/*
htop - FreeBSDProcessList.c
(C) 2014 Hisham H. Muhammad
Released under the GNU GPL, see the COPYING file
in the source distribution for its full text.
*/

#include "ProcessList.h"
#include "FreeBSDProcessList.h"
#include "FreeBSDProcess.h"

#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/sysctl.h>
#include <sys/user.h>
#include <err.h>
#include <fcntl.h>
#include <limits.h>
#include <string.h>

/*{

#include <kvm.h>
#include <sys/param.h>
#include <sys/jail.h>
#include <sys/uio.h>
#include <sys/resource.h>

typedef struct CPUData_ {

   double userPercent;
   double nicePercent;
   double systemPercent;
   double irqPercent;
   double idlePercent;
   double systemAllPercent;

} CPUData;

typedef struct FreeBSDProcessList_ {
   ProcessList super;
   kvm_t* kd;

   int zfsArcEnabled;

   unsigned long long int memWire;
   unsigned long long int memActive;
   unsigned long long int memInactive;
   unsigned long long int memFree;
   unsigned long long int memZfsArc;


   CPUData* cpus;

   unsigned long   *cp_time_o;
   unsigned long   *cp_time_n;

   unsigned long  *cp_times_o;
   unsigned long  *cp_times_n;

} FreeBSDProcessList;

}*/


static int MIB_hw_physmem[2];
static int MIB_vm_stats_vm_v_page_count[4];
static int pageSize;
static int pageSizeKb;

static int MIB_vm_stats_vm_v_wire_count[4];
static int MIB_vm_stats_vm_v_active_count[4];
static int MIB_vm_stats_vm_v_cache_count[4];
static int MIB_vm_stats_vm_v_inactive_count[4];
static int MIB_vm_stats_vm_v_free_count[4];

static int MIB_vfs_bufspace[2];

static int MIB_kstat_zfs_misc_arcstats_size[5];

static int MIB_kern_cp_time[2];
static int MIB_kern_cp_times[2];
static int kernelFScale;

ProcessList* ProcessList_new(UsersTable* usersTable, Hashtable* pidWhiteList, uid_t userId) {
   size_t len;
   char errbuf[_POSIX2_LINE_MAX];
   FreeBSDProcessList* fpl = xCalloc(1, sizeof(FreeBSDProcessList));
   ProcessList* pl = (ProcessList*) fpl;
   ProcessList_init(pl, Class(FreeBSDProcess), usersTable, pidWhiteList, userId);

   // physical memory in system: hw.physmem
   // physical page size: hw.pagesize
   // usable pagesize : vm.stats.vm.v_page_size
   len = 2; sysctlnametomib("hw.physmem", MIB_hw_physmem, &len);

   len = sizeof(pageSize);
   if (sysctlbyname("vm.stats.vm.v_page_size", &pageSize, &len, NULL, 0) == -1) {
      pageSize = PAGE_SIZE;
      pageSizeKb = PAGE_SIZE_KB;
   } else {
      pageSizeKb = pageSize / ONE_K;
   }

   // usable page count vm.stats.vm.v_page_count
   // actually usable memory : vm.stats.vm.v_page_count * vm.stats.vm.v_page_size
   len = 4; sysctlnametomib("vm.stats.vm.v_page_count", MIB_vm_stats_vm_v_page_count, &len);

   len = 4; sysctlnametomib("vm.stats.vm.v_wire_count", MIB_vm_stats_vm_v_wire_count, &len);
   len = 4; sysctlnametomib("vm.stats.vm.v_active_count", MIB_vm_stats_vm_v_active_count, &len);
   len = 4; sysctlnametomib("vm.stats.vm.v_cache_count", MIB_vm_stats_vm_v_cache_count, &len);
   len = 4; sysctlnametomib("vm.stats.vm.v_inactive_count", MIB_vm_stats_vm_v_inactive_count, &len);
   len = 4; sysctlnametomib("vm.stats.vm.v_free_count", MIB_vm_stats_vm_v_free_count, &len);

   len = 2; sysctlnametomib("vfs.bufspace", MIB_vfs_bufspace, &len);

   len = sizeof(fpl->memZfsArc);
   if (sysctlbyname("kstat.zfs.misc.arcstats.size", &fpl->memZfsArc, &len,
	    NULL, 0) == 0 && fpl->memZfsArc != 0) {
      sysctlnametomib("kstat.zfs.misc.arcstats.size", MIB_kstat_zfs_misc_arcstats_size, &len);
		  fpl->zfsArcEnabled = 1;
   } else {
		  fpl->zfsArcEnabled = 0;
   }


   int smp = 0;
   len = sizeof(smp);

   if (sysctlbyname("kern.smp.active", &smp, &len, NULL, 0) != 0 || len != sizeof(smp)) {
      smp = 0;
   }

   int cpus = 1;
   len = sizeof(cpus);

   if (smp) {
      int err = sysctlbyname("kern.smp.cpus", &cpus, &len, NULL, 0);
      if (err) cpus = 1;
   } else {
      cpus = 1;
   }

   size_t sizeof_cp_time_array = sizeof(unsigned long) * CPUSTATES;
   len = 2; sysctlnametomib("kern.cp_time", MIB_kern_cp_time, &len);
   fpl->cp_time_o = xCalloc(cpus, sizeof_cp_time_array);
   fpl->cp_time_n = xCalloc(cpus, sizeof_cp_time_array);
   len = sizeof_cp_time_array;

