// c99 -o ew_gen_kin -Wall -I ../.. -I ../../amos/ -O2 -ggdb -DQPMS_VECTORS_NICE_TRANSFORMATIONS -DLATTICESUMS32 2dlattice_ewald.c ../translations.c ../ewald.c ../ewaldsf.c ../gaunt.c ../lattices2d.c ../latticegens.c ../bessel.c -lgsl -lm -lblas ../../amos/libamos.a -lgfortran ../error.c

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "transop_ewald_cmdline.h"

#include <stdio.h>
#include <math.h>
#include <string.h>
#include <errno.h>
#define LATTICESUMS32
#include <qpms/translations.h>
#include <qpms/lattices.h>
#include <gsl/gsl_const_mksa.h>

// Command line order:
// outfile b1.x b1.y b2.x b2.y lMax scuffomega refindex npart part0.x part0.y [part1.x part1.y [...]]
//
// Standard input (per line):
// k.x k.y
//
// Output data format (line):
//


// TODO move to qpmslib later.
/** Parse doubles from a string.
 *
 * The doubles can be separated by whitespaces, comma or semicolon.
 * The parsed numbers are saved into an array specified by *target
 * that has been preallocated with malloc() to contain at least start_index
 * members. If start_index is nonzero, the newly parsed numbers are 
 * saved to the positions starting from start_index.
 *
 * If *target is NULL, the function allocates the necessary space.
 *
 * \return Number of newly parsed doubles + start_index.
 */
size_t qpms_parse_doubles(
  double **target,
  size_t start_index,
  const char *orig
) {
  QPMS_ENSURE(target, "The target parameter must not be NULL");
  char * const dup = strdup(orig);
  QPMS_ENSURE(dup, "Memory error in a strdup() call.");

  size_t capacity = start_index * 2;
  if (capacity < 128) capacity = 128;

  // Replace commas and semicolons with whitespaces
  for (char *c = dup; *c; ++c) 
    if (*c == ',' || *c == ';')
      *c = ' ';

  size_t i = start_index;

  const char *beg = dup;
  do {
    char *endptr;
    errno = 0;
    double parsed = strtod(beg, endptr);
    if (endptr > beg) {
      (*target)[i] = parsed;
      ++i;
      if (i >= capacity) {
        capacity *= 2;
        QPMS_CRASHING_REALLOC(*target, capacity * sizeof(double));
      }
    } else {
      while (*beg) {
        if (!isspace(*beg)) {
          QPMS_WARN("Invalid character (expected a double), leaving the rest of the string unprocessed: %s\n", beg);
          errno = EILSEQ;
          goto qpms_parse_doubles_cleanup;
        }
        ++beg;
      }
    }

qpms_parse_doubles_cleanup:
  free(dup);
  return i;
}

#define MAXKCOUNT 200 // 200 // serves as klist default buffer size 
//#define KMINCOEFF 0.783 //0.9783 // 0.783 // not used if KSTDIN defined
//#define KMAXCOEFF 1.217 //1.0217 // 1.217 // not used if KSTDIN defined
#define KLAYERS 20
#define RLAYERS 20

const double s3 = 1.732050807568877293527446341505872366942805253810380628055;

//const qpms_y_t lMax = 3;
//const double REFINDEX = 1.52;
static const double SCUFF_OMEGAUNIT = 3e14;
static const double hbar = GSL_CONST_MKSA_PLANCKS_CONSTANT_HBAR;
static const double eV = GSL_CONST_MKSA_ELECTRON_CHARGE;
static const double c0 = GSL_CONST_MKSA_SPEED_OF_LIGHT;

int main (int argc, char **argv) {
  struct gengetopt_args_info args_info;

  int retval = cmdline_parser(argc, argv, *args_info);
  if (retval) return retval;

  cart2_t b1 = {strtod(argv[2], NULL), strtod(argv[3], NULL)},
          b2 = {strtod(argv[4], NULL), strtod(argv[5], NULL)};
  const qpms_l_t lMax = strtol(argv[6], NULL, 10); assert(lMax>0);
  const double scuffomega = strtod(argv[7], NULL);
  const double refindex = strtod(argv[8], NULL);
  const int npart = strtol(argv[9], NULL, 10);  assert(npart>0);
  assert(argc >= 2*npart + 10);
  assert(npart > 0);
  cart2_t part_positions[npart];
  for(int p = 0; p < npart; ++p) {
    part_positions[p].x = strtod(argv[10+2*p], NULL);
    part_positions[p].y = strtod(argv[10+2*p+1], NULL);
  }

