package net.curisit.securis;

import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Retrieve HW info
 * 
 * @author cesarcalvo
 * 
 */
public class HWInfo {

	private static final Logger log = LoggerFactory.getLogger(HWInfo.class);

	public static String getOsName() {
		return System.getProperty("os.name");
	}

	public static String getArch() {
		return System.getProperty("os.arch");
	}

	public static int getNumCpus() {
		return Runtime.getRuntime().availableProcessors();
	}

	/**
	 * Get MAC address
	 * 
	 * @return
	 */
	public static List<String> getMACAddress() throws SeCurisException {
		List<byte[]> macs = new ArrayList<byte[]>();
		try {
			// Get MAC for ethX interface, where X is the lower number with MAC address != null
			for (NetworkInterface network : Collections.list(NetworkInterface.getNetworkInterfaces())) {
				if (!network.isLoopback() && !network.isVirtual() && !network.isPointToPoint() && network.getHardwareAddress() != null) {
					macs.add(network.getHardwareAddress());
					log.debug("Interface added {}, MAC: {}", network.getName(), network.getHardwareAddress());
					logInterface(network);
				}
			}

			// If not found interface ethX
			if (macs.isEmpty()) {
				NetworkInterface network = NetworkInterface.getByInetAddress(InetAddress.getLocalHost());
				if (network.getHardwareAddress() != null)
					macs.add(network.getHardwareAddress());
				log.debug("Selected interface (Inet Address rule)");
				logInterface(network);
			}

			// If not found interface, last attempt, we get any mac
			if (macs.isEmpty()) {
				for (NetworkInterface network : Collections.list(NetworkInterface.getNetworkInterfaces())) {
					if (!network.isLoopback() && !network.isVirtual() && !network.isPointToPoint() && network.getHardwareAddress() != null) {
						if (network.getHardwareAddress() != null)
							macs.add(network.getHardwareAddress());
						log.debug("Selected interface (Any with MAC rule)");
						logInterface(network);
						break;
					}
				}
			}

			if (macs.isEmpty())
				throw new SeCurisException("Unable to get MAC address");

			List<String> macAddresses = new ArrayList<String>();
			for (byte[] mac : macs) {
				macAddresses.add(printMacAddress(mac));
			}
			log.info("MAC Addresses: {}", macAddresses);
			return macAddresses;

		} catch (UnknownHostException e) {
			throw new SeCurisException("Unable to get MAC address", e);
		} catch (SocketException e) {
			throw new SeCurisException("Unable to get MAC address", e);
		} catch (Exception e) {
			throw new SeCurisException("Unable to get MAC address", e);
		}
	}

	/**
	 * Get microprocessor name
	 * 
	 * @return
	 */
	public static String getCPUName() throws SeCurisException {
		return System.getenv("PROCESSOR_IDENTIFIER");
	}

	private static void logInterface(NetworkInterface network) {
		log.debug("Interface name: {}", network.getName());
		log.debug("Interface display name: {}", network.getDisplayName());
		try {
			log.debug("Interface mac: {}", printMacAddress(network.getHardwareAddress()));
		} catch (SocketException e) {
			// Silent
		}
	}

	private static String printMacAddress(byte[] mac) {
		StringBuilder sb = new StringBuilder();
		for (int i = 0; i < mac.length; i++) {
			sb.append(String.format("%s%02X", (i > 0) ? "-" : "", mac[i]));
		}
		return sb.toString();

	}

}