#ifndef OT_LAYOUT_GPOS_MARKBASEPOSFORMAT1_HH

#define OT_LAYOUT_GPOS_MARKBASEPOSFORMAT1_HH

#include "MarkArray.hh"

namespace OT {

namespace Layout {

namespace GPOS_impl {

typedef AnchorMatrix BaseArray;         /* base-major--

                                         * in order of BaseCoverage Index--,

                                         * mark-minor--

                                         * ordered by class--zero-based. */

template <typename Types>

struct MarkBasePosFormat1_2

{

  protected:

  HBUINT16      format;                 /* Format identifier--format = 1 */

  typename Types::template OffsetTo<Coverage>

                markCoverage;           /* Offset to MarkCoverage table--from

                                         * beginning of MarkBasePos subtable */

  typename Types::template OffsetTo<Coverage>

                baseCoverage;           /* Offset to BaseCoverage table--from

                                         * beginning of MarkBasePos subtable */

  HBUINT16      classCount;             /* Number of classes defined for marks */

  typename Types::template OffsetTo<MarkArray>

                markArray;              /* Offset to MarkArray table--from

                                         * beginning of MarkBasePos subtable */

  typename Types::template OffsetTo<BaseArray>

                baseArray;              /* Offset to BaseArray table--from

                                         * beginning of MarkBasePos subtable */

  public:

  DEFINE_SIZE_STATIC (4 + 4 * Types::size);

    bool sanitize (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

    return_trace (c->check_struct (this) &&

                  markCoverage.sanitize (c, this) &&

                  baseCoverage.sanitize (c, this) &&

                  markArray.sanitize (c, this) &&

                  baseArray.sanitize (c, this, (unsigned int) classCount));

  }

  bool intersects (const hb_set_t *glyphs) const

  {

    return (this+markCoverage).intersects (glyphs) &&

           (this+baseCoverage).intersects (glyphs);

  }

  void closure_lookups (hb_closure_lookups_context_t *c) const {}

  void collect_variation_indices (hb_collect_variation_indices_context_t *c) const

  {

    + hb_zip (this+markCoverage, this+markArray)

    | hb_filter (c->glyph_set, hb_first)

    | hb_map (hb_second)

    | hb_apply ([&] (const MarkRecord& record) { record.collect_variation_indices (c, &(this+markArray)); })

    ;

    hb_map_t klass_mapping;

    Markclass_closure_and_remap_indexes (this+markCoverage, this+markArray, *c->glyph_set, &klass_mapping);

    unsigned basecount = (this+baseArray).rows;

    auto base_iter =

    + hb_zip (this+baseCoverage, hb_range (basecount))

    | hb_filter (c->glyph_set, hb_first)

    | hb_map (hb_second)

    ;

    hb_sorted_vector_t<unsigned> base_indexes;

    for (const unsigned row : base_iter)

    {

      + hb_range ((unsigned) classCount)

      | hb_filter (klass_mapping)

      | hb_map ([&] (const unsigned col) { return row * (unsigned) classCount + col; })

      | hb_sink (base_indexes)

      ;

    }

    (this+baseArray).collect_variation_indices (c, base_indexes.iter ());

  }

  void collect_glyphs (hb_collect_glyphs_context_t *c) const

  {

    if (unlikely (!(this+markCoverage).collect_coverage (c->input))) return;

    if (unlikely (!(this+baseCoverage).collect_coverage (c->input))) return;

  }

  const Coverage &get_coverage () const { return this+markCoverage; }

  static inline bool accept (hb_buffer_t *buffer, unsigned idx)

  {

    /* We only want to attach to the first of a MultipleSubst sequence.

     * https://github.com/harfbuzz/harfbuzz/issues/740

     * Reject others...

     * ...but stop if we find a mark in the MultipleSubst sequence:

     * https://github.com/harfbuzz/harfbuzz/issues/1020 */

    return !_hb_glyph_info_multiplied (&buffer->info[idx]) ||

     0 == _hb_glyph_info_get_lig_comp (&buffer->info[idx]) ||

     (idx == 0 ||

      _hb_glyph_info_is_mark (&buffer->info[idx - 1]) ||

      !_hb_glyph_info_multiplied (&buffer->info[idx - 1]) ||

      _hb_glyph_info_get_lig_id (&buffer->info[idx]) !=

      _hb_glyph_info_get_lig_id (&buffer->info[idx - 1]) ||

      _hb_glyph_info_get_lig_comp (&buffer->info[idx]) !=

      _hb_glyph_info_get_lig_comp (&buffer->info[idx - 1]) + 1

      );

  }

  bool apply (hb_ot_apply_context_t *c) const

  {

    TRACE_APPLY (this);

    hb_buffer_t *buffer = c->buffer;

    unsigned int mark_index = (this+markCoverage).get_coverage  (buffer->cur().codepoint);

    if (likely (mark_index == NOT_COVERED)) return_trace (false);

    /* Now we search backwards for a non-mark glyph.

