/*
 * showbatt.c -- print remaining battery life to standart output.
 *
 * Copyright (C) 1995 Yasuo Hibara <hibara@psrc.isac.co.jp>
 *
 * adaptation against apm driver 1.2 or later
 * (C)Copyright 1998 by Hiroshi Takekawa <t80679@hongo.ecc.u-tokyo.ac.jp>
 *
 * This showbatt.c is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This showbatt.c 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 showbatt.c; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

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

const char sAPM_PROC[] = "/proc/apm";
const char sAPM_BIOS[] = "/dev/apm_bios";

char *name = "showbatt";
int opt_t = 0;

/* apm information structure... not same as in apmd's apm.h */
typedef struct _apm_info {
  int driver_version;
  int bios_version;
  int bios_flags;
  int ac_status;
  int battery_status;
  int battery_flags;
  int percentage;
  int time; /* minutes ! */
} apm_info;

void usage(void)
{
  fprintf(stderr,
	  "%s version 0.01\n",
	  "Usage: %s [ -t ] [ <interval seconds> ]\n"
	  "  -t:  append remaining time of battery life\n"
	  "  update status per <interval seconds> (default 30)\n",
	  name);
  exit(EXIT_FAILURE);
}

int getproc(apm_info *info)
{
  int fd, i, dvh, dvl, abvh, abvl, abf, acs, bs, bf, percent, time;
  char units[8], image[48];

  if ((fd = open(sAPM_PROC, O_RDONLY)) < 0) {
    fprintf(stderr, "can't open %s\n", sAPM_PROC);
    exit(EXIT_FAILURE);
  }

  if (read(fd, image, 48) < 0) {
    fprintf(stderr, "can't read %s\n", sAPM_PROC);
    exit(EXIT_FAILURE);
  }

  close(fd);

  /* driver_version apm_bios_version ac_line_status battery_status batter_flag percentage time units */
  i = sscanf(image, "%d.%d %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
             &dvh, &dvl, &abvh, &abvl, &abf, &acs, &bs, &bf, &percent, &time, units);

  if (i < 7) {
    fprintf(stderr, "can't parse /proc/apm ... maybe older driver?\n");
    exit(EXIT_FAILURE);
  }

  if (strcmp(units, "seconds") == 0) {
    info->time = time / 60;
  } else {
    info->time = time;
  }

  info->driver_version = (dvh << 8) + dvl;
  info->bios_version   = (abvh << 8) + abvl;
  info->bios_flags     = abf;
  info->ac_status      = acs;
  info->battery_status = bs;
  info->battery_flags  = bf;
  info->percentage     = percent;

  return i;
}

void showbatt(void)
{
  char image[32], *p;
  int percent, minutes, l, i;
  apm_info info;

  percent = minutes = -1;
  p = image;

  l = getproc(&info);

  if (info.bios_flags & (1 << 3)) {
    fprintf(stderr, "APM BIOS disabled\n");
    exit(EXIT_FAILURE);
  }

  if (info.ac_status & 1)
    *p++ = '[';
  else if (info.ac_status & 2)
    *p++ = '#';
  else if (info.ac_status != 0)
    *p++ = '-';
  else if (info.battery_status & 1)
    *p++ = ')';
  else if (info.battery_status & 2)
    *p++ = '>';
  else
    *p++ = '|';

  if (info.percentage >= 0) {
    sprintf(p, "%3d%%  ", info.percentage);
    p += 4;
  } else {
    *p++ = '-';
    *p++ = '-';
  }

  if (opt_t) {
    if (minutes >= 0)
      sprintf(p, " %1d:%02d", minutes / 60, minutes % 60);
    else
      strcpy(p, " -:--");
    p += 5;
  }

  if (info.battery_flags & 1)
    *p++ = ']';
  else if (info.battery_flags & 2)
    *p++ = '(';
  else if (info.battery_flags & 4)
    *p++ = '<';
  else if (info.battery_flags & 8)
    *p++ = '|';
  else
    *p++ = '-';

  strcat(p, "\n");
  
  write(STDOUT_FILENO, image, strlen(image));
}

int main(int argc, char **argv)
{
  int timeout = 30;
  fd_set fds;
  int fd,n,i;
  apm_event_t events[32];
  char c[1];
  struct timeval tv;
  
  name = argv[0];
  
  if ( argc > 1 && strcmp(argv[1], "-t") == 0 ) {
    opt_t = 1;
    argc--; argv++;
  }
  if ( argc > 1 ) {
    if ( argc > 2 ||
	sscanf(argv[1], "%d%c", &timeout, &c) != 1 ||
	timeout < 0 ) usage();
  }
  
  if ( (fd = open(sAPM_BIOS, O_RDONLY)) == -1 ) {
    fprintf(stderr, "can't open %s\n", sAPM_BIOS);
    exit(EXIT_FAILURE);
  }
  
  for ( ; ; ) {
    showbatt();
    FD_ZERO(&fds); FD_SET(fd, &fds);
    if ( timeout > 0 ) {
      tv.tv_sec = timeout; tv.tv_usec = 0;
      n = select(fd+1, &fds, NULL, NULL, &tv);
    } else {
      n = select(fd+1, &fds, NULL, NULL, NULL);
    }
    if ( n > 0 ) {
      n = read(fd, events, sizeof(events))/sizeof(*events);
      for ( i = 0; i < n; i++ ) {
	switch ( events[i] ) {
	case APM_SYS_STANDBY: case APM_USER_STANDBY:
	  ioctl(fd, APM_IOC_STANDBY); break;
	case APM_SYS_SUSPEND: case APM_USER_SUSPEND:
	  ioctl(fd, APM_IOC_SUSPEND); break;
	}
      }
    }
  }
  return EXIT_FAILURE;
}