/******************************************************************************/
/* POINTERS *******************************************************************/
/******************************************************************************/

#ifndef _H_LW_LIB_POINTERS
#define _H_LW_LIB_POINTERS
#include <lw/lib/Utilities.hh>
namespace lw {

template< typename T > class T_OwnPtr;
template< typename T > class T_SharedPtr;
template< typename T > class T_WeakPtr;

/*= OWNING POINTERS ==========================================================*/

template< typename T >
class T_OwnPtr
{
	template< typename RT , typename... AT >
	friend T_OwnPtr< RT > NewOwned( AT&& ... arguments );

	template<
		typename RT
	> friend T_OwnPtr< RT > OwnRawPointer( RT*& ) noexcept;

	template<
		typename RT , typename OT ,
		T_EnableForChild< RT , OT >
	> friend T_OwnPtr< RT > OwnRawPointer( OT*& ) noexcept;

	template<
		typename RT , typename OT ,
		T_EnableForParent< RT , OT >
	> friend T_OwnPtr< RT > OwnRawPointer( OT*& );

	template< typename >
	friend class T_OwnPtr;

	friend T_SharedPtr< T >;

   private:
	typedef T_OwnPtr< T > MyType_;

	T* p_;

	T_OwnPtr( T* p ) noexcept;

   public:
	T_OwnPtr( );
	~T_OwnPtr( );

	T_OwnPtr( MyType_ const& ) = delete;
	MyType_& operator= ( MyType_ const& ) = delete;

	// ---------------------------------------------------------------------

	template< typename Q , T_EnableForChild< T , Q > = true >
		T_OwnPtr( T_OwnPtr< Q >&& source ) noexcept;

	template< typename Q , T_EnableForParent< T , Q > = false >
		explicit T_OwnPtr( T_OwnPtr< Q >&& source );

	// ---------------------------------------------------------------------

	template< typename Q , T_EnableForChild< T , Q > = true >
		MyType_& operator= ( T_OwnPtr< Q >&& source ) noexcept;

	template< typename Q , T_EnableForParent< T , Q > = false >
		MyType_& operator= ( T_OwnPtr< Q >&& source );

	// ---------------------------------------------------------------------

	template< typename TP >
	friend void swap( T_OwnPtr< TP >& lhs , T_OwnPtr< TP >& rhs ) noexcept;

	void clear( );

	bool operator== ( const T* p ) const;
	bool operator!= ( const T* p ) const;
	operator bool ( ) const;
	bool operator! ( ) const;

	T * get( ) const;
	T* operator-> ( ) const;
	T& operator* ( ) const;

	T_SharedPtr< T > makeShared( );
};


// NewOwned< T >( ... ) - New T as an owned pointer
template<
	typename Type ,
	typename... ArgTypes
	>
T_OwnPtr< Type > NewOwned( ArgTypes&& ... arguments );

// OwnRawPointer< T >( pointer ) - Transfer a raw pointer to an owned pointer.
// The raw pointer will be set to nullptr.
template< typename Type >
T_OwnPtr< Type > OwnRawPointer( Type*& pointer ) noexcept;

template<
	typename Type , typename Other ,
	T_EnableForChild< Type , Other > = true ,
	std::enable_if_t< !std::is_same< Type , Other >::value , bool > = true
> T_OwnPtr< Type > OwnRawPointer( Other*& pointer ) noexcept;

template<
	typename Type , typename Other ,
	T_EnableForParent< Type , Other > = false
> T_OwnPtr< Type > OwnRawPointer( Other*& pointer );


/*= SHARED POINTERS ==========================================================*/
/* WARNING: these pointers are NOT thread-safe! */

class T_Reference_;

// Weak pointer chaining
struct T_WeakChain_
{
	T_Reference_* * const ref;
	T_WeakChain_* prev;
	T_WeakChain_* next;

	explicit T_WeakChain_( T_Reference_*& ref );
	void unchain( );
	void init( );
};


// Base class for shared and weak pointers
template< typename T >
class T_BasePtr_
{
   protected:
	typedef T_BasePtr_< T > T_Base_;

	T_Reference_* ref_;

	explicit T_BasePtr_( T_Reference_* ref ) noexcept;

	T_BasePtr_( ) = delete;
	T_BasePtr_( T_Base_ const& ) = delete;
	T_BasePtr_( T_Base_&& ) = delete;

   public:
	operator bool ( ) const;
	bool operator! ( ) const;

	T* operator-> ( ) const;
	explicit operator T* ( ) const;
	T& operator* ( ) const;
};


