#include <getopt.h>
#include <vector>
#include <cmath>
#include <iostream>
#include <fftw3.h>
#include <complex>
#include <fstream>

using Real = double;
using Complex = std::complex<Real>;
using namespace std::complex_literals;

inline Real fP(unsigned p, Real q) {
  return 0.5 * pow(q, p);
}

inline Real dfP(unsigned p, Real q) {
  return 0.5 * p * pow(q, p - 1);
}

inline Real ddfP(unsigned p, Real q) {
  return 0.5 * p * (p - 1) * pow(q, p - 2);
}

inline Real f(Real λ, unsigned p, unsigned s, Real q) {
  return (1 - λ) * fP(p, q) + λ * fP(s, q);
}

inline Real df(Real λ, unsigned p, unsigned s, Real q) {
  return (1 - λ) * dfP(p, q) + λ * dfP(s, q);
}

inline Real ddf(Real λ, unsigned p, unsigned s, Real q) {
  return (1 - λ) * ddfP(p, q) + λ * ddfP(s, q);
}

int main(int argc, char* argv[]) {
  unsigned p = 2;
  unsigned s = 2;
  Real λ = 0.5;
  Real τ₀ = 0;
  Real y₀ = 0;
  Real yₘₐₓ = 0.5;
  Real Δy = 0.05;

  unsigned log2n = 8;
  Real τₘₐₓ = 20;

  int opt;

  while ((opt = getopt(argc, argv, "p:s:2:T:t:0:y:d:")) != -1) {
    switch (opt) {
    case 'p':
      p = atoi(optarg);
      break;
    case 's':
      s = atoi(optarg);
      break;
    case '2':
      log2n = atoi(optarg);
      break;
    case 'T':
      τₘₐₓ = atof(optarg);
      break;
    case 't':
      τ₀ = atof(optarg);
      break;
    case '0':
      y₀ = atof(optarg);
      break;
    case 'y':
      yₘₐₓ = atof(optarg);
      break;
    case 'd':
      Δy = atof(optarg);
      break;
    default:
      exit(1);
    }
  }

  unsigned n = pow(2, log2n);

  Real Δτ = τₘₐₓ / M_PI / n;

  Real y = y₀;

  while (y += Δy, y <= yₘₐₓ) {
    std::vector<Real> C(2 * n);
    std::vector<Real> R(2 * n);

    std::string file_end = std::to_string(p) + "_" + std::to_string(s) + "_" + std::to_string(λ) + "_" + std::to_string(τ₀) + "_" + std::to_string(y) + "_" + std::to_string(log2n) + "_" + std::to_string(τₘₐₓ) + ".dat";
    std::ifstream cfile("C_"+file_end, std::ios::binary);
    cfile.read((char*)(C.data()), C.size() * sizeof(Real));
    cfile.close();
    std::ifstream rfile("R_"+file_end, std::ios::binary);
    rfile.read((char*)(R.data()), R.size() * sizeof(Real));
    rfile.close();

    Real energy = 0;

    for (unsigned i = 0; i < n; i++) {
      energy += y * R[i] * df(λ, p, s, C[i]) * M_PI * Δτ;
    }

    std::cerr << y << " " << energy << std::endl;
  }

  return 0;
}