/* ----------------------------------------------------------------------------

   libconfig - A library for processing structured configuration files

   Copyright (C) 2005-2010  Mark A Lindner

   This file is part of libconfig.

   This library 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.

   This library 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 Library General Public

   License along with this library; if not, see

   <http://www.gnu.org/licenses/>.

   ----------------------------------------------------------------------------

*/

#include "scanctx.h"

#include "wincompat.h"

#include <stddef.h>

#include <stdlib.h>

#include <string.h>

#define STRING_BLOCK_SIZE 64

#define CHUNK_SIZE 32

/* ------------------------------------------------------------------------- */

static const char *err_bad_include = "cannot open include file";

static const char *err_include_too_deep = "include file nesting too deep";

/* ------------------------------------------------------------------------- */

static const char *__scanctx_add_filename(struct scan_context *ctx,

                                          const char *filename)

{

  unsigned int count = ctx->num_filenames;

  const char **f;

  for(f = ctx->filenames; count > 0; ++f, --count)

  {

    if(!strcmp(*f, filename))

    {

      free((void *)filename);

      return(*f); /* already in list */

    }

  }

  if((ctx->num_filenames % CHUNK_SIZE) == 0)

  {

    ctx->filenames = (const char **)realloc(

      (void *)ctx->filenames,

      (ctx->num_filenames + CHUNK_SIZE) * sizeof(const char *));

  }

  ctx->filenames[ctx->num_filenames] = filename;

  ++ctx->num_filenames;

  return(filename);

}

/* ------------------------------------------------------------------------- */

void scanctx_init(struct scan_context *ctx, const char *top_filename)

{

  memset(ctx, 0, sizeof(struct scan_context));

  if(top_filename)

    ctx->top_filename = __scanctx_add_filename(ctx, strdup(top_filename));

}

/* ------------------------------------------------------------------------- */

const char **scanctx_cleanup(struct scan_context *ctx,

                             unsigned int *num_filenames)

{

  int i;

  for(i = 0; i < ctx->depth; ++i)

    fclose(ctx->streams[i]);

  free((void *)(strbuf_release(&(ctx->string))));

  *num_filenames = ctx->num_filenames;

  return(ctx->filenames);

}

/* ------------------------------------------------------------------------- */

FILE *scanctx_push_include(struct scan_context *ctx, void *buffer,

                           const char **error)

{

  FILE *fp = NULL;

  const char *file;

  char *full_file = NULL;

  *error = NULL;

  if(ctx->depth == MAX_INCLUDE_DEPTH)

  {

    *error = err_include_too_deep;

    return(NULL);

  }

  file = scanctx_take_string(ctx);

  if(ctx->config->include_dir)

  {

    full_file = (char *)malloc(strlen(ctx->config->include_dir) + strlen(file)

                               + 2);

    strcpy(full_file, ctx->config->include_dir);

    strcat(full_file, FILE_SEPARATOR);

    strcat(full_file, file);

  }

  fp = fopen(full_file ? full_file : file, "rt");

  free((void *)full_file);

  if(fp)

  {

    ctx->streams[ctx->depth] = fp;

    ctx->files[ctx->depth] = __scanctx_add_filename(ctx, file);

    ctx->buffers[ctx->depth] = buffer;

    ++(ctx->depth);

  }

  else

  {

    free((void *)file);

    *error = err_bad_include;

  }

  return(fp);

}

/* ------------------------------------------------------------------------- */

void *scanctx_pop_include(struct scan_context *ctx)

{

  void *buffer;

  if(ctx->depth == 0)

    return(NULL); /* stack underflow */

  --(ctx->depth);

  buffer = ctx->buffers[ctx->depth];

  fclose(ctx->streams[ctx->depth]);

  return(buffer);

}

/* ------------------------------------------------------------------------- */

char *scanctx_take_string(struct scan_context *ctx)

{

  char *r = strbuf_release(&(ctx->string));

  return(r ? r : strdup(""));

}

/* ------------------------------------------------------------------------- */

const char *scanctx_current_filename(struct scan_context *ctx)

{

  return((ctx->depth == 0) ? ctx->top_filename : ctx->files[ctx->depth - 1]);

}

/* ------------------------------------------------------------------------- */

/* eof */