#ifndef __slice_h__
#define __slice_h__

#include "multi_array_base.h"
#include "multi_array_operation.h"

namespace MultiArrayTools
{
    template <typename T, class... SRanges>
    class Slice : public MutableMultiArrayBase<T,SRanges...>
    {
    public:

	typedef ContainerRange<T,SRanges...> CRange;
	typedef MultiArrayBase<T,SRanges...> MAB;
	typedef ContainerIndex<T,typename SRanges::IndexType...> IType;
	
	DEFAULT_MEMBERS(Slice);

	Slice(const std::shared_ptr<SRanges>&... ranges, T* data = nullptr);
	    
	virtual const T& operator[](const IType& i) const override;
	virtual T& operator[](const IType& i) override;
	virtual const T& at(const typename IType::MetaType& meta) const override;
	virtual T& at(const typename IType::MetaType& meta) override;

	virtual const T* data() const override;
	virtual T* data() override;

	virtual bool isSlice() const override;

	virtual auto begin() const -> IType override;
	virtual auto end() const -> IType override;

	auto define(const std::shared_ptr<typename SRanges::IndexType>&... inds)
	    -> SliceDef<T,SRanges...>;
	
    private:
	friend SliceDef<T,SRanges...>;

	void format(const std::array<size_t,sizeof...(SRanges)+1>& blocks);
	
	T* mData;
    };


    template <typename T, class... SRanges>
    class SliceDef
    {
    public:
	typedef ContainerIndex<T,typename SRanges::IndexType...> IType;
	
    private:
	IType mIndex;
	Slice<T,SRanges...>& mSl;
	
	SliceDef() = default;
    public:
	SliceDef(Slice<T,SRanges...>& sl,
		 const std::shared_ptr<typename SRanges::IndexType>&... inds);

	template <class... ORanges>
	SliceDef& operator=(const OperationRoot<T,ORanges...>& op);
    };
    
} // end namespace MultiArrayTools

/* ========================= *
 * ---   TEMPLATE CODE   --- *
 * ========================= */

namespace MultiArrayTools
{
    
    /*************
     *  Slice    *
     *************/

    template <typename T, class... SRanges>
    void Slice<T,SRanges...>::format(const std::array<size_t,sizeof...(SRanges)+1>& blocks)
    {
	MAB::mProtoI->format(blocks);
    }
    
    template <typename T, class... SRanges>
    Slice<T,SRanges...>::Slice(const std::shared_ptr<SRanges>&... ranges, T* data) :
	MutableMultiArrayBase<T,SRanges...>(ranges...),
	mData(data) {}
    
    template <typename T, class... SRanges>
    const T& Slice<T,SRanges...>::operator[](const IType& i) const
    {
	//assert(i.sliceMode()); // -> compare objects !!!!!
	assert(i.container() == reinterpret_cast<std::intptr_t>(this));
	return mData[ i.pos() ];
    }
    
    template <typename T, class... SRanges>
    T& Slice<T,SRanges...>::operator[](const IType& i)
    {
	//assert(i.sliceMode());
	assert(i.container() == reinterpret_cast<std::intptr_t>(this));
	return mData[ i.pos() ];
    }
    
    template <typename T, class... SRanges>
    const T& Slice<T,SRanges...>::at(const typename IType::MetaType& meta) const
    {
	//auto x = begin().at(meta);
	//VCHECK(x.pos());
	return mData[ begin().at(meta).pos() ];
    }
    
    template <typename T, class... SRanges>
    T& Slice<T,SRanges...>::at(const typename IType::MetaType& meta)
    {
	//auto x = begin().at(meta);
	//VCHECK(x.pos());
	return mData[ begin().at(meta).pos() ];
    }
    
    template <typename T, class... SRanges>
    const T* Slice<T,SRanges...>::data() const
    {
	return mData;
    }

    template <typename T, class... SRanges>
    T* Slice<T,SRanges...>::data()
    {
	return mData;
    }

    template <typename T, class... SRanges>
    bool Slice<T,SRanges...>::isSlice() const
    {
	return true;
    }

    template <typename T, class... SRanges>
    auto Slice<T,SRanges...>::begin() const -> Slice<T,SRanges...>::IType 
    {
	IType i(*MAB::mProtoI);
	i = 0;
	//i = mStartPos;
	return i.setData(data());
    }

    template <typename T, class... SRanges>
    auto Slice<T,SRanges...>::end() const -> Slice<T,SRanges...>::IType 
    {
	IType i(*MAB::mProtoI);
	i = i.max(); // CHECK !!!
	//i = std::get<sizeof...(SRanges)>(mBlockSizes);
	return i.setData(data());
    }

    template <typename T, class... SRanges>
    auto Slice<T,SRanges...>::define(const std::shared_ptr<typename SRanges::IndexType>&... inds)
	-> SliceDef<T,SRanges...>
    {
	return SliceDef<T,SRanges...>(*this, inds...);
    }
    
    template <typename T, class... SRanges>
    SliceDef<T,SRanges...>::SliceDef(Slice<T,SRanges...>& sl,
				     const std::shared_ptr<typename SRanges::IndexType>&... inds) :
	mIndex(sl.begin()),
	mSl(sl)
    {
	mIndex(inds...);
    }

    template <typename T, class... SRanges>
    template <class... ORanges>
    SliceDef<T,SRanges...>& SliceDef<T,SRanges...>::operator=(const OperationRoot<T,ORanges...>& op)
    {
	std::array<size_t,sizeof...(SRanges)+1> blocks;
	PackNum<sizeof...(SRanges)-1>::
	    template mkSliceBlocks<T,OperationRoot<T,ORanges...>,SRanges...>(blocks, mIndex, op);
	mSl.format(blocks);
	//VCHECK(blocks[0]);
	//VCHECK(blocks[1]);
	mSl.mData = op.data();
	return *this;
    }
    

} // end namespace MultiArrayTools

#endif