/*
htop - DarwinProcess.c
(C) 2015 Hisham H. Muhammad
Released under the GNU GPLv2+, see the COPYING file
in the source distribution for its full text.
*/

#include "darwin/DarwinProcess.h"

#include <libproc.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <mach/mach.h>

#include "CRT.h"
#include "Process.h"
#include "darwin/Platform.h"


const ProcessFieldData Process_fields[LAST_PROCESSFIELD] = {
   [0] = { .name = "", .title = NULL, .description = NULL, .flags = 0, },
   [PID] = { .name = "PID", .title = "PID", .description = "Process/thread ID", .flags = 0, .pidColumn = true, },
   [COMM] = { .name = "Command", .title = "Command ", .description = "Command line", .flags = 0, },
   [STATE] = { .name = "STATE", .title = "S ", .description = "Process state (S sleeping, R running, D disk, Z zombie, T traced, W paging)", .flags = 0, },
   [PPID] = { .name = "PPID", .title = "PPID", .description = "Parent process ID", .flags = 0, .pidColumn = true, },
   [PGRP] = { .name = "PGRP", .title = "PGRP", .description = "Process group ID", .flags = 0, .pidColumn = true, },
   [SESSION] = { .name = "SESSION", .title = "SID", .description = "Process's session ID", .flags = 0, .pidColumn = true, },
   [TTY] = { .name = "TTY", .title = "TTY      ", .description = "Controlling terminal", .flags = 0, },
   [TPGID] = { .name = "TPGID", .title = "TPGID", .description = "Process ID of the fg process group of the controlling terminal", .flags = 0, .pidColumn = true, },
   [MINFLT] = { .name = "MINFLT", .title = "     MINFLT ", .description = "Number of minor faults which have not required loading a memory page from disk", .flags = 0, .defaultSortDesc = true, },
   [MAJFLT] = { .name = "MAJFLT", .title = "     MAJFLT ", .description = "Number of major faults which have required loading a memory page from disk", .flags = 0, .defaultSortDesc = true, },
   [PRIORITY] = { .name = "PRIORITY", .title = "PRI ", .description = "Kernel's internal priority for the process", .flags = 0, },
   [NICE] = { .name = "NICE", .title = " NI ", .description = "Nice value (the higher the value, the more it lets other processes take priority)", .flags = 0, },
   [STARTTIME] = { .name = "STARTTIME", .title = "START ", .description = "Time the process was started", .flags = 0, },
   [ELAPSED] = { .name = "ELAPSED", .title = "ELAPSED  ", .description = "Time since the process was started", .flags = 0, },
   [PROCESSOR] = { .name = "PROCESSOR", .title = "CPU ", .description = "Id of the CPU the process last executed on", .flags = 0, },
   [M_VIRT] = { .name = "M_VIRT", .title = " VIRT ", .description = "Total program size in virtual memory", .flags = 0, .defaultSortDesc = true, },
   [M_RESIDENT] = { .name = "M_RESIDENT", .title = "  RES ", .description = "Resident set size, size of the text and data sections, plus stack usage", .flags = 0, .defaultSortDesc = true, },
   [ST_UID] = { .name = "ST_UID", .title = "  UID ", .description = "User ID of the process owner", .flags = 0, },
   [PERCENT_CPU] = { .name = "PERCENT_CPU", .title = "CPU% ", .description = "Percentage of the CPU time the process used in the last sampling", .flags = 0, .defaultSortDesc = true, },
   [PERCENT_NORM_CPU] = { .name = "PERCENT_NORM_CPU", .title = "NCPU%", .description = "Normalized percentage of the CPU time the process used in the last sampling (normalized by cpu count)", .flags = 0, .defaultSortDesc = true, },
   [PERCENT_MEM] = { .name = "PERCENT_MEM", .title = "MEM% ", .description = "Percentage of the memory the process is using, based on resident memory size", .flags = 0, .defaultSortDesc = true, },
   [USER] = { .name = "USER", .title = "USER      ", .description = "Username of the process owner (or user ID if name cannot be determined)", .flags = 0, },
   [TIME] = { .name = "TIME", .title = "  TIME+  ", .description = "Total time the process has spent in user and system time", .flags = 0, .defaultSortDesc = true, },
   [NLWP] = { .name = "NLWP", .title = "NLWP ", .description = "Number of threads in the process", .flags = 0, },
   [TGID] = { .name = "TGID", .title = "TGID", .description = "Thread group ID (i.e. process ID)", .flags = 0, .pidColumn = true, },
   [PROC_EXE] = { .name = "EXE", .title = "EXE             ", .description = "Basename of exe of the process from /proc/[pid]/exe", .flags = 0, },
   [CWD] = { .name = "CWD", .title = "CWD                       ", .description = "The current working directory of the process", .flags = PROCESS_FLAG_CWD, },
   [TRANSLATED] = { .name = "TRANSLATED", .title = "T ", .description = "Translation info (T translated, N native)", .flags = 0, },
};

