/*
    * Copyright 2016-2024 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.hardware.platform.mac;
   
   import static oshi.util.Memoizer.memoize;
   
   import java.nio.charset.StandardCharsets;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Set;
  import java.util.function.Supplier;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.sun.jna.Native;
  import com.sun.jna.platform.mac.IOKit.IOIterator;
  import com.sun.jna.platform.mac.IOKit.IORegistryEntry;
  import com.sun.jna.platform.mac.IOKitUtil;
  import com.sun.jna.platform.mac.SystemB;
  
  import oshi.annotation.concurrent.ThreadSafe;
  import oshi.hardware.CentralProcessor.ProcessorCache.Type;
  import oshi.hardware.common.AbstractCentralProcessor;
  import oshi.jna.ByRef.CloseableIntByReference;
  import oshi.jna.ByRef.CloseablePointerByReference;
  import oshi.jna.Struct.CloseableHostCpuLoadInfo;
  import oshi.util.ExecutingCommand;
  import oshi.util.FormatUtil;
  import oshi.util.ParseUtil;
  import oshi.util.Util;
  import oshi.util.platform.mac.SysctlUtil;
  import oshi.util.tuples.Quartet;
  
  /**
   * A CPU.
   */
  @ThreadSafe
  final class MacCentralProcessor extends AbstractCentralProcessor {
  
      private static final Logger LOG = LoggerFactory.getLogger(MacCentralProcessor.class);
  
      private static final Set<String> ARM_P_CORES = Stream
              .of("apple,firestorm arm,v8", "apple,avalanche arm,v8", "apple,everest arm,v8").collect(Collectors.toSet());
  
      private static final int ARM_CPUTYPE = 0x0100000C;
      private static final int M1_CPUFAMILY = 0x1b588bb3;
      private static final int M2_CPUFAMILY = 0xda33d83d;
      private static final int M3_CPUFAMILY = 0x8765edea;
      private static final long DEFAULT_FREQUENCY = 2_400_000_000L;
      private static final Pattern CPU_N = Pattern.compile("^cpu(\\d+)");
  
      private final Supplier<String> vendor = memoize(MacCentralProcessor::platformExpert);
      private final boolean isArmCpu = isArmCpu();
  
      // Equivalents of hw.cpufrequency on Apple Silicon, defaulting to Rosetta value
      // Will update during initialization
      private long performanceCoreFrequency = DEFAULT_FREQUENCY;
      private long efficiencyCoreFrequency = DEFAULT_FREQUENCY;
  
      @Override
      protected ProcessorIdentifier queryProcessorId() {
          String cpuName = SysctlUtil.sysctl("machdep.cpu.brand_string", "");
          String cpuVendor;
          String cpuStepping;
          String cpuModel;
          String cpuFamily;
          String processorID;
          // Initial M1 chips said "Apple Processor". Later branding includes M1, M1 Pro,
          // M1 Max, M2, etc. So if it starts with Apple it's M-something.
          if (cpuName.startsWith("Apple")) {
              // Processing an M1 chip
              cpuVendor = vendor.get();
              cpuStepping = "0"; // No correlation yet
              cpuModel = "0"; // No correlation yet
              int type;
              int family;
              if (isArmCpu) {
                  type = ARM_CPUTYPE;
                  int mSeries = ParseUtil.getFirstIntValue(cpuName);
                  switch (mSeries) {
                  case 2:
                      family = M2_CPUFAMILY;
                      break;
                  case 3:
                      family = M3_CPUFAMILY;
                      break;
                 default:
                     // Some M1 did not brand as such
                     family = M1_CPUFAMILY;
                 }
             } else {
                 type = SysctlUtil.sysctl("hw.cputype", 0);
                 family = SysctlUtil.sysctl("hw.cpufamily", 0);
             }
             // Translate to output
             cpuFamily = String.format(Locale.ROOT, "0x%08x", family);
             // Processor ID is an intel concept but CPU type + family conveys same info
             processorID = String.format(Locale.ROOT, "%08x%08x", type, family);
         } else {
             // Processing an Intel chip
             cpuVendor = SysctlUtil.sysctl("machdep.cpu.vendor", "");
             int i = SysctlUtil.sysctl("machdep.cpu.stepping", -1);
             cpuStepping = i < 0 ? "" : Integer.toString(i);
             i = SysctlUtil.sysctl("machdep.cpu.model", -1);
             cpuModel = i < 0 ? "" : Integer.toString(i);
             i = SysctlUtil.sysctl("machdep.cpu.family", -1);
             cpuFamily = i < 0 ? "" : Integer.toString(i);
             long processorIdBits = 0L;
             processorIdBits |= SysctlUtil.sysctl("machdep.cpu.signature", 0);
             processorIdBits |= (SysctlUtil.sysctl("machdep.cpu.feature_bits", 0L) & 0xffffffff) << 32;
             processorID = String.format(Locale.ROOT, "%016x", processorIdBits);
         }
         if (isArmCpu) {
             calculateNominalFrequencies();
         }
         long cpuFreq = isArmCpu ? performanceCoreFrequency : SysctlUtil.sysctl("hw.cpufrequency", 0L);
         boolean cpu64bit = SysctlUtil.sysctl("hw.cpu64bit_capable", 0) != 0;
 
