/*

 * Copyright (c) 2001-2002 Michael David Adams.

 * All rights reserved.

 */

/* __START_OF_JASPER_LICENSE__

 * 

 * JasPer License Version 2.0

 * 

 * Copyright (c) 2001-2006 Michael David Adams

 * Copyright (c) 1999-2000 Image Power, Inc.

 * Copyright (c) 1999-2000 The University of British Columbia

 * 

 * All rights reserved.

 * 

 * Permission is hereby granted, free of charge, to any person (the

 * "User") obtaining a copy of this software and associated documentation

 * files (the "Software"), to deal in the Software without restriction,

 * including without limitation the rights to use, copy, modify, merge,

 * publish, distribute, and/or sell copies of the Software, and to permit

 * persons to whom the Software is furnished to do so, subject to the

 * following conditions:

 * 

 * 1.  The above copyright notices and this permission notice (which

 * includes the disclaimer below) shall be included in all copies or

 * substantial portions of the Software.

 * 

 * 2.  The name of a copyright holder shall not be used to endorse or

 * promote products derived from the Software without specific prior

 * written permission.

 * 

 * THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS

 * LICENSE.  NO USE OF THE SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER

 * THIS DISCLAIMER.  THE SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS

 * "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING

 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A

 * PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.  IN NO

 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL

 * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING

 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,

 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION

 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.  NO ASSURANCES ARE

 * PROVIDED BY THE COPYRIGHT HOLDERS THAT THE SOFTWARE DOES NOT INFRINGE

 * THE PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OF ANY OTHER ENTITY.

 * EACH COPYRIGHT HOLDER DISCLAIMS ANY LIABILITY TO THE USER FOR CLAIMS

 * BROUGHT BY ANY OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL

 * PROPERTY RIGHTS OR OTHERWISE.  AS A CONDITION TO EXERCISING THE RIGHTS

 * GRANTED HEREUNDER, EACH USER HEREBY ASSUMES SOLE RESPONSIBILITY TO SECURE

 * ANY OTHER INTELLECTUAL PROPERTY RIGHTS NEEDED, IF ANY.  THE SOFTWARE

 * IS NOT FAULT-TOLERANT AND IS NOT INTENDED FOR USE IN MISSION-CRITICAL

 * SYSTEMS, SUCH AS THOSE USED IN THE OPERATION OF NUCLEAR FACILITIES,

 * AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL

 * SYSTEMS, DIRECT LIFE SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH

 * THE FAILURE OF THE SOFTWARE OR SYSTEM COULD LEAD DIRECTLY TO DEATH,

 * PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH

 * RISK ACTIVITIES").  THE COPYRIGHT HOLDERS SPECIFICALLY DISCLAIM ANY

 * EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR HIGH RISK ACTIVITIES.

 * 

 * __END_OF_JASPER_LICENSE__

 */

/*

 * Tag-Value Parser Library

 *

 * $Id$

 */

/******************************************************************************\

* Includes.

\******************************************************************************/

#define JAS_FOR_INTERNAL_USE_ONLY

#include "jasper/jas_tvp.h"

#include "jasper/jas_malloc.h"

#include "jasper/jas_string.h"

#include <ctype.h>

#include <string.h>

/******************************************************************************\

* Macros.

\******************************************************************************/

/* Is the specified character valid for a tag name? */

#define JAS_TVP_ISTAG(x) \

  (isalpha(x) || (x) == '_' || isdigit(x))

/******************************************************************************\

* Code for creating and destroying a tag-value parser.

\******************************************************************************/

jas_tvparser_t *jas_tvparser_create(const char *s)

{

  jas_tvparser_t *tvp;

  if (!(tvp = jas_malloc(sizeof(jas_tvparser_t)))) {

    return 0;

  }

  if (!(tvp->buf = jas_strdup(s))) {

    jas_tvparser_destroy(tvp);

    return 0;

  }

  tvp->pos = tvp->buf;

  tvp->tag = 0;

  tvp->val = 0;

  return tvp;

}

void jas_tvparser_destroy(jas_tvparser_t *tvp)

{

  if (tvp->buf) {

    jas_free(tvp->buf);

  }

  jas_free(tvp);

}

/******************************************************************************\

* Main parsing code.

\******************************************************************************/

/* Get the next tag-value pair. */

int jas_tvparser_next(jas_tvparser_t *tvp)

{

  char *p;

  char *tag;

  char *val;

  /* Skip any leading whitespace. */

  p = tvp->pos;

  while (*p != '\0' && isspace(JAS_CAST(unsigned char, *p))) {

    ++p;

  }

  /* Has the end of the input data been reached? */

  if (*p == '\0') {

    /* No more tags are present. */

    tvp->pos = p;

    return 1;

  }

  /* Does the tag name begin with a valid character? */

  if (!JAS_TVP_ISTAG(JAS_CAST(unsigned char, *p))) {

    return -1;

  }

  /* Remember where the tag name begins. */

  tag = p;

  /* Find the end of the tag name. */

  while (*p != '\0' && JAS_TVP_ISTAG(JAS_CAST(unsigned char, *p))) {

    ++p;

  }

  /* Has the end of the input data been reached? */

  if (*p == '\0') {

    /* The value field is empty. */

    tvp->tag = tag;

    tvp->val = "";

    tvp->pos = p;

    return 0;

  }

  /* Is a value field not present? */

  if (*p != '=') {

    if (*p != '\0' && !isspace(JAS_CAST(unsigned char, *p))) {

      return -1;

    }

    *p++ = '\0';

    tvp->tag = tag;

    tvp->val = "";

    tvp->pos = p;

    return 0;

  }

  *p++ = '\0';

  val = p;

  while (*p != '\0' && !isspace(JAS_CAST(unsigned char, *p))) {

    ++p;

  }

  if (*p != '\0') {

    *p++ = '\0';

  }

  tvp->pos = p;

  tvp->tag = tag;

  tvp->val = val;

  return 0;

}

/******************************************************************************\

* Code for querying the current tag/value.

\******************************************************************************/

/* Get the current tag. */

const char *jas_tvparser_gettag(const jas_tvparser_t *tvp)

{

  return tvp->tag;

}

/* Get the current value. */

const char *jas_tvparser_getval(const jas_tvparser_t *tvp)

{

  return tvp->val;

}

/******************************************************************************\

* Miscellaneous code.

\******************************************************************************/

/* Lookup a tag by name. */

const jas_taginfo_t *jas_taginfos_lookup(const jas_taginfo_t *taginfos, const char *name)

{

  const jas_taginfo_t *taginfo;

  taginfo = taginfos;

  while (taginfo->id >= 0) {

    if (!strcmp(taginfo->name, name)) {

      return taginfo;

    }

    ++taginfo;

  }

  return 0;

}

/* This function is simply for convenience. */

/* One can avoid testing for the special case of a null pointer, by

  using this function.   This function never returns a null pointer.  */

const jas_taginfo_t *jas_taginfo_nonull(const jas_taginfo_t *taginfo)

{

  static const jas_taginfo_t invalidtaginfo = {

    -1, 0

  };

  return taginfo ? taginfo : &invalidtaginfo;

}