/*

 * Copyright © 2018  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_AAT_LAYOUT_FEAT_TABLE_HH

#define HB_AAT_LAYOUT_FEAT_TABLE_HH

#include "hb-aat-layout-common.hh"

/*

 * feat -- Feature Name

 * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6feat.html

 */

#define HB_AAT_TAG_feat HB_TAG('f','e','a','t')

namespace AAT {

struct SettingName

{

  friend struct FeatureName;

  int cmp (hb_aat_layout_feature_selector_t key) const

  { return (int) key - (int) setting; }

  hb_aat_layout_feature_selector_t get_selector () const

  { return (hb_aat_layout_feature_selector_t) (unsigned) setting; }

  hb_aat_layout_feature_selector_info_t get_info (hb_aat_layout_feature_selector_t default_selector) const

  {

    return {

      nameIndex,

      (hb_aat_layout_feature_selector_t) (unsigned int) setting,

      default_selector == HB_AAT_LAYOUT_FEATURE_SELECTOR_INVALID

  ? (hb_aat_layout_feature_selector_t) (setting + 1)

  : default_selector,

      0

    };

  }

  bool sanitize (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

    return_trace (c->check_struct (this));

  }

  protected:

  HBUINT16  setting;  /* The setting. */

  NameID  nameIndex;  /* The name table index for the setting's name. */

  public:

  DEFINE_SIZE_STATIC (4);

};

DECLARE_NULL_NAMESPACE_BYTES (AAT, SettingName);

struct feat;

struct FeatureName

{

  int cmp (hb_aat_layout_feature_type_t key) const

  { return (int) key - (int) feature; }

  enum {

    Exclusive = 0x8000, /* If set, the feature settings are mutually exclusive. */

    NotDefault  = 0x4000, /* If clear, then the setting with an index of 0 in

         * the setting name array for this feature should

         * be taken as the default for the feature

         * (if one is required). If set, then bits 0-15 of this

         * featureFlags field contain the index of the setting

         * which is to be taken as the default. */

    IndexMask = 0x00FF  /* If bits 30 and 31 are set, then these sixteen bits

         * indicate the index of the setting in the setting name

         * array for this feature which should be taken

         * as the default. */

  };

  unsigned int get_selector_infos (unsigned int                           start_offset,

           unsigned int                          *selectors_count, /* IN/OUT.  May be NULL. */

           hb_aat_layout_feature_selector_info_t *selectors,       /* OUT.     May be NULL. */

           unsigned int                          *pdefault_index,  /* OUT.     May be NULL. */

           const void *base) const

  {

    hb_array_t< const SettingName> settings_table = (base+settingTableZ).as_array (nSettings);

    static_assert (Index::NOT_FOUND_INDEX == HB_AAT_LAYOUT_NO_SELECTOR_INDEX, "");

    hb_aat_layout_feature_selector_t default_selector = HB_AAT_LAYOUT_FEATURE_SELECTOR_INVALID;

    unsigned int default_index = Index::NOT_FOUND_INDEX;

    if (featureFlags & Exclusive)

    {

      default_index = (featureFlags & NotDefault) ? featureFlags & IndexMask : 0;

      default_selector = settings_table[default_index].get_selector ();

    }

    if (pdefault_index)

      *pdefault_index = default_index;

    if (selectors_count)

    {

      + settings_table.sub_array (start_offset, selectors_count)

      | hb_map ([=] (const SettingName& setting) { return setting.get_info (default_selector); })

      | hb_sink (hb_array (selectors, *selectors_count))

      ;

    }

    return settings_table.length;

  }

  hb_aat_layout_feature_type_t get_feature_type () const

  { return (hb_aat_layout_feature_type_t) (unsigned int) feature; }

  hb_ot_name_id_t get_feature_name_id () const { return nameIndex; }

  bool is_exclusive () const { return featureFlags & Exclusive; }

  /* A FeatureName with no settings is meaningless */

  bool has_data () const { return nSettings; }

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

  {

    TRACE_SANITIZE (this);

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

        hb_barrier () &&

        (base+settingTableZ).sanitize (c, nSettings)));

  }

  protected:

  HBUINT16  feature;  /* Feature type. */

  HBUINT16  nSettings;  /* The number of records in the setting name array. */

  NNOffset32To<UnsizedArrayOf<SettingName>>

    settingTableZ;  /* Offset in bytes from the beginning of this table to

         * this feature's setting name array. The actual type of

         * record this offset refers to will depend on the

         * exclusivity value, as described below. */

  HBUINT16  featureFlags; /* Single-bit flags associated with the feature type. */

  HBINT16 nameIndex;  /* The name table index for the feature's name.

         * This index has values greater than 255 and

         * less than 32768. */

  public:

  DEFINE_SIZE_STATIC (12);

};

struct feat

{

  static constexpr hb_tag_t tableTag = HB_AAT_TAG_feat;

  bool has_data () const { return version.to_int (); }

  unsigned int get_feature_types (unsigned int                  start_offset,

          unsigned int                 *count,

          hb_aat_layout_feature_type_t *features) const

  {

    if (count)

    {

      + namesZ.as_array (featureNameCount).sub_array (start_offset, count)

      | hb_map (&FeatureName::get_feature_type)

      | hb_sink (hb_array (features, *count))

      ;

    }

    return featureNameCount;

  }

  bool exposes_feature (hb_aat_layout_feature_type_t feature_type) const

  { return get_feature (feature_type).has_data (); }

  const FeatureName& get_feature (hb_aat_layout_feature_type_t feature_type) const

  { return namesZ.bsearch (featureNameCount, feature_type); }

  hb_ot_name_id_t get_feature_name_id (hb_aat_layout_feature_type_t feature) const

  { return get_feature (feature).get_feature_name_id (); }

  unsigned int get_selector_infos (hb_aat_layout_feature_type_t           feature_type,

           unsigned int                           start_offset,

           unsigned int                          *selectors_count, /* IN/OUT.  May be NULL. */

           hb_aat_layout_feature_selector_info_t *selectors,       /* OUT.     May be NULL. */

           unsigned int                          *default_index    /* OUT.     May be NULL. */) const

  {

    return get_feature (feature_type).get_selector_infos (start_offset, selectors_count, selectors,

                default_index, this);

  }

  bool sanitize (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

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

        hb_barrier () &&

        version.major == 1 &&

        namesZ.sanitize (c, featureNameCount, this)));

  }

  protected:

  FixedVersion<>version;  /* Version number of the feature name table

         * (0x00010000 for the current version). */

  HBUINT16  featureNameCount;

        /* The number of entries in the feature name array. */

  HBUINT16  reserved1;  /* Reserved (set to zero). */

  HBUINT32  reserved2;  /* Reserved (set to zero). */

  SortedUnsizedArrayOf<FeatureName>

    namesZ;   /* The feature name array. */

  public:

  DEFINE_SIZE_ARRAY (12, namesZ);

};

} /* namespace AAT */

#endif /* HB_AAT_LAYOUT_FEAT_TABLE_HH */