#ifndef OT_LAYOUT_GSUB_MULTIPLESUBSTFORMAT1_HH

#define OT_LAYOUT_GSUB_MULTIPLESUBSTFORMAT1_HH

#include "Common.hh"

#include "Sequence.hh"

namespace OT {

namespace Layout {

namespace GSUB_impl {

template <typename Types>

struct MultipleSubstFormat1_2

{

  protected:

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

  typename Types::template OffsetTo<Coverage>

                coverage;               /* Offset to Coverage table--from

                                         * beginning of Substitution table */

  Array16Of<typename Types::template OffsetTo<Sequence<Types>>>

                sequence;               /* Array of Sequence tables

                                         * ordered by Coverage Index */

  public:

  DEFINE_SIZE_ARRAY (4 + Types::size, sequence);

  bool sanitize (hb_sanitize_context_t *c) const

  {

    TRACE_SANITIZE (this);

    return_trace (coverage.sanitize (c, this) && sequence.sanitize (c, this));

  }

  bool intersects (const hb_set_t *glyphs) const

  { return (this+coverage).intersects (glyphs); }

  bool may_have_non_1to1 () const

  { return true; }

  void closure (hb_closure_context_t *c) const

  {

    + hb_zip (this+coverage, sequence)

    | hb_filter (c->parent_active_glyphs (), hb_first)

    | hb_map (hb_second)

    | hb_map (hb_add (this))

    | hb_apply ([c] (const Sequence<Types> &_) { _.closure (c); })

    ;

  }

  void closure_lookups (hb_closure_lookups_context_t *c) const {}

  void collect_glyphs (hb_collect_glyphs_context_t *c) const

  {

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

    + hb_zip (this+coverage, sequence)

    | hb_map (hb_second)

    | hb_map (hb_add (this))

    | hb_apply ([c] (const Sequence<Types> &_) { _.collect_glyphs (c); })

    ;

  }

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

  bool would_apply (hb_would_apply_context_t *c) const

  { return c->len == 1 && (this+coverage).get_coverage (c->glyphs[0]) != NOT_COVERED; }

  bool apply (hb_ot_apply_context_t *c) const

  {

    TRACE_APPLY (this);

    unsigned int index = (this+coverage).get_coverage (c->buffer->cur().codepoint);

    if (index == NOT_COVERED) return_trace (false);

    return_trace ((this+sequence[index]).apply (c));

  }

  template<typename Iterator,

           hb_requires (hb_is_sorted_iterator (Iterator))>

  bool serialize (hb_serialize_context_t *c,

      Iterator it)

  {

    TRACE_SERIALIZE (this);

    auto sequences =

      + it

      | hb_map (hb_second)

      ;

    auto glyphs =

      + it

      | hb_map_retains_sorting (hb_first)

      ;

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

    if (unlikely (!sequence.serialize (c, sequences.length))) return_trace (false);

    for (auto& pair : hb_zip (sequences, sequence))

    {

      if (unlikely (!pair.second

        .serialize_serialize (c, pair.first)))

        return_trace (false);

    }

    return_trace (coverage.serialize_serialize (c, glyphs));

  }

  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_sorted_vector_t<hb_codepoint_t> new_coverage;

    + hb_zip (this+coverage, sequence)

    | hb_filter (glyphset, hb_first)

    | hb_filter (subset_offset_array (c, out->sequence, this), hb_second)

    | hb_map (hb_first)

    | hb_map (glyph_map)

    | hb_sink (new_coverage)

    ;

    out->coverage.serialize_serialize (c->serializer, new_coverage.iter ());

    return_trace (bool (new_coverage));

  }

};

}

}

}

#endif /* OT_LAYOUT_GSUB_MULTIPLESUBSTFORMAT1_HH */