/*
htop - NetBSDProcessList.c
(C) 2014 Hisham H. Muhammad
(C) 2015 Michael McConville
(C) 2021 Santhosh Raju
(C) 2021 htop dev team
Released under the GNU GPLv2, see the COPYING file
in the source distribution for its full text.
*/

#include "netbsd/NetBSDProcessList.h"

#include <kvm.h>
#include <math.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mount.h>
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/swap.h>
#include <sys/sysctl.h>
#include <sys/types.h>
#include <uvm/uvm_extern.h>

#include "CRT.h"
#include "Macros.h"
#include "Object.h"
#include "Process.h"
#include "ProcessList.h"
#include "Settings.h"
#include "XUtils.h"
#include "netbsd/NetBSDProcess.h"


static long fscale;
static int pageSize;
static int pageSizeKB;

static const struct {
   const char* name;
   long int scale;
} freqSysctls[] = {
   { "machdep.est.frequency.current",            1 },
   { "machdep.powernow.frequency.current",       1 },
   { "machdep.intrepid.frequency.current",       1 },
   { "machdep.loongson.frequency.current",       1 },
   { "machdep.cpu.frequency.current",            1 },
   { "machdep.frequency.current",                1 },
   { "machdep.tsc_freq",                   1000000 },
};

static void NetBSDProcessList_updateCPUcount(ProcessList* super) {
   NetBSDProcessList* opl = (NetBSDProcessList*) super;

   // Definitions for sysctl(3), cf. https://nxr.netbsd.org/xref/src/sys/sys/sysctl.h#813
   const int mib_ncpu_existing[] = { CTL_HW, HW_NCPU }; // Number of existing CPUs
   const int mib_ncpu_online[] = { CTL_HW, HW_NCPUONLINE }; // Number of online/active CPUs

   int r;
   unsigned int value;
   size_t size;

   bool change = false;

   // Query the number of active/online CPUs.
   size = sizeof(value);
   r = sysctl(mib_ncpu_online, 2, &value, &size, NULL, 0);
   if (r < 0 || value < 1) {
      value = 1;
   }

   if (value != super->activeCPUs) {
      super->activeCPUs = value;
      change = true;
   }

   // Query the total number of CPUs.
   size = sizeof(value);
   r = sysctl(mib_ncpu_existing, 2, &value, &size, NULL, 0);
   if (r < 0 || value < 1) {
      value = super->activeCPUs;
   }

   if (value != super->existingCPUs) {
      opl->cpuData = xReallocArray(opl->cpuData, value + 1, sizeof(CPUData));
      super->existingCPUs = value;
      change = true;
   }

   // Reset CPU stats when number of online/existing CPU cores changed
   if (change) {
      CPUData* dAvg = &opl->cpuData[0];
      memset(dAvg, '\0', sizeof(CPUData));
      dAvg->totalTime = 1;
      dAvg->totalPeriod = 1;

      for (unsigned int i = 0; i < super->existingCPUs; i++) {
         CPUData* d = &opl->cpuData[i + 1];
         memset(d, '\0', sizeof(CPUData));
         d->totalTime = 1;
         d->totalPeriod = 1;
      }
   }
}

ProcessList* ProcessList_new(UsersTable* usersTable, Hashtable* dynamicMeters, Hashtable* dynamicColumns, Hashtable* pidMatchList, uid_t userId) {
   const int fmib[] = { CTL_KERN, KERN_FSCALE };
   size_t size;
   char errbuf[_POSIX2_LINE_MAX];

   NetBSDProcessList* npl = xCalloc(1, sizeof(NetBSDProcessList));
   ProcessList* pl = (ProcessList*) npl;
   ProcessList_init(pl, Class(NetBSDProcess), usersTable, dynamicMeters, dynamicColumns, pidMatchList, userId);

   NetBSDProcessList_updateCPUcount(pl);

   size = sizeof(fscale);
   if (sysctl(fmib, 2, &fscale, &size, NULL, 0) < 0) {
      CRT_fatalError("fscale sysctl call failed");
   }

   if ((pageSize = sysconf(_SC_PAGESIZE)) == -1)
      CRT_fatalError("pagesize sysconf call failed");
   pageSizeKB = pageSize / ONE_K;

   npl->kd = kvm_openfiles(NULL, NULL, NULL, KVM_NO_FILES, errbuf);
   if (npl->kd == NULL) {
      CRT_fatalError("kvm_openfiles() failed");
   }

   return pl;
}

void ProcessList_delete(ProcessList* this) {
   NetBSDProcessList* npl = (NetBSDProcessList*) this;

   if (npl->kd) {
      kvm_close(npl->kd);
   }

   free(npl->cpuData);

