/*
    KSysGuard, the KDE System Guard

    Copyright (c) 2000-2001 Chris Schlaeger <cs@kde.org>

    This program is free software; you can redistribute it and/or
    modify it under the terms of version 2 of the GNU General Public
    License as published by the Free Software Foundation.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

*/

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <time.h>

#include "Command.h"
#include "ksysguardd.h"

#include "cpuinfo.h"

static int CpuInfoOK = 0;
static int numProcessors = 0; /* Total number of physical processors */
static int HighNumProcessors = 0; /* Highest # number of physical processors ever seen */
static int* ProcessorCores = 0; /* Array with one entry per processor */
static int numCores = 0; /* Total # of cores */
static int HighNumCores = 0; /* Highest # of cores ever seen */
static float* Clocks = 0; /* Array with one entry per core */

#define CPUINFOBUFSIZE (32 * 1024)
static char CpuInfoBuf[ CPUINFOBUFSIZE ];
static int Dirty = 0;
static struct SensorModul *CpuInfoSM;

static void processCpuInfo( void )
{
  char format[ 32 ];
  char tag[ 32 ];
  char value[ 256 ];
  char* cibp = CpuInfoBuf;

  /* coreUniqueId is not per processor; it is a counter of the number of cores encountered
   * by the parse thus far */
  int coreUniqueId = 0;

  /* Reset global variables */
  numCores = 0;
  numProcessors = 0;

  if ( !CpuInfoOK )
    return;

  sprintf( format, "%%%d[^:]: %%%d[^\n]\n", (int)sizeof( tag ) - 1,
           (int)sizeof( value ) - 1 );

  while ( sscanf( cibp, format, tag, value ) == 2 ) {
    char* p;

    tag[ sizeof( tag ) - 1 ] = '\0';
    value[ sizeof( value ) - 1 ] = '\0';

    /* remove trailing whitespaces */
    p = tag + strlen( tag ) - 1;
    /* remove trailing whitespaces */
    while ( ( *p == ' ' || *p == '\t' ) && p > tag )
      *p-- = '\0';

    if ( strcmp( tag, "processor" ) == 0 ) {
      if ( sscanf( value, "%d", &coreUniqueId ) == 1 ) {
        if ( coreUniqueId >= HighNumCores ) {
	  /* Found a new processor core. Maybe even a new processor. (We'll check later) */
          char cmdName[ 24 ];

	  HighNumCores = coreUniqueId + 1;

	  /* Each core has a clock speed. Allocate one per core found. */
	  Clocks = (float*) realloc( Clocks, HighNumCores * sizeof( float ) );

	  snprintf( cmdName, sizeof( cmdName ) - 1, "cpu/cpu%d/clock", coreUniqueId );
          registerMonitor( cmdName, "float", printCPUxClock, printCPUxClockInfo,
                           CpuInfoSM );
	}
      }
    } else if ( strcmp( tag, "cpu MHz" ) == 0 ) {
      if (HighNumCores > coreUniqueId) {
        /* The if statement above *should* always be true, but there's no harm in being safe. */
        sscanf( value, "%f", &Clocks[ coreUniqueId ] );
      }
    } else if ( strcmp( tag, "core id" ) == 0 ) {
      /* the core id is per processor */
      int curCore;
      
      if ( (sscanf( value, "%d", &curCore ) == 1) && curCore == 0 ) {
	/* core id is back at 0. We just found a new processor. */
	numProcessors++;

	if (numProcessors > HighNumProcessors) {
	    HighNumProcessors = numProcessors;
	    ProcessorCores = (int*) realloc( ProcessorCores, HighNumProcessors * sizeof( int ) );
	}
      }
    } else if ( strcmp( tag, "cpu cores" ) == 0 ) {
      if (numProcessors > 0) {
        /* numProcessors *should* be > 0, we were just making sure. */
        sscanf( value, "%d", &ProcessorCores[ numProcessors - 1 ] );
      }
    }

    /* Move cibp to beginning of next line, if there is one. */
    cibp = strchr( cibp, '\n' );
    if ( cibp )
      cibp++;
    else
      cibp = CpuInfoBuf + strlen( CpuInfoBuf );
  }

  numCores = coreUniqueId + 1;

  Dirty = 0;
}

/*
================================ public part =================================
*/

void initCpuInfo( struct SensorModul* sm )
{
  CpuInfoSM = sm;

  if ( updateCpuInfo() < 0 )
    return;

  registerMonitor( "system/processors", "integer", printNumCpus, printNumCpusInfo,
                           CpuInfoSM );
  registerMonitor( "system/cores", "integer", printNumCores, printNumCoresInfo,
                           CpuInfoSM );

  processCpuInfo();
}

void exitCpuInfo( void )
{
  CpuInfoOK = -1;

  free( Clocks );
}

int updateCpuInfo( void )
{
  size_t n;
  int fd;

  if ( CpuInfoOK < 0 )
    return -1;

  if ( ( fd = open( "/proc/cpuinfo", O_RDONLY ) ) < 0 ) {
    if ( CpuInfoOK != 0 )
      print_error( "Cannot open file \'/proc/cpuinfo\'!\n"
                   "The kernel needs to be compiled with support\n"
                   "for /proc file system enabled!\n" );
    CpuInfoOK = -1;
    return -1;
  }

  n = read( fd, CpuInfoBuf, CPUINFOBUFSIZE - 1 );
  if ( n == CPUINFOBUFSIZE - 1 || n <= 0 ) {
    log_error( "Internal buffer too small to read \'/proc/cpuinfo\'" );
    CpuInfoOK = 0;

    close( fd );
    return -1;
  }

  close( fd );
  CpuInfoOK = 1;
  CpuInfoBuf[ n ] = '\0';
  Dirty = 1;

  return 0;
}

void printCPUxClock( const char* cmd )
{
  int id;

  if ( Dirty )
    processCpuInfo();

  sscanf( cmd + 7, "%d", &id );
  output( "%f\n", Clocks[ id ] );
}

void printCPUxClockInfo( const char* cmd )
{
  int id;

  sscanf( cmd + 7, "%d", &id );
  output( "CPU%d Clock Frequency\t0\t0\tMHz\n", id );
}

void printNumCpus( const char* cmd )
{
  (void) cmd;
	
  if ( Dirty )
    processCpuInfo();

  output( "%d\n", numProcessors );
}

void printNumCpusInfo( const char* cmd )
{
  (void) cmd;
  
  output( "Number of physical CPUs\t0\t0\t\n" );
}

void printNumCores( const char* cmd )
{
  (void) cmd;

  if ( Dirty )
    processCpuInfo();

  output( "%d\n", numCores );
}

void printNumCoresInfo( const char* cmd )
{
  (void) cmd;

  output( "Total number of processor cores\t0\t0\t\n" );
}
