// This is NEW CODE to demonstrate the drvinf syscall by printing convenient
// information about drives to the console.
#include <stdio.h>
#include "../kernel/syscdefs.h"

#define DRIVE_SEARCH_MAX 1000

// Inline definition of the syscall
int drvinf(int drivenumber, struct __syscdefs_driveinfo* structure);

#define SIZEOUTPUTLENGTH 40
#define KB 1024ULL
#define MB (KB*1024)
#define GB (MB*1024)
#define TB (GB*1024)

void formatsizevalue(char* output, long long value) {
  int ntb = value/TB;
  value -= ntb*TB;
  int ngb = value/GB;
  value -= ngb*GB;
  int nmb = value/MB;
  value -= nmb*MB;
  int nkb = value/KB;
  value -= nkb*KB;
  int nb = (int) value; // The remainder is any leftover bytes
  if (ntb > 0) {
    if (nb > 0) {
      snprintf(output, SIZEOUTPUTLENGTH, "%dTB %dGB %dMB %dKB %d bytes", ntb, ngb, nmb, nkb, nb);
    } else {
      snprintf(output, SIZEOUTPUTLENGTH, "%dTB %dGB %dMB %dKB", ntb, ngb, nmb, nkb);
    }
  } else if (ngb > 0) {
    if (nb > 0) {
      snprintf(output, SIZEOUTPUTLENGTH, "%dGB %dMB %dKB %d bytes", ngb, nmb, nkb, nb);
    } else {
      snprintf(output, SIZEOUTPUTLENGTH, "%dGB %dMB %dKB", ngb, nmb, nkb);
    }
  } else if (nmb > 0) {
    if (nb > 0) {
      snprintf(output, SIZEOUTPUTLENGTH, "%dMB %dKB %d bytes", nmb, nkb, nb);
    } else {
      snprintf(output, SIZEOUTPUTLENGTH, "%dMB %dKB", nmb, nkb);
    }
  } else if (nkb > 0) {
    if (nb > 0) {
      snprintf(output, SIZEOUTPUTLENGTH, "%dKB %d bytes", nkb, nb);
    } else {
      snprintf(output, SIZEOUTPUTLENGTH, "%dKB", nkb);
    }
  } else {
    snprintf(output, SIZEOUTPUTLENGTH, "%d bytes", nb);
  }
}

  char totalbuf[SIZEOUTPUTLENGTH];
  char freebuf[SIZEOUTPUTLENGTH];

void printinfo(struct __syscdefs_driveinfo* info) {
  //printf("[#%d] %s: %d * %lld, %lld free [%s]\n", info->drivenumber, info->name, info->blocksize, info->totalblocks, info->freedatablocks, info->fsname);
  
  formatsizevalue(totalbuf, info->blocksize * info->totalblocks);
  formatsizevalue(freebuf, info->blocksize * info->freedatablocks);
  printf("[#%d] %s:\t%s total\t%s free\t[%s]\n", info->drivenumber, info->name, totalbuf, freebuf, info->fsname);
}

int main(int argc, char** argv) {
  struct __syscdefs_driveinfo info;
  //int isfirst = 1;
  for (int i = 0; i < DRIVE_SEARCH_MAX; i++) {
    int result = drvinf(i, &info);
    if (result >= 0) {
      /*if (isfirst) {
        isfirst = 0;
      } else {
        printf("\n");
      }*/
      printinfo(&info);
    }
  }
}