   // fetch initial single (or average) CPU clicks from kernel
   sysctl(MIB_kern_cp_time, 2, fpl->cp_time_o, &len, NULL, 0);

   // on smp box, fetch rest of initial CPU's clicks
   if (cpus > 1) {
      len = 2; sysctlnametomib("kern.cp_times", MIB_kern_cp_times, &len);
      fpl->cp_times_o = xCalloc(cpus, sizeof_cp_time_array);
      fpl->cp_times_n = xCalloc(cpus, sizeof_cp_time_array);
      len = cpus * sizeof_cp_time_array;
      sysctl(MIB_kern_cp_times, 2, fpl->cp_times_o, &len, NULL, 0);
   }

   pl->cpuCount = MAX(cpus, 1);

   if (cpus == 1 ) {
     fpl->cpus = xRealloc(fpl->cpus, sizeof(CPUData));
   } else {
     // on smp we need CPUs + 1 to store averages too (as kernel kindly provides that as well)
     fpl->cpus = xRealloc(fpl->cpus, (pl->cpuCount + 1) * sizeof(CPUData));
   }


   len = sizeof(kernelFScale);
   if (sysctlbyname("kern.fscale", &kernelFScale, &len, NULL, 0) == -1) {
      //sane default for kernel provided CPU percentage scaling, at least on x86 machines, in case this sysctl call failed
      kernelFScale = 2048;
   }

   fpl->kd = kvm_openfiles(NULL, "/dev/null", NULL, 0, errbuf);
   if (fpl->kd == NULL) {
      errx(1, "kvm_open: %s", errbuf);
   }

   return pl;
}

void ProcessList_delete(ProcessList* this) {
   const FreeBSDProcessList* fpl = (FreeBSDProcessList*) this;
   if (fpl->kd) kvm_close(fpl->kd);

   free(fpl->cp_time_o);
   free(fpl->cp_time_n);
   free(fpl->cp_times_o);
   free(fpl->cp_times_n);
   free(fpl->cpus);

   ProcessList_done(this);
   free(this);
}

static inline void FreeBSDProcessList_scanCPUTime(ProcessList* pl) {
   const FreeBSDProcessList* fpl = (FreeBSDProcessList*) pl;

   int cpus   = pl->cpuCount;   // actual CPU count
   int maxcpu = cpus;           // max iteration (in case we have average + smp)
   int cp_times_offset;

   assert(cpus > 0);

   size_t sizeof_cp_time_array;

   unsigned long     *cp_time_n; // old clicks state
   unsigned long     *cp_time_o; // current clicks state

   unsigned long cp_time_d[CPUSTATES];
   double        cp_time_p[CPUSTATES];

   // get averages or single CPU clicks
   sizeof_cp_time_array = sizeof(unsigned long) * CPUSTATES;
   sysctl(MIB_kern_cp_time, 2, fpl->cp_time_n, &sizeof_cp_time_array, NULL, 0);

   // get rest of CPUs
   if (cpus > 1) {
       // on smp systems FreeBSD kernel concats all CPU states into one long array in
       // kern.cp_times sysctl OID
       // we store averages in fpl->cpus[0], and actual cores after that
       maxcpu = cpus + 1;
       sizeof_cp_time_array = cpus * sizeof(unsigned long) * CPUSTATES;
       sysctl(MIB_kern_cp_times, 2, fpl->cp_times_n, &sizeof_cp_time_array, NULL, 0);
   }

   for (int i = 0; i < maxcpu; i++) {
      if (cpus == 1) {
         // single CPU box
         cp_time_n = fpl->cp_time_n;
         cp_time_o = fpl->cp_time_o;
      } else {
         if (i == 0 ) {
           // average
           cp_time_n = fpl->cp_time_n;
           cp_time_o = fpl->cp_time_o;
         } else {
           // specific smp cores
           cp_times_offset = i - 1;
           cp_time_n = fpl->cp_times_n + (cp_times_offset * CPUSTATES);
           cp_time_o = fpl->cp_times_o + (cp_times_offset * CPUSTATES);
         }
      }

      // diff old vs new
      unsigned long long total_o = 0;
      unsigned long long total_n = 0;
      unsigned long long total_d = 0;
      for (int s = 0; s < CPUSTATES; s++) {
        cp_time_d[s] = cp_time_n[s] - cp_time_o[s];
        total_o += cp_time_o[s];
        total_n += cp_time_n[s];
      }

      // totals
      total_d = total_n - total_o;
      if (total_d < 1 ) total_d = 1;

