#include "log-fourier.hpp"
#include <getopt.h>
#include <iostream>

int main(int argc, char* argv[]) {
  /* Model parameters */
  unsigned p = 2;
  unsigned s = 2;
  Real λ = 0.5;
  Real τ₀ = 0;

  /* Log-Fourier parameters */
  unsigned log2n = 8;
  Real Δτ = 0.1;
  Real k = 0.1;

  /* Iteration parameters */
  Real ε = 1e-14;
  Real γ₀ = 1;
  Real β₀ = 0;
  Real βₘₐₓ = 0.7;
  Real Δβ = 0.01;
  bool loadData = false;
  unsigned stepsToRespond = 1000;

  int opt;

  while ((opt = getopt(argc, argv, "p:s:2:T:t:b:d:g:k:D:e:0:lS:")) != -1) {
    switch (opt) {
    case 'p':
      p = atoi(optarg);
      break;
    case 's':
      s = atoi(optarg);
      break;
    case '2':
      log2n = atoi(optarg);
      break;
    case 't':
      τ₀ = atof(optarg);
      break;
    case 'b':
      βₘₐₓ = atof(optarg);
      break;
    case 'd':
      Δβ = atof(optarg);
      break;
    case 'g':
      γ₀ = atof(optarg);
      break;
    case 'k':
      k = atof(optarg);
      break;
    case 'D':
      Δτ = atof(optarg);
      break;
    case 'e':
      ε = atof(optarg);
      break;
    case '0':
      β₀ = atof(optarg);
      break;
    case 'l':
      loadData = true;
      break;
    case 'S':
      stepsToRespond = atoi(optarg);
      break;
    default:
      exit(1);
    }
  }

  unsigned N = pow(2, log2n);

  LogarithmicFourierTransform fft(N, k, Δτ, 4);

  Real Γ₀ = 1.0;
  Real μₜ₋₁ = Γ₀;
  if (τ₀ > 0) {
    μₜ₋₁ = (sqrt(1+4*Γ₀*τ₀)-1)/(2*τ₀);
  }

  std::vector<Real> Cₜ₋₁(N);
  std::vector<Real> Rₜ₋₁(N);
  std::vector<Complex> Ĉₜ₋₁(N);
  std::vector<Complex> Ȓₜ₋₁(N);

  if (!loadData) {
    /* Start from the exact solution for β = 0 */
    for (unsigned n = 0; n < N; n++) {
      if (τ₀ > 0) {
        if (τ₀ == 2) {
          Cₜ₋₁[n] = Γ₀ * exp(-fft.t(n) / 2) * (1 + fft.t(n) / 2);
        } else {
          Cₜ₋₁[n] = Γ₀ * (exp(-μₜ₋₁ * fft.t(n)) - μₜ₋₁ * τ₀ * exp(-fft.t(n) / τ₀)) / (μₜ₋₁ - pow(μₜ₋₁, 3) * pow(τ₀, 2));
        }
      } else {
        Cₜ₋₁[n] = Γ₀ * exp(-μₜ₋₁ * fft.t(n)) / μₜ₋₁;
      }
      Rₜ₋₁[n] = exp(-μₜ₋₁ * fft.t(n));

      Ĉₜ₋₁[n] = 2 * Γ₀ / (pow(μₜ₋₁, 2) + pow(fft.ν(n), 2)) / (1 + pow(τ₀ * fft.ν(n), 2));
      Ȓₜ₋₁[n] = 1.0 / (μₜ₋₁ + 1i * fft.ν(n));
    }
  } else {
    logFourierLoad(Cₜ₋₁, Rₜ₋₁, Ĉₜ₋₁, Ȓₜ₋₁, p, s, λ, τ₀, β₀, log2n, Δτ, k);
    μₜ₋₁ = estimateZ(fft, Cₜ₋₁, Ĉₜ₋₁, Rₜ₋₁, Ȓₜ₋₁, p, s, λ, τ₀, β₀);
  }

  std::vector<Real> Cₜ = Cₜ₋₁;
  std::vector<Real> Rₜ = Rₜ₋₁;
  std::vector<Complex> Ĉₜ = Ĉₜ₋₁;
  std::vector<Complex> Ȓₜ = Ȓₜ₋₁;
  Real μₜ = μₜ₋₁;