         return new ProcessorIdentifier(cpuVendor, cpuName, cpuFamily, cpuModel, cpuStepping, processorID, cpu64bit,
                 cpuFreq);
     }
 
     @Override
     protected Quartet<List<LogicalProcessor>, List<PhysicalProcessor>, List<ProcessorCache>, List<String>> initProcessorCounts() {
         int logicalProcessorCount = SysctlUtil.sysctl("hw.logicalcpu", 1);
         int physicalProcessorCount = SysctlUtil.sysctl("hw.physicalcpu", 1);
         int physicalPackageCount = SysctlUtil.sysctl("hw.packages", 1);
         List<LogicalProcessor> logProcs = new ArrayList<>(logicalProcessorCount);
         Set<Integer> pkgCoreKeys = new HashSet<>();
         for (int i = 0; i < logicalProcessorCount; i++) {
             int coreId = i * physicalProcessorCount / logicalProcessorCount;
             int pkgId = i * physicalPackageCount / logicalProcessorCount;
             logProcs.add(new LogicalProcessor(i, coreId, pkgId));
             pkgCoreKeys.add((pkgId << 16) + coreId);
         }
         Map<Integer, String> compatMap = queryCompatibleStrings();
         int perflevels = SysctlUtil.sysctl("hw.nperflevels", 1);
         List<PhysicalProcessor> physProcs = pkgCoreKeys.stream().sorted().map(k -> {
             String compat = compatMap.getOrDefault(k, "").toLowerCase(Locale.ROOT);
             // This is brittle. A better long term solution is to use sysctls
             // hw.perflevel1.physicalcpu: 2
             // hw.perflevel0.physicalcpu: 8
             // Note the 1 and 0 values are reversed from OSHI API definition
             int efficiency = ARM_P_CORES.contains(compat) ? 1 : 0;
             return new PhysicalProcessor(k >> 16, k & 0xffff, efficiency, compat);
         }).collect(Collectors.toList());
         List<ProcessorCache> caches = orderedProcCaches(getCacheValues(perflevels));
         List<String> featureFlags = getFeatureFlagsFromSysctl();
         return new Quartet<>(logProcs, physProcs, caches, featureFlags);
     }
 
     private Set<ProcessorCache> getCacheValues(int perflevels) {
         int linesize = (int) SysctlUtil.sysctl("hw.cachelinesize", 0L);
         int l1associativity = SysctlUtil.sysctl("machdep.cpu.cache.L1_associativity", 0, false);
         int l2associativity = SysctlUtil.sysctl("machdep.cpu.cache.L2_associativity", 0, false);
         Set<ProcessorCache> caches = new HashSet<>();
         for (int i = 0; i < perflevels; i++) {
             int size = SysctlUtil.sysctl("hw.perflevel" + i + ".l1icachesize", 0, false);
             if (size > 0) {
                 caches.add(new ProcessorCache(1, l1associativity, linesize, size, Type.INSTRUCTION));
             }
             size = SysctlUtil.sysctl("hw.perflevel" + i + ".l1dcachesize", 0, false);
             if (size > 0) {
                 caches.add(new ProcessorCache(1, l1associativity, linesize, size, Type.DATA));
             }
             size = SysctlUtil.sysctl("hw.perflevel" + i + ".l2cachesize", 0, false);
             if (size > 0) {
                 caches.add(new ProcessorCache(2, l2associativity, linesize, size, Type.UNIFIED));
             }
             size = SysctlUtil.sysctl("hw.perflevel" + i + ".l3cachesize", 0, false);
             if (size > 0) {
                 caches.add(new ProcessorCache(3, 0, linesize, size, Type.UNIFIED));
             }
         }
         return caches;
     }
 
     private List<String> getFeatureFlagsFromSysctl() {
         List<String> x86Features = Arrays.asList("features", "extfeatures", "leaf7_features").stream().map(f -> {
             String key = "machdep.cpu." + f;
             String features = SysctlUtil.sysctl(key, "", false);
             return Util.isBlank(features) ? null : (key + ": " + features);
         }).filter(Objects::nonNull).collect(Collectors.toList());
         return x86Features.isEmpty() ? ExecutingCommand.runNative("sysctl -a hw.optional") : x86Features;
     }
 
