/*******************************************************************************
*
* McXtrace, X-ray tracing package
*         Copyright, All rights reserved
*         DTU Physics, Kgs. Lyngby, Denmark
*         Synchrotron SOLEIL, Saint-Aubin, France
*
* Component: SasView_gauss_lorentz_gel
*
* %Identification
* Written by: Jose Robledo
* Based on sasmodels from SasView
* Origin: FZJ / DTU / ESS DMSC
*
*
* SasView gauss_lorentz_gel model component as sample description.
*
* %Description
*
* SasView_gauss_lorentz_gel component, generated from gauss_lorentz_gel.c in sasmodels.
*
* Example: 
*  SasView_gauss_lorentz_gel(gauss_scale, cor_length_static, lorentz_scale, cor_length_dynamic, 
*     model_scale=1.0, model_abs=0.0, xwidth=0.01, yheight=0.01, zdepth=0.005, R=0, 
*     int target_index=1, target_x=0, target_y=0, target_z=1,
*     focus_xw=0.5, focus_yh=0.5, focus_aw=0, focus_ah=0, focus_r=0, 
*     pd_cor_length_static=0.0, pd_cor_length_dynamic=0.0)
*
* %Parameters
* INPUT PARAMETERS:
* gauss_scale: [] ([-inf, inf]) Gauss scale factor.
* cor_length_static: [Ang] ([0, inf]) Static correlation length.
* lorentz_scale: [] ([-inf, inf]) Lorentzian scale factor.
* cor_length_dynamic: [Ang] ([0, inf]) Dynamic correlation length.
* Optional parameters:
* model_abs: [ ] Absorption cross section density at 2200 m/s.
* model_scale: [ ] Global scale factor for scattering kernel. For systems without inter-particle interference, the form factors can be related to the scattering intensity by the particle volume fraction.
* xwidth: [m] ([-inf, inf]) Horiz. dimension of sample, as a width.
* yheight: [m] ([-inf, inf]) vert . dimension of sample, as a height for cylinder/box
* zdepth: [m] ([-inf, inf]) depth of sample
* R: [m] Outer radius of sample in (x,z) plane for cylinder/sphere.
* target_x: [m] relative focus target position.
* target_y: [m] relative focus target position.
* target_z: [m] relative focus target position.
* target_index: [ ] Relative index of component to focus at, e.g. next is +1.
* focus_xw: [m] horiz. dimension of a rectangular area.
* focus_yh: [m], vert. dimension of a rectangular area.
* focus_aw: [deg], horiz. angular dimension of a rectangular area.
* focus_ah: [deg], vert. angular dimension of a rectangular area.
* focus_r: [m] case of circular focusing, focusing radius.
* pd_cor_length_static: [] (0,inf) defined as (dx/x), where x is de mean value and dx the standard devition of the variable.
* pd_cor_length_dynamic: [] (0,inf) defined as (dx/x), where x is de mean value and dx the standard devition of the variable
*
* %Link
* %End
*******************************************************************************/
DEFINE COMPONENT SasView_gauss_lorentz_gel

SETTING PARAMETERS (
        gauss_scale=100.0,
        cor_length_static=100.0,
        lorentz_scale=50.0,
        cor_length_dynamic=20.0,
        model_scale=1.0,
        model_abs=0.0,
        xwidth=0.01,
        yheight=0.01,
        zdepth=0.005,
        R=0,
        target_x=0,
        target_y=0,
        target_z=1,
        int target_index=1,
        focus_xw=0.5,
        focus_yh=0.5,
        focus_aw=0,
        focus_ah=0,
        focus_r=0,
        pd_cor_length_static=0.0,
        pd_cor_length_dynamic=0.0)


SHARE %{
%include "sas_kernel_header.c"

/* BEGIN Required header for SASmodel gauss_lorentz_gel */
#define HAS_Iq

#ifndef SAS_HAVE_gauss_lorentz_gel
#define SAS_HAVE_gauss_lorentz_gel

#line 1 "gauss_lorentz_gel"
    
double Iq_gauss_lorentz_gel(double q, double gauss_scale, double cor_length_static, double lorentz_scale, double cor_length_dynamic);

#pragma acc routine seq
double Iq_gauss_lorentz_gel(double q, double gauss_scale, double cor_length_static, double lorentz_scale, double cor_length_dynamic) {
    // Calculate the Gaussian and Lorentzian terms separately
    double term1 = gauss_scale * exp(-q * q * cor_length_static * cor_length_static / 2.0);
    double term2 = lorentz_scale / (1.0 + q * q * cor_length_dynamic * cor_length_dynamic);

