/*
 * Copyright © 2022 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
 */

#include "graph.hh"
#include "../OT/Layout/Common/Coverage.hh"

#ifndef GRAPH_COVERAGE_GRAPH_HH
#define GRAPH_COVERAGE_GRAPH_HH

namespace graph {

struct CoverageFormat1 : public OT::Layout::Common::CoverageFormat1_3<SmallTypes>
{
 bool sanitize (graph_t::vertex_t& vertex) const
 {
 int64_t vertex_len = vertex.obj.tail - vertex.obj.head;
 constexpr unsigned min_size = OT::Layout::Common::CoverageFormat1_3<SmallTypes>::min_size;
 if (vertex_len < min_size) return false;
 hb_barrier ();
 return vertex_len >= min_size + glyphArray.get_size () - glyphArray.len.get_size ();
 }
};

struct CoverageFormat2 : public OT::Layout::Common::CoverageFormat2_4<SmallTypes>
{
 bool sanitize (graph_t::vertex_t& vertex) const
 {
 int64_t vertex_len = vertex.obj.tail - vertex.obj.head;
 constexpr unsigned min_size = OT::Layout::Common::CoverageFormat2_4<SmallTypes>::min_size;
 if (vertex_len < min_size) return false;
 hb_barrier ();
 return vertex_len >= min_size + rangeRecord.get_size () - rangeRecord.len.get_size ();
 }
};

struct Coverage : public OT::Layout::Common::Coverage
{
 static Coverage* clone_coverage (gsubgpos_graph_context_t& c,
 unsigned coverage_id,
 unsigned new_parent_id,
 unsigned link_position,
 unsigned start, unsigned end)

 {
 unsigned coverage_size = c.graph.vertices_[coverage_id].table_size ();
 auto& coverage_v = c.graph.vertices_[coverage_id];
 Coverage* coverage_table = (Coverage*) coverage_v.obj.head;
 if (!coverage_table || !coverage_table->sanitize (coverage_v))
 return nullptr;

 auto new_coverage =
 + hb_zip (coverage_table->iter (), hb_range ())
 | hb_filter ([&] (hb_pair_t<unsigned, unsigned> p) {
 return p.second >= start && p.second < end;
 })
 | hb_map_retains_sorting (hb_first)
 ;

 return add_coverage (c, new_parent_id, link_position, new_coverage, coverage_size);
 }

 template<typename It>
 static Coverage* add_coverage (gsubgpos_graph_context_t& c,
 unsigned parent_id,
 unsigned link_position,
 It glyphs,
 unsigned max_size)
 {
 unsigned coverage_prime_id = c.graph.new_node (nullptr, nullptr);
 auto& coverage_prime_vertex = c.graph.vertices_[coverage_prime_id];
 if (!make_coverage (c, glyphs, coverage_prime_id, max_size))
 return nullptr;

 auto* coverage_link = c.graph.vertices_[parent_id].obj.real_links.push ();
 coverage_link->width = SmallTypes::size;
 coverage_link->objidx = coverage_prime_id;
 coverage_link->position = link_position;
 coverage_prime_vertex.add_parent (parent_id);

 return (Coverage*) coverage_prime_vertex.obj.head;
 }

 template<typename It>
 static bool make_coverage (gsubgpos_graph_context_t& c,
 It glyphs,
 unsigned dest_obj,
 unsigned max_size)
 {
 char* buffer = (char*) hb_calloc (1, max_size);
 hb_serialize_context_t serializer (buffer, max_size);
 OT::Layout::Common::Coverage_serialize (&serializer, glyphs);
 serializer.end_serialize ();
 if (serializer.in_error ())
 {
 hb_free (buffer);
 return false;
 }

 hb_bytes_t coverage_copy = serializer.copy_bytes ();
 if (!coverage_copy.arrayZ) return false;
 // Give ownership to the context, it will cleanup the buffer.
 if (!c.add_buffer ((char *) coverage_copy.arrayZ))
 {
 hb_free ((char *) coverage_copy.arrayZ);
 return false;
 }

 auto& obj = c.graph.vertices_[dest_obj].obj;
 obj.head = (char *) coverage_copy.arrayZ;
 obj.tail = obj.head + coverage_copy.length;

 hb_free (buffer);
 return true;
 }

 bool sanitize (graph_t::vertex_t& vertex) const
 {
 int64_t vertex_len = vertex.obj.tail - vertex.obj.head;
 if (vertex_len < OT::Layout::Common::Coverage::min_size) return false;
 hb_barrier ();
 switch (u.format)
 {
 case 1: return ((CoverageFormat1*)this)->sanitize (vertex);
 case 2: return ((CoverageFormat2*)this)->sanitize (vertex);
#ifndef HB_NO_BEYOND_64K
 // Not currently supported
 case 3:
 case 4:
#endif
 default: return false;
 }
 }
};


}

#endif // GRAPH_COVERAGE_GRAPH_HH