/*
    * Copyright 2019-2023 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.demo;
   
   import java.util.HashMap;
   import java.util.List;
   import java.util.Locale;
  import java.util.Map;
  import java.util.Properties;
  
  import oshi.SystemInfo;
  import oshi.annotation.SuppressForbidden;
  import oshi.hardware.HardwareAbstractionLayer;
  import oshi.hardware.NetworkIF;
  import oshi.util.FileUtil;
  
  /**
   * Uses OSHI to attempt to identify whether the user is on a Virtual Machine
   */
  public class DetectVM {
  
      private static final String OSHI_VM_MAC_ADDR_PROPERTIES = "oshi.vmmacaddr.properties";
      private static final Properties vmMacAddressProps = FileUtil
              .readPropertiesFromFilename(OSHI_VM_MAC_ADDR_PROPERTIES);
  
      // Constant for CPU vendor string
      private static final Map<String, String> vmVendor = new HashMap<>();
      static {
          vmVendor.put("bhyve bhyve", "bhyve");
          vmVendor.put("KVMKVMKVM", "KVM");
          vmVendor.put("TCGTCGTCGTCG", "QEMU");
          vmVendor.put("Microsoft Hv", "Microsoft Hyper-V or Windows Virtual PC");
          vmVendor.put("lrpepyh vr", "Parallels");// (endianness mismatch of "prl hyperv ")
          vmVendor.put("VMwareVMware", "VMware");
          vmVendor.put("XenVMMXenVMM", "Xen HVM");
          vmVendor.put("ACRNACRNACRN", "Project ACRN");
          vmVendor.put("QNXQVMBSQG", "QNX Hypervisor");
      }
  
      private static final String[] vmModelArray = new String[] { "Linux KVM", "Linux lguest", "OpenVZ", "Qemu",
              "Microsoft Virtual PC", "VMWare", "linux-vserver", "Xen", "FreeBSD Jail", "VirtualBox", "Parallels",
              "Linux Containers", "LXC" };
  
      /**
       * The main method, executing the {@link #identifyVM} method.
       *
       * @param args Arguments, ignored.
       */
      @SuppressForbidden(reason = "Using System.out in a demo class")
      public static void main(String[] args) {
          String vmString = identifyVM();
  
          if (vmString.isEmpty()) {
              System.out.println("You do not appear to be on a Virtual Machine.");
          } else {
              System.out.println("You appear to be on a VM: " + vmString);
          }
      }
  
      /**
       * The function attempts to identify which Virtual Machine (VM) based on common VM signatures in MAC address and
       * computer model.
       *
       * @return A string indicating the machine's virtualization info if it can be determined, or an emptry string
       *         otherwise.
       */
      public static String identifyVM() {
          SystemInfo si = new SystemInfo();
          HardwareAbstractionLayer hw = si.getHardware();
          // Check CPU Vendor
          String vendor = hw.getProcessor().getProcessorIdentifier().getVendor().trim();
          if (vmVendor.containsKey(vendor)) {
              return vmVendor.get(vendor);
          }
  
          // Try well known MAC addresses
          List<NetworkIF> nifs = hw.getNetworkIFs();
          for (NetworkIF nif : nifs) {
              String mac = nif.getMacaddr().toUpperCase(Locale.ROOT);
              String oui = mac.length() > 7 ? mac.substring(0, 8) : mac;
              if (vmMacAddressProps.containsKey(oui)) {
                  return vmMacAddressProps.getProperty(oui);
              }
          }
  
          // Try well known models
          String model = hw.getComputerSystem().getModel();
          for (String vm : vmModelArray) {
              if (model.contains(vm)) {
                  return vm;
              }
          }
          String manufacturer = hw.getComputerSystem().getManufacturer();
          if ("Microsoft Corporation".equals(manufacturer) && "Virtual Machine".equals(model)) {
              return "Microsoft Hyper-V";
          }
  
         // Couldn't find VM, return empty string
         return "";
     }
 }