/*

 * Copyright © 2012,2013  Google, Inc.

 *

 *  This is part of HarfBuzz, a text shaping library.

 *

 * Permission is hereby granted, without written agreement and without

 * license or royalty fees, to use, copy, modify, and distribute this

 * software and its documentation for any purpose, provided that the

 * above copyright notice and the following two paragraphs appear in

 * all copies of this software.

 *

 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR

 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES

 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN

 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 *

 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,

 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND

 * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS

 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO

 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.

 *

 * Google Author(s): Behdad Esfahbod

 */

#include "hb-buffer-private.hh"

static const char *serialize_formats[] = {

  "text",

  "json",

  NULL

};

/**

 * hb_buffer_serialize_list_formats:

 *

 * Returns a list of supported buffer serialization formats.

 *

 * Return value: (transfer none):

 * A string array of buffer serialization formats. Should not be freed.

 *

 * Since: 0.9.7

 **/

const char **

hb_buffer_serialize_list_formats (void)

{

  return serialize_formats;

}

/**

 * hb_buffer_serialize_format_from_string:

 * @str: (array length=len) (element-type uint8_t): a string to parse

 * @len: length of @str, or -1 if string is %NULL terminated

 *

 * Parses a string into an #hb_buffer_serialize_format_t. Does not check if

 * @str is a valid buffer serialization format, use

 * hb_buffer_serialize_list_formats() to get the list of supported formats.

 *

 * Return value: 

 * The parsed #hb_buffer_serialize_format_t.

 *

 * Since: 0.9.7

 **/

hb_buffer_serialize_format_t

hb_buffer_serialize_format_from_string (const char *str, int len)

{

  /* Upper-case it. */

  return (hb_buffer_serialize_format_t) (hb_tag_from_string (str, len) & ~0x20202020u);

}

/**

 * hb_buffer_serialize_format_to_string:

 * @format: an #hb_buffer_serialize_format_t to convert.

 *

 * Converts @format to the string corresponding it, or %NULL if it is not a valid

 * #hb_buffer_serialize_format_t.

 *

 * Return value: (transfer none):

 * A %NULL terminated string corresponding to @format. Should not be freed.

 *

 * Since: 0.9.7

 **/

const char *

hb_buffer_serialize_format_to_string (hb_buffer_serialize_format_t format)

{

  switch (format)

  {

    case HB_BUFFER_SERIALIZE_FORMAT_TEXT:	return serialize_formats[0];

    case HB_BUFFER_SERIALIZE_FORMAT_JSON:	return serialize_formats[1];

    default:

    case HB_BUFFER_SERIALIZE_FORMAT_INVALID:	return NULL;

  }

}

static unsigned int

_hb_buffer_serialize_glyphs_json (hb_buffer_t *buffer,

				  unsigned int start,

				  unsigned int end,

				  char *buf,

				  unsigned int buf_size,

				  unsigned int *buf_consumed,

				  hb_font_t *font,

				  hb_buffer_serialize_flags_t flags)

{

  hb_glyph_info_t *info = hb_buffer_get_glyph_infos (buffer, NULL);

  hb_glyph_position_t *pos = (flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS) ?

			     NULL : hb_buffer_get_glyph_positions (buffer, NULL);

  *buf_consumed = 0;

  for (unsigned int i = start; i < end; i++)

  {

    char b[1024];

    char *p = b;

    /* In the following code, we know b is large enough that no overflow can happen. */

#define APPEND(s) HB_STMT_START { strcpy (p, s); p += strlen (s); } HB_STMT_END

    if (i)

      *p++ = ',';

    *p++ = '{';

    APPEND ("\"g\":");

    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES))

    {

      char g[128];

      hb_font_glyph_to_string (font, info[i].codepoint, g, sizeof (g));

      *p++ = '"';

      for (char *q = g; *q; q++) {

        if (*q == '"')

	  *p++ = '\\';

	*p++ = *q;

      }

      *p++ = '"';

    }

    else

      p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "%u", info[i].codepoint));

    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS)) {

      p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"cl\":%u", info[i].cluster));

    }

    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS))

    {

      p += snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"dx\":%d,\"dy\":%d",

		     pos[i].x_offset, pos[i].y_offset);

      p += snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"ax\":%d,\"ay\":%d",

		     pos[i].x_advance, pos[i].y_advance);

    }

    if (flags & HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS)

    {

      hb_glyph_extents_t extents;

      hb_font_get_glyph_extents(font, info[i].codepoint, &extents);

      p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"xb\":%d,\"yb\":%d",

        extents.x_bearing, extents.y_bearing));

      p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",\"w\":%d,\"h\":%d",

        extents.width, extents.height));

