#include <getopt.h>

#include <wolff.h>
#include <correlation.h>
#include <measure.h>

typedef orthogonal_t <N_COMP, double> orthogonal_R_t;
typedef vector_t <N_COMP, double> vector_R_t;
typedef state_t <orthogonal_R_t, vector_R_t> On_t;

// angle from the x-axis of a two-vector
double theta(vector_R_t v) {
  double x = v.x[0];
  double y = v.x[1];

  double val = atan(y / x);

  if (x < 0.0 && y > 0.0) {
    return M_PI + val;
  } else if ( x < 0.0 && y < 0.0 ) {
    return - M_PI + val;
  } else {
    return val;
  }
}

double H_modulated(vector_R_t v, int order, double mag) {
  return mag * cos(order * theta(v));
}

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

  count_t N = (count_t)1e7;

  D_t D = 2;
  L_t L = 128;
  double T = 2.26918531421;
  double *H_vec = (double *)calloc(MAX_Q, sizeof(double));

  bool silent = false;
  bool use_pert = false;

  bool modulated_field = false;
  int order = 2;

  int opt;
  q_t J_ind = 0;
  q_t H_ind = 0;
  double epsilon = 1;

  unsigned char measurement_flags = measurement_energy | measurement_clusterSize;

  while ((opt = getopt(argc, argv, "N:q:D:L:T:J:H:spe:mo:M:")) != -1) {
    switch (opt) {
    case 'N': // number of steps
      N = (count_t)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. nth call couples to state n
      H_vec[H_ind] = atof(optarg);
      H_ind++;
      break;
    case 's': // don't print anything during simulation. speeds up slightly
      silent = true;
      break;
    case 'p':
      use_pert = true;
      break;
    case 'e':
      epsilon = atof(optarg);
      break;
    case 'm':
      modulated_field = true;
      break;
    case 'M':
      measurement_flags |= 1 << atoi(optarg);
      break;
    case 'o':
      order = atoi(optarg);
      break;
    default:
      exit(EXIT_FAILURE);
    }
  }

  unsigned long timestamp;

  {
    struct timespec spec;
    clock_gettime(CLOCK_REALTIME, &spec);
    timestamp = spec.tv_sec*1000000000LL + spec.tv_nsec;
  }

  const char *pert_type;

  std::function <orthogonal_R_t(gsl_rng *, const On_t *)> gen_R;

  if (use_pert) {
    gen_R = std::bind(generate_rotation_perturbation <N_COMP>, std::placeholders::_1, std::placeholders::_2, epsilon);
    pert_type = "PERTURB";
  } else {
    gen_R = generate_rotation_uniform <N_COMP>;
    pert_type = "UNIFORM";
  }


  FILE *outfile_info = fopen("wolff_metadata.txt", "a");

  fprintf(outfile_info, "<| \"ID\" -> %lu, \"MODEL\" -> \"%s\", \"q\" -> %d, \"D\" -> %" PRID ", \"L\" -> %" PRIL ", \"NV\" -> %" PRIv ", \"NE\" -> %" PRIv ", \"T\" -> %.15f, \"H\" -> {", timestamp, ON_strings[N_COMP], N_COMP, D, L, pow(L, D), D * pow(L, D), T);

  for (q_t i = 0; i < N_COMP; i++) {
    fprintf(outfile_info, "%.15f", H_vec[i]);
    if (i < N_COMP - 1) {
      fprintf(outfile_info, ", ");
    }
  }

  fprintf(outfile_info, "}, \"GENERATOR\" -> \"%s\", \"EPS\" -> %g |>\n", pert_type, epsilon);

  fclose(outfile_info);

  unsigned int n_measurements = 0;
  std::function <void(const On_t *)> *measurements = (std::function <void(const On_t *)> *)calloc(POSSIBLE_MEASUREMENTS, sizeof(std::function <void(const On_t *)>));
  FILE *outfile_M, *outfile_E, *outfile_S, *outfile_F;
  double *fftw_in, *fftw_out;
  fftw_plan plan;

  if (measurement_flags & measurement_energy) {
    char *filename_E = (char *)malloc(255 * sizeof(char));
    sprintf(filename_E, "wolff_%lu_E.dat", timestamp);
    outfile_E = fopen(filename_E, "wb");
    free(filename_E);
    measurements[n_measurements] = measurement_energy_file<orthogonal_R_t, vector_R_t> (outfile_E);
    n_measurements++;
  }

  if (measurement_flags & measurement_clusterSize) {
    char *filename_S = (char *)malloc(255 * sizeof(char));
    sprintf(filename_S, "wolff_%lu_S.dat", timestamp);
    outfile_S = fopen(filename_S, "wb");
    free(filename_S);
    measurements[n_measurements] = measurement_cluster_file<orthogonal_R_t, vector_R_t> (outfile_S);
    n_measurements++;
  }

  if (measurement_flags & measurement_magnetization) {
    char *filename_M = (char *)malloc(255 * sizeof(char));
    sprintf(filename_M, "wolff_%lu_M.dat", timestamp);
    outfile_M = fopen(filename_M, "wb");
    free(filename_M);
    measurements[n_measurements] = measurement_magnetization_file<orthogonal_R_t, vector_R_t> (outfile_M);
    n_measurements++;
  }

  if (measurement_flags & measurement_fourierZero) {
    char *filename_F = (char *)malloc(255 * sizeof(char));
    sprintf(filename_F, "wolff_%lu_F.dat", timestamp);
    outfile_F = fopen(filename_F, "wb");
    free(filename_F);

    fftw_in = (double *)fftw_malloc(pow(L, D) * sizeof(double));
    fftw_out = (double *)fftw_malloc(pow(L, D) * sizeof(double));
    int rank = D;
    int *n = (int *)malloc(rank * sizeof(int));
    fftw_r2r_kind *kind = (fftw_r2r_kind *)malloc(rank * sizeof(fftw_r2r_kind));
    for (D_t i = 0; i < rank; i++) {
      n[i] = L;
      kind[i] = FFTW_R2HC;
    }
    plan = fftw_plan_r2r(rank, n, fftw_in, fftw_out, kind, 0);

    free(n);
    free(kind);

    measurements[n_measurements] = measurement_fourier_file<orthogonal_R_t, vector_R_t> (outfile_F, plan, fftw_in, fftw_out);
    n_measurements++;
  }

  std::function <double(vector_R_t)> H;

  if (modulated_field) {
    H = std::bind(H_modulated, std::placeholders::_1, order, H_vec[0]);
  } else {
    H = std::bind(H_vector <N_COMP, double>, std::placeholders::_1, H_vec);
  }

  wolff <orthogonal_R_t, vector_R_t> (N, D, L, T, dot <N_COMP, double>, H, gen_R, n_measurements, measurements, silent);

  free(measurements);

  if (measurement_flags & measurement_energy) {
    fclose(outfile_E);
  }
  if (measurement_flags & measurement_clusterSize) {
    fclose(outfile_S);
  }
  if (measurement_flags & measurement_magnetization) {
    fclose(outfile_M);
  }
  if (measurement_flags & measurement_fourierZero) {
    fclose(outfile_F);
    fftw_destroy_plan(plan);
    fftw_free(fftw_in);
    fftw_free(fftw_out);
    fftw_cleanup(); // fftw is only used if fourier modes are measured!
  }

  free(H_vec);

  return 0;
}