/* playback.c
 * Midi playback for a specific portion of
 * a score
 *
 * (c) 2000-2005 Adam Tee
 */


#include <denemo/denemo.h>
#include "exportmudela.h"
#include "exportmidi.h"
#include "staffops.h"
#include "scoreops.h"
#include "dialogs.h"
#include "prefops.h"
#include "utils.h"
#include "external.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <signal.h>
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#ifdef HAVE_WAIT_H
#include <wait.h>
#endif
#include <errno.h>

/* start or restart an external midi player
 * trying avoid multiple instances of it
 */
void
ext_midi_playback (GtkAction * action, DenemoGUI * gui)
{
  GString *mididata = NULL;
  GString *pidpath = NULL;
  GString *cmdline = NULL;
  GPid playerpid = -1;
  FILE *fp;
  int got = 0;

  /* need to by synchronised (one player at a time) */

  /* need: singleton access lock (because multiple views)
   * the old *NIX and *BSD on descriptors : <fcntl.h>
   * the SYSV and POSIX on buffered FILE* : <stdio.h>
   */

  pidpath = get_temp_filename (ext_pidfiles[EXT_MIDI]);
  fp = fopen (pidpath->str, "r+");
  if (ftrylockfile (fp))	/* might not exist on old BSD's */
    {
#ifdef DEBUG
      fprintf (stderr, "ext_midi: another instance is working\n");
#endif
      /* better chance next time */
      fclose (fp);
      g_string_free (pidpath, TRUE);
      return;
    }
  /* ok, it's our turn: */
  got = fscanf (fp, "%d", (int *) &playerpid);
  rewind (fp);
#ifdef DEBUG
  fprintf (stderr, "ext_midi: got player %d\n", playerpid);
#endif
  /* ensure we got something */
  if (got && (playerpid > 0))
    {
#ifdef DEBUG
      fprintf (stderr, "ext_midi: killing player: %d\n", playerpid);
#endif
      kill (playerpid, SIGTERM);
      g_spawn_close_pid (playerpid);
      /* fix leaks on win32 */
    }
  mididata = get_temp_filename ("denemoplayback.mid");
  exportmidi (mididata->str, gui->si, gui->si->start, gui->si->end);
  cmdline = g_string_new (gui->prefs->midiplayer->str);
  cmdline = g_string_append (cmdline, "\t");
  cmdline = g_string_append (cmdline, mididata->str);
  playerpid = spawn_external (cmdline);
#ifdef DEBUG
  fprintf (stderr, "ext_midi: spawned %d\n", playerpid);
#endif
  if (playerpid > 0)
    fprintf (fp, "%d", playerpid);
  funlockfile (fp);		/* might not exist on old BSD's */
  fclose (fp);
  g_string_free (mididata, TRUE);
  g_string_free (pidpath, TRUE);
  return;
}

void
playback_local (gpointer callback_data, guint callback_action,
		GtkWidget * widget)
{
  /* what is it ? */
  return;
}