DENSITY_PIN 34
#define CROWDING_ALERT_PIN 35
#define RED_LED_PIN 25
#define YELLOW_LED_PIN 26
#define GREEN_LED_PIN 27

// RFID module
MFRC522 rfid(SS_PIN, RST_PIN);

// DHT sensor
DHT dht(CROWDING_ALERT_PIN, DHT22);

// Wi-Fi credentials
const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

// Server endpoint
const char* serverName = "http://your_server.com/api/traffic-data";

void setup() {
  Serial.begin(115200);

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

  // Initialize DHT sensor
  dht.begin();

  // Initialize Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // Initialize pins
  pinMode(QR_BUTTON_PIN, INPUT_PULLUP);
  pinMode(QR_LED_PIN, OUTPUT);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(RED_LED_PIN, OUTPUT);
  pinMode(YELLOW_LED_PIN, OUTPUT);
  pinMode(GREEN_LED_PIN, OUTPUT);

  // Set initial LED states
  digitalWrite(RED_LED_PIN, LOW);
  digitalWrite(YELLOW_LED_PIN, LOW);
  digitalWrite(GREEN_LED_PIN, HIGH); // Start with green
}

void loop() {
  // RFID Reading
  if (rfid.PICC_IsNewCardPresent() && rfid.PICC_ReadCardSerial()) {
    Serial.println("RFID Tag Detected");
    // Send data to server
    sendData("rfid", rfid.uid.uidByte, rfid.uid.size);
    delay(1000);
    rfid.PICC_HaltA();
  }

  // QR Code Simulation
  if (digitalRead(QR_BUTTON_PIN) == LOW) {
    Serial.println("QR Code Scanned");
    digitalWrite(QR_LED_PIN, HIGH);
    delay(1000);
    digitalWrite(QR_LED_PIN, LOW);

    // Send data to server
    sendData("qr", "QR Code Scanned", 0);
  }

  // Parking Space Tracking
  long duration, distance;
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  duration = pulseIn(ECHO_PIN, HIGH);
  distance = (duration / 2) * 0.0343;

  if (distance < 100) { // Example threshold
    Serial.println("Parking Spot Occupied");
    // Send data to server
    sendData("parking", "Occupied", distance);
  } else {
    Serial.println("Parking Spot Available");
    // Send data to server
    sendData("parking", "Available", distance);
  }

  // Traffic Jam Monitoring
  int trafficDensity = analogRead(TRAFFIC_DENSITY_PIN);
  Serial.print("Traffic Density: ");
  Serial.println(trafficDensity);

  // Crowding Alerts
  int crowdDensity = analogRead(CROWDING_ALERT_PIN);
  Serial.print("Crowd Density: ");
  Serial.println(crowdDensity);

  if (trafficDensity > 2000 || crowdDensity > 2000) { // Example thresholds
    digitalWrite(RED_LED_PIN, HIGH);
    digitalWrite(YELLOW_LED_PIN, LOW);
    digitalWrite(GREEN_LED_PIN, LOW);
    Serial.println("Traffic Jam Detected! Signal Red.");
    sendData("traffic", "Jam Detected", trafficDensity);
  } else {
    digitalWrite(RED_LED_PIN, LOW);
    digitalWrite(YELLOW_LED_PIN, LOW);
    digitalWrite(GREEN_LED_PIN, HIGH);
    Serial.println("Traffic Flowing. Signal Green.");
    sendData("traffic", "Flowing", trafficDensity);
  }

  delay(2000); // Delay between cycles
}

void sendData(const char* sensorType, const char* data, int value) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;

    http.begin(serverName);
    http.addHeader("Content-Type", "application/json");

    String jsonData = "{\"sensor\":\"" + String(sensorType) + "\",\"data\":\"" + String(data) + "\",\"value\":" + String(value) + "}";
    
    int httpResponseCode = http.POST(jsonData);

    if (httpResponseCode > 0) {
      String response = http.getString();
      Serial.println(httpResponseCode);
      Serial.println(response);
    } else {
      Serial.print("Error on sending POST: ");
      Serial.println(httpResponseCode);
    }

    http.end();
  } else {
    Serial.println("Error in WiFi connection");
  }
}