   ProcessList_done(this);
   free(this);
}

static void NetBSDProcessList_scanMemoryInfo(ProcessList* pl) {
   static int uvmexp_mib[] = {CTL_VM, VM_UVMEXP2};
   struct uvmexp_sysctl uvmexp;
   size_t size_uvmexp = sizeof(uvmexp);

   if (sysctl(uvmexp_mib, 2, &uvmexp, &size_uvmexp, NULL, 0) < 0) {
      CRT_fatalError("uvmexp sysctl call failed");
   }

   pl->totalMem = uvmexp.npages * pageSizeKB;
   pl->buffersMem = 0;
   pl->cachedMem = (uvmexp.filepages + uvmexp.execpages) * pageSizeKB;
   pl->usedMem = (uvmexp.active + uvmexp.wired) * pageSizeKB;
   pl->totalSwap = uvmexp.swpages * pageSizeKB;
   pl->usedSwap = uvmexp.swpginuse * pageSizeKB;
}

static void NetBSDProcessList_updateExe(const struct kinfo_proc2* kproc, Process* proc) {
   const int mib[] = { CTL_KERN, KERN_PROC_ARGS, kproc->p_pid, KERN_PROC_PATHNAME };
   char buffer[2048];
   size_t size = sizeof(buffer);
   if (sysctl(mib, 4, buffer, &size, NULL, 0) != 0) {
      Process_updateExe(proc, NULL);
      return;
   }

   /* Kernel threads return an empty buffer */
   if (buffer[0] == '\0') {
      Process_updateExe(proc, NULL);
      return;
   }

   Process_updateExe(proc, buffer);
}

static void NetBSDProcessList_updateCwd(const struct kinfo_proc2* kproc, Process* proc) {
   const int mib[] = { CTL_KERN, KERN_PROC_ARGS, kproc->p_pid, KERN_PROC_CWD };
   char buffer[2048];
   size_t size = sizeof(buffer);
   if (sysctl(mib, 4, buffer, &size, NULL, 0) != 0) {
      free(proc->procCwd);
      proc->procCwd = NULL;
      return;
   }

   /* Kernel threads return an empty buffer */
   if (buffer[0] == '\0') {
      free(proc->procCwd);
      proc->procCwd = NULL;
      return;
   }

   free_and_xStrdup(&proc->procCwd, buffer);
}

static void NetBSDProcessList_updateProcessName(kvm_t* kd, const struct kinfo_proc2* kproc, Process* proc) {
   Process_updateComm(proc, kproc->p_comm);

   /*
    * Like NetBSD's top(1), we try to fall back to the command name
    * (argv[0]) if we fail to construct the full command.
    */
   char** arg = kvm_getargv2(kd, kproc, 500);
   if (arg == NULL || *arg == NULL) {
      Process_updateCmdline(proc, kproc->p_comm, 0, strlen(kproc->p_comm));
      return;
   }

   size_t len = 0;
   for (int i = 0; arg[i] != NULL; i++) {
      len += strlen(arg[i]) + 1;   /* room for arg and trailing space or NUL */
   }

   /* don't use xMalloc here - we want to handle huge argv's gracefully */
   char* s;
   if ((s = malloc(len)) == NULL) {
      Process_updateCmdline(proc, kproc->p_comm, 0, strlen(kproc->p_comm));
      return;
   }

   *s = '\0';

   int start = 0;
   int end = 0;
   for (int i = 0; arg[i] != NULL; i++) {
      size_t n = strlcat(s, arg[i], len);
      if (i == 0) {
         end = MINIMUM(n, len - 1);
         /* check if cmdline ended earlier, e.g 'kdeinit5: Running...' */
         for (int j = end; j > 0; j--) {
            if (arg[0][j] == ' ' && arg[0][j - 1] != '\\') {
               end = (arg[0][j - 1] == ':') ? (j - 1) : j;
            }
         }
      }
      /* the trailing space should get truncated anyway */
      strlcat(s, " ", len);
   }

