/*

 * Copyright © 2023  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): Garret Rieger, Qunxin Liu, Roderick Sheeter

 */

#include "hb-subset-plan.hh"

#include "hb-ot-layout-gdef-table.hh"

#include "hb-ot-layout-gpos-table.hh"

#include "hb-ot-layout-gsub-table.hh"

using OT::Layout::GSUB;

using OT::Layout::GPOS;

#ifndef HB_NO_SUBSET_LAYOUT

void

remap_used_mark_sets (hb_subset_plan_t *plan,

                      hb_map_t& used_mark_sets_map)

{

  hb_blob_ptr_t<OT::GDEF> gdef = plan->source_table<OT::GDEF> ();

  if (!gdef->has_data () || !gdef->has_mark_glyph_sets ())

  {

    gdef.destroy ();

    return;

  }

  hb_set_t used_mark_sets;

  gdef->get_mark_glyph_sets ().collect_used_mark_sets (plan->_glyphset_gsub, used_mark_sets);

  gdef.destroy ();

  remap_indexes (&used_mark_sets, &used_mark_sets_map);

}

/*

 * Removes all tags from 'tags' that are not in filter. Additionally eliminates any duplicates.

 * Returns true if anything was removed (not including duplicates).

 */

static bool _filter_tag_list(hb_vector_t<hb_tag_t>* tags, /* IN/OUT */

                             const hb_set_t* filter)

{

  hb_vector_t<hb_tag_t> out;

  out.alloc (tags->get_size() + 1); // +1 is to allocate room for the null terminator.

  bool removed = false;

  hb_set_t visited;

  for (hb_tag_t tag : *tags)

  {

    if (!tag) continue;

    if (visited.has (tag)) continue;

    if (!filter->has (tag))

    {

      removed = true;

      continue;

    }

    visited.add (tag);

    out.push (tag);

  }

  // The collect function needs a null element to signal end of the array.

  out.push (HB_TAG_NONE);

  hb_swap (out, *tags);

  return removed;

}

template <typename T>

static void _collect_layout_indices (hb_subset_plan_t     *plan,

                                     const T&              table,

                                     hb_set_t     *lookup_indices, /* OUT */

                                     hb_set_t     *feature_indices, /* OUT */

                                     hb_hashmap_t<unsigned, hb::shared_ptr<hb_set_t>> *feature_record_cond_idx_map, /* OUT */

                                     hb_hashmap_t<unsigned, const OT::Feature*> *feature_substitutes_map, /* OUT */

                                     hb_set_t& catch_all_record_feature_idxes, /* OUT */

                                     hb_hashmap_t<unsigned, hb_pair_t<const void*, const void*>>& catch_all_record_idx_feature_map /* OUT */)

{

  unsigned num_features = table.get_feature_count ();

  hb_vector_t<hb_tag_t> features;

  if (!plan->check_success (features.resize (num_features))) return;

  table.get_feature_tags (0, &num_features, features.arrayZ);

  bool retain_all_features = !_filter_tag_list (&features, &plan->layout_features);

  unsigned num_scripts = table.get_script_count ();

  hb_vector_t<hb_tag_t> scripts;

  if (!plan->check_success (scripts.resize (num_scripts))) return;

  table.get_script_tags (0, &num_scripts, scripts.arrayZ);

  bool retain_all_scripts = !_filter_tag_list (&scripts, &plan->layout_scripts);

  if (!plan->check_success (!features.in_error ()) || !features

      || !plan->check_success (!scripts.in_error ()) || !scripts)

    return;

  hb_ot_layout_collect_features (plan->source,

                                 T::tableTag,

                                 retain_all_scripts ? nullptr : scripts.arrayZ,

                                 nullptr,

                                 retain_all_features ? nullptr : features.arrayZ,

                                 feature_indices);

#ifndef HB_NO_VAR

  // collect feature substitutes with variations

  if (!plan->user_axes_location.is_empty ())

  {

    hb_hashmap_t<hb::shared_ptr<hb_map_t>, unsigned> conditionset_map;

