/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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#include <dbase/DIndexIter.hxx>
#include <com/sun/star/sdb/SQLFilterOperator.hpp>

using namespace ::com::sun::star::sdb;
using namespace connectivity;
using namespace connectivity::dbase;
using namespace connectivity::file;

// OIndexIterator

OIndexIterator::~OIndexIterator() {}

sal_uInt32 OIndexIterator::First() { return Find(true); }

sal_uInt32 OIndexIterator::Next() { return Find(false); }

sal_uInt32 OIndexIterator::Find(bool bFirst)
{
    sal_uInt32 nRes = NODE_NOTFOUND;

    if (bFirst)
    {
        m_aRoot = m_xIndex->getRoot();
        m_aCurLeaf.Clear();
    }

    if (!m_pOperator)
    {
        // Preparation, position on the smallest element
        if (bFirst)
        {
            ONDXPage* pPage = m_aRoot;
            while (pPage && !pPage->IsLeaf())
                pPage = pPage->GetChild(m_xIndex.get());

            m_aCurLeaf = pPage;
            m_nCurNode = NODE_NOTFOUND;
        }
        ONDXKey* pKey = GetNextKey();
        nRes = pKey ? pKey->GetRecord() : NODE_NOTFOUND;
    }
    else if (dynamic_cast<const OOp_ISNOTNULL*>(m_pOperator) != nullptr)
        nRes = GetNotNull(bFirst);
    else if (dynamic_cast<const OOp_ISNULL*>(m_pOperator) != nullptr)
        nRes = GetNull(bFirst);
    else if (dynamic_cast<const OOp_LIKE*>(m_pOperator) != nullptr)
        nRes = GetLike(bFirst);
    else if (dynamic_cast<const OOp_COMPARE*>(m_pOperator) != nullptr)
        nRes = GetCompare(bFirst);

    return nRes;
}

ONDXKey* OIndexIterator::GetFirstKey(ONDXPage* pPage, const OOperand& rKey)
{
    // searches a given key
    // Speciality: At the end of the algorithm
    // the actual page and the position of the node which fulfil the
    // '<='-condition are saved. this is considered for inserts.
    //  ONDXIndex* m_pIndex = GetNDXIndex();
    OOp_COMPARE aTempOp(SQLFilterOperator::GREATER);
    sal_uInt16 i = 0;

    if (pPage->IsLeaf())
    {
        // in the leaf the actual operation is run, otherwise temp. (>)
        while (i < pPage->Count() && !m_pOperator->operate(&((*pPage)[i]).GetKey(), &rKey))
            i++;
    }
    else
        while (i < pPage->Count() && !aTempOp.operate(&((*pPage)[i]).GetKey(), &rKey))
            i++;

    ONDXKey* pFoundKey = nullptr;
    if (!pPage->IsLeaf())
    {
        // descend further
        ONDXPagePtr aPage = (i == 0) ? pPage->GetChild(m_xIndex.get())
                                     : ((*pPage)[i - 1]).GetChild(m_xIndex.get(), pPage);
        pFoundKey = aPage.Is() ? GetFirstKey(aPage, rKey) : nullptr;
    }
    else if (i == pPage->Count())
    {
        pFoundKey = nullptr;
    }
    else
    {
        pFoundKey = &(*pPage)[i].GetKey();
        if (!m_pOperator->operate(pFoundKey, &rKey))
            pFoundKey = nullptr;

        m_aCurLeaf = pPage;
        m_nCurNode = pFoundKey ? i : sal_uInt16(i - 1);
    }
    return pFoundKey;
}

sal_uInt32 OIndexIterator::GetCompare(bool bFirst)
{
    ONDXKey* pKey = nullptr;
    sal_Int32 ePredicateType = dynamic_cast<file::OOp_COMPARE&>(*m_pOperator).getPredicateType();

    if (bFirst)
    {
        // Preparation, position on the smallest element
        ONDXPage* pPage = m_aRoot;
        switch (ePredicateType)
        {
            case SQLFilterOperator::NOT_EQUAL:
            case SQLFilterOperator::LESS:
            case SQLFilterOperator::LESS_EQUAL:
                while (pPage && !pPage->IsLeaf())
                    pPage = pPage->GetChild(m_xIndex.get());