   Process_updateCmdline(proc, s, start, end);
}

/*
 * Borrowed with modifications from NetBSD's top(1).
 */
static double getpcpu(const struct kinfo_proc2* kp) {
   if (fscale == 0)
      return 0.0;

   return 100.0 * (double)kp->p_pctcpu / fscale;
}

static void NetBSDProcessList_scanProcs(NetBSDProcessList* this) {
   const Settings* settings = this->super.settings;
   bool hideKernelThreads = settings->hideKernelThreads;
   bool hideUserlandThreads = settings->hideUserlandThreads;
   int count = 0;

   const struct kinfo_proc2* kprocs = kvm_getproc2(this->kd, KERN_PROC_ALL, 0, sizeof(struct kinfo_proc2), &count);

   for (int i = 0; i < count; i++) {
      const struct kinfo_proc2* kproc = &kprocs[i];

      bool preExisting = false;
      Process* proc = ProcessList_getProcess(&this->super, kproc->p_pid, &preExisting, NetBSDProcess_new);

      proc->show = ! ((hideKernelThreads && Process_isKernelThread(proc)) || (hideUserlandThreads && Process_isUserlandThread(proc)));

      if (!preExisting) {
         proc->pid = kproc->p_pid;
         proc->ppid = kproc->p_ppid;
         proc->tpgid = kproc->p_tpgid;
         proc->tgid = kproc->p_pid;
         proc->session = kproc->p_sid;
         proc->pgrp = kproc->p__pgid;
         proc->isKernelThread = !!(kproc->p_flag & P_SYSTEM);
         proc->isUserlandThread = proc->pid != proc->tgid;
         proc->starttime_ctime = kproc->p_ustart_sec;
         Process_fillStarttimeBuffer(proc);
         ProcessList_add(&this->super, proc);

         proc->tty_nr = kproc->p_tdev;
         const char* name = ((dev_t)kproc->p_tdev != KERN_PROC_TTY_NODEV) ? devname(kproc->p_tdev, S_IFCHR) : NULL;
         if (!name) {
            free(proc->tty_name);
            proc->tty_name = NULL;
         } else {
            free_and_xStrdup(&proc->tty_name, name);
         }

         NetBSDProcessList_updateExe(kproc, proc);
         NetBSDProcessList_updateProcessName(this->kd, kproc, proc);
      } else {
         if (settings->updateProcessNames) {
            NetBSDProcessList_updateProcessName(this->kd, kproc, proc);
         }
      }

      if (settings->flags & PROCESS_FLAG_CWD) {
         NetBSDProcessList_updateCwd(kproc, proc);
      }

      if (proc->st_uid != kproc->p_uid) {
         proc->st_uid = kproc->p_uid;
         proc->user = UsersTable_getRef(this->super.usersTable, proc->st_uid);
      }

      proc->m_virt = kproc->p_vm_vsize;
      proc->m_resident = kproc->p_vm_rssize;
      proc->percent_mem = (proc->m_resident * pageSizeKB) / (double)(this->super.totalMem) * 100.0;
      proc->percent_cpu = CLAMP(getpcpu(kproc), 0.0, this->super.activeCPUs * 100.0);
      proc->nlwp = kproc->p_nlwps;
      proc->nice = kproc->p_nice - 20;
      proc->time = 100 * (kproc->p_rtime_sec + ((kproc->p_rtime_usec + 500000) / 1000000));
      proc->priority = kproc->p_priority - PZERO;
      proc->processor = kproc->p_cpuid;
      proc->minflt = kproc->p_uru_minflt;
      proc->majflt = kproc->p_uru_majflt;

      int nlwps = 0;
      const struct kinfo_lwp* klwps = kvm_getlwps(this->kd, kproc->p_pid, kproc->p_paddr, sizeof(struct kinfo_lwp), &nlwps);

      switch (kproc->p_realstat) {
      case SIDL:     proc->state = 'I'; break;
      case SACTIVE:
         // We only consider the first LWP with a one of the below states.
         for (int j = 0; j < nlwps; j++) {
            if (klwps) {
               switch (klwps[j].l_stat) {
               case LSONPROC: proc->state = 'P'; break;
               case LSRUN:    proc->state = 'R'; break;
               case LSSLEEP:  proc->state = 'S'; break;
               case LSSTOP:   proc->state = 'T'; break;
               default:       proc->state = '?';
               }
               if (proc->state != '?')
                  break;
            } else {
               proc->state = '?';
               break;
            }
         }
         break;
      case SSTOP:    proc->state = 'T'; break;
      case SZOMB:    proc->state = 'Z'; break;
      case SDEAD:    proc->state = 'D'; break;
      default:       proc->state = '?';
      }

      if (Process_isKernelThread(proc)) {
         this->super.kernelThreads++;
      } else if (Process_isUserlandThread(proc)) {
         this->super.userlandThreads++;
      }

      this->super.totalTasks++;
      // SRUN ('R') means runnable, not running
      if (proc->state == 'P') {
         this->super.runningTasks++;
      }
      proc->updated = true;
   }
}

static void getKernelCPUTimes(int cpuId, u_int64_t* times) {
   const int mib[] = { CTL_KERN, KERN_CP_TIME, cpuId };
   size_t length = sizeof(*times) * CPUSTATES;
   if (sysctl(mib, 3, times, &length, NULL, 0) == -1 || length != sizeof(*times) * CPUSTATES) {
      CRT_fatalError("sysctl kern.cp_time2 failed");
   }
}

