#pragma once

#include <memory>
#include "Test.h"

namespace smart_pointer {
// `exception` class definition
class exception : std::exception {
  using base_class = std::exception;
  using base_class::base_class;
};

// `SmartPointer` class declaration
template<
    typename T,
    typename Allocator
>
class SmartPointer {
  // don't remove this macro
  ENABLE_CLASS_TESTS;
 public:
  using value_type = T;

  SmartPointer(value_type * p = nullptr) {
      core = new Core();
      core->pointer = p;
      if (p != nullptr) {
          core->countpointers = 1;
      }
  }

  // copy constructor
  SmartPointer(const SmartPointer &smart_pointer) {
      core = smart_pointer.core;
      core->countpointers++;
  }

  // move constructor
  SmartPointer(SmartPointer &&smart_pointer) {
      core = smart_pointer.core;
      core->countpointers++;
      smart_pointer.core = nullptr;
  }

  // copy assigment
  SmartPointer &operator=(const SmartPointer &smart_pointer) {
      core = smart_pointer.core;
      core->countpointers++;
  }

  // move assigment
  SmartPointer &operator=(SmartPointer &&smart_pointer) {
      core = smart_pointer.core;
      core->countpointers++;
      smart_pointer.core = nullptr;
  }

  //
  SmartPointer &operator=(value_type * p) {
      core->pointer = p;
  }

  ~SmartPointer() {
      core = nullptr;
  }

  // return reference to the object of class/type T
  // if SmartPointer contains nullptr throw `SmartPointer::exception`
  value_type &operator*() {
      if (core->pointer == nullptr) {
          throw exception();
      }
      return *core->pointer;
  }
  const value_type &operator*() const {
      if (core->pointer == nullptr) {
          throw exception();
      }
      return *core->pointer;
  }

  // return pointer to the object of class/type T
  value_type *operator->() const {
      return core->pointer;
  }

  value_type *get() const {
      if (operator bool()) {
          return core->pointer;
      }
      return nullptr;
  }

  // if pointer == nullptr => return false
  operator bool() const {
      return core->pointer != nullptr;
  }

  // if pointers points to the same address or both null => true
  template<typename U, typename AnotherAllocator>
  bool operator==(const SmartPointer<U, AnotherAllocator> &sm) const {
      return sm.core->pointer == core->pointer;
  }

  // if pointers points to the same address or both null => false
  template<typename U, typename AnotherAllocator>
  bool operator!=(const SmartPointer<U, AnotherAllocator> &sm) const {
      return sm.core->pointer != core->pointer;
  }

  // if smart pointer contains non-nullptr => return count owners
  // if smart pointer contains nullptr => return 0
  std::size_t count_owners() const {
      if (core->pointer == nullptr) {
          return 0;
      }
      return core->countpointers;
  }

 private:
  class Core {
   public:
    size_t countpointers;
    value_type * pointer;
  };
  Core *core;
};
}