/*

 * Copyright © 2022 Behdad Esfahbod

 *

 *  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.

 */

#ifndef HB_CPLUSPLUS_HH

#define HB_CPLUSPLUS_HH

#include "hb.h"

#ifdef __cplusplus

#include <functional>

#include <utility>

#if 0

#if !(__cplusplus >= 201103L)

#error "HarfBuzz C++ helpers require C++11"

#endif

#endif

namespace hb {

template <typename T>

struct vtable;

template <typename T>

struct shared_ptr

{

  using element_type = T;

  using v = vtable<T>;

  explicit shared_ptr (T *p = nullptr) : p (p) {}

  shared_ptr (const shared_ptr &o) : p (v::reference (o.p)) {}

  shared_ptr (shared_ptr &&o)  noexcept : p (o.p) { o.p = nullptr; }

  shared_ptr& operator = (const shared_ptr &o) { if (p != o.p) { destroy (); p = o.p; reference (); } return *this; }

Unexecuted instantiation: hb::shared_ptr<hb_map_t>::operator=(hb::shared_ptr<hb_map_t> const&)

Unexecuted instantiation: hb::shared_ptr<hb_set_t>::operator=(hb::shared_ptr<hb_set_t> const&)

  shared_ptr& operator = (shared_ptr &&o)  noexcept { v::destroy (p); p = o.p; o.p = nullptr; return *this; }

Unexecuted instantiation: hb::shared_ptr<hb_map_t>::operator=(hb::shared_ptr<hb_map_t>&&)

Unexecuted instantiation: hb::shared_ptr<hb_set_t>::operator=(hb::shared_ptr<hb_set_t>&&)

  ~shared_ptr () { v::destroy (p); p = nullptr; }

  T* get() const { return p; }

Unexecuted instantiation: hb::shared_ptr<hb_set_t>::get() const

Unexecuted instantiation: hb::shared_ptr<hb_map_t>::get() const

  void swap (shared_ptr &o)  noexcept { std::swap (p, o.p); }

  friend void swap (shared_ptr &a, shared_ptr &b)  noexcept { std::swap (a.p, b.p); }

  operator T * () const { return p; }

  T& operator * () const { return *get (); }

  T* operator -> () const { return get (); }

  operator bool () const { return p; }

  bool operator == (const shared_ptr &o) const { return p == o.p; }

  bool operator != (const shared_ptr &o) const { return p != o.p; }

  static T* get_empty() { return v::get_empty (); }

  T* reference() { return v::reference (p); }

Unexecuted instantiation: hb::shared_ptr<hb_map_t>::reference()

Unexecuted instantiation: hb::shared_ptr<hb_set_t>::reference()

  void destroy() { v::destroy (p); }

Unexecuted instantiation: hb::shared_ptr<hb_map_t>::destroy()

Unexecuted instantiation: hb::shared_ptr<hb_set_t>::destroy()

  void set_user_data (hb_user_data_key_t *key,

          void *value,

          hb_destroy_func_t destroy,

          hb_bool_t replace) { v::set_user_data (p, key, value, destroy, replace); } 

  void * get_user_data (hb_user_data_key_t *key) { return v::get_user_data (p, key); }

  private:

  T *p;

};

template<typename T> struct is_shared_ptr : std::false_type {};

template<typename T> struct is_shared_ptr<shared_ptr<T>> : std::true_type {};

template <typename T>

struct unique_ptr

{

  using element_type = T;

  using v = vtable<T>;

  explicit unique_ptr (T *p = nullptr) : p (p) {}

  unique_ptr (const unique_ptr &o) = delete;

  unique_ptr (unique_ptr &&o)  noexcept : p (o.p) { o.p = nullptr; }

  unique_ptr& operator = (const unique_ptr &o) = delete;

  unique_ptr& operator = (unique_ptr &&o)  noexcept { v::destroy (p); p = o.p; o.p = nullptr; return *this; }

  ~unique_ptr () { v::destroy (p); p = nullptr; }

  T* get() const { return p; }

  T* release () { T* v = p; p = nullptr; return v; }

  void swap (unique_ptr &o)  noexcept { std::swap (p, o.p); }

  friend void swap (unique_ptr &a, unique_ptr &b)  noexcept { std::swap (a.p, b.p); }

  operator T * () const { return p; }

  T& operator * () const { return *get (); }

  T* operator -> () const { return get (); }

  operator bool () { return p; }

  private:

  T *p;

};

template<typename T> struct is_unique_ptr : std::false_type {};

template<typename T> struct is_unique_ptr<unique_ptr<T>> : std::true_type {};

template <typename T,

    T * (*_get_empty) (void),

    T * (*_reference) (T *),

    void (*_destroy) (T *),

    hb_bool_t (*_set_user_data) (T *,

               hb_user_data_key_t *,

               void *,

               hb_destroy_func_t,

               hb_bool_t),

    void * (*_get_user_data) (const T *,

            hb_user_data_key_t *)>

struct vtable_t

{

  static constexpr auto get_empty = _get_empty;

  static constexpr auto reference = _reference;

  static constexpr auto destroy = _destroy;

  static constexpr auto set_user_data = _set_user_data;

  static constexpr auto get_user_data = _get_user_data;

};

#define HB_DEFINE_VTABLE(name) \

  template<> \

  struct vtable<hb_##name##_t> \

       : vtable_t<hb_##name##_t, \

      &hb_##name##_get_empty, \

      &hb_##name##_reference, \

      &hb_##name##_destroy, \

      &hb_##name##_set_user_data, \

      &hb_##name##_get_user_data> {}

HB_DEFINE_VTABLE (buffer);

HB_DEFINE_VTABLE (blob);

HB_DEFINE_VTABLE (face);

HB_DEFINE_VTABLE (font);

HB_DEFINE_VTABLE (font_funcs);

HB_DEFINE_VTABLE (map);

HB_DEFINE_VTABLE (set);

HB_DEFINE_VTABLE (shape_plan);

HB_DEFINE_VTABLE (unicode_funcs);

HB_DEFINE_VTABLE (draw_funcs);

HB_DEFINE_VTABLE (paint_funcs);

#undef HB_DEFINE_VTABLE

#ifdef HB_SUBSET_H

#define HB_DEFINE_VTABLE(name) \

  template<> \

  struct vtable<hb_##name##_t> \

       : vtable_t<hb_##name##_t, \

      nullptr, \

      &hb_##name##_reference, \

      &hb_##name##_destroy, \

      &hb_##name##_set_user_data, \

      &hb_##name##_get_user_data> {}

HB_DEFINE_VTABLE (subset_input);

HB_DEFINE_VTABLE (subset_plan);

#undef HB_DEFINE_VTABLE

#endif

} // namespace hb

/* Workaround for GCC < 7, see:

 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480

 * https://stackoverflow.com/a/25594741 */

namespace std {

template<typename T>

struct hash<hb::shared_ptr<T>>

{

    std::size_t operator()(const hb::shared_ptr<T>& v) const noexcept

    {

        std::size_t h = std::hash<decltype (v.get ())>{}(v.get ());

        return h;

    }

};

template<typename T>

struct hash<hb::unique_ptr<T>>

{

    std::size_t operator()(const hb::unique_ptr<T>& v) const noexcept

    {

        std::size_t h = std::hash<decltype (v.get ())>{}(v.get ());

        return h;

    }

};

} // namespace std

#endif /* __cplusplus */

#endif /* HB_CPLUSPLUS_HH */