// ==========================================================================
//                 SeqAn - The Library for Sequence Analysis
// ==========================================================================
// Copyright (c) 2006-2026, Knut Reinert, FU Berlin
// All rights reserved.
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// modification, are permitted provided that the following conditions are met:
//
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//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//     * Neither the name of Knut Reinert or the FU Berlin nor the names of
//       its contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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// ==========================================================================
// Author: Christopher Pockrandt <christopher.pockrandt@fu-berlin.de>
// ==========================================================================

//SEQAN_NO_DDDOC:do not generate documentation for this file

#ifndef INDEX_BIFM_STREE_H_
#define INDEX_BIFM_STREE_H_

namespace seqan2 {

// ============================================================================
// Functions
// ============================================================================

template <typename TText, typename TOccSpec, typename TIndexSpec, typename TSpec, typename TDirection>
inline void _update(Iter<Index<TText, BidirectionalIndex<FMIndex<TOccSpec, TIndexSpec> > >, VSTree<TopDown<TSpec> > > & it, TDirection)
{
    typedef typename IfC<IsSameType<TDirection, Tag<BidirectionalFwd_> >::VALUE, Rev, Fwd>::Type TOppositeDirection;

    auto & dirIter = _iter(it, TDirection());
    auto & oppDirIter = _iter(it, TOppositeDirection());

    value(oppDirIter).range.i1 += value(dirIter).smaller;
    value(oppDirIter).range.i2 = value(oppDirIter).range.i1 + value(dirIter).range.i2 - value(dirIter).range.i1;

    value(oppDirIter).repLen = value(dirIter).repLen;
}

template <typename TText, typename TOccSpec, typename TIndexSpec, typename TSpec, typename TDirection>
inline void _updateOnGoRight(Iter<Index<TText, BidirectionalIndex<FMIndex<TOccSpec, TIndexSpec> > >, VSTree<TopDown<TSpec> > > & it, TDirection)
{
    typedef typename IfC<IsSameType<TDirection, Tag<BidirectionalFwd_> >::VALUE, Rev, Fwd>::Type TOppositeDirection;

    auto & dirIter = _iter(it, TDirection());
    auto & oppDirIter = _iter(it, TOppositeDirection());

    value(oppDirIter).range.i1 = nodeUp(oppDirIter).range.i1 + value(dirIter).smaller;
    value(oppDirIter).range.i2 = value(oppDirIter).range.i1 + value(dirIter).range.i2 - value(dirIter).range.i1;
}

template <typename TText, typename TOccSpec, typename TIndexSpec, typename TSpec, typename TString, typename TSize, typename TDirection>
inline bool
_goDownString(Iter<Index<TText, BidirectionalIndex<FMIndex<TOccSpec, TIndexSpec> > >, VSTree<TopDown<TSpec> > > &it,
              TString const & string,
              TSize & lcp,
              TDirection)
{
    typedef Index<TText, FMIndex<TOccSpec, TIndexSpec> >        TIndex;
    typedef typename Size<TIndex>::Type                         TSize2;
    typedef Pair<TSize2>                                        TRange;
    typedef typename Iterator<TString const, Standard>::Type    TStringIter;
    typedef typename IfC<IsSameType<TDirection, Tag<BidirectionalFwd_> >::VALUE, Rev, Fwd>::Type TOppositeDirection;

    TStringIter stringIt = begin(string, Standard());
    TStringIter stringEnd = end(string, Standard());

    if (SEQAN_UNLIKELY(stringIt == stringEnd))
        return true;

    _historyPush(_iter(it, TDirection()));
    _historyPush(_iter(it, TOppositeDirection()));

    for (lcp = 0; stringIt != stringEnd; ++stringIt, ++lcp)
    {
        TRange _range;
        TSize2 _smaller = 0;

        // NOTE(esiragusa): this should be faster only for texts over small alphabets consisting of few/long sequences.
        if (isLeaf(_iter(it, TDirection())) || !_getNodeByChar(_iter(it, TDirection()), value(_iter(it, TDirection())), _range, _smaller, value(stringIt))) break;

        value(_iter(it, TDirection())).range = _range;
        value(_iter(it, TDirection())).smaller = _smaller;
        _update(it, TDirection());
    }

    value(_iter(it, Fwd())).repLen += lcp;
    value(_iter(it, Rev())).repLen += lcp;

    if (lcp) value(_iter(it, TDirection())).lastChar = value(stringIt - 1);

    return stringIt == stringEnd;
}

}

#endif /* INDEX_BIFM_STREE_H_ */