     @Override
     public long[] querySystemCpuLoadTicks() {
         long[] ticks = new long[TickType.values().length];
         int machPort = SystemB.INSTANCE.mach_host_self();
         try (CloseableHostCpuLoadInfo cpuLoadInfo = new CloseableHostCpuLoadInfo();
                 CloseableIntByReference size = new CloseableIntByReference(cpuLoadInfo.size())) {
             if (0 != SystemB.INSTANCE.host_statistics(machPort, SystemB.HOST_CPU_LOAD_INFO, cpuLoadInfo, size)) {
                 LOG.error("Failed to get System CPU ticks. Error code: {} ", Native.getLastError());
                 return ticks;
             }
 
             ticks[TickType.USER.getIndex()] = cpuLoadInfo.cpu_ticks[SystemB.CPU_STATE_USER];
             ticks[TickType.NICE.getIndex()] = cpuLoadInfo.cpu_ticks[SystemB.CPU_STATE_NICE];
             ticks[TickType.SYSTEM.getIndex()] = cpuLoadInfo.cpu_ticks[SystemB.CPU_STATE_SYSTEM];
             ticks[TickType.IDLE.getIndex()] = cpuLoadInfo.cpu_ticks[SystemB.CPU_STATE_IDLE];
         }
         // Leave IOWait and IRQ values as 0
         return ticks;
     }
 
     @Override
     public long[] queryCurrentFreq() {
         if (isArmCpu) {
             Map<Integer, Long> physFreqMap = new HashMap<>();
             getPhysicalProcessors().stream().forEach(p -> physFreqMap.put(p.getPhysicalProcessorNumber(),
                     p.getEfficiency() > 0 ? performanceCoreFrequency : efficiencyCoreFrequency));
             return getLogicalProcessors().stream().map(LogicalProcessor::getPhysicalProcessorNumber)
                     .map(p -> physFreqMap.getOrDefault(p, performanceCoreFrequency)).mapToLong(f -> f).toArray();
         }
         return new long[] { getProcessorIdentifier().getVendorFreq() };
     }
 
     @Override
     public long queryMaxFreq() {
         if (isArmCpu) {
             return performanceCoreFrequency;
         }
         return SysctlUtil.sysctl("hw.cpufrequency_max", getProcessorIdentifier().getVendorFreq());
     }
 
     @Override
     public double[] getSystemLoadAverage(int nelem) {
         if (nelem < 1 || nelem > 3) {
             throw new IllegalArgumentException("Must include from one to three elements.");
         }
         double[] average = new double[nelem];
         int retval = SystemB.INSTANCE.getloadavg(average, nelem);
         if (retval < nelem) {
             Arrays.fill(average, -1d);
         }
         return average;
     }
 
     @Override
     public long[][] queryProcessorCpuLoadTicks() {
         long[][] ticks = new long[getLogicalProcessorCount()][TickType.values().length];
 
         int machPort = SystemB.INSTANCE.mach_host_self();
         try (CloseableIntByReference procCount = new CloseableIntByReference();
                 CloseablePointerByReference procCpuLoadInfo = new CloseablePointerByReference();
                 CloseableIntByReference procInfoCount = new CloseableIntByReference()) {
             if (0 != SystemB.INSTANCE.host_processor_info(machPort, SystemB.PROCESSOR_CPU_LOAD_INFO, procCount,
                     procCpuLoadInfo, procInfoCount)) {
                 LOG.error("Failed to update CPU Load. Error code: {}", Native.getLastError());
                 return ticks;
             }
 
             int[] cpuTicks = procCpuLoadInfo.getValue().getIntArray(0, procInfoCount.getValue());
             for (int cpu = 0; cpu < procCount.getValue(); cpu++) {
                 int offset = cpu * SystemB.CPU_STATE_MAX;
                 ticks[cpu][TickType.USER.getIndex()] = FormatUtil
                         .getUnsignedInt(cpuTicks[offset + SystemB.CPU_STATE_USER]);
                 ticks[cpu][TickType.NICE.getIndex()] = FormatUtil
                         .getUnsignedInt(cpuTicks[offset + SystemB.CPU_STATE_NICE]);
                 ticks[cpu][TickType.SYSTEM.getIndex()] = FormatUtil
                         .getUnsignedInt(cpuTicks[offset + SystemB.CPU_STATE_SYSTEM]);
                 ticks[cpu][TickType.IDLE.getIndex()] = FormatUtil
                         .getUnsignedInt(cpuTicks[offset + SystemB.CPU_STATE_IDLE]);
             }
         }
         return ticks;
     }
 
