RegionSetMatcher.hpp

/*
  Copyright 2024 Equinor ASA.

  This file is part of the Open Porous Media project (OPM).

  OPM 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.

  OPM 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 OPM.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef REGION_SET_MATCHER_HPP
#define REGION_SET_MATCHER_HPP

#include <cstddef>
#include <iterator>
#include <memory>
#include <optional>
#include <string>
#include <string_view>
#include <utility>
#include <vector>


namespace Opm {
    class FIPRegionStatistics;
} // namespace Opm

namespace Opm {

class RegionSetMatcher;

class RegionSetMatchResult
{
public:
    class RegionIndexRange
    {
    public:
        class Iterator
        {
        public:
            using iterator_category = std::forward_iterator_tag;

            using value_type = int;

            using difference_type = int;

            using pointer = int*;

            using reference = int&;

            Iterator& operator++()
            {
                ++this->i_;

                return *this;
            }

            Iterator operator++(int)
            {
                auto iter = *this;

                ++(*this);

                return iter;
            }

            reference operator*() { return this->i_; }

            pointer operator->() { return &this->i_; }

            bool operator==(Iterator that) const
            {
                return this->i_ == that.i_;
            }

            bool operator!=(Iterator that) const
            {
                return ! (*this == that);
            }

            friend class RegionIndexRange;

        private:
            explicit Iterator(int i) : i_{i} {}

            int i_;
        };

        Iterator begin() const { return Iterator{this->begin_}; }

        Iterator end() const { return Iterator{this->end_}; }

        bool empty() const { return this->end_ <= this->begin_; }

        std::string_view regionSet() const { return this->region_; }

        friend class RegionSetMatchResult;

    private:
        int begin_{};

        int end_{};

        std::string_view region_{};

        RegionIndexRange() = default;

        RegionIndexRange(int beginID, int endID, std::string_view region)
            : begin_  { beginID }
            , end_    { endID }
            , region_ { region }
        {}
    };

    bool empty() const
    {
        return this->regionIDRange_.empty();
    }

    bool isScalar() const
    {
        return (this->regionIDRange_.size() == std::vector<int>::size_type{2})
            && (this->regionIDRange_.back() == this->regionIDRange_.front() + 1);
    }

    std::vector<std::string_view> regionSets() const;

    std::size_t numRegionSets() const
    {
        return this->regionSets_.size();
    }

    RegionIndexRange regions(std::string_view regSet) const;

    RegionIndexRange regions(const std::size_t regSet) const;

    friend class RegionSetMatcher;

private:
    std::vector<std::string> regionSets_{};

    std::vector<std::vector<std::string>::size_type> regionSetIndex_{};

    std::vector<int> regionIDRange_{};

    void establishNameLookupIndex();

    void addRegionIndices(const std::string& regSet,
                          int                beginRegID,
                          int                endRegID);
};

class RegionSetMatcher
{
public:
    class SetDescriptor
    {
    public:
        SetDescriptor& regionID(const int region);

        SetDescriptor& regionID(std::string_view region);

        const std::optional<int>& regionID() const
        {
            return this->regionId_;
        }

        SetDescriptor& vectorName(std::string_view vector);

        const std::optional<std::string>& regionSet() const
        {
            return this->regionSet_;
        }

    private:
        std::optional<std::string> regionSet_{};

        std::optional<int> regionId_{};
    };

    RegionSetMatcher() = delete;

    explicit RegionSetMatcher(const FIPRegionStatistics& fipRegStats);

    RegionSetMatcher(const RegionSetMatcher& rhs) = delete;

    RegionSetMatcher(RegionSetMatcher&& rhs);

    RegionSetMatcher& operator=(const RegionSetMatcher& rhs) = delete;

    RegionSetMatcher& operator=(RegionSetMatcher&& rhs);

    ~RegionSetMatcher();

    RegionSetMatchResult findRegions(const SetDescriptor& regSet) const;

private:
    class Impl;

    std::unique_ptr<Impl> pImpl_{};
};

} // namespace Opm

#endif // REGION_SET_MATCHER_HPP