//   Copyright Naoki Shibata and contributors 2010 - 2025.
// Distributed under the Boost Software License, Version 1.0.
//    (See accompanying file LICENSE.txt or copy at
//          http://www.boost.org/LICENSE_1_0.txt)

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <time.h>

#include <math.h>
#include <complex.h>

#include "sleef.h"
#include "sleefdft.h"

#include <fftw3.h>

#ifndef MODE
#define MODE SLEEF_MODE_DEBUG
#endif

#if BASETYPEID == 1
#define THRES 1e-30
#define SleefDFT_init2d SleefDFT_double_init2d
#define SleefDFT_execute SleefDFT_double_execute
typedef double real;
#elif BASETYPEID == 2
#define THRES 1e-13
#define SleefDFT_init2d SleefDFT_float_init2d
#define SleefDFT_execute SleefDFT_float_execute
typedef float real;
#else
#error BASETYPEID not set
#endif

static double squ(double x) { return x * x; }

// complex forward
double check_cf(int n, int m) {
  fftw_complex *in  = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * n * m);
  fftw_complex *out = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * n * m);

  if (!in || !out) {
    fprintf(stderr, "Memory allocation failed");
    exit(-1);
  }

  fftw_plan w = fftw_plan_dft_2d(n, m, in, out, FFTW_FORWARD, FFTW_ESTIMATE);

  real *sx = (real *)Sleef_malloc(n*m*2*sizeof(real));
  real *sy = (real *)Sleef_malloc(n*m*2*sizeof(real));

  if (!sx || !sy) {
    fprintf(stderr, "Memory allocation failed");
    exit(-1);
  }

  struct SleefDFT *p = SleefDFT_init2d(n, m, sx, sy, MODE);

  for(int i=0;i<n*m;i++) {
    double re = (2.0 * random() - 1) / (double)RAND_MAX;
    double im = (2.0 * random() - 1) / (double)RAND_MAX;
    sx[(i*2+0)] = re;
    sx[(i*2+1)] = im;
    in[i] = re + im * _Complex_I;
  }

  SleefDFT_execute(p, NULL, NULL);
  fftw_execute(w);

  double rmsn = 0, rmsd = 0;

  for(int i=0;i<n*m;i++) {
    rmsn += squ(sy[i*2+0] - creal(out[i])) + squ(sy[i*2+1] - cimag(out[i]));
    rmsd += squ(            creal(out[i])) + squ(            cimag(out[i]));
  }

  fftw_destroy_plan(w);
  fftw_free(in);
  fftw_free(out);

  Sleef_free(sx);
  Sleef_free(sy);
  SleefDFT_dispose(p);

  return rmsn / rmsd;
}

// complex backward
double check_cb(int n, int m) {
  fftw_complex *in  = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * n * m);
  fftw_complex *out = (fftw_complex*) fftw_malloc(sizeof(fftw_complex) * n * m);

  if (!in || !out) {
    fprintf(stderr, "Memory allocation failed");
    exit(-1);
  }

  fftw_plan w = fftw_plan_dft_2d(n, m, in, out, FFTW_BACKWARD, FFTW_ESTIMATE);
  
  real *sx = (real *)Sleef_malloc(n*m*2*sizeof(real));
  real *sy = (real *)Sleef_malloc(n*m*2*sizeof(real));

  if (!sx || !sy) {
    fprintf(stderr, "Memory allocation failed");
    exit(-1);
  }

  struct SleefDFT *p = SleefDFT_init2d(n, m, sx, sy, SLEEF_MODE_BACKWARD | MODE);

  for(int i=0;i<n*m;i++) {
    double re = (2.0 * random() - 1) / (double)RAND_MAX;
    double im = (2.0 * random() - 1) / (double)RAND_MAX;
    sx[(i*2+0)] = re;
    sx[(i*2+1)] = im;
    in[i] = re + im * _Complex_I;
  }

  SleefDFT_execute(p, NULL, NULL);
  fftw_execute(w);

  double rmsn = 0, rmsd = 0;

  for(int i=0;i<n*m;i++) {
    rmsn += squ(sy[i*2+0] - creal(out[i])) + squ(sy[i*2+1] - cimag(out[i]));
    rmsd += squ(            creal(out[i])) + squ(            cimag(out[i]));
  }

  fftw_destroy_plan(w);
  fftw_free(in);
  fftw_free(out);

  Sleef_free(sx);
  Sleef_free(sy);
  SleefDFT_dispose(p);

  return rmsn / rmsd;
}

int main(int argc, char **argv) {
  if (argc != 3) {
    fprintf(stderr, "%s <log2n> <log2m>\n", argv[0]);
    exit(-1);
  }

  const int n = 1 << atoi(argv[1]);
  const int m = 1 << atoi(argv[2]);

  srand((unsigned int)time(NULL));

  SleefDFT_setPlanFilePath(NULL, NULL, SLEEF_PLAN_RESET | SLEEF_PLAN_READONLY);

  //

  int success = 1;
  double e;

  e = check_cf(n, m);
  success = success && e < THRES;
  printf("complex forward   : %s (%g)\n", e < THRES ? "OK" : "NG", e);
  e = check_cb(n, m);
  success = success && e < THRES;
  printf("complex backward  : %s (%g)\n", e < THRES ? "OK" : "NG", e);

  exit(success ? 0 : -1);
}
