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#pragma once

#include <google/protobuf/repeated_field.h>
#include <util/generic/vector.h>

template <typename T>
void RemoveRepeatedPtrFieldElement(google::protobuf::RepeatedPtrField<T>* repeated, unsigned index) {
    google::protobuf::RepeatedPtrField<T> r;
    Y_ASSERT(index < (unsigned)repeated->size()); 
    for (unsigned i = 0; i < (unsigned)repeated->size(); ++i) { 
        if (i == index) {
            continue;
        }
        r.Add()->Swap(repeated->Mutable(i));
    }
    r.Swap(repeated);
}

namespace NProtoBuf {
    /// Move item to specified position 
    template <typename TRepeated> 
    static void MoveRepeatedFieldItem(TRepeated* field, size_t indexFrom, size_t indexTo) { 
        if (!field->size() || indexFrom >= static_cast<size_t>(field->size()) || indexFrom == indexTo) 
            return; 
        if (indexTo >= static_cast<size_t>(field->size())) 
            indexTo = field->size() - 1; 
        if (indexFrom > indexTo) { 
            for (size_t i = indexFrom; i > indexTo; --i) 
                field->SwapElements(i, i - 1); 
        } else { 
            for (size_t i = indexFrom; i < indexTo; ++i) 
                field->SwapElements(i, i + 1); 
        } 
    } 

    template <typename T> 
    static T* InsertRepeatedFieldItem(NProtoBuf::RepeatedPtrField<T>* field, size_t index) { 
        T* ret = field->Add(); 
        MoveRepeatedFieldItem(field, field->size() - 1, index); 
        return ret; 
    }

    template <typename TRepeated> // suitable both for RepeatedField and RepeatedPtrField 
    static void RemoveRepeatedFieldItem(TRepeated* field, size_t index) { 
        if ((int)index >= field->size()) 
            return; 

        for (int i = index + 1; i < field->size(); ++i) 
            field->SwapElements(i - 1, i); 

        field->RemoveLast(); 
    } 

    template <typename TRepeated, typename TPred> // suitable both for RepeatedField and RepeatedPtrField 
    static void RemoveRepeatedFieldItemIf(TRepeated* repeated, TPred p) { 
        auto last = std::remove_if(repeated->begin(), repeated->end(), p); 
        if (last != repeated->end()) { 
            size_t countToRemove = repeated->end() - last; 
            while (countToRemove--) 
                repeated->RemoveLast(); 
        } 
    } 

    namespace NImpl { 
        template <typename TRepeated> 
        static void ShiftLeft(TRepeated* field, int begIndex, int endIndex, size_t shiftSize) { 
            Y_ASSERT(begIndex <= field->size()); 
            Y_ASSERT(endIndex <= field->size()); 
            size_t shiftIndex = (int)shiftSize < begIndex ? begIndex - shiftSize : 0; 
            for (int i = begIndex; i < endIndex; ++i, ++shiftIndex) 
                field->SwapElements(shiftIndex, i); 
        } 
    }

    // Remove several items at once, could be more efficient compared to calling RemoveRepeatedFieldItem several times 
    template <typename TRepeated>
    static void RemoveRepeatedFieldItems(TRepeated* field, const TVector<size_t>& sortedIndices) { 
        if (sortedIndices.empty()) 
            return; 

        size_t shift = 1; 
        for (size_t i = 1; i < sortedIndices.size(); ++i, ++shift) 
            NImpl::ShiftLeft(field, sortedIndices[i - 1] + 1, sortedIndices[i], shift); 
        NImpl::ShiftLeft(field, sortedIndices.back() + 1, field->size(), shift); 

        for (; shift > 0; --shift) 
            field->RemoveLast(); 
    } 

    template <typename TRepeated> 
    static void ReverseRepeatedFieldItems(TRepeated* field) { 
        for (int i1 = 0, i2 = field->size() - 1; i1 < i2; ++i1, --i2) 
            field->SwapElements(i1, i2); 
    } 

}