/*
    * Copyright 2020-2024 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.driver.linux.proc;
   
   import static oshi.util.platform.linux.ProcPath.CPUINFO;
   
   import java.util.List;
  import java.util.Locale;
  import java.util.stream.Collectors;
  
  import oshi.annotation.concurrent.ThreadSafe;
  import oshi.util.Constants;
  import oshi.util.FileUtil;
  import oshi.util.ParseUtil;
  import oshi.util.tuples.Quartet;
  
  /**
   * Utility to read CPU info from {@code /proc/cpuinfo}
   */
  @ThreadSafe
  public final class CpuInfo {
  
      private CpuInfo() {
      }
  
      /**
       * Gets the CPU manufacturer from {@code /proc/cpuinfo}
       *
       * @return The manufacturer if known, null otherwise
       */
      public static String queryCpuManufacturer() {
          List<String> cpuInfo = FileUtil.readFile(CPUINFO);
          for (String line : cpuInfo) {
              if (line.startsWith("CPU implementer")) {
                  int part = ParseUtil.parseLastInt(line, 0);
                  switch (part) {
                  case 0x41:
                      return "ARM";
                  case 0x42:
                      return "Broadcom";
                  case 0x43:
                      return "Cavium";
                  case 0x44:
                      return "DEC";
                  case 0x4e:
                      return "Nvidia";
                  case 0x50:
                      return "APM";
                  case 0x51:
                      return "Qualcomm";
                  case 0x53:
                      return "Samsung";
                  case 0x56:
                      return "Marvell";
                  case 0x66:
                      return "Faraday";
                  case 0x69:
                      return "Intel";
                  default:
                      return null;
                  }
              }
          }
          return null;
      }
  
      /**
       * Gets the board manufacturer, model, version, and serial number from {@code /proc/cpuinfo}
       *
       * @return A quartet of strings for manufacturer, model, version, and serial number. Each one may be null if
       *         unknown.
       */
      public static Quartet<String, String, String, String> queryBoardInfo() {
          String pcManufacturer = null;
          String pcModel = null;
          String pcVersion = null;
          String pcSerialNumber = null;
  
          List<String> cpuInfo = FileUtil.readFile(CPUINFO);
          for (String line : cpuInfo) {
              String[] splitLine = ParseUtil.whitespacesColonWhitespace.split(line);
              if (splitLine.length < 2) {
                  continue;
              }
              switch (splitLine[0]) {
              case "Hardware":
                  pcModel = splitLine[1];
                  break;
              case "Revision":
                  pcVersion = splitLine[1];
                  if (pcVersion.length() > 1) {
                      pcManufacturer = queryBoardManufacturer(pcVersion.charAt(1));
                  }
                  break;
              case "Serial":
                  pcSerialNumber = splitLine[1];
                  break;
             default:
                 // Do nothing
             }
         }
         return new Quartet<>(pcManufacturer, pcModel, pcVersion, pcSerialNumber);
     }
 
     private static String queryBoardManufacturer(char digit) {
         switch (digit) {
         case '0':
             return "Sony UK";
         case '1':
             return "Egoman";
         case '2':
             return "Embest";
         case '3':
             return "Sony Japan";
         case '4':
             return "Embest";
         case '5':
             return "Stadium";
         default:
             return Constants.UNKNOWN;
         }
     }
 
     public static List<String> queryFeatureFlags() {
         return FileUtil.readFile(CPUINFO).stream().filter(f -> {
             String s = f.toLowerCase(Locale.ROOT);
             return s.startsWith("flags") || s.startsWith("features");
         }).distinct().collect(Collectors.toList());
     }
 }