/*

Copyright (c) 2015, Project OSRM contributors
All rights reserved.

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are permitted provided that the following conditions are met:

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list of conditions and the following disclaimer in the documentation and/or
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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*/

#ifndef MATRIX_GRAPH_WRAPPER_H
#define MATRIX_GRAPH_WRAPPER_H

#include <vector>
#include <cstddef>
#include <iterator>

#include "../typedefs.h"

// This Wrapper provides all methods that are needed for TarjanSCC, when the graph is given in a
// matrix representation (e.g. as output from a distance table call)

template <typename T> class MatrixGraphWrapper
{
  public:
    MatrixGraphWrapper(std::vector<T> table, const std::size_t number_of_nodes)
        : table_(std::move(table)), number_of_nodes_(number_of_nodes){};

    std::size_t GetNumberOfNodes() const { return number_of_nodes_; }

    std::vector<T> GetAdjacentEdgeRange(const NodeID node) const
    {

        std::vector<T> edges;
        // find all valid adjacent edges and move to vector `edges`
        for (std::size_t i = 0; i < number_of_nodes_; ++i)
        {
            if (*(std::begin(table_) + node * number_of_nodes_ + i) != INVALID_EDGE_WEIGHT)
            {
                edges.push_back(i);
            }
        }
        return edges;
    }

    EdgeWeight GetTarget(const EdgeWeight edge) const { return edge; }

  private:
    const std::vector<T> table_;
    const std::size_t number_of_nodes_;
};

#endif // MATRIX_GRAPH_WRAPPER_H