/*
    * Copyright 2020-2022 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.driver.windows.perfmon;
   
   import static oshi.driver.windows.perfmon.PerfmonConstants.SYSTEM;
   import static oshi.driver.windows.perfmon.PerfmonConstants.WIN32_PERF_RAW_DATA_PERF_OS_SYSTEM;
   
  import java.util.Collections;
  import java.util.Map;
  
  import oshi.annotation.concurrent.ThreadSafe;
  import oshi.util.platform.windows.PerfCounterQuery;
  import oshi.util.platform.windows.PerfCounterQuery.PdhCounterProperty;
  
  /**
   * Utility to query System performance counters
   */
  @ThreadSafe
  public final class SystemInformation {
  
      /**
       * Context switch property
       */
      public enum ContextSwitchProperty implements PdhCounterProperty {
          CONTEXTSWITCHESPERSEC(null, "Context Switches/sec");
  
          private final String instance;
          private final String counter;
  
          ContextSwitchProperty(String instance, String counter) {
              this.instance = instance;
              this.counter = counter;
          }
  
          @Override
          public String getInstance() {
              return instance;
          }
  
          @Override
          public String getCounter() {
              return counter;
          }
      }
  
      /**
       * Processor Queue Length property
       */
      public enum ProcessorQueueLengthProperty implements PdhCounterProperty {
          PROCESSORQUEUELENGTH(null, "Processor Queue Length");
  
          private final String instance;
          private final String counter;
  
          ProcessorQueueLengthProperty(String instance, String counter) {
              this.instance = instance;
              this.counter = counter;
          }
  
          @Override
          public String getInstance() {
              return instance;
          }
  
          @Override
          public String getCounter() {
              return counter;
          }
      }
  
      private SystemInformation() {
      }
  
      /**
       * Returns system context switch counters.
       *
       * @return Context switches counter for the total of all processors.
       */
      public static Map<ContextSwitchProperty, Long> queryContextSwitchCounters() {
          if (PerfmonDisabled.PERF_OS_DISABLED) {
              return Collections.emptyMap();
          }
          return PerfCounterQuery.queryValues(ContextSwitchProperty.class, SYSTEM, WIN32_PERF_RAW_DATA_PERF_OS_SYSTEM);
      }
  
      /**
       * Returns processor queue length.
       *
       * @return Processor Queue Length.
       */
      public static Map<ProcessorQueueLengthProperty, Long> queryProcessorQueueLength() {
          if (PerfmonDisabled.PERF_OS_DISABLED) {
              return Collections.emptyMap();
          }
          return PerfCounterQuery.queryValues(ProcessorQueueLengthProperty.class, SYSTEM,
                  WIN32_PERF_RAW_DATA_PERF_OS_SYSTEM);
      }
 }