/* wydawca - automatic release submission daemon
   Copyright (C) 2007, 2008, 2009, 2010 Sergey Poznyakoff

   Wydawca 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 3 of the License, or (at your
   option) any later version.

   Wydawca 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 wydawca. If not, see <http://www.gnu.org/licenses/>. */

#include "wydawca.h"
#include "sql.h"

static const char *
meta_expand (struct metadef *def, void *data)
{
  if (!def->value)
    {
      if (def->expand)
	return def->expand (def, data);
      def->value = "INTERNAL ERROR: NONEXPANDABLE DATA";
    }
  return def->value;
}

static const char *
find_expansion_char (int c, struct metadef *def, void *data)
{
  for (; def->kw; def++)
    if (def->kw[1] == 0 && def->kw[0] == c)
      return meta_expand (def, data);
  return NULL;
}

static const char *
find_expansion_word (const char *kw, size_t len,
		     struct metadef *def, void *data)
{
  for (; def->kw; def++)
    if (strlen (def->kw) == len && memcmp (def->kw, kw, len) == 0)
      return meta_expand (def, data);
  return NULL;
}

char *
meta_expand_string (const char *string, struct metadef *def, void *data,
		    struct dictionary *dict, void *handle)
{
  const char *p, *s;
  char *res;
  struct obstack stk;

  if (!string)
    return NULL;

  obstack_init (&stk);

  for (p = string; *p;)
    {
      char *e;
      size_t len = strcspn (p, "$");

      obstack_grow (&stk, p, len);
      p += len;
      if (*p == '$')
	{
	  switch (*++p)
	    {
	    case '$':
	      obstack_grow (&stk, p, 1);
	      p++;
	      break;

	    case '-':
	      if (*++p)
		p++;
	      break;
	      
	    case '{':
	      e = strchr (p + 1, '}');
	      if (e && (s = find_expansion_word (p + 1, e - p - 1, def, data)))
		{
		  if (dict)
		    {
		      char *newval;
		      size_t len;
		      /* FIXME: Return value? */
		      dictionary_quote_string (dict, handle, s, &newval, &len);
		      obstack_grow (&stk, newval, len);
		      free (newval);
		    }
		  else
		    obstack_grow (&stk, s, strlen (s));
		  p = e + 1;
		}
	      else
		{
		  obstack_grow (&stk, p - 1, 2);
		  p++;
		}
	      break;

	    default:
	      if ((s = find_expansion_char (*p, def, data)) != NULL)
		len = strlen (s);
	      else
		{
		  s = p - 1;
		  len = 1;
		}
	      
	      if (dict)
		{
		  char *newval;
		  size_t len;
		  /* FIXME: Return value? */
		  dictionary_quote_string (dict, handle, s, &newval, &len);
		  obstack_grow (&stk, newval, len);
		  free (newval);
		}
	      else
		obstack_grow (&stk, s, len);
	      p++;
	    }
	}
      else
	obstack_grow (&stk, p, 1);
    }
  obstack_1grow (&stk, 0);
  res = xstrdup (obstack_finish (&stk));
  obstack_free (&stk, NULL);
  return res;
}

void
meta_free (struct metadef *def)
{
  for (; def->kw; def++)
    {
      if (def->storage)
	{
	  free (def->storage);
	  def->value = def->storage = NULL;
	}
    }
}