    OT::hb_collect_feature_substitutes_with_var_context_t c =

    {

      &plan->axes_old_index_tag_map,

      &plan->axes_location,

      feature_record_cond_idx_map,

      feature_substitutes_map,

      catch_all_record_feature_idxes,

      feature_indices,

      false,

      false,

      false,

      0,

      &conditionset_map

    };

    table.collect_feature_substitutes_with_variations (&c);

  }

#endif

  for (unsigned feature_index : *feature_indices)

  {

    const OT::Feature* f = &(table.get_feature (feature_index));

    const OT::Feature **p = nullptr;

    if (feature_substitutes_map->has (feature_index, &p))

      f = *p;

    f->add_lookup_indexes_to (lookup_indices);

  }

#ifndef HB_NO_VAR

  if (catch_all_record_feature_idxes)

  {

    for (unsigned feature_index : catch_all_record_feature_idxes)

    {

      const OT::Feature& f = table.get_feature (feature_index);

      f.add_lookup_indexes_to (lookup_indices);

      const void *tag = reinterpret_cast<const void*> (&(table.get_feature_list ().get_tag (feature_index)));

      catch_all_record_idx_feature_map.set (feature_index, hb_pair (&f, tag));

    }

  }

  // If all axes are pinned then all feature variations will be dropped so there's no need

  // to collect lookups from them.

  if (!plan->all_axes_pinned)

    table.feature_variation_collect_lookups (feature_indices,

                                             plan->user_axes_location.is_empty () ? nullptr: feature_record_cond_idx_map,

                                             lookup_indices);

#endif

}

Unexecuted instantiation: hb-subset-plan-layout.cc:void _collect_layout_indices<OT::Layout::GSUB>(hb_subset_plan_t*, OT::Layout::GSUB const&, hb_set_t*, hb_set_t*, hb_hashmap_t<unsigned int, hb::shared_ptr<hb_set_t>, false>*, hb_hashmap_t<unsigned int, OT::Feature const*, false>*, hb_set_t&, hb_hashmap_t<unsigned int, hb_pair_t<void const*, void const*>, false>&)

Unexecuted instantiation: hb-subset-plan-layout.cc:void _collect_layout_indices<OT::Layout::GPOS>(hb_subset_plan_t*, OT::Layout::GPOS const&, hb_set_t*, hb_set_t*, hb_hashmap_t<unsigned int, hb::shared_ptr<hb_set_t>, false>*, hb_hashmap_t<unsigned int, OT::Feature const*, false>*, hb_set_t&, hb_hashmap_t<unsigned int, hb_pair_t<void const*, void const*>, false>&)

static inline void

_GSUBGPOS_find_duplicate_features (const OT::GSUBGPOS &g,

           const hb_map_t *lookup_indices,

           const hb_set_t *feature_indices,

           const hb_hashmap_t<unsigned, const OT::Feature*> *feature_substitutes_map,

           hb_map_t *duplicate_feature_map /* OUT */)

{

  if (feature_indices->is_empty ()) return;

  hb_hashmap_t<hb_tag_t, hb::unique_ptr<hb_set_t>> unique_features;

  //find out duplicate features after subset

  for (unsigned i : feature_indices->iter ())

  {

    hb_tag_t t = g.get_feature_tag (i);

    if (t == HB_MAP_VALUE_INVALID) continue;

    if (!unique_features.has (t))

    {

      if (unlikely (!unique_features.set (t, hb::unique_ptr<hb_set_t> {hb_set_create ()})))

  return;

      if (unique_features.has (t))

  unique_features.get (t)->add (i);

      duplicate_feature_map->set (i, i);

      continue;

    }

    bool found = false;

    hb_set_t* same_tag_features = unique_features.get (t);

    for (unsigned other_f_index : same_tag_features->iter ())

    {

      const OT::Feature* f = &(g.get_feature (i));

      const OT::Feature **p = nullptr;

      if (feature_substitutes_map->has (i, &p))

        f = *p;

      const OT::Feature* other_f = &(g.get_feature (other_f_index));

      if (feature_substitutes_map->has (other_f_index, &p))

        other_f = *p;

      auto f_iter =

      + hb_iter (f->lookupIndex)

      | hb_filter (lookup_indices)

      ;

      auto other_f_iter =

      + hb_iter (other_f->lookupIndex)

      | hb_filter (lookup_indices)

