import java.io.InputStreamReader;

import java.net.HttpURLConnection;

import java.net.InetAddress;

import java.net.URL;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class IPScanner {

    public static void main(String[] args) throws Exception {

        // Define the subnet (adjust it to your network)

        String subnet = "192.168.20";  // Change this to your subnet (e.g., 192.168.0)

        System.out.println("Starting IP Scan on subnet: " + subnet);

        System.out.println("---------------------------------------------------");

        // Loop through all IP addresses in the subnet (1 to 254)

        for (int i = 1; i <= 30; i++) {

            String host = subnet + "." + i;

            // Ping the host to check if it's reachable

            try {

            if (pingHost(host)||true) {

                System.out.println("Host: " + host);

                // Get the device (hostname)

                String deviceName = getHostName(host);

                System.out.println("Device Name: " + deviceName);

                // Get the MAC address

                String macAddress = getMacAddress(host);

                System.out.println("MAC Address: " + macAddress);

                // Get the manufacturer

                String manufacturer = getManufacturer(macAddress);

                System.out.println("Manufacturer: " + manufacturer);

                System.out.println("---------------------------------------------------");

            }

            }catch(Exception e) {

             e.printStackTrace();

            }

        }

    }

    // Function to ping the host to check if it's reachable

    public static boolean pingHost(String host) {

        try {

            InetAddress inet = InetAddress.getByName(host);

            return inet.isReachable(1000);  // Timeout in milliseconds

        } catch (Exception e) {

            return false;

        }

    }

    // Function to get the host/device name (hostname) using reverse DNS lookup

    public static String getHostName(String host) {

        try {

            InetAddress inet = InetAddress.getByName(host);

            return inet.getHostName();  // Returns the hostname if available

        } catch (Exception e) {

            return "Unknown Device";

        }

    }

    // Function to get the MAC address by running the ARP command

    public static String getMacAddress(String host) {

        try {

            // Run the ARP command

            Process p = Runtime.getRuntime().exec("arp -a " + host);

            BufferedReader reader = new BufferedReader(new InputStreamReader(p.getInputStream()));

            String line;

            while ((line = reader.readLine()) != null) {

                if (line.contains(host)) {

                    // Use regex to extract the MAC address

                    String regex = "([0-9A-Fa-f]{2}[:-]){5}([0-9A-Fa-f]{2})";

                    Pattern pattern = Pattern.compile(regex);

                    Matcher matcher = pattern.matcher(line);

                    if (matcher.find()) {

                        return matcher.group(0);

                    }

                }

            }

        } catch (Exception e) {

            e.printStackTrace();

        }

        return "MAC Address not found";

    }

    // Function to get Manufacturer using the macvendors API based on the MAC address

    public static String getManufacturer(String macAddress) {

        if (macAddress.equals("MAC Address not found")) {

            return "Manufacturer not found";

        }

        try {

            // Call macvendors API

            URL url = new URL("https://api.macvendors.com/" + macAddress);

            HttpURLConnection conn = (HttpURLConnection) url.openConnection();

            conn.setRequestMethod("GET");

            BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream()));

            String inputLine;

            StringBuilder response = new StringBuilder();

            // Read the response from the API

            while ((inputLine = in.readLine()) != null) {

                response.append(inputLine);

            }

            in.close();

            // Return the manufacturer name

            return response.toString();

        } catch (Exception e) {

            e.printStackTrace();

        }

        return "Manufacturer not found";

    }

}