     @Override
     public long queryContextSwitches() {
         // Not available on macOS since at least 10.3.9. Early versions may have
         // provided access to the vmmeter structure using sysctl [CTL_VM, VM_METER] but
         // it now fails (ENOENT) and there is no other reference to it in source code
         return 0L;
     }
 
     @Override
     public long queryInterrupts() {
         // Not available on macOS since at least 10.3.9. Early versions may have
         // provided access to the vmmeter structure using sysctl [CTL_VM, VM_METER] but
         // it now fails (ENOENT) and there is no other reference to it in source code
         return 0L;
     }
 
     private static String platformExpert() {
         String manufacturer = null;
         IORegistryEntry platformExpert = IOKitUtil.getMatchingService("IOPlatformExpertDevice");
         if (platformExpert != null) {
             // Get manufacturer from IOPlatformExpertDevice
             byte[] data = platformExpert.getByteArrayProperty("manufacturer");
             if (data != null) {
                 manufacturer = Native.toString(data, StandardCharsets.UTF_8);
             }
             platformExpert.release();
         }
         return Util.isBlank(manufacturer) ? "Apple Inc." : manufacturer;
     }
 
     // Called by initProcessorCount in the constructor
     // These populate the physical processor id strings
     private static Map<Integer, String> queryCompatibleStrings() {
         Map<Integer, String> compatibleStrMap = new HashMap<>();
         // All CPUs are an IOPlatformDevice
         // Iterate each CPU and save frequency and "compatible" strings
         IOIterator iter = IOKitUtil.getMatchingServices("IOPlatformDevice");
         if (iter != null) {
             IORegistryEntry cpu = iter.next();
             while (cpu != null) {
                 Matcher m = CPU_N.matcher(cpu.getName().toLowerCase(Locale.ROOT));
                 if (m.matches()) {
                     int procId = ParseUtil.parseIntOrDefault(m.group(1), 0);
                     // Compatible key is null-delimited C string array in byte array
                     byte[] data = cpu.getByteArrayProperty("compatible");
                     if (data != null) {
                         // Byte array is null delimited
                         // Example value for M2: "apple,blizzard", "ARM,v8"
                         compatibleStrMap.put(procId,
                                 new String(data, StandardCharsets.UTF_8).replace('\0', ' ').trim());
                     }
                 }
                 cpu.release();
                 cpu = iter.next();
             }
             iter.release();
         }
         return compatibleStrMap;
     }
 
     // Called when initiating instance variables which occurs after constructor has
     // populated physical processors
     private boolean isArmCpu() {
         return getPhysicalProcessors().stream().map(PhysicalProcessor::getIdString).anyMatch(id -> id.contains("arm"));
     }
 
     private void calculateNominalFrequencies() {
         IOIterator iter = IOKitUtil.getMatchingServices("AppleARMIODevice");
         if (iter != null) {
             try {
                 IORegistryEntry device = iter.next();
                 try {
                     while (device != null) {
                         if (device.getName().equalsIgnoreCase("pmgr")) {
                             performanceCoreFrequency = getMaxFreqFromByteArray(
                                     device.getByteArrayProperty("voltage-states5-sram"));
                             efficiencyCoreFrequency = getMaxFreqFromByteArray(
                                     device.getByteArrayProperty("voltage-states1-sram"));
                             return;
                         }
                         device.release();
                         device = iter.next();
                     }
                 } finally {
                     if (device != null) {
                         device.release();
                     }
                 }
             } finally {
                 iter.release();
             }
         }
     }
 
     private long getMaxFreqFromByteArray(byte[] data) {
         // Max freq is 8 bytes from the end of the array
         if (data != null && data.length >= 8) {
             byte[] freqData = Arrays.copyOfRange(data, data.length - 8, data.length - 4);
             return ParseUtil.byteArrayToLong(freqData, 4, false);
         }
         return DEFAULT_FREQUENCY;
     }
 }