#ifndef __helper_tools_h__
#define __helper_tools_h__

#include "base_def.h"
#include "slice.h"

namespace MultiArrayTools
{

    template <class RangeType>
    auto getIndex(std::shared_ptr<RangeType> range)
	-> std::shared_ptr<typename RangeType::IndexType>;

    // only if 'RangeType' is defaultable and unique (Singleton)
    template <class RangeType>
    auto getIndex() -> std::shared_ptr<typename RangeType::IndexType>;

    template <class... RangeTypes>
    auto mkMulti(std::shared_ptr<RangeTypes>... ranges)
	-> std::shared_ptr<MultiRange<RangeTypes...> >;

    template <class... IndexTypes>
    auto mkMIndex(std::shared_ptr<IndexTypes>... indices)
	-> decltype( getIndex( mkMulti( indices.range()... ) ) );

    template <class... RangeTypes>
    auto mkMulti(std::tuple<std::shared_ptr<RangeTypes>...> rangesTuple)
	-> MultiRange<RangeTypes...>;
}

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

namespace MultiArrayTools
{
    template <class RangeType>
    auto getIndex(std::shared_ptr<RangeType> range)
	-> std::shared_ptr<typename RangeType::IndexType>
    {
	return std::make_shared<typename RangeType::IndexType>(range);
    }

    template <class RangeType>
    auto getIndex()
	-> std::shared_ptr<typename RangeType::IndexType>
    {
	static_assert( RangeType::defaultable,
		       /*typeid(typename RangeType).name() + */" is not defaultable" );
	static auto f = RangeType::factory();
	static auto r = std::dynamic_pointer_cast<RangeType>( f.create() );
	return std::make_shared<typename RangeType::IndexType>(r);
    }
    
    template <class... RangeTypes>
    auto mkMulti(std::shared_ptr<RangeTypes>... ranges)
	-> std::shared_ptr<MultiRange<RangeTypes...> >
    {
	MultiRangeFactory<RangeTypes...> mrf( ranges... );
	return std::dynamic_pointer_cast<MultiRange<RangeTypes...> >( mrf.create() );
    }

    template <class... IndexTypes>
    auto mkMIndex(std::shared_ptr<IndexTypes>... indices)
	-> decltype( getIndex( mkMulti( indices->range()... ) ) )
    {
	auto mi = getIndex( mkMulti( indices->range()... ) );	    
	(*mi)( indices... );
	return mi;
    }

    template <class... RangeTypes>
    auto mkMulti(std::tuple<std::shared_ptr<RangeTypes>...> rangesTuple)
	-> MultiRange<RangeTypes...>
    {
	MultiRangeFactory<RangeTypes...> mrf( rangesTuple );
	return std::dynamic_pointer_cast<MultiRange<RangeTypes...> >( mrf.create() );
    }

}

#endif