                m_aCurLeaf = pPage;
                m_nCurNode = NODE_NOTFOUND;
        }

        switch (ePredicateType)
        {
            case SQLFilterOperator::NOT_EQUAL:
                while ((pKey = GetNextKey()) != nullptr)
                    if (m_pOperator->operate(pKey, m_pOperand))
                        break;
                break;
            case SQLFilterOperator::LESS:
                while ((pKey = GetNextKey()) != nullptr)
                    if (!pKey->getValue().isNull())
                        break;
                break;
            case SQLFilterOperator::LESS_EQUAL:
                while ((pKey = GetNextKey()) != nullptr)
                    ;
                break;
            case SQLFilterOperator::GREATER_EQUAL:
            case SQLFilterOperator::EQUAL:
                pKey = GetFirstKey(m_aRoot, *m_pOperand);
                break;
            case SQLFilterOperator::GREATER:
                pKey = GetFirstKey(m_aRoot, *m_pOperand);
                if (!pKey)
                    while ((pKey = GetNextKey()) != nullptr)
                        if (m_pOperator->operate(pKey, m_pOperand))
                            break;
        }
    }
    else
    {
        switch (ePredicateType)
        {
            case SQLFilterOperator::NOT_EQUAL:
                while ((pKey = GetNextKey()) != nullptr)
                    if (m_pOperator->operate(pKey, m_pOperand))
                        break;
                break;
            case SQLFilterOperator::LESS:
            case SQLFilterOperator::LESS_EQUAL:
            case SQLFilterOperator::EQUAL:
                pKey = GetNextKey();
                if (pKey == nullptr || !m_pOperator->operate(pKey, m_pOperand))
                {
                    pKey = nullptr;
                    m_aCurLeaf.Clear();
                }
                break;
            case SQLFilterOperator::GREATER_EQUAL:
            case SQLFilterOperator::GREATER:
                pKey = GetNextKey();
        }
    }

    return pKey ? pKey->GetRecord() : NODE_NOTFOUND;
}

sal_uInt32 OIndexIterator::GetLike(bool bFirst)
{
    if (bFirst)
    {
        ONDXPage* pPage = m_aRoot;

        while (pPage && !pPage->IsLeaf())
            pPage = pPage->GetChild(m_xIndex.get());

        m_aCurLeaf = pPage;
        m_nCurNode = NODE_NOTFOUND;
    }

    ONDXKey* pKey;
    while ((pKey = GetNextKey()) != nullptr)
        if (m_pOperator->operate(pKey, m_pOperand))
            break;
    return pKey ? pKey->GetRecord() : NODE_NOTFOUND;
}

sal_uInt32 OIndexIterator::GetNull(bool bFirst)
{
    if (bFirst)
    {
        ONDXPage* pPage = m_aRoot;
        while (pPage && !pPage->IsLeaf())
            pPage = pPage->GetChild(m_xIndex.get());

        m_aCurLeaf = pPage;
        m_nCurNode = NODE_NOTFOUND;
    }

    ONDXKey* pKey = GetNextKey();
    if (pKey == nullptr || !pKey->getValue().isNull())
    {
        pKey = nullptr;
        m_aCurLeaf.Clear();
    }
    return pKey ? pKey->GetRecord() : NODE_NOTFOUND;
}

sal_uInt32 OIndexIterator::GetNotNull(bool bFirst)
{
    ONDXKey* pKey;
    if (bFirst)
    {
        // go through all NULL values first
        for (sal_uInt32 nRec = GetNull(bFirst); nRec != NODE_NOTFOUND; nRec = GetNull(false))
            ;
        pKey = m_aCurLeaf.Is() ? &(*m_aCurLeaf)[m_nCurNode].GetKey() : nullptr;
    }
    else
        pKey = GetNextKey();

    return pKey ? pKey->GetRecord() : NODE_NOTFOUND;
}

ONDXKey* OIndexIterator::GetNextKey()
{
    if (m_aCurLeaf.Is() && ((++m_nCurNode) >= m_aCurLeaf->Count()))
    {
        ONDXPage* pPage = m_aCurLeaf;
        // search next page
        while (pPage)
        {
            ONDXPage* pParentPage = pPage->GetParent();
            if (pParentPage)
            {
                sal_uInt16 nPos = pParentPage->Search(pPage);
                if (nPos != pParentPage->Count() - 1)
                { // page found
                    pPage = (*pParentPage)[o3tl::sanitizing_inc(nPos)].GetChild(m_xIndex.get(),
                                                                                pParentPage);
                    break;
                }
            }
            pPage = pParentPage;
        }

        // now go on with leaf
        while (pPage && !pPage->IsLeaf())
            pPage = pPage->GetChild(m_xIndex.get());

        m_aCurLeaf = pPage;
        m_nCurNode = 0;
    }
    return m_aCurLeaf.Is() ? &(*m_aCurLeaf)[m_nCurNode].GetKey() : nullptr;
}

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