/* Copyright 2007 Red Hat, Inc.
 *
 * Portions extraced from various ALSA code:
 *  Copyright (c) by Abramo Bagnara <abramo@alsa-project.org>
 *                   Jaroslav Kysela <perex@suse.cz>
 *
 * This software may be freely redistributed under the terms of the GNU
 * public license.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

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

#include <alsa/asoundlib.h>

#define ALSA_CONFIG_PATH	"/etc/alsa/asound.state"
#define ALL_CARDS         	(-1)


int get_card_number()
{
  char *devname, *action;

  action = getenv("ACTION");
  if (!action || strcmp(action, "add"))
    return -1;
  devname = getenv("DEVNAME");
  if (!devname)
    return -1;
  if (!strncmp(devname, "/dev/snd/controlC", 17))
    return atoi(devname + 17);
  if (!strncmp(devname, "/dev/snd/pcmC", 13))
    return atoi(devname + 13);
  return -1;
}

int has_config(int index)
{
  int rc = 0;
  snd_config_t *config, *control;
  snd_input_t *in;
  snd_ctl_t *handle;
  snd_ctl_card_info_t *info;
  const char *id;
  char path[32];  
  
  rc = snd_config_top(&config);
  if (rc < 0)
    goto out;
  rc = snd_input_stdio_open(&in, ALSA_CONFIG_PATH, "r");
  if (rc >= 0) {
    rc = snd_config_load(config, in);
    snd_input_close(in);
    if (rc < 0)
      goto out;
  }
  sprintf(path, "hw:%d", index);
  rc = snd_ctl_open(&handle, path, 0);
  if (rc < 0)
    goto out;
  snd_ctl_card_info_alloca(&info);
  rc = snd_ctl_card_info(handle, info);
  if (rc < 0)
    goto out_close;
  id = snd_ctl_card_info_get_id(info);
  rc = snd_config_searchv(config, &control, "state", id, "control", 0);
out_close:
  snd_ctl_close(handle);
out:
  return !rc;

}

void load_volume_settings(int index)
{
  char *args[] = { "/sbin/alsactl", "-f", ALSA_CONFIG_PATH, "restore", NULL, NULL };
  char  num[10];

  if(index != ALL_CARDS) {
    snprintf(num, 10, "%d", index);
    args[4] = num;
  }
  
  execv(args[0], args);  
}

void save_volume_settings(int index)
{
  char *args[] = { "/sbin/alsactl", "-f", ALSA_CONFIG_PATH, "store", NULL, NULL };
  char  num[10];
  
  if(index != ALL_CARDS) {
    snprintf(num, 10, "%d", index);
    args[4] = num;    
  }
  
  execv(args[0], args);
}

void frob_mixer(int index)
{
  char tmp[100];  
  snprintf(tmp, 100, "%d", index);
  tmp[99] = '\0';
  execl("/bin/alsaunmute","/bin/alsaunmute", tmp, "-v", NULL);
}

void banner(void)
{
  printf("ALSA volume settings handler, Copyright 2007 Red Hat, Inc.\n");
  printf("This software may be freely redistributed under\nthe terms of the GNU public license.\n\n");
  
  printf("Usage: salsa [options] [card number]\n\n");
  printf(" Options:\n");
  printf("    -l      - Load volume settings\n");
  printf("    -s      - Save volume settings\n\n");
  printf(" Card number:\n");
  printf("    ##      - An affected card. If it isn't specified,\n");
  printf("              configure all installed sound cards.\n\n");
  
  exit(0);   
}

int main(int argc, char **argv)
{
  int i;
  
  if(argc == 1) {
    i = get_card_number();
    if (i < 0) {
      return 0;
    }
    if (has_config(i)) {
      load_volume_settings(i);
    }
    else {
      frob_mixer(i);
    }
  }
  else if(argc >= 2) {
    
    int card_number = ALL_CARDS;
    if(argc == 3) {
      card_number = atoi(argv[2]);
    }
    
    if(argv[1][1] == 'l') {
      load_volume_settings(card_number);
    }
    else if(argv[1][1] == 's') {
      save_volume_settings(card_number);
    }
    else {
      banner();
    }
  }
  
  return(0);
}