#include "infrastructure/ProcReader.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>

uint8_t countCpuCores(void)
{
  uint8_t count = 0;
  char line[256];
  FILE* fp = fopen("/proc/cpuinfo", "r");
  if (fp == NULL) {
    fprintf(stderr, "Unable to open /proc/cpuinfo\n");
    return 0;
  }

  while (fgets(line, sizeof(line), fp)) {
    if (strncmp(line, "core id", 7) == 0) {
      ++count;
    }
  }
  fclose(fp);
  return count;  
}

void readCpuStats(CpuStats* stats, uint8_t numCores)
{
  // https://www.linuxhowtos.org/System/procstat.htm

  char line[256];
  FILE* fp = fopen("/proc/stat", "r");
  if (fp == NULL) {
    fprintf(stderr, "Unable to open /proc/stat\n");
    exit(1);
  }

  fgets(line, sizeof(line), fp); // ignore the first line
  for (int i = 0; i < numCores; i++) {
    fgets(line, sizeof(line), fp);
    sscanf(line, "%s %" PRIu64 " %" PRIu64 " %" PRIu64 " %" PRIu64, 
      stats[i].cpuName,
      &stats[i].user,
      &stats[i].nice,
      &stats[i].system,
      &stats[i].idle);
  }

  fclose(fp);
}