//#ifdef KSTDIN
  size_t kcount = 0;
  size_t klist_capacity = MAXKCOUNT;
  cart2_t *klist = malloc(sizeof(cart2_t) * klist_capacity);
  while (scanf("%lf %lf", &(klist[kcount].x), &(klist[kcount].y)) == 2) {
    ++kcount;
    if(kcount >= klist_capacity) {
      klist_capacity *= 2;
      klist = realloc(klist, sizeof(cart2_t) * klist_capacity);
      if (klist == NULL) abort();
    }
  }
//#else
#if 0
  cart2_t klist[MAXKCOUNT];
  int kcount = MAXKCOUNT;
  for (int i = 0; i <  kcount; ++i) { // TODO this should depend on orientation...
    klist[i].x = 0;
    klist[i].y = (4.* M_PI / 3. / LATTICE_A) * (KMINCOEFF + (KMAXCOEFF-KMINCOEFF)/kcount*i);
  }
#endif

  const double unitcell_area = l2d_unitcell_area(b1, b2);
  l2d_reduceBasis(b1, b2, &b1, &b2);
  
  // TODO more clever way of determining the cutoff
  const double a = sqrt(unitcell_area); // N.B. different meaning than before
  const double maxR = 25 * a;
  const double maxK = 25 * 2*M_PI/a;

  qpms_trans_calculator *c = qpms_trans_calculator_init(lMax, QPMS_NORMALISATION_POWER_CS); // vai POWER_CS?

  FILE *out, *ferr = NULL;
  if (args_info.error_estimate_output_given) {
    if (!strcmp(args_info.error_estimate_output_arg, "-"))
      ferr = stdout;
    else 
      ferr = fopen(args_info.error_estimate_output_arg, "w");
    QPMS_ENSURE(ferr, "Could not open error output file %s", 
        args_info.error_estimate_output_arg);
  if (args_info.output_given && !strcmp(args_info.output_arg, "-")
      && args_info.output_arg[0]) {
    out = fopen(args_info.output_arg, "w");
    QPMS_ENSURE(out, "Could not open output file %s", args_info.output_arg);
  } else
    out = stdout;

  {
    const double omega = scuffomega * SCUFF_OMEGAUNIT;
    const double EeV = omega * hbar / eV;
    const double k0_vac = omega / c0;
    const double k0_eff  = k0_vac * refindex;
    const double eta = 5.224/a; // FIXME quite arbitrary, but this one should work

    // indices : destpart (A/B-particle), srcpart (A/B-particle), coeff type (A/B- type), desty, srcy
    complex double W[npart][npart][2][c->nelem][c->nelem];
    double Werr[npart][npart][npart][c->nelem][c->nelem];

    for (size_t ki = 0; ki < kcount; ++ki) {
      cart2_t beta = klist[ki];
      memset(W, 0, sizeof(W));
      if(ferr)
        memset(Werr, 0, sizeof(Werr));

      const ptrdiff_t deststride = &(W[0][0][0][1][0]) - &(W[0][0][0][0][0]);
      const ptrdiff_t srcstride = &(W[0][0][0][0][1]) - &(W[0][0][0][0][0]);
      assert (srcstride == 1 && deststride == c->nelem);

      for (size_t ps = 0; ps < npart; ++ps) for (size_t pd = 0; pd < npart; ++pd) 
        // TODO optimize (calculate only once for each particle shift; especially if pd == ps)
        qpms_trans_calculator_get_AB_arrays_e32(c,
            &(W[pd][ps][0][0][0]), ferr ? &(Werr[pd][ps][0][0][0]) : NULL, // Adest, Aerr,
            &(W[pd][ps][1][0][0]), ferr ? &(Werr[pd][ps][1][0][0]) : NULL, // Bdest, Berr,
            deststride, srcstride,
            eta, k0_eff, b1, b2,
            beta,
            cart2_substract(part_positions[pd], part_positions[ps]),  // CHECKSIGN
            maxR, maxK 
            );
        // TODO CHECK B<-A vs. A<-B relation

      fprintf(out, "%.16g\t%.16g\t%.16g\t%.16g\t%.16g\t",
          scuffomega, EeV, k0_eff, beta.x, beta.y);
      if(ferr) fprintf(ferr, "%.16g\t%.16g\t%16g\t%.16g\t%.16g\t",
          scuffomega, EeV, k0_eff, beta.x, beta.y);
      size_t totalelems = sizeof(W) / sizeof(complex double);
      for (size_t i = 0; i < totalelems; ++i) {
        complex double w = ((complex double *)W)[i];
        fprintf(out, "%.16g\t%.16g\t", creal(w), cimag(w));
        if (ferr) 
          fprintf(ferr, "%.3g\t", ((double *)Werr)[i]);
      }
      fputc('\n', out);
      if(ferr) fputc('\n', ferr);
    }
  }

  fclose(out);
  if(ferr) fclose(ferr);

//#ifdef KSTDIN
  free(klist);
//#endif

  qpms_trans_calculator_free(c);

}