      // save current state as old and calc percentages
      for (int s = 0; s < CPUSTATES; ++s) {
        cp_time_o[s] = cp_time_n[s];
        cp_time_p[s] = ((double)cp_time_d[s]) / ((double)total_d) * 100;
      }

      CPUData* cpuData = &(fpl->cpus[i]);
      cpuData->userPercent      = cp_time_p[CP_USER];
      cpuData->nicePercent      = cp_time_p[CP_NICE];
      cpuData->systemPercent    = cp_time_p[CP_SYS];
      cpuData->irqPercent       = cp_time_p[CP_INTR];
      cpuData->systemAllPercent = cp_time_p[CP_SYS] + cp_time_p[CP_INTR];
      // this one is not really used, but we store it anyway
      cpuData->idlePercent      = cp_time_p[CP_IDLE];
   }
}

static inline void FreeBSDProcessList_scanMemoryInfo(ProcessList* pl) {
   FreeBSDProcessList* fpl = (FreeBSDProcessList*) pl;

   // @etosan:
   // memory counter relationships seem to be these:
   //  total = active + wired + inactive + cache + free
   //  htop_used (unavail to anybody) = active + wired
   //  htop_cache (for cache meter)   = buffers + cache
   //  user_free (avail to procs)     = buffers + inactive + cache + free
   //
   // with ZFS ARC situation becomes bit muddled, as ARC behaves like "user_free"
   // and belongs into cache, but is reported as wired by kernel
   //
   // htop_used   = active + (wired - arc)
   // htop_cache  = buffers + cache + arc
   size_t len = sizeof(pl->totalMem);

   //disabled for now, as it is always smaller than phycal amount of memory...
   //...to avoid "where is my memory?" questions
   //sysctl(MIB_vm_stats_vm_v_page_count, 4, &(pl->totalMem), &len, NULL, 0);
   //pl->totalMem *= pageSizeKb;
   sysctl(MIB_hw_physmem, 2, &(pl->totalMem), &len, NULL, 0);
   pl->totalMem /= 1024;

   sysctl(MIB_vm_stats_vm_v_active_count, 4, &(fpl->memActive), &len, NULL, 0);
   fpl->memActive *= pageSizeKb;

   sysctl(MIB_vm_stats_vm_v_wire_count, 4, &(fpl->memWire), &len, NULL, 0);
   fpl->memWire *= pageSizeKb;

   sysctl(MIB_vfs_bufspace, 2, &(pl->buffersMem), &len, NULL, 0);
   pl->buffersMem /= 1024;

   sysctl(MIB_vm_stats_vm_v_cache_count, 4, &(pl->cachedMem), &len, NULL, 0);
   pl->cachedMem *= pageSizeKb;

   if (fpl->zfsArcEnabled) {
      len = sizeof(fpl->memZfsArc);
      sysctl(MIB_kstat_zfs_misc_arcstats_size, 5, &(fpl->memZfsArc), &len , NULL, 0);
      fpl->memZfsArc /= 1024;
      fpl->memWire -= fpl->memZfsArc;
      pl->cachedMem += fpl->memZfsArc;
      // maybe when we learn how to make custom memory meter
      // we could do custom arc breakdown?
   }

   pl->usedMem = fpl->memActive + fpl->memWire;

   //currently unused, same as with arc, custom meter perhaps
   //sysctl(MIB_vm_stats_vm_v_inactive_count, 4, &(fpl->memInactive), &len, NULL, 0);
   //sysctl(MIB_vm_stats_vm_v_free_count, 4, &(fpl->memFree), &len, NULL, 0);
   //pl->freeMem  = fpl->memInactive + fpl->memFree;
   //pl->freeMem *= pageSizeKb;

   struct kvm_swap swap[16];
   int nswap = kvm_getswapinfo(fpl->kd, swap, sizeof(swap)/sizeof(swap[0]), 0);
   pl->totalSwap = 0;
   pl->usedSwap = 0;
   for (int i = 0; i < nswap; i++) {
      pl->totalSwap += swap[i].ksw_total;
      pl->usedSwap += swap[i].ksw_used;
   }
   pl->totalSwap *= pageSizeKb;
   pl->usedSwap *= pageSizeKb;

   pl->sharedMem = 0;  // currently unused
}

void ProcessList_goThroughEntries(ProcessList* this) {
   FreeBSDProcessList* fpl = (FreeBSDProcessList*) this;

   FreeBSDProcessList_scanMemoryInfo(this);
   FreeBSDProcessList_scanCPUTime(this);

   int count = 0;
   struct kinfo_proc* kprocs = kvm_getprocs(fpl->kd, KERN_PROC_PROC, 0, &count);

   FreeBSDProcessScanData psd;
   psd.pageSizeKb = pageSizeKb;
   psd.kernelFScale = kernelFScale;

   for (int i = 0; i < count; i++) {
      struct kinfo_proc* kproc = &kprocs[i];
      psd.kproc = kproc;
      ProcessList_scanProcess(this, kproc->ki_pid, (ProcessScanData*) &psd);
   }
}