static void kernelCPUTimesToHtop(const u_int64_t* times, CPUData* cpu) {
   unsigned long long totalTime = 0;
   for (int i = 0; i < CPUSTATES; i++) {
      totalTime += times[i];
   }

   unsigned long long sysAllTime = times[CP_INTR] + times[CP_SYS];

   cpu->totalPeriod = saturatingSub(totalTime, cpu->totalTime);
   cpu->userPeriod = saturatingSub(times[CP_USER], cpu->userTime);
   cpu->nicePeriod = saturatingSub(times[CP_NICE], cpu->niceTime);
   cpu->sysPeriod = saturatingSub(times[CP_SYS], cpu->sysTime);
   cpu->sysAllPeriod = saturatingSub(sysAllTime, cpu->sysAllTime);
   cpu->intrPeriod = saturatingSub(times[CP_INTR], cpu->intrTime);
   cpu->idlePeriod = saturatingSub(times[CP_IDLE], cpu->idleTime);

   cpu->totalTime = totalTime;
   cpu->userTime = times[CP_USER];
   cpu->niceTime = times[CP_NICE];
   cpu->sysTime = times[CP_SYS];
   cpu->sysAllTime = sysAllTime;
   cpu->intrTime = times[CP_INTR];
   cpu->idleTime = times[CP_IDLE];
}

static void NetBSDProcessList_scanCPUTime(NetBSDProcessList* this) {
   u_int64_t kernelTimes[CPUSTATES] = {0};
   u_int64_t avg[CPUSTATES] = {0};

   for (unsigned int i = 0; i < this->super.existingCPUs; i++) {
      getKernelCPUTimes(i, kernelTimes);
      CPUData* cpu = &this->cpuData[i + 1];
      kernelCPUTimesToHtop(kernelTimes, cpu);

      avg[CP_USER] += cpu->userTime;
      avg[CP_NICE] += cpu->niceTime;
      avg[CP_SYS] += cpu->sysTime;
      avg[CP_INTR] += cpu->intrTime;
      avg[CP_IDLE] += cpu->idleTime;
   }

   for (int i = 0; i < CPUSTATES; i++) {
      avg[i] /= this->super.activeCPUs;
   }

   kernelCPUTimesToHtop(avg, &this->cpuData[0]);
}

static void NetBSDProcessList_scanCPUFrequency(NetBSDProcessList* this) {
   unsigned int cpus = this->super.existingCPUs;
   bool match = false;
   char name[64];
   long int freq = 0;
   size_t freqSize;

   for (unsigned int i = 0; i < cpus; i++) {
      this->cpuData[i + 1].frequency = NAN;
   }

   /* newer hardware supports per-core frequency, for e.g. ARM big.LITTLE */
   for (unsigned int i = 0; i < cpus; i++) {
      xSnprintf(name, sizeof(name), "machdep.cpufreq.cpu%u.current", i);
      freqSize = sizeof(freq);
      if (sysctlbyname(name, &freq, &freqSize, NULL, 0) != -1) {
         this->cpuData[i + 1].frequency = freq; /* already in MHz */
         match = true;
      }
   }

   if (match) {
      return;
   }

   /*
    * Iterate through legacy sysctl nodes for single-core frequency until
    * we find a match...
    */
   for (size_t i = 0; i < ARRAYSIZE(freqSysctls); i++) {
      freqSize = sizeof(freq);
      if (sysctlbyname(freqSysctls[i].name, &freq, &freqSize, NULL, 0) != -1) {
         freq /= freqSysctls[i].scale; /* scale to MHz */
         match = true;
         break;
      }
   }

   if (match) {
      for (unsigned int i = 0; i < cpus; i++) {
         this->cpuData[i + 1].frequency = freq;
      }
   }
}

void ProcessList_goThroughEntries(ProcessList* super, bool pauseProcessUpdate) {
   NetBSDProcessList* npl = (NetBSDProcessList*) super;

   NetBSDProcessList_scanMemoryInfo(super);
   NetBSDProcessList_scanCPUTime(npl);

   if (super->settings->showCPUFrequency) {
      NetBSDProcessList_scanCPUFrequency(npl);
   }

   // in pause mode only gather global data for meters (CPU/memory/...)
   if (pauseProcessUpdate) {
      return;
   }

   NetBSDProcessList_scanProcs(npl);
}

bool ProcessList_isCPUonline(const ProcessList* super, unsigned int id) {
   assert(id < super->existingCPUs);

   // TODO: Support detecting online / offline CPUs.
   return true;
}