Ranges.h

/* Ranges.h */
/*
 * Copyright (C) 2011-2024 Michael Lugmair
 *
 * This file is part of sayonara player
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#ifndef SAYONARA_PLAYER_RANGES_H
#define SAYONARA_PLAYER_RANGES_H
 
#include "Utils/Algorithm.h"
 
#include <utility>
#include <vector>
 
namespace Util
{
    using Range = std::pair<int, int>;
    using RangeList = std::vector<Range>;
 
    template<typename Element, template<typename> typename Container>
    Range getNextRange(const Container<Element>& ids, int startIndex)
    {
        if(startIndex >= ids.size())
        {
            return std::make_pair(-1, -1);
        }
 
        auto result = std::make_pair(startIndex, startIndex);
 
        auto currentIndex = startIndex;
        auto currentValue = ids[currentIndex];
        auto expectedValue = currentValue;
 
        while(currentValue == expectedValue)
        {
            result.second = currentIndex;
 
            currentIndex += 1;
 
            if(currentIndex == ids.size())
            {
                break;
            }
 
            expectedValue += 1;
            currentValue = ids[currentIndex];
        }
 
        return result;
    }
 
    template<typename Element, template<typename> typename Container>
    RangeList getRangesFromList(const Container<Element>& ids)
    {
        if(ids.empty())
        {
            return RangeList {};
        }
 
        RangeList result;
        auto p = getNextRange(ids, 0);
        while(p.first != -1)
        {
            result.push_back(p);
            p = getNextRange(ids, p.second + 1);
        }
 
        return result;
    }
 
    template<typename Element, template<typename> typename Container>
    auto prepareContainerForRangeCalculation(Container<Element> container) -> Container <Element>
    {
        std::sort(container.begin(), container.end());
        Util::Algorithm::remove_duplicates(container);
 
        return container;
    }
}
 
#endif //SAYONARA_PLAYER_RANGES_H