/* debug.c - helpful output in desperate situations
   Copyright (C) 2000 Werner Koch (dd9jn)
   Copyright (C) 2001, 2002, 2003, 2004, 2005 g10 Code GmbH
 
   This file is part of GPGME.

   GPGME is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of
   the License, or (at your option) any later version.
   
   GPGME 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
   Lesser General Public License for more details.
   
   You should have received a copy of the GNU Lesser General Public
   License along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301, USA.  */

#if HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <ctype.h>
#ifndef HAVE_DOSISH_SYSTEM
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>
#endif
#include <assert.h>

#include "util.h"
#include "sema.h"


/* Lock to serialize initialization of the debug output subsystem and
   output of actual debug messages.  */
DEFINE_STATIC_LOCK (debug_lock);

/* The amount of detail requested by the user, per environment
   variable GPGME_DEBUG.  */
static int debug_level;

/* The output stream for the debug messages.  */
static FILE *errfp;


/* Remove leading and trailing white spaces.  */
static char *
trim_spaces (char *str)
{
  char *string, *p, *mark;

  string = str;
  /* Find first non space character.  */
  for (p = string; *p && isspace (*(unsigned char *) p); p++)
    ;
  /* Move characters.  */
  for (mark = NULL; (*string = *p); string++, p++)
    if (isspace (*(unsigned char *) p))
      {
	if (!mark)
	  mark = string;
      }
    else
      mark = NULL;
  if (mark)
    *mark = '\0';	/* Remove trailing spaces.  */

  return str;
}


static void
debug_init (void)
{
  static int initialized;

  LOCK (debug_lock);
  if (!initialized)
    {
      gpgme_error_t err;
      char *e;
      const char *s1, *s2;;

      err = _gpgme_getenv ("GPGME_DEBUG", &e);
      if (err)
	{
	  UNLOCK (debug_lock);
	  return;
	}

      initialized = 1;
      errfp = stderr;
      if (e)
	{
	  debug_level = atoi (e);
	  s1 = strchr (e, PATHSEP_C);
	  if (s1)
	    {
#ifndef HAVE_DOSISH_SYSTEM
	      if (getuid () == geteuid ())
		{
#endif
		  char *p;
		  FILE *fp;

		  s1++;
		  if (!(s2 = strchr (s1, PATHSEP_C)))
		    s2 = s1 + strlen (s1);
		  p = malloc (s2 - s1 + 1);
		  if (p)
		    {
		      memcpy (p, s1, s2 - s1);
		      p[s2-s1] = 0;
		      trim_spaces (p);
		      fp = fopen (p,"a");
		      if (fp)
			{
			  setvbuf (fp, NULL, _IOLBF, 0);
			  errfp = fp;
			}
		      free (p);
		    }
#ifndef HAVE_DOSISH_SYSTEM
		}
#endif
	    }
	  free (e);
        }

      if (debug_level > 0)
	fprintf (errfp, "gpgme_debug: level=%d\n", debug_level);
    }
  UNLOCK (debug_lock);
}


/* Log the formatted string FORMAT at debug level LEVEL or higher.  */
void
_gpgme_debug (int level, const char *format, ...)
{
  va_list arg_ptr;

  debug_init ();
  if (debug_level < level)
    return;
    
  va_start (arg_ptr, format);
  LOCK (debug_lock);
  vfprintf (errfp, format, arg_ptr);
  va_end (arg_ptr);
  if(format && *format && format[strlen (format) - 1] != '\n')
    putc ('\n', errfp);
  UNLOCK (debug_lock);
  fflush (errfp);
}


/* Start a new debug line in *LINE, logged at level LEVEL or higher,
   and starting with the formatted string FORMAT.  */
void
_gpgme_debug_begin (void **line, int level, const char *format, ...)
{
  va_list arg_ptr;

  debug_init ();
  if (debug_level < level)
    {
      /* Disable logging of this line.  */
      *line = NULL;
      return;
    }

  va_start (arg_ptr, format);
  vasprintf ((char **) line, format, arg_ptr);
  va_end (arg_ptr);
}


/* Add the formatted string FORMAT to the debug line *LINE.  */
void
_gpgme_debug_add (void **line, const char *format, ...)
{
  va_list arg_ptr;
  char *toadd;
  char *result;

  if (!*line)
    return;

  va_start (arg_ptr, format);
  vasprintf (&toadd, format, arg_ptr);
  va_end (arg_ptr);
  asprintf (&result, "%s%s", *(char **) line, toadd);
  free (*line);
  free (toadd);
  *line = result;
}


/* Finish construction of *LINE and send it to the debug output
   stream.  */
void
_gpgme_debug_end (void **line)
{
  if (!*line)
    return;

  /* The smallest possible level is 1, so force logging here by
     using that.  */
  _gpgme_debug (1, "%s", *line);
  free (*line);
  *line = NULL;
}