     * We don't use skippy_iter.prev() to avoid O(n^2) behavior. */

    hb_ot_apply_context_t::skipping_iterator_t &skippy_iter = c->iter_input;

    skippy_iter.set_lookup_props (LookupFlag::IgnoreMarks);

    if (c->last_base_until > buffer->idx)

    {

      c->last_base_until = 0;

      c->last_base = -1;

    }

    unsigned j;

    for (j = buffer->idx; j > c->last_base_until; j--)

    {

      auto match = skippy_iter.match (buffer->info[j - 1]);

      if (match == skippy_iter.MATCH)

      {

        // https://github.com/harfbuzz/harfbuzz/issues/4124

  if (!accept (buffer, j - 1) &&

      NOT_COVERED == (this+baseCoverage).get_coverage  (buffer->info[j - 1].codepoint))

    match = skippy_iter.SKIP;

      }

      if (match == skippy_iter.MATCH)

      {

  c->last_base = (signed) j - 1;

  break;

      }

    }

    c->last_base_until = buffer->idx;

    if (c->last_base == -1)

    {

      buffer->unsafe_to_concat_from_outbuffer (0, buffer->idx + 1);

      return_trace (false);

    }

    unsigned idx = (unsigned) c->last_base;

    /* Checking that matched glyph is actually a base glyph by GDEF is too strong; disabled */

    //if (!_hb_glyph_info_is_base_glyph (&buffer->info[idx])) { return_trace (false); }

    unsigned int base_index = (this+baseCoverage).get_coverage  (buffer->info[idx].codepoint);

    if (base_index == NOT_COVERED)

    {

      buffer->unsafe_to_concat_from_outbuffer (idx, buffer->idx + 1);

      return_trace (false);

    }

    return_trace ((this+markArray).apply (c, mark_index, base_index, this+baseArray, classCount, idx));

  }

  bool subset (hb_subset_context_t *c) const

  {

    TRACE_SUBSET (this);

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

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

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

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

    out->format = format;

    hb_map_t klass_mapping;

    Markclass_closure_and_remap_indexes (this+markCoverage, this+markArray, glyphset, &klass_mapping);

    if (!klass_mapping.get_population ()) return_trace (false);

    out->classCount = klass_mapping.get_population ();

    auto mark_iter =

    + hb_zip (this+markCoverage, this+markArray)

    | hb_filter (glyphset, hb_first)

    ;

    hb_sorted_vector_t<hb_codepoint_t> new_coverage;

    + mark_iter

    | hb_map (hb_first)

    | hb_map (glyph_map)

    | hb_sink (new_coverage)

    ;

    if (!out->markCoverage.serialize_serialize (c->serializer, new_coverage.iter ()))

      return_trace (false);

    if (unlikely (!out->markArray.serialize_subset (c, markArray, this,

                (this+markCoverage).iter (),

                &klass_mapping)))

      return_trace (false);

    unsigned basecount = (this+baseArray).rows;

    auto base_iter =

    + hb_zip (this+baseCoverage, hb_range (basecount))

    | hb_filter (glyphset, hb_first)

    ;

    new_coverage.reset ();

    + base_iter

    | hb_map (hb_first)

    | hb_map (glyph_map)

    | hb_sink (new_coverage)

    ;

    if (!out->baseCoverage.serialize_serialize (c->serializer, new_coverage.iter ()))

      return_trace (false);

    hb_sorted_vector_t<unsigned> base_indexes;

    for (const unsigned row : + base_iter

                              | hb_map (hb_second))

    {

      + hb_range ((unsigned) classCount)

      | hb_filter (klass_mapping)

      | hb_map ([&] (const unsigned col) { return row * (unsigned) classCount + col; })

      | hb_sink (base_indexes)

      ;

    }

    return_trace (out->baseArray.serialize_subset (c, baseArray, this,

               base_iter.len (),

               base_indexes.iter ()));

  }

};

}

}

}

#endif /* OT_LAYOUT_GPOS_MARKBASEPOSFORMAT1_HH */