#pragma once

#include <iterator>


//-----------------------------------------------------------------------------
//		BaseIterator
//		迭代器的基本类
//-----------------------------------------------------------------------------
namespace ReverseIterator
{
	template <typename IterType> class __BaseIterator
	{
	public:
		//	构造一个全空的迭代器, 用于容器指针为空的情形
		__BaseIterator ()
		{
			m_Count = -1;
			m_Index = 0;
		}

		__BaseIterator (const __BaseIterator & from)
		{
			CopyAssign (from);
		}

		__BaseIterator (__BaseIterator && from)
		{
			MoveAssign (from);
		}

		~__BaseIterator () {}

	public:
		inline __BaseIterator & operator = (const __BaseIterator & from)
		{
			CopyAssign (from);

			return (*this);
		}

	public:
//		inline operator bool () const { return (m_Index >= 0) && (m_Index < m_Count); }
//		inline operator bool () const { return (Iter._Ptr != nullptr) && (Iter != _end); }
		inline operator bool () const { return (m_Count > 0) && (Iter != _end); }

		inline int  Index () const { return m_Index; }

		inline int  Count () const { return m_Count; }

		inline void Next ()
		{
			if (m_Index >= 0)
			{
				++ Iter;
				-- m_Index;
			}
		}

		inline void operator ++ ()			// ++ Iter;
		{
			Next ();
		}

		inline void operator ++ (int)		// Iter ++;
		{
			Next ();
		}


		inline void Prev ()
		{
			if (m_Index > 0)
			{
				-- Iter;
				++ m_Index;
			}
			else
			{
				Iter = _end;
				m_Index = -1;
			}
		}

		inline void operator -- ()			// -- Iter;
		{
			Prev ();
		}

		inline void operator -- (int)		// Iter --;
		{
			Prev ();
		}

	public:
		inline void Restart ()
		{
			Iter = _begin;
			m_Index = m_Count - 1;
		}

	protected:
		inline void CopyAssign (const __BaseIterator & from)
		{
			Iter    = from.Iter;
			_begin  = from._begin;
			_end    = from._end;
			m_Count = from.m_Count;
			m_Index = from.m_Index;
		}

		inline void MoveAssign (__BaseIterator & from)
		{
			Iter    = from.Iter;
			_begin  = from._begin;
			_end    = from._end;
			m_Count = from.m_Count;
			m_Index = from.m_Index;

			from.Iter = from._begin = from._end;
			from.m_Count = 0;
			from.m_Index = 0;
		}

	protected:
		typename IterType Iter;
		typename IterType _begin;
		typename IterType _end;

		int  m_Count;
		int  m_Index;
	};
}