/*
    * Copyright 2019-2023 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.demo;
   
   import java.util.Arrays;
   import java.util.List;
   import java.util.Locale;
  
  import oshi.SystemInfo;
  import oshi.annotation.SuppressForbidden;
  import oshi.hardware.CentralProcessor;
  import oshi.hardware.ComputerSystem;
  import oshi.hardware.HardwareAbstractionLayer;
  import oshi.software.os.OperatingSystem;
  import oshi.util.Constants;
  
  /**
   * Attempts to create a unique computer identifier. Note that serial numbers won't work on Linux without user
   * cooperation.
   */
  public class ComputerID {
  
      public static final List<String> NON_UNIQUE_UUIDS = Arrays.asList("03000200-0400-0500-0006-000700080009",
              "FFFFFFFF-FFFF-FFFF-FFFF-FFFFFFFFFFFF", "00000000-0000-0000-0000-000000000000");
  
      /**
       * <p>
       * main.
       * </p>
       *
       * @param args an array of {@link java.lang.String} objects.
       */
      @SuppressForbidden(reason = "Using System.out in a demo class")
      public static void main(String[] args) {
          String unknownHash = String.format(Locale.ROOT, "%08x", Constants.UNKNOWN.hashCode());
  
          System.out.println("Here's a unique (?) id for your computer.");
          System.out.println(getComputerIdentifier());
          System.out.println("If any field is " + unknownHash
                  + " then I couldn't find a serial number or unique uuid, and running as sudo might change this.");
      }
  
      /**
       * Generates a Computer Identifier, which may be part of a strategy to construct a licence key. (The identifier may
       * not be unique as in one case hashcode could be same for multiple values, and the result may differ based on
       * whether the program is running with sudo/root permission.) The identifier string is based upon the processor
       * serial number, vendor, system UUID, processor identifier, and total processor count.
       *
       * @return A string containing four hyphen-delimited fields representing the processor; the first 3 are 32-bit
       *         hexadecimal values and the last one is an integer value.
       */
      public static String getComputerIdentifier() {
          SystemInfo systemInfo = new SystemInfo();
          OperatingSystem operatingSystem = systemInfo.getOperatingSystem();
          HardwareAbstractionLayer hardwareAbstractionLayer = systemInfo.getHardware();
          CentralProcessor centralProcessor = hardwareAbstractionLayer.getProcessor();
          ComputerSystem computerSystem = hardwareAbstractionLayer.getComputerSystem();
  
          String vendor = operatingSystem.getManufacturer();
          String processorSerialNumber = computerSystem.getSerialNumber();
          String uuid = computerSystem.getHardwareUUID();
          if (NON_UNIQUE_UUIDS.contains(uuid.toUpperCase(Locale.ROOT))) {
              uuid = Constants.UNKNOWN;
          }
          String processorIdentifier = centralProcessor.getProcessorIdentifier().getIdentifier();
          int processors = centralProcessor.getLogicalProcessorCount();
  
          String delimiter = "-";
  
          return String.format(Locale.ROOT, "%08x", vendor.hashCode()) + delimiter
                  + String.format(Locale.ROOT, "%08x", processorSerialNumber.hashCode()) + delimiter
                  + String.format(Locale.ROOT, "%08x", uuid.hashCode()) + delimiter
                  + String.format(Locale.ROOT, "%08x", processorIdentifier.hashCode()) + delimiter + processors;
      }
  }