    }

    *p++ = '}';

    unsigned int l = p - b;

    if (buf_size > l)

    {

      memcpy (buf, b, l);

      buf += l;

      buf_size -= l;

      *buf_consumed += l;

      *buf = '\0';

    } else

      return i - start;

  }

  return end - start;

}

static unsigned int

_hb_buffer_serialize_glyphs_text (hb_buffer_t *buffer,

				  unsigned int start,

				  unsigned int end,

				  char *buf,

				  unsigned int buf_size,

				  unsigned int *buf_consumed,

				  hb_font_t *font,

				  hb_buffer_serialize_flags_t flags)

{

  hb_glyph_info_t *info = hb_buffer_get_glyph_infos (buffer, NULL);

  hb_glyph_position_t *pos = (flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS) ?

			     NULL : hb_buffer_get_glyph_positions (buffer, NULL);

  *buf_consumed = 0;

  for (unsigned int i = start; i < end; i++)

  {

    char b[1024];

    char *p = b;

    /* In the following code, we know b is large enough that no overflow can happen. */

    if (i)

      *p++ = '|';

    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES))

    {

      hb_font_glyph_to_string (font, info[i].codepoint, p, 128);

      p += strlen (p);

    }

    else

      p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "%u", info[i].codepoint));

    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS)) {

      p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "=%u", info[i].cluster));

    }

    if (!(flags & HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS))

    {

      if (pos[i].x_offset || pos[i].y_offset)

	p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "@%d,%d", pos[i].x_offset, pos[i].y_offset));

      *p++ = '+';

      p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "%d", pos[i].x_advance));

      if (pos[i].y_advance)

	p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), ",%d", pos[i].y_advance));

    }

    if (flags & HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS)

    {

      hb_glyph_extents_t extents;

      hb_font_get_glyph_extents(font, info[i].codepoint, &extents);

      p += MAX (0, snprintf (p, ARRAY_LENGTH (b) - (p - b), "<%d,%d,%d,%d>", extents.x_bearing, extents.y_bearing, extents.width, extents.height));

    }

    unsigned int l = p - b;

    if (buf_size > l)

    {

      memcpy (buf, b, l);

      buf += l;

      buf_size -= l;

      *buf_consumed += l;

      *buf = '\0';

    } else

      return i - start;

  }

  return end - start;

}

/**

 * hb_buffer_serialize_glyphs:

 * @buffer: an #hb_buffer_t buffer.

 * @start: the first item in @buffer to serialize.

 * @end: the last item in @buffer to serialize.

 * @buf: (out) (array length=buf_size) (element-type uint8_t): output string to

 *       write serialized buffer into.

 * @buf_size: the size of @buf.

 * @buf_consumed: (out) (allow-none): if not %NULL, will be set to the number of byes written into @buf.

 * @font: (allow-none): the #hb_font_t used to shape this buffer, needed to

 *        read glyph names and extents. If %NULL, and empty font will be used.

 * @format: the #hb_buffer_serialize_format_t to use for formatting the output.

 * @flags: the #hb_buffer_serialize_flags_t that control what glyph properties

 *         to serialize.

 *

 * Serializes @buffer into a textual representation of its glyph content,

 * useful for showing the contents of the buffer, for example during debugging.

 * There are currently two supported serialization formats:

 *

 * ## text

 * A human-readable, plain text format.

 * The serialized glyphs will look something like:

 *

 * ```

 * [uni0651=0@518,0+0|uni0628=0+1897]

 * ```

 * - The serialized glyphs are delimited with `[` and `]`.

 * - Glyphs are separated with `|`

 * - Each glyph starts with glyph name, or glyph index if

 *   #HB_BUFFER_SERIALIZE_FLAG_NO_GLYPH_NAMES flag is set. Then,

 *   - If #HB_BUFFER_SERIALIZE_FLAG_NO_CLUSTERS is not set, `=` then #hb_glyph_info_t.cluster.

 *   - If #HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS is not set, the #hb_glyph_position_t in the format:

 *     - If both #hb_glyph_position_t.x_offset and #hb_glyph_position_t.y_offset are not 0, `@x_offset,y_offset`. Then,

 *     - `+x_advance`, then `,y_advance` if #hb_glyph_position_t.y_advance is not 0. Then,

 *   - If #HB_BUFFER_SERIALIZE_FLAG_GLYPH_EXTENTS is set, the

 *     #hb_glyph_extents_t in the format

 *     `<x_bearing,y_bearing,width,height>`

 *

 * ## json

 * TODO.

 *

 * Return value: 

 * The number of serialized items.