Process* DarwinProcess_new(const Settings* settings) {
   DarwinProcess* this = xCalloc(1, sizeof(DarwinProcess));
   Object_setClass(this, Class(DarwinProcess));
   Process_init(&this->super, settings);

   this->utime = 0;
   this->stime = 0;
   this->taskAccess = true;
   this->translated = false;

   return &this->super;
}

void Process_delete(Object* cast) {
   DarwinProcess* this = (DarwinProcess*) cast;
   Process_done(&this->super);
   // free platform-specific fields here
   free(this);
}

static void DarwinProcess_writeField(const Process* this, RichString* str, ProcessField field) {
   const DarwinProcess* dp = (const DarwinProcess*) this;
   char buffer[256]; buffer[255] = '\0';
   int attr = CRT_colors[DEFAULT_COLOR];
   int n = sizeof(buffer) - 1;
   switch (field) {
   // add Platform-specific fields here
   case TRANSLATED: xSnprintf(buffer, n, "%c ", dp->translated ? 'T' : 'N'); break;
   default:
      Process_writeField(this, str, field);
      return;
   }
   RichString_appendWide(str, attr, buffer);
}

static int DarwinProcess_compareByKey(const Process* v1, const Process* v2, ProcessField key) {
   const DarwinProcess* p1 = (const DarwinProcess*)v1;
   const DarwinProcess* p2 = (const DarwinProcess*)v2;

   switch (key) {
   // add Platform-specific fields here
   case TRANSLATED:
      return SPACESHIP_NUMBER(p1->translated, p2->translated);
   default:
      return Process_compareByKey_Base(v1, v2, key);
   }
}

static void DarwinProcess_updateExe(pid_t pid, Process* proc) {
   char path[PROC_PIDPATHINFO_MAXSIZE];

   int r = proc_pidpath(pid, path, sizeof(path));
   if (r <= 0)
      return;

   Process_updateExe(proc, path);
}

static void DarwinProcess_updateCwd(pid_t pid, Process* proc) {
   struct proc_vnodepathinfo vpi;

   int r = proc_pidinfo(pid, PROC_PIDVNODEPATHINFO, 0, &vpi, sizeof(vpi));
   if (r <= 0) {
      free(proc->procCwd);
      proc->procCwd = NULL;
      return;
   }

   if (!vpi.pvi_cdir.vip_path[0]) {
      free(proc->procCwd);
      proc->procCwd = NULL;
      return;
   }

   free_and_xStrdup(&proc->procCwd, vpi.pvi_cdir.vip_path);
}

static void DarwinProcess_updateCmdLine(const struct kinfo_proc* k, Process* proc) {
   Process_updateComm(proc, k->kp_proc.p_comm);

   /* This function is from the old Mac version of htop. Originally from ps? */
   int mib[3], argmax, nargs, c = 0;
   size_t size;
   char *procargs, *sp, *np, *cp;

   /* Get the maximum process arguments size. */
   mib[0] = CTL_KERN;
   mib[1] = KERN_ARGMAX;

   size = sizeof( argmax );
   if ( sysctl( mib, 2, &argmax, &size, NULL, 0 ) == -1 ) {
      goto ERROR_A;
   }

   /* Allocate space for the arguments. */
   procargs = (char*)malloc(argmax);
   if ( procargs == NULL ) {
      goto ERROR_A;
   }

   /*
    * Make a sysctl() call to get the raw argument space of the process.
    * The layout is documented in start.s, which is part of the Csu
    * project.  In summary, it looks like:
    *
    * /---------------\ 0x00000000
    * :               :
    * :               :
    * |---------------|
    * | argc          |
    * |---------------|
    * | arg[0]        |
    * |---------------|
    * :               :
    * :               :
    * |---------------|
    * | arg[argc - 1] |
    * |---------------|
    * | 0             |
    * |---------------|
    * | env[0]        |
    * |---------------|
    * :               :
    * :               :
    * |---------------|
    * | env[n]        |
    * |---------------|
    * | 0             |
    * |---------------| <-- Beginning of data returned by sysctl() is here.
    * | argc          |
    * |---------------|
    * | exec_path     |
    * |:::::::::::::::|
    * |               |
    * | String area.  |
    * |               |
    * |---------------| <-- Top of stack.
    * :               :
    * :               :
    * \---------------/ 0xffffffff
    */
   mib[0] = CTL_KERN;
   mib[1] = KERN_PROCARGS2;
   mib[2] = k->kp_proc.p_pid;

   size = ( size_t ) argmax;
   if ( sysctl( mib, 3, procargs, &size, NULL, 0 ) == -1 ) {
      goto ERROR_B;
   }

   memcpy( &nargs, procargs, sizeof( nargs ) );
   cp = procargs + sizeof( nargs );

