#include <getopt.h>
#include <iostream>
#include <chrono>
#include <fstream>

#define WOLFF_USE_FINITE_STATES

#include "wolff/lib/wolff_models/ising.hpp"

using namespace wolff;

class Timeseries : public measurement<ising_t, ising_t, graph<>> {
private:
  signed M;
  std::ofstream file;

public:
  Timeseries(unsigned D, unsigned L, double T, double H, const wolff::system<ising_t, ising_t, graph<>>& S) : file("series.dat", std::ios::app) {
    M = 0;
    for (const ising_t& s : S.s) {
      M = M + S.s0.act_inverse(s);
    }
    file << D << " " << L << " " << T << " " << H << " " << M;
  }

  ~Timeseries() {
    file << "\n";
    file.close();
  }

  void ghost_bond_visited(const wolff::system<ising_t, ising_t, graph<>>&, const typename graph<>::vertex&,
                          const ising_t& s_old, const ising_t& s_new, double dE) override {
    M += s_new - s_old;
  }

  void post_cluster(unsigned, unsigned, const wolff::system<ising_t, ising_t, graph<>>& S) override {
    file << " " << M;
  }
};

int main(int argc, char *argv[]) {

  // set defaults
  unsigned N = (unsigned)1e4;
  unsigned D = 2;
  unsigned L = 128;
  double T = 2.26918531421;
  double H = 0.0;

  int opt;

  // take command line arguments
  while ((opt = getopt(argc, argv, "N:D:L:T:H:")) != -1) {
    switch (opt) {
    case 'N': // number of steps
      N = (unsigned)atof(optarg);
      break;
    case 'D': // dimension
      D = atoi(optarg);
      break;
    case 'L': // linear size
      L = atoi(optarg);
      break;
    case 'T': // temperature
      T = atof(optarg);
      break;
    case 'H': // external field
      H = atof(optarg);
      break;
    default:
      exit(EXIT_FAILURE);
    }
  }

  // define the spin-spin coupling
  std::function <double(const ising_t&, const ising_t&)> Z = [] (const ising_t& s1, const ising_t& s2) -> double {
    return (double)(s1 * s2);
  };

  // define the spin-field coupling
  std::function <double(const ising_t&)> B = [=] (const ising_t& s) -> double {
    return H * s;
  };

  // initialize the lattice
  graph<> G(D, L);

  // initialize the system
  wolff::system<ising_t, ising_t, graph<>> S(G, T, Z, B);

  // initialize the random number generator
  auto seed = std::chrono::high_resolution_clock::now().time_since_epoch().count();
  std::mt19937 rng(seed);

  // define function that generates self-inverse rotations
  std::function <ising_t(std::mt19937&, const wolff::system<ising_t, ising_t, graph<>>&, const graph<>::vertex&)> gen_r = gen_ising<graph<>>;

  // initailze the measurement object
  Timeseries A(D, L, T, H, S);

  // run wolff N times
  S.run_wolff(N, gen_r, A, rng);

  // exit
  return 0;
}