package mac;
import java.io.BufferedReader;
import java.io.File;
import java.io.InputStreamReader;
import java.net.NetworkInterface;
import java.security.MessageDigest;
import java.util.Enumeration;

public class MachineCodeGenerator {

    public static String getMachineCode() throws Exception {
        // ×éºÏ¶à¸öϵͳ±êʶ·û
        StringBuilder sb = new StringBuilder();
        
        // 1. ²Ù×÷ϵͳÃû³ÆºÍ¼Ü¹¹
        sb.append(System.getProperty("os.name"));
        sb.append(System.getProperty("os.arch"));
        
        // 2. »ñÈ¡MACµØÖ·
        sb.append(getMacAddress());
        
        // 3. »ñȡϵͳÌض¨±êʶ·û
        String os = System.getProperty("os.name").toLowerCase();
        if (os.contains("win")) {
            sb.append(getWindowsIdentifier());
        } else if (os.contains("nix") || os.contains("nux") || os.contains("aix")) {
            sb.append(getLinuxIdentifier());
        }
        
        // 4. ʹÓùþÏ£Ëã·¨Éú³É¹Ì¶¨³¤¶ÈµÄ»úÆ÷Âë
        return generateHash(sb.toString());
    }

    private static String getMacAddress() throws Exception {
        Enumeration<NetworkInterface> networkInterfaces = NetworkInterface.getNetworkInterfaces();
        while (networkInterfaces.hasMoreElements()) {
            NetworkInterface network = networkInterfaces.nextElement();
            if (network == null || network.isLoopback() || network.isVirtual() || !network.isUp()) {
                continue;
            }
            
            byte[] mac = network.getHardwareAddress();
            if (mac != null) {
                StringBuilder macAddress = new StringBuilder();
                for (int i = 0; i < mac.length; i++) {
                    macAddress.append(String.format("%02X", mac[i]));
                }
                return macAddress.toString();
            }
        }
        return "NO_MAC";
    }

    private static String getWindowsIdentifier() throws Exception {
        // ³¢ÊÔ»ñÈ¡Ó²ÅÌÐòÁкÅ
        try {
            Process process = Runtime.getRuntime().exec(
                new String[]{"wmic", "diskdrive", "get", "serialnumber"});
            process.waitFor();
            
            BufferedReader reader = new BufferedReader(
                new InputStreamReader(process.getInputStream()));
            
            String line;
            while ((line = reader.readLine()) != null) {
                if (line.trim().length() > 0 && !line.contains("SerialNumber")) {
                    return line.trim();
                }
            }
        } catch (Exception e) {
            // ±¸Ó÷½°¸£º»ñÈ¡Ö÷°åÐòÁкÅ
            try {
                Process process = Runtime.getRuntime().exec(
                    new String[]{"wmic", "baseboard", "get", "serialnumber"});
                process.waitFor();
                
                BufferedReader reader = new BufferedReader(
                    new InputStreamReader(process.getInputStream()));
                
                String line;
                while ((line = reader.readLine()) != null) {
                    if (line.trim().length() > 0 && !line.contains("SerialNumber")) {
                        return line.trim();
                    }
                }
            } catch (Exception ex) {
                // ×îÖÕ±¸ÓãºÊ¹ÓÃÓû§Ãû
                return System.getProperty("user.name");
            }
        }
        return "WIN_ID";
    }

    private static String getLinuxIdentifier() throws Exception {
        // ³¢ÊÔ¶ÁÈ¡»úÆ÷IDÎļþ
        File machineIdFile = new File("/etc/machine-id");
        if (machineIdFile.exists() && machineIdFile.canRead()) {
            java.util.Scanner scanner = new java.util.Scanner(machineIdFile);
            try {
                if (scanner.hasNextLine()) {
                    return scanner.nextLine().trim();
                }
            } finally {
                scanner.close();
            }
        }
        
        // ±¸Ó÷½°¸£º¶ÁÈ¡²úÆ·UUID
        File productUuidFile = new File("/sys/class/dmi/id/product_uuid");
        if (productUuidFile.exists() && productUuidFile.canRead()) {
            java.util.Scanner scanner = new java.util.Scanner(productUuidFile);
            try {
                if (scanner.hasNextLine()) {
                    return scanner.nextLine().trim();
                }
            } finally {
                scanner.close();
            }
        }
        
        // ×îÖÕ±¸ÓãºÊ¹ÓÃÖ÷»úÃû
        return java.net.InetAddress.getLocalHost().getHostName();
    }

    private static String generateHash(String input) throws Exception {
        MessageDigest md = MessageDigest.getInstance("SHA-256");
        byte[] hash = md.digest(input.getBytes("UTF-8"));
        
        // ת»»ÎªÊ®Áù½øÖÆ×Ö·û´®
        StringBuilder hexString = new StringBuilder();
        for (byte b : hash) {
            String hex = Integer.toHexString(0xff & b);
            if (hex.length() == 1) hexString.append('0');
            hexString.append(hex);
        }
        
        // È¡Ç°16¸ö×Ö·û×÷Ϊ»úÆ÷Âë
        return hexString.toString().substring(0, 16).toUpperCase();
    }
}