#include "torsmo.h"
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <fcntl.h>

/* linux */
#ifdef HAVE_SYS_STATFS_H
#include <sys/statfs.h>
#endif

/* freebsd && netbsd */
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_SYS_MOUNT_H
#include <sys/mount.h>
#endif

/* TODO: benchmark which is faster, fstatvfs() or pre-opened fd and
 * statvfs() (fstatvfs() would handle mounts I think...) */

static struct fs_stat fs_stats_[64];
struct fs_stat *fs_stats = fs_stats_;

void update_fs_stats() {
  unsigned int i;
  struct statfs s;
  for (i=0; i<16; i++) {
    if (fs_stats[i].fd <= 0)
      break;

    fstatfs(fs_stats[i].fd, &s);

    fs_stats[i].size = (long long) s.f_blocks * s.f_bsize;
    /* bfree (root) or bavail (non-roots) ? */
    fs_stats[i].avail = (long long) s.f_bavail * s.f_bsize;
  }
}

void clear_fs_stats() {
  unsigned int i;
  for (i=0; i<16; i++) {
    if (fs_stats[i].fd) {
      close(fs_stats[i].fd);
      fs_stats[i].fd = -1;
    }

    if (fs_stats[i].path != NULL) {
      free(fs_stats[i].path);
      fs_stats[i].path = NULL;
    }
  }
}

struct fs_stat *prepare_fs_stat(const char *s) {
  unsigned int i;

  for (i=0; i<16; i++) {
    struct fs_stat *fs = &fs_stats[i];

    if (fs->path && strcmp(fs->path, s) == 0)
      return fs;

    if (fs->fd <= 0) {
      /* when compiled with icc, it crashes when leaving function and open()
       * is used, I don't know why */

      /* this icc workaround didn't seem to work */
#if 0
      {
        FILE *fp = fopen(s, "r");
        if(fp)
          fs->fd = fileno(fp);
        else
          fs->fd = -1;
      }
#endif

      fs->fd = open(s, O_RDONLY);

      if (fs->fd <= 0) { /* 0 isn't error but actually it is :) */
        ERR("open '%s': %s", s, strerror(errno));
        return 0;
      }

      fs->path = strdup(s);
      update_fs_stats();
      return fs;
    }
  }

  ERR("too many fs stats");
  return 0;
}