/* acpi.c - show power state
 *
 * Written by Isaac Dunham, 2013
 *
 * No standard.

USE_ACPI(NEWTOY(acpi, "ab", TOYFLAG_USR|TOYFLAG_BIN))

config ACPI
  bool "acpi"
  default y
  help
    usage: acpi [-ab]
    
    Show status of power sources.

    -a	show power adapters
    -b	show batteries
*/

#define FOR_acpi
#include "toys.h"

GLOBALS(
  int ac;
  int bat;
)

int read_int_at(int dirfd, char *name)
{
  int fd, ret=0;
  FILE *fil;

  if ((fd = openat(dirfd, name, O_RDONLY)) < 0) return -1;
  fscanf(fil = xfdopen(fd, "r"), "%d", &ret);
  fclose(fil);

  return ret;
}

int acpi_callback(struct dirtree *tree)
{
  int dfd, fd, len, on;

  errno = 0;

  if (tree->name[0]=='.') return 0;

  if (strlen(dirtree_path(tree, NULL)) < 26)
    return DIRTREE_RECURSE | DIRTREE_SYMFOLLOW;

  if (0 <= (dfd = open(dirtree_path(tree, NULL), O_RDONLY))) {
    if ((fd = openat(dfd, "type", O_RDONLY)) < 0) goto done;
    len = readall(fd, toybuf, sizeof(toybuf));
    close(fd);
    if (len < 1) goto done;

    if (!strncmp(toybuf, "Battery", 7)) {
      if ((toys.optflags & FLAG_b) || (!toys.optflags)) {
        int cap = 0, curr = 0, max = 0;

        if ((cap = read_int_at(dfd, "capacity")) < 0) {
          if ((max = read_int_at(dfd, "charge_full")) > 0)
            curr = read_int_at(dfd, "charge_now");
          else if ((max = read_int_at(dfd, "energy_full")) > 0)
            curr = read_int_at(dfd, "energy_now");
          if (max > 0 && curr >= 0) cap = 100 * curr / max;
        }
        if (cap >= 0) printf("Battery %d: %d%%\n", TT.bat++, cap);
      }
    } else if (toys.optflags & FLAG_a) {
      if ((on = read_int_at(dfd, "online")) >= 0)
        printf("Adapter %d: %s-line\n", TT.ac++, (on ? "on" : "off"));
    }
done:
    close(dfd);
  }

  return 0;
}

void acpi_main(void)
{
  dirtree_read("/sys/class/power_supply", acpi_callback);
}