   /* Skip the saved exec_path. */
   for ( ; cp < &procargs[size]; cp++ ) {
      if ( *cp == '\0' ) {
         /* End of exec_path reached. */
         break;
      }
   }
   if ( cp == &procargs[size] ) {
      goto ERROR_B;
   }

   /* Skip trailing '\0' characters. */
   for ( ; cp < &procargs[size]; cp++ ) {
      if ( *cp != '\0' ) {
         /* Beginning of first argument reached. */
         break;
      }
   }
   if ( cp == &procargs[size] ) {
      goto ERROR_B;
   }
   /* Save where the argv[0] string starts. */
   sp = cp;

   int end = 0;
   for ( np = NULL; c < nargs && cp < &procargs[size]; cp++ ) {
      if ( *cp == '\0' ) {
         c++;
         if ( np != NULL ) {
            /* Convert previous '\0'. */
            *np = ' ';
         }
         /* Note location of current '\0'. */
         np = cp;
         if (end == 0) {
            end = cp - sp;
         }
      }
   }

   /*
    * sp points to the beginning of the arguments/environment string, and
    * np should point to the '\0' terminator for the string.
    */
   if ( np == NULL || np == sp ) {
      /* Empty or unterminated string. */
      goto ERROR_B;
   }
   if (end == 0) {
      end = np - sp;
   }

   Process_updateCmdline(proc, sp, 0, end);

   /* Clean up. */
   free( procargs );

   return;

ERROR_B:
   free( procargs );

ERROR_A:
   Process_updateCmdline(proc, k->kp_proc.p_comm, 0, strlen(k->kp_proc.p_comm));
}

// Converts nanoseconds to hundredths of a second (centiseconds) as needed by the "time" field of the Process struct.
static long long int nanosecondsToCentiseconds(uint64_t nanoseconds) {
   const uint64_t centiseconds_per_second = 100;
   const uint64_t nanoseconds_per_second = 1e9;
   return nanoseconds / nanoseconds_per_second * centiseconds_per_second;
}

void DarwinProcess_setFromKInfoProc(Process* proc, const struct kinfo_proc* ps, bool exists) {
   DarwinProcess* dp = (DarwinProcess*)proc;

   const struct extern_proc* ep = &ps->kp_proc;

   /* UNSET HERE :
    *
    * processor
    * user (set at ProcessList level)
    * nlwp
    * percent_cpu
    * percent_mem
    * m_virt
    * m_resident
    * minflt
    * majflt
    */

   /* First, the "immutable" parts */
   if (!exists) {
      /* Set the PID/PGID/etc. */
      proc->pid = ep->p_pid;
      proc->ppid = ps->kp_eproc.e_ppid;
      proc->pgrp = ps->kp_eproc.e_pgid;
      proc->session = 0; /* TODO Get the session id */
      proc->tpgid = ps->kp_eproc.e_tpgid;
      proc->tgid = proc->pid;
      proc->isKernelThread = false;
      proc->isUserlandThread = false;
      dp->translated = ps->kp_proc.p_flag & P_TRANSLATED;

      proc->tty_nr = ps->kp_eproc.e_tdev;
      const char* name = (ps->kp_eproc.e_tdev != NODEV) ? devname(ps->kp_eproc.e_tdev, S_IFCHR) : NULL;
      if (!name) {
         free(proc->tty_name);
         proc->tty_name = NULL;
      } else {
         free_and_xStrdup(&proc->tty_name, name);
      }

      proc->starttime_ctime = ep->p_starttime.tv_sec;
      Process_fillStarttimeBuffer(proc);

      DarwinProcess_updateExe(ep->p_pid, proc);
      DarwinProcess_updateCmdLine(ps, proc);

      if (proc->settings->flags & PROCESS_FLAG_CWD) {
         DarwinProcess_updateCwd(ep->p_pid, proc);
      }
   }

   /* Mutable information */
   proc->nice = ep->p_nice;
   proc->priority = ep->p_priority;

   proc->state = (ep->p_stat == SZOMB) ? 'Z' : '?';

