#pragma once
#include "nodesoup.hpp"
#include <vector>

namespace nodesoup {
// https://gist.github.com/terakun/b7eff90c889c1485898ec9256ca9f91d
// https://graphsharp.codeplex.com/SourceControl/latest#Source/Graph#/Algorithms/Layout/Simple/FDP/KKLayoutAlgorithm.cs
class KamadaKawai {
public:
    struct Spring {
        double length;
        double strength;
    };

    KamadaKawai(const adj_list_t& g, double k = 300.0, double energy_threshold = 1e-2);
    void operator()(std::vector<Point2D>& positions) const;

private:
    const adj_list_t& g_;
    const double energy_threshold_;
    std::vector<std::vector<Spring>> springs_;

    static std::vector<std::vector<vertex_id_t>> floyd_warshall_(const adj_list_t& g);
    // p m
    double find_max_vertex_energy_(const std::vector<Point2D>& positions, vertex_id_t& max_energy_v_id) const;
    // delta m
    double compute_vertex_energy_(vertex_id_t v_id, const std::vector<Point2D>& positions) const;
    Point2D compute_next_vertex_position_(vertex_id_t v_id, const std::vector<Point2D>& positions) const;
};
}