 *

 * Since: 0.9.7

 **/

unsigned int

hb_buffer_serialize_glyphs (hb_buffer_t *buffer,

			    unsigned int start,

			    unsigned int end,

			    char *buf,

			    unsigned int buf_size,

			    unsigned int *buf_consumed,

			    hb_font_t *font,

			    hb_buffer_serialize_format_t format,

			    hb_buffer_serialize_flags_t flags)

{

  assert (start <= end && end <= buffer->len);

  unsigned int sconsumed;

  if (!buf_consumed)

    buf_consumed = &sconsumed;

  *buf_consumed = 0;

  if (buf_size)

    *buf = '\0';

  assert ((!buffer->len && buffer->content_type == HB_BUFFER_CONTENT_TYPE_INVALID) ||

	  buffer->content_type == HB_BUFFER_CONTENT_TYPE_GLYPHS);

  if (!buffer->have_positions)

    flags |= HB_BUFFER_SERIALIZE_FLAG_NO_POSITIONS;

  if (unlikely (start == end))

    return 0;

  if (!font)

    font = hb_font_get_empty ();

  switch (format)

  {

    case HB_BUFFER_SERIALIZE_FORMAT_TEXT:

      return _hb_buffer_serialize_glyphs_text (buffer, start, end,

					       buf, buf_size, buf_consumed,

					       font, flags);

    case HB_BUFFER_SERIALIZE_FORMAT_JSON:

      return _hb_buffer_serialize_glyphs_json (buffer, start, end,

					       buf, buf_size, buf_consumed,

					       font, flags);

    default:

    case HB_BUFFER_SERIALIZE_FORMAT_INVALID:

      return 0;

  }

}

static hb_bool_t

parse_uint (const char *pp, const char *end, uint32_t *pv)

{

  char buf[32];

  unsigned int len = MIN (ARRAY_LENGTH (buf) - 1, (unsigned int) (end - pp));

  strncpy (buf, pp, len);

  buf[len] = '\0';

  char *p = buf;

  char *pend = p;

  uint32_t v;

  errno = 0;

  v = strtol (p, &pend, 10);

  if (errno || p == pend || pend - p != end - pp)

    return false;

  *pv = v;

  return true;

}

static hb_bool_t

parse_int (const char *pp, const char *end, int32_t *pv)

{

  char buf[32];

  unsigned int len = MIN (ARRAY_LENGTH (buf) - 1, (unsigned int) (end - pp));

  strncpy (buf, pp, len);

  buf[len] = '\0';

  char *p = buf;

  char *pend = p;

  int32_t v;

  errno = 0;

  v = strtol (p, &pend, 10);

  if (errno || p == pend || pend - p != end - pp)

    return false;

  *pv = v;

  return true;

}

#include "hb-buffer-deserialize-json.hh"

#include "hb-buffer-deserialize-text.hh"

/**

 * hb_buffer_deserialize_glyphs:

 * @buffer: an #hb_buffer_t buffer.

 * @buf: (array length=buf_len):

 * @buf_len: 

 * @end_ptr: (out):

 * @font: 

 * @format: 

 *

 * 

 *

 * Return value: 

 *

 * Since: 0.9.7

 **/

hb_bool_t

hb_buffer_deserialize_glyphs (hb_buffer_t *buffer,

			      const char *buf,

			      int buf_len, /* -1 means nul-terminated */

			      const char **end_ptr, /* May be NULL */

			      hb_font_t *font, /* May be NULL */

			      hb_buffer_serialize_format_t format)

{

  const char *end;

  if (!end_ptr)

    end_ptr = &end;

  *end_ptr = buf;

  assert ((!buffer->len && buffer->content_type == HB_BUFFER_CONTENT_TYPE_INVALID) ||

	  buffer->content_type == HB_BUFFER_CONTENT_TYPE_GLYPHS);

  if (buf_len == -1)

    buf_len = strlen (buf);

  if (!buf_len)

  {

    *end_ptr = buf;

    return false;

  }

  hb_buffer_set_content_type (buffer, HB_BUFFER_CONTENT_TYPE_GLYPHS);

  if (!font)

    font = hb_font_get_empty ();

  switch (format)

  {

    case HB_BUFFER_SERIALIZE_FORMAT_TEXT:

      return _hb_buffer_deserialize_glyphs_text (buffer,

						 buf, buf_len, end_ptr,

						 font);

    case HB_BUFFER_SERIALIZE_FORMAT_JSON:

      return _hb_buffer_deserialize_glyphs_json (buffer,

						 buf, buf_len, end_ptr,

						 font);

    default:

    case HB_BUFFER_SERIALIZE_FORMAT_INVALID:

      return false;

  }

}