      ;

      bool is_equal = true;

      for (; f_iter && other_f_iter; f_iter++, other_f_iter++)

      {

  unsigned a = *f_iter;

  unsigned b = *other_f_iter;

  if (a != b) { is_equal = false; break; }

      }

      if (is_equal == false || f_iter || other_f_iter) continue;

      found = true;

      duplicate_feature_map->set (i, other_f_index);

      break;

    }

    if (found == false)

    {

      same_tag_features->add (i);

      duplicate_feature_map->set (i, i);

    }

  }

}

static void

remap_feature_indices (const hb_set_t &feature_indices,

                       const hb_map_t &duplicate_feature_map,

                       const hb_hashmap_t<unsigned, hb_pair_t<const void*, const void*>>& catch_all_record_idx_feature_map,

                       hb_map_t       *mapping, /* OUT */

                       hb_map_t       *mapping_w_duplicates /* OUT */)

{

  unsigned i = 0;

  for (const auto _ : feature_indices)

  {

    // retain those features in case we need to insert a catch-all record to reinstate the old features

    if (catch_all_record_idx_feature_map.has (_))

    {

      mapping->set (_, i);

      mapping_w_duplicates->set (_, i);

      i++;

    }

    else

    {

      uint32_t f_idx = duplicate_feature_map.get (_);

      uint32_t *new_idx;

      if (mapping-> has (f_idx, &new_idx))

      {

        mapping_w_duplicates->set (_, *new_idx);

      }

      else

      {

        mapping->set (_, i);

        mapping_w_duplicates->set (_, i);

        i++;

      }

    }

  }

}

template <typename T>

static void

_closure_glyphs_lookups_features (hb_subset_plan_t   *plan,

         hb_set_t      *gids_to_retain,

         hb_map_t      *lookups,

         hb_map_t      *features,

         hb_map_t      *features_w_duplicates,

         script_langsys_map *langsys_map,

         hb_hashmap_t<unsigned, hb::shared_ptr<hb_set_t>> *feature_record_cond_idx_map,

         hb_hashmap_t<unsigned, const OT::Feature*> *feature_substitutes_map,

                                 hb_set_t &catch_all_record_feature_idxes,

                                 hb_hashmap_t<unsigned, hb_pair_t<const void*, const void*>>& catch_all_record_idx_feature_map)

{

  hb_blob_ptr_t<T> table = plan->source_table<T> ();

  hb_tag_t table_tag = table->tableTag;

  hb_set_t lookup_indices, feature_indices;

  _collect_layout_indices<T> (plan,

                              *table,

                              &lookup_indices,

                              &feature_indices,

                              feature_record_cond_idx_map,

                              feature_substitutes_map,

                              catch_all_record_feature_idxes,

                              catch_all_record_idx_feature_map);

  if (table_tag == HB_OT_TAG_GSUB && !(plan->flags & HB_SUBSET_FLAGS_NO_LAYOUT_CLOSURE))

    hb_ot_layout_lookups_substitute_closure (plan->source,

                                             &lookup_indices,

               gids_to_retain);

  table->closure_lookups (plan->source,

        gids_to_retain,

                          &lookup_indices);

  remap_indexes (&lookup_indices, lookups);

  // prune features

  table->prune_features (lookups,

                         plan->user_axes_location.is_empty () ? nullptr : feature_record_cond_idx_map,

                         feature_substitutes_map,

                         &feature_indices);

  hb_map_t duplicate_feature_map;

  _GSUBGPOS_find_duplicate_features (*table, lookups, &feature_indices, feature_substitutes_map, &duplicate_feature_map);

  feature_indices.clear ();

  table->prune_langsys (&duplicate_feature_map, &plan->layout_scripts, langsys_map, &feature_indices);

  remap_feature_indices (feature_indices, duplicate_feature_map, catch_all_record_idx_feature_map, features, features_w_duplicates);

  table.destroy ();

}

Unexecuted instantiation: hb-subset-plan-layout.cc:void _closure_glyphs_lookups_features<OT::Layout::GSUB>(hb_subset_plan_t*, hb_set_t*, hb_map_t*, hb_map_t*, hb_map_t*, hb_hashmap_t<unsigned int, hb::unique_ptr<hb_set_t>, false>*, hb_hashmap_t<unsigned int, hb::shared_ptr<hb_set_t>, false>*, hb_hashmap_t<unsigned int, OT::Feature const*, false>*, hb_set_t&, hb_hashmap_t<unsigned int, hb_pair_t<void const*, void const*>, false>&)

