/*

 * Copyright © 2019  Ebrahim Byagowi

 *

 *  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.

 */

#ifndef HB_OT_META_TABLE_HH

#define HB_OT_META_TABLE_HH

#include "hb-open-type.hh"

/*

 * meta -- Metadata Table

 * https://docs.microsoft.com/en-us/typography/opentype/spec/meta

 * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6meta.html

 */

#define HB_OT_TAG_meta HB_TAG ('m','e','t','a')

namespace OT {

struct DataMap

{

  int cmp (hb_tag_t a) const { return tag.cmp (a); }

  hb_tag_t get_tag () const { return tag; }

  hb_blob_t *reference_entry (hb_blob_t *meta_blob) const

  { return hb_blob_create_sub_blob (meta_blob, dataZ, dataLength); }

  bool sanitize (hb_sanitize_context_t *c, const void *base) const

  {

    TRACE_SANITIZE (this);

    return_trace (likely (c->check_struct (this) &&

        hb_barrier () &&

        dataZ.sanitize (c, base, dataLength)));

  }

  protected:

  Tag   tag;    /* A tag indicating the type of metadata. */

  NNOffset32To<UnsizedArrayOf<HBUINT8>>

    dataZ;    /* Offset in bytes from the beginning of the

         * metadata table to the data for this tag. */

  HBUINT32  dataLength; /* Length of the data. The data is not required to

         * be padded to any byte boundary. */

  public:

  DEFINE_SIZE_STATIC (12);

};

struct meta

{

  static constexpr hb_tag_t tableTag = HB_OT_TAG_meta;

  struct accelerator_t

  {

    accelerator_t (hb_face_t *face)

    { table = hb_sanitize_context_t ().reference_table<meta> (face); }

    ~accelerator_t () { table.destroy (); }

    hb_blob_t *reference_entry (hb_tag_t tag) const

    { return table->dataMaps.lsearch (tag).reference_entry (table.get_blob ()); }

    unsigned int get_entries (unsigned int      start_offset,

            unsigned int     *count,

            hb_ot_meta_tag_t *entries) const

    {

      if (count)

      {

  + table->dataMaps.as_array ().sub_array (start_offset, count)

  | hb_map (&DataMap::get_tag)

  | hb_map ([](hb_tag_t tag) { return (hb_ot_meta_tag_t) tag; })

  | hb_sink (hb_array (entries, *count))

  ;

      }

      return table->dataMaps.len;

    }

    private:

    hb_blob_ptr_t<meta> table;

  };

  bool sanitize (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

    return_trace (likely (c->check_struct (this) &&

        hb_barrier () &&

        version == 1 &&

        dataMaps.sanitize (c, this)));

  }

  protected:

  HBUINT32  version;  /* Version number of the metadata table — set to 1. */

  HBUINT32  flags;    /* Flags — currently unused; set to 0. */

  HBUINT32  dataOffset;

        /* Per Apple specification:

         * Offset from the beginning of the table to the data.

         * Per OT specification:

         * Reserved. Not used; should be set to 0. */

  Array32Of<DataMap>

    dataMaps;/* Array of data map records. */

  public:

  DEFINE_SIZE_ARRAY (16, dataMaps);

};

struct meta_accelerator_t : meta::accelerator_t {

  meta_accelerator_t (hb_face_t *face) : meta::accelerator_t (face) {}

};

} /* namespace OT */

#endif /* HB_OT_META_TABLE_HH */