   /* Make sure the updated flag is set */
   proc->updated = true;
}

void DarwinProcess_setFromLibprocPidinfo(DarwinProcess* proc, DarwinProcessList* dpl, double timeIntervalNS) {
   struct proc_taskinfo pti;

   if (sizeof(pti) == proc_pidinfo(proc->super.pid, PROC_PIDTASKINFO, 0, &pti, sizeof(pti))) {
      uint64_t total_existing_time_ns = proc->stime + proc->utime;

      uint64_t user_time_ns = Platform_machTicksToNanoseconds(pti.pti_total_user);
      uint64_t system_time_ns = Platform_machTicksToNanoseconds(pti.pti_total_system);

      uint64_t total_current_time_ns = user_time_ns + system_time_ns;

      if (total_existing_time_ns && 1E-6 < timeIntervalNS) {
         uint64_t total_time_diff_ns = total_current_time_ns - total_existing_time_ns;
         proc->super.percent_cpu = ((double)total_time_diff_ns / timeIntervalNS) * 100.0;
      } else {
         proc->super.percent_cpu = 0.0;
      }

      proc->super.time = nanosecondsToCentiseconds(total_current_time_ns);
      proc->super.nlwp = pti.pti_threadnum;
      proc->super.m_virt = pti.pti_virtual_size / ONE_K;
      proc->super.m_resident = pti.pti_resident_size / ONE_K;
      proc->super.majflt = pti.pti_faults;
      proc->super.percent_mem = (double)pti.pti_resident_size * 100.0
                              / (double)dpl->host_info.max_mem;

      proc->stime = system_time_ns;
      proc->utime = user_time_ns;

      dpl->super.kernelThreads += 0; /*pti.pti_threads_system;*/
      dpl->super.userlandThreads += pti.pti_threadnum; /*pti.pti_threads_user;*/
      dpl->super.totalTasks += pti.pti_threadnum;
      dpl->super.runningTasks += pti.pti_numrunning;
   }
}

/*
 * Scan threads for process state information.
 * Based on: http://stackoverflow.com/questions/6788274/ios-mac-cpu-usage-for-thread
 * and       https://github.com/max-horvath/htop-osx/blob/e86692e869e30b0bc7264b3675d2a4014866ef46/ProcessList.c
 */
void DarwinProcess_scanThreads(DarwinProcess* dp) {
   Process* proc = (Process*) dp;
   kern_return_t ret;

   if (!dp->taskAccess) {
      return;
   }

   if (proc->state == 'Z') {
      return;
   }

   task_t port;
   ret = task_for_pid(mach_task_self(), proc->pid, &port);
   if (ret != KERN_SUCCESS) {
      dp->taskAccess = false;
      return;
   }

   task_info_data_t tinfo;
   mach_msg_type_number_t task_info_count = TASK_INFO_MAX;
   ret = task_info(port, TASK_BASIC_INFO, (task_info_t) tinfo, &task_info_count);
   if (ret != KERN_SUCCESS) {
      dp->taskAccess = false;
      return;
   }

   thread_array_t thread_list;
   mach_msg_type_number_t thread_count;
   ret = task_threads(port, &thread_list, &thread_count);
   if (ret != KERN_SUCCESS) {
      dp->taskAccess = false;
      mach_port_deallocate(mach_task_self(), port);
      return;
   }

   integer_t run_state = 999;
   for (unsigned int i = 0; i < thread_count; i++) {
      thread_info_data_t thinfo;
      mach_msg_type_number_t thread_info_count = THREAD_BASIC_INFO_COUNT;
      ret = thread_info(thread_list[i], THREAD_BASIC_INFO, (thread_info_t)thinfo, &thread_info_count);
      if (ret == KERN_SUCCESS) {
         thread_basic_info_t basic_info_th = (thread_basic_info_t) thinfo;
         if (basic_info_th->run_state < run_state) {
            run_state = basic_info_th->run_state;
         }
         mach_port_deallocate(mach_task_self(), thread_list[i]);
      }
   }
   vm_deallocate(mach_task_self(), (vm_address_t) thread_list, sizeof(thread_port_array_t) * thread_count);
   mach_port_deallocate(mach_task_self(), port);

   char state = '?';
   switch (run_state) {
      case TH_STATE_RUNNING: state = 'R'; break;
      case TH_STATE_STOPPED: state = 'S'; break;
      case TH_STATE_WAITING: state = 'W'; break;
      case TH_STATE_UNINTERRUPTIBLE: state = 'U'; break;
      case TH_STATE_HALTED: state = 'H'; break;
   }
   proc->state = state;
}


const ProcessClass DarwinProcess_class = {
   .super = {
      .extends = Class(Process),
      .display = Process_display,
      .delete = Process_delete,
      .compare = Process_compare
   },
   .writeField = DarwinProcess_writeField,
   .compareByKey = DarwinProcess_compareByKey,
};