Unexecuted instantiation: hb-subset-plan-layout.cc:void _closure_glyphs_lookups_features<OT::Layout::GPOS>(hb_subset_plan_t*, hb_set_t*, hb_map_t*, hb_map_t*, hb_map_t*, hb_hashmap_t<unsigned int, hb::unique_ptr<hb_set_t>, false>*, hb_hashmap_t<unsigned int, hb::shared_ptr<hb_set_t>, false>*, hb_hashmap_t<unsigned int, OT::Feature const*, false>*, hb_set_t&, hb_hashmap_t<unsigned int, hb_pair_t<void const*, void const*>, false>&)

void layout_nameid_closure (hb_subset_plan_t* plan,

                             hb_set_t* drop_tables)

{

  if (!drop_tables->has (HB_OT_TAG_GPOS))

  {

    hb_blob_ptr_t<GPOS> gpos = plan->source_table<GPOS> ();

    gpos->collect_name_ids (&plan->gpos_features, &plan->name_ids);

    gpos.destroy ();

  }

  if (!drop_tables->has (HB_OT_TAG_GSUB))

  {

    hb_blob_ptr_t<GSUB> gsub = plan->source_table<GSUB> ();

    gsub->collect_name_ids (&plan->gsub_features, &plan->name_ids);

    gsub.destroy ();

  }

}

void

layout_populate_gids_to_retain (hb_subset_plan_t* plan,

                    hb_set_t* drop_tables) {

  if (!drop_tables->has (HB_OT_TAG_GSUB))

    // closure all glyphs/lookups/features needed for GSUB substitutions.

    _closure_glyphs_lookups_features<GSUB> (

        plan,

        &plan->_glyphset_gsub,

        &plan->gsub_lookups,

        &plan->gsub_features,

        &plan->gsub_features_w_duplicates,

        &plan->gsub_langsys,

        &plan->gsub_feature_record_cond_idx_map,

        &plan->gsub_feature_substitutes_map,

        plan->gsub_old_features,

        plan->gsub_old_feature_idx_tag_map);

  if (!drop_tables->has (HB_OT_TAG_GPOS))

    _closure_glyphs_lookups_features<GPOS> (

        plan,

        &plan->_glyphset_gsub,

        &plan->gpos_lookups,

        &plan->gpos_features,

        &plan->gpos_features_w_duplicates,

        &plan->gpos_langsys,

        &plan->gpos_feature_record_cond_idx_map,

        &plan->gpos_feature_substitutes_map,

        plan->gpos_old_features,

        plan->gpos_old_feature_idx_tag_map);

}

#ifndef HB_NO_VAR

void

collect_layout_variation_indices (hb_subset_plan_t* plan)

{

  hb_blob_ptr_t<OT::GDEF> gdef = plan->source_table<OT::GDEF> ();

  hb_blob_ptr_t<GPOS> gpos = plan->source_table<GPOS> ();

  if (!gdef->has_data () || !gdef->has_var_store ())

  {

    gdef.destroy ();

    gpos.destroy ();

    return;

  }

  hb_set_t varidx_set;

  OT::hb_collect_variation_indices_context_t c (&varidx_set,

                                                &plan->_glyphset_gsub,

                                                &plan->gpos_lookups);

  gdef->collect_variation_indices (&c);

  if (hb_ot_layout_has_positioning (plan->source))

    gpos->collect_variation_indices (&c);

  remap_variation_indices (gdef->get_var_store (),

                           varidx_set, plan->normalized_coords,

                           !plan->pinned_at_default,

                           plan->all_axes_pinned,

                           plan->layout_variation_idx_delta_map);

  unsigned subtable_count = gdef->get_var_store ().get_sub_table_count ();

  generate_varstore_inner_maps (varidx_set, subtable_count, plan->gdef_varstore_inner_maps);

  gdef.destroy ();

  gpos.destroy ();

}

#endif

#endif