/*
    * Copyright 2021-2022 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.hardware.platform.unix.openbsd;
   
   import static oshi.util.Memoizer.defaultExpiration;
   import static oshi.util.Memoizer.memoize;
   
  import java.util.ArrayList;
  import java.util.List;
  import java.util.function.Supplier;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import oshi.annotation.concurrent.ThreadSafe;
  import oshi.driver.unix.openbsd.disk.Disklabel;
  import oshi.hardware.HWDiskStore;
  import oshi.hardware.HWPartition;
  import oshi.hardware.common.AbstractHWDiskStore;
  import oshi.util.ExecutingCommand;
  import oshi.util.ParseUtil;
  import oshi.util.platform.unix.openbsd.OpenBsdSysctlUtil;
  import oshi.util.tuples.Quartet;
  
  /**
   * OpenBSD hard disk implementation.
   */
  @ThreadSafe
  public final class OpenBsdHWDiskStore extends AbstractHWDiskStore {
  
      private final Supplier<List<String>> iostat = memoize(OpenBsdHWDiskStore::querySystatIostat, defaultExpiration());
  
      private long reads = 0L;
      private long readBytes = 0L;
      private long writes = 0L;
      private long writeBytes = 0L;
      private long currentQueueLength = 0L;
      private long transferTime = 0L;
      private long timeStamp = 0L;
      private List<HWPartition> partitionList;
  
      private OpenBsdHWDiskStore(String name, String model, String serial, long size) {
          super(name, model, serial, size);
      }
  
      /**
       * Gets the disks on this machine.
       *
       * @return a list of {@link HWDiskStore} objects representing the disks
       */
      public static List<HWDiskStore> getDisks() {
          List<HWDiskStore> diskList = new ArrayList<>();
          List<String> dmesg = null; // Lazily fetch in loop if needed
  
          // Get list of disks from sysctl
          // hw.disknames=sd0:2cf69345d371cd82,cd0:,sd1:
          String[] devices = OpenBsdSysctlUtil.sysctl("hw.disknames", "").split(",");
          OpenBsdHWDiskStore store;
          String diskName;
          for (String device : devices) {
              diskName = device.split(":")[0];
              // get partitions using disklabel command (requires root)
              Quartet<String, String, Long, List<HWPartition>> diskdata = Disklabel.getDiskParams(diskName);
              String model = diskdata.getA();
              long size = diskdata.getC();
              if (size <= 1) {
                  if (dmesg == null) {
                      dmesg = ExecutingCommand.runNative("dmesg");
                  }
                  Pattern diskAt = Pattern.compile(diskName + " at .*<(.+)>.*");
                  Pattern diskMB = Pattern
                          .compile(diskName + ":.* (\\d+)MB, (?:(\\d+) bytes\\/sector, )?(?:(\\d+) sectors).*");
                  for (String line : dmesg) {
                      Matcher m = diskAt.matcher(line);
                      if (m.matches()) {
                          model = m.group(1);
                      }
                      m = diskMB.matcher(line);
                      if (m.matches()) {
                          // Group 3 is sectors
                          long sectors = ParseUtil.parseLongOrDefault(m.group(3), 0L);
                          // Group 2 is optional capture of bytes per sector
                          long bytesPerSector = ParseUtil.parseLongOrDefault(m.group(2), 0L);
                          if (bytesPerSector == 0 && sectors > 0) {
                              // if we don't have bytes per sector guess at it based on total size and number
                              // of sectors
                              // Group 1 is size in MB, which may round
                              size = ParseUtil.parseLongOrDefault(m.group(1), 0L) << 20;
                              // Estimate bytes per sector. Should be "near" a power of 2
                              bytesPerSector = size / sectors;
                              // Multiply by 1.5 and round down to nearest power of 2:
                              bytesPerSector = Long.highestOneBit(bytesPerSector + bytesPerSector >> 1);
                          }
                          size = bytesPerSector * sectors;
                          break;
                      }
                  }
              }
             store = new OpenBsdHWDiskStore(diskName, model, diskdata.getB(), size);
             store.partitionList = diskdata.getD();
             store.updateAttributes();
 
             diskList.add(store);
         }
         return diskList;
     }
 
     @Override
     public long getReads() {
         return reads;
     }
 
     @Override
     public long getReadBytes() {
         return readBytes;
     }
 
     @Override
     public long getWrites() {
         return writes;
     }
 
     @Override
     public long getWriteBytes() {
         return writeBytes;
     }
 
     @Override
     public long getCurrentQueueLength() {
         return currentQueueLength;
     }
 
     @Override
     public long getTransferTime() {
         return transferTime;
     }
 
     @Override
     public long getTimeStamp() {
         return timeStamp;
     }
 
     @Override
     public List<HWPartition> getPartitions() {
         return this.partitionList;
     }
 
     @Override
     public boolean updateAttributes() {
         /*-
         └─ $ ▶ systat -b iostat
                 0 users Load 2.04 4.02 3.96                          thinkpad.local 00:14:35
                 DEVICE          READ    WRITE     RTPS    WTPS     SEC            STATS
                 sd0           49937M   25774M  1326555 1695370   945.9
                 cd0                0        0        0       0     0.0
                 sd1          1573888      204       29       0     0.1
                 Totals        49939M   25774M  1326585 1695371   946.0
                                                                                126568 total pages
                                                                                126568 dma pages
                                                                                   100 dirty pages
                                                                                    14 delwri bufs
                                                                                     0 busymap bufs
                                                                                  6553 avail kvaslots
                                                                                  6553 kvaslots
                                                                                     0 pending writes
                                                                                    12 pending reads
                                                                                     0 cache hits
                                                                                     0 high flips
                                                                                     0 high flops
                                                                                     0 dma flips
         */
         long now = System.currentTimeMillis();
         boolean diskFound = false;
         for (String line : iostat.get()) {
             String[] split = ParseUtil.whitespaces.split(line);
             if (split.length < 7 && split[0].equals(getName())) {
                 diskFound = true;
                 this.readBytes = ParseUtil.parseMultipliedToLongs(split[1]);
                 this.writeBytes = ParseUtil.parseMultipliedToLongs(split[2]);
                 this.reads = (long) ParseUtil.parseDoubleOrDefault(split[3], 0d);
                 this.writes = (long) ParseUtil.parseDoubleOrDefault(split[4], 0d);
                 // In seconds, multiply for ms
                 this.transferTime = (long) (ParseUtil.parseDoubleOrDefault(split[5], 0d) * 1000);
                 this.timeStamp = now;
             }
         }
         return diskFound;
     }
 
     private static List<String> querySystatIostat() {
         return ExecutingCommand.runNative("systat -ab iostat");
     }
 }