// Exception thrown when makeOwned( ) is called on a shared pointers that has
// more than one reference.
class X_TooManyReferences : public std::runtime_error
{
    public:
	X_TooManyReferences( );
};


// T_SharedPtr< T > - Shared pointer implementation
template< typename T >
class T_SharedPtr : public T_BasePtr_< T >
{
   private:
	typedef T_BasePtr_< T > T_Base_;
	typedef T_SharedPtr< T > T_Self_;
	typedef T_WeakPtr< T > T_Weak_;

	template< typename >
	friend class T_SharedPtr;

	template< typename >
	friend class T_WeakPtr;

	template<
		typename RT
	> friend T_SharedPtr< RT > ShareRawPointer( RT*& ) noexcept;

	template<
		typename RT , typename OT ,
		T_EnableForChild< RT , OT >
	> friend T_SharedPtr< RT > ShareRawPointer( OT*& ) noexcept;

	template<
		typename RT , typename OT ,
		T_EnableForParent< RT , OT >
	> friend T_SharedPtr< RT > ShareRawPointer( OT*& );

	template< typename OT , typename... AT >
	friend T_SharedPtr< OT > NewShared( AT&& ... arguments );
	friend T_OwnPtr< T >;

	using T_Base_::ref_;

	T_Reference_ * setRef( T_Reference_* from );
	void clearRef( );

	explicit T_SharedPtr( T* ptr );

   public:
	T_SharedPtr( ) noexcept;
	~T_SharedPtr( );

	// ---------------------------------------------------------------------
	// Copy constructors

	T_SharedPtr( T_Self_ const& source );

	template< typename Q , T_EnableForChild< T , Q > = true >
		T_SharedPtr( T_SharedPtr< Q > const& source );

	template< typename Q , T_EnableForParent< T , Q > = false >
		explicit T_SharedPtr( T_SharedPtr< Q > const& source );

	// ---------------------------------------------------------------------
	// Move constructors

	template< typename Q , T_EnableForChild< T , Q > = true >
		T_SharedPtr( T_SharedPtr< Q >&& source ) noexcept;

	template< typename Q , T_EnableForParent< T , Q > = false >
		explicit T_SharedPtr( T_SharedPtr< Q >&& source );

	// ---------------------------------------------------------------------
	// Copy assignment operators

	T_Self_& operator= ( T_Self_ const& other );

	template< typename Q , T_EnableForChild< T , Q > = true >
		T_Self_& operator= ( T_SharedPtr< Q > const& other );

	template< typename Q , T_EnableForParent< T , Q > = false >
		T_Self_& operator= ( T_SharedPtr< Q > const& other );

	// ---------------------------------------------------------------------
	// Move assignment operators

	template< typename Q , T_EnableForChild< T , Q > = true >
		T_Self_& operator= ( T_SharedPtr< Q >&& other ) noexcept;

	template< typename Q , T_EnableForParent< T , Q > = false >
		T_Self_& operator= ( T_SharedPtr< Q >&& other );

	// ---------------------------------------------------------------------

	template< typename TP >
	friend void swap( T_SharedPtr< TP >& lhs , T_SharedPtr< TP >& rhs ) noexcept;

	bool operator== ( T_Self_ const& other ) const;
	bool operator!= ( T_Self_ const& other ) const;
	bool operator== ( T_Weak_ const& other ) const;
	bool operator!= ( T_Weak_ const& other ) const;

	void clear( );

	T_OwnPtr< T > makeOwned( );
};


// T_WeakPtr< T > - Weak pointer implementation
template< typename T >
class T_WeakPtr : public T_BasePtr_< T >
{
   private:
	typedef T_BasePtr_< T > T_Base_;
	typedef T_SharedPtr< T > T_Shared_;
	typedef T_WeakPtr< T > T_Self_;

	template< typename > friend class T_SharedPtr;
	template< typename > friend class T_WeakPtr;
	friend T_Reference_;

	using T_Base_::ref_;

	T_WeakChain_ chain_;

	T_WeakPtr( T_Reference_* ref );

   public:

	T_WeakPtr( );
	~T_WeakPtr( );

	// ---------------------------------------------------------------------
	// Copy constructors

	T_WeakPtr( T_Self_ const& other );

	template< typename Q , T_EnableForChild< T , Q > = true >
		T_WeakPtr( T_WeakPtr< Q > const& other );

	template< typename Q , T_EnableForParent< T , Q > = false >
		explicit T_WeakPtr( T_WeakPtr< Q > const& other );