  Real β = β₀ + Δβ;
  while (β < βₘₐₓ) {
    Real γ = γ₀;
    Real ΔCmin = 1000;
    Real ΔCₜ = 100;
    unsigned stepsDown = 0;
    unsigned stepsUp = 0;
    while (ΔCₜ > ε) {
      auto [RddfCt, dfCt] = RddfCtdfCt(fft, Cₜ, Rₜ, p, s, λ);

      std::vector<Complex> Ĉₜ₊₁(N);
      std::vector<Complex> Ȓₜ₊₁(N);
      for (unsigned n = 0; n < N; n++) {
        Ȓₜ₊₁[n] = (1.0 + pow(β, 2) * RddfCt[n] * Ȓₜ[n]) / (μₜ + 1i * fft.ν(n));
        Ĉₜ₊₁[n] = (2 * Γ₀ * std::conj(Ȓₜ[n]) / (1 + pow(τ₀ * fft.ν(n), 2)) + pow(β, 2) * (RddfCt[n] * Ĉₜ[n] + dfCt[n] * std::conj(Ȓₜ[n]))) / (μₜ + 1i * fft.ν(n));
      }
      std::vector<Real> Rₜ₊₁ = fft.inverse(Ȓₜ₊₁);
      std::vector<Real> Cₜ₊₁ = fft.inverse(Ĉₜ₊₁);

      μₜ *= pow(tanh(Cₜ₊₁[0]-1)+1, 0.05);

      ΔCₜ = 0;
      for (unsigned i = 0; i < N; i++) {
        ΔCₜ += std::norm(Ĉₜ[i] - Ĉₜ₊₁[i]);
        ΔCₜ += std::norm(Ȓₜ[i] - Ȓₜ₊₁[i]);
      }
      ΔCₜ = sqrt(ΔCₜ) / (2*N);

      if (ΔCₜ < ΔCmin) {
        ΔCmin = ΔCₜ;
        stepsUp = 0;
        stepsDown++;
      } else {
        stepsDown = 0;
        stepsUp++;
      }

      if (stepsUp > stepsToRespond) {
        γ = std::max(γ/2, 1e-4);
        stepsUp = 0;
      }

      if (stepsDown > stepsToRespond) {
        γ = std::min(2*γ, 1.0);
        stepsDown = 0;
      }

      for (unsigned i = 0; i < N; i++) {
        Cₜ[i] += γ * (Cₜ₊₁[i] - Cₜ[i]);
        Rₜ[i] += γ * (Rₜ₊₁[i] - Rₜ[i]);
        Ĉₜ[i] += γ * (Ĉₜ₊₁[i] - Ĉₜ[i]);
        Ȓₜ[i] += γ * (Ȓₜ₊₁[i] - Ȓₜ[i]);
      }

      std::cerr << "\x1b[2K" << "\r";
      std::cerr << β << " " << μₜ << " " << ΔCₜ << " " << γ << " " << Cₜ[0];
    }

    if (std::isnan(Cₜ[0])) {
      γ₀ /= 2;
      Cₜ = Cₜ₋₁;
      Rₜ = Rₜ₋₁;
      Ĉₜ = Ĉₜ₋₁;
      Ȓₜ = Ȓₜ₋₁;
      μₜ = μₜ₋₁;
    } else {
      Real E = energy(fft, Cₜ, Rₜ, p, s, λ, β);

      std::cerr << "\x1b[2K" << "\r";
      std::cerr << β << " " << μₜ << " " << Ĉₜ[0].real() << " " << E << " " << γ << std::endl;

      logFourierSave(Cₜ, Rₜ, Ĉₜ, Ȓₜ, p, s, λ, τ₀, β, log2n, Δτ, k);

      β += Δβ;
      Cₜ₋₁ = Cₜ;
      Rₜ₋₁ = Rₜ;
      Ĉₜ₋₁ = Ĉₜ;
      Ȓₜ₋₁ = Ȓₜ;
      μₜ₋₁ = μₜ;
    }
  }

  return 0;
}