#ifndef OT_LAYOUT_GSUB_LIGATURE_HH

#define OT_LAYOUT_GSUB_LIGATURE_HH

#include "Common.hh"

namespace OT {

namespace Layout {

namespace GSUB_impl {

template <typename Types>

struct Ligature

{

  public:

  typename Types::HBGlyphID

    ligGlyph;               /* GlyphID of ligature to substitute */

  HeadlessArray16Of<typename Types::HBGlyphID>

    component;              /* Array of component GlyphIDs--start

                                         * with the second  component--ordered

                                         * in writing direction */

  public:

  DEFINE_SIZE_ARRAY (Types::size + 2, component);

  bool sanitize (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

    return_trace (ligGlyph.sanitize (c) && component.sanitize (c));

  }

  bool intersects (const hb_set_t *glyphs) const

  { return hb_all (component, glyphs); }

  bool intersects_lig_glyph (const hb_set_t *glyphs) const

  { return glyphs->has(ligGlyph); }

  void closure (hb_closure_context_t *c) const

  {

    if (!intersects (c->glyphs)) return;

    c->output->add (ligGlyph);

  }

  void depend (hb_depend_context_t *c, hb_codepoint_t first) const

  {

    // Build the complete ligature set upfront before adding any edges

    hb_set_t complete_ligset;

    complete_ligset.add (first);

    + hb_iter (component) | hb_sink (complete_ligset);

    if (unlikely (complete_ligset.in_error ()))

    {

      c->depend_data->fail ();

      return;

    }

    hb_codepoint_t ligset_idx = c->depend_data->new_ligature_set(complete_ligset);

    if (unlikely (ligset_idx == HB_CODEPOINT_INVALID))

      return;

    // Track whether any edge using this ligset_idx was actually added

    bool any_added = false;

    // Now add all edges with the complete, immutable set

    if (c->depend_data->add_gsub_lookup (first, c->lookup_index, ligGlyph, ligset_idx))

      any_added = true;

    + hb_iter (component)

    | hb_apply ([&] (const hb_codepoint_t &gid) {

        if (c->depend_data->add_gsub_lookup (gid, c->lookup_index, ligGlyph, ligset_idx))

          any_added = true;

      })

    ;

    // If no edges were added, the ligset_idx is unused - free it for reuse

    if (!any_added)

      c->depend_data->free_ligature_set(ligset_idx);

  }

  void collect_glyphs (hb_collect_glyphs_context_t *c) const

  {

    c->input->add_array (component.arrayZ, component.get_length ());

    c->output->add (ligGlyph);

  }

  template <typename set_t>

  void collect_second (set_t &s) const

  {

    if (unlikely (!component.get_length ()))

    {

      // A ligature without any components. Anything matches.

      s = set_t::full ();

      return;

    }

    s.add (component.arrayZ[0]);

  }

  bool would_apply (hb_would_apply_context_t *c) const

  {

    if (c->len != component.lenP1)

      return false;

    for (unsigned int i = 1; i < c->len; i++)

      if (likely (c->glyphs[i] != component[i]))

        return false;

    return true;

  }

  bool apply (hb_ot_apply_context_t *c) const

  {

    TRACE_APPLY (this);

    unsigned int count = component.lenP1;

    if (unlikely (!count)) return_trace (false);

    /* Special-case to make it in-place and not consider this

     * as a "ligated" substitution. */

    if (unlikely (count == 1))

    {

      if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())

      {

  c->buffer->sync_so_far ();

  c->buffer->message (c->font,

          "replacing glyph at %u (ligature substitution)",

          c->buffer->idx);

      }

      c->replace_glyph (ligGlyph);

      if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())

      {

  c->buffer->message (c->font,

          "replaced glyph at %u (ligature substitution)",

          c->buffer->idx - 1u);

      }

      return_trace (true);

    }

    unsigned int total_component_count = 0;

    if (unlikely (count > HB_MAX_CONTEXT_LENGTH)) return false;

    unsigned int match_end = 0;

    if (likely (!match_input (c, count,

                              &component[1],

                              match_glyph,

                              nullptr,

                              &match_end,

                              &total_component_count)))

    {

      c->buffer->unsafe_to_concat (c->buffer->idx, match_end);

      return_trace (false);

    }

    unsigned pos = 0;

    if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())

    {

      unsigned delta = c->buffer->sync_so_far ();

      pos = c->buffer->idx;

      char buf[HB_MAX_CONTEXT_LENGTH * 16] = {0};

      char *p = buf;

      match_end += delta;

      for (unsigned i = 0; i < count; i++)

      {

  c->match_positions[i] += delta;

  if (i)

    *p++ = ',';

  snprintf (p, sizeof(buf) - (p - buf), "%u", c->match_positions[i]);

  p += strlen(p);

      }

      c->buffer->message (c->font,

        "ligating glyphs at %s",

        buf);

    }

    ligate_input (c,

                  count,

                  match_end,

                  ligGlyph,

                  total_component_count);

    if (HB_BUFFER_MESSAGE_MORE && c->buffer->messaging ())

    {

      c->buffer->sync_so_far ();

      c->buffer->message (c->font,

        "ligated glyph at %u",

        pos);

    }

    return_trace (true);

  }

  template <typename Iterator,

            hb_requires (hb_is_source_of (Iterator, hb_codepoint_t))>

  bool serialize (hb_serialize_context_t *c,

                  hb_codepoint_t ligature,

                  Iterator components /* Starting from second */)

  {

    TRACE_SERIALIZE (this);

    if (unlikely (!c->extend_min (this))) return_trace (false);

    ligGlyph = ligature;

    if (unlikely (!component.serialize (c, components))) return_trace (false);

    return_trace (true);

  }

Unexecuted instantiation: _ZN2OT6Layout9GSUB_impl8LigatureINS0_10SmallTypesEE9serializeI10hb_array_tIKNS_11HBGlyphID16EETnPN12hb_enable_ifIXsr15hb_is_source_ofIT_jEE5valueEvE4typeELPv0EEEbP22hb_serialize_context_tjSB_

Unexecuted instantiation: _ZN2OT6Layout9GSUB_impl8LigatureINS0_10SmallTypesEE9serializeI13hb_map_iter_tI10hb_array_tIKNS_11HBGlyphID16EERK8hb_map_tL24hb_function_sortedness_t0ELPv0EETnPN12hb_enable_ifIXsr15hb_is_source_ofIT_jEE5valueEvE4typeELSF_0EEEbP22hb_serialize_context_tjSI_

  bool subset (hb_subset_context_t *c, unsigned coverage_idx) const

  {

    TRACE_SUBSET (this);

    const hb_set_t &glyphset = *c->plan->glyphset_gsub ();

    const hb_map_t &glyph_map = *c->plan->glyph_map;

    if (!intersects (&glyphset) || !glyphset.has (ligGlyph)) return_trace (false);

    // Ensure Coverage table is always packed after this.

    c->serializer->add_virtual_link (coverage_idx);

    auto it =

      + hb_iter (component)

      | hb_map (glyph_map)

      ;

    auto *out = c->serializer->start_embed (*this);

    return_trace (out->serialize (c->serializer,

                                  glyph_map[ligGlyph],

                                  it));  }

};

}

}

}

#endif  /* OT_LAYOUT_GSUB_LIGATURE_HH */