	// ---------------------------------------------------------------------
	// Move constructors

	template< typename Q , T_EnableForChild< T , Q > = true >
		T_WeakPtr( T_WeakPtr< Q >&& other ) noexcept;

	template< typename Q , T_EnableForParent< T , Q > = false >
		explicit T_WeakPtr( T_WeakPtr< Q >&& other );

	// ---------------------------------------------------------------------
	// Construct from shared pointer

	explicit T_WeakPtr( T_Shared_ const& shared );

	template< typename Q , T_EnableForChild< T , Q > = true >
		explicit T_WeakPtr( T_SharedPtr< Q > const& shared );

	template< typename Q , T_EnableForParent< T , Q > = false >
		explicit T_WeakPtr( T_SharedPtr< Q > const& shared );

	explicit T_WeakPtr( T_Shared_&& shared ) = delete;

	// ---------------------------------------------------------------------
	// Copy assignment operators

	T_Self_& operator= ( T_Self_ const& other );

	template< typename Q , T_EnableForChild< T , Q > = true >
		T_Self_& operator =( T_WeakPtr< Q > const& other );

	template< typename Q , T_EnableForParent< T , Q > = false >
		T_Self_& operator =( T_WeakPtr< Q > const& other );

	// ---------------------------------------------------------------------
	// Move assignment operators

	template< typename Q , T_EnableForChild< T , Q > = true >
		T_Self_& operator =( T_WeakPtr< Q >&& other );

	template< typename Q , T_EnableForParent< T , Q > = false >
		T_Self_& operator =( T_WeakPtr< Q >&& other );

	// ---------------------------------------------------------------------
	// Assign from shared pointer

	T_Self_& operator= ( T_Shared_ const& shared );

	template< typename Q , T_EnableForChild< T , Q > = true >
		T_Self_& operator= ( T_SharedPtr< Q > const& shared );

	template< typename Q , T_EnableForParent< T , Q > = false >
		T_Self_& operator= ( T_SharedPtr< Q > const& shared );

	T_Self_& operator= ( T_Shared_&& ) = delete;

	// ---------------------------------------------------------------------

	template< typename TP >
	friend void swap( T_WeakPtr< TP >& lhs , T_WeakPtr< TP >& rhs );

	bool operator== ( T_Self_ const& other ) const;
	bool operator!= ( T_Self_ const& other ) const;
	bool operator== ( T_Shared_ const& other ) const;
	bool operator!= ( T_Shared_ const& other ) const;

	void clear( );
};


// NewShared< T >( ... ) - New T as shared pointer
template<
	typename Type ,
	typename... ArgTypes
	>
T_SharedPtr< Type > NewShared( ArgTypes&& ... arguments );

// ShareRawPointer< T >( pointer ) - Transfer a raw pointer to a shared pointer.
// The raw pointer will be set to nullptr.
template< typename Type >
T_SharedPtr< Type > ShareRawPointer(
		Type*& pointer ) noexcept;

template<
	typename Type , typename Other ,
	T_EnableForChild< Type , Other > = true ,
	std::enable_if_t< !std::is_same< Type , Other >::value , bool > = true
> T_SharedPtr< Type > ShareRawPointer(
		Other*& pointer ) noexcept;

template<
	typename Type , typename Other ,
	T_EnableForParent< Type , Other > = false
> T_SharedPtr< Type > ShareRawPointer( Other*& pointer );


/*= HELPER MACROS ============================================================*/

#define M_CLASS_POINTERS( NAME ) \
	typedef T_ ## NAME* RP_ ## NAME; \
	typedef T_ ## NAME const* RPC_ ## NAME; \
	typedef T_OwnPtr< T_ ## NAME > OP_ ## NAME; \
	typedef T_SharedPtr< T_ ## NAME > SP_ ## NAME; \
	typedef T_WeakPtr< T_ ## NAME > WP_ ## NAME

#define M_ABSTRACT_POINTERS( NAME ) \
	typedef A_ ## NAME* RP_ ## NAME; \
	typedef A_ ## NAME const* RPC_ ## NAME; \
	typedef T_OwnPtr< A_ ## NAME > OP_ ## NAME; \
	typedef T_SharedPtr< A_ ## NAME > SP_ ## NAME; \
	typedef T_WeakPtr< A_ ## NAME > WP_ ## NAME

#define M_TEMPLATE_POINTERS( NAME ) \
	typedef NAME* RP; \
	typedef NAME const* RPC; \
	typedef T_OwnPtr< NAME > OP; \
	typedef T_SharedPtr< NAME > SP; \
	typedef T_WeakPtr< NAME > WP


} // namespace
#endif // _H_LW_LIB_POINTERS
#include <lw/lib/inline/Pointers.hh>