    // Return the sum of the two terms
    return term1 + term2;
}





#endif // SAS_HAVE_gauss_lorentz_gel



/* END Required header for SASmodel gauss_lorentz_gel */
%}
    DECLARE
%{
  double shape;
  double my_a_k;
%}

INITIALIZE
%{
  shape = -1; /* -1:no shape, 0:cyl, 1:box, 2:sphere  */
  if (xwidth && yheight && zdepth)
    shape = 1;
  else if (R > 0 && yheight)
    shape = 0;
  else if (R > 0 && !yheight)
    shape = 2;
  if (shape < 0)
    exit (fprintf (stderr,
                   "SasView_model: %s: sample has invalid dimensions.\n"
                   "ERROR     Please check parameter values.\n",
                   NAME_CURRENT_COMP));

  /* now compute target coords if a component index is supplied */
  if (!target_index && !target_x && !target_y && !target_z)
    target_index = 1;
  if (target_index) {
    Coords ToTarget;
    ToTarget = coords_sub (POS_A_COMP_INDEX (INDEX_CURRENT_COMP + target_index), POS_A_CURRENT_COMP);
    ToTarget = rot_apply (ROT_A_CURRENT_COMP, ToTarget);
    coords_get (ToTarget, &target_x, &target_y, &target_z);
  }

  if (!(target_x || target_y || target_z)) {
    printf ("SasView_model: %s: The target is not defined. Using direct beam (Z-axis).\n", NAME_CURRENT_COMP);
    target_z = 1;
  }

  /*TODO fix absorption*/
  my_a_k = model_abs; /* assume absorption is given in 1/m */
%}


TRACE
%{
  double l0, l1, k, l_full, l, dl, d_Phi;
  double aim_x = 0, aim_y = 0, aim_z = 1, axis_x, axis_y, axis_z;
  double f, solid_angle, kx_i, ky_i, kz_i, q, qx, qy, qz;
  char intersect = 0;

  /* Intersection photon trajectory / sample (sample surface) */
  if (shape == 0) {
    intersect = cylinder_intersect (&l0, &l1, x, y, z, kx, ky, kz, R, yheight);
  } else if (shape == 1) {
    intersect = box_intersect (&l0, &l1, x, y, z, kx, ky, kz, xwidth, yheight, zdepth);
  } else if (shape == 2) {
    intersect = sphere_intersect (&l0, &l1, x, y, z, kx, ky, kz, R);
  }
  if (intersect) {
    if (l0 < 0)
      ABSORB;

    /* Photon enters at l0. */
    k = sqrt (kx * kx + ky * ky + kz * kz);
    l_full = (l1 - l0);              /* Length of full path through sample */
    dl = rand01 () * (l1 - l0) + l0; /* Point of scattering */
    PROP_DL (dl);                    /* Point of scattering */
    l = (dl - l0);                   /* Penetration in sample */

    kx_i = kx;
    ky_i = ky;
    kz_i = kz;
    if ((target_x || target_y || target_z)) {
      aim_x = target_x - x; /* Vector pointing at target (anal./det.) */
      aim_y = target_y - y;
      aim_z = target_z - z;
    }
    if (focus_aw && focus_ah) {
      randvec_target_rect_angular (&kx, &ky, &kz, &solid_angle, aim_x, aim_y, aim_z, focus_aw, focus_ah, ROT_A_CURRENT_COMP);
    } else if (focus_xw && focus_yh) {
      randvec_target_rect (&kx, &ky, &kz, &solid_angle, aim_x, aim_y, aim_z, focus_xw, focus_yh, ROT_A_CURRENT_COMP);
    } else {
      randvec_target_circle (&kx, &ky, &kz, &solid_angle, aim_x, aim_y, aim_z, focus_r);
    }
    NORM (kx, ky, kz);
    kx *= k;
    ky *= k;
    kz *= k;
    qx = (kx_i - kx);
    qy = (ky_i - ky);
    qz = (kz_i - kz);
    q = sqrt (qx * qx + qy * qy + qz * qz);

    double trace_cor_length_static = cor_length_static;
    double trace_cor_length_dynamic = cor_length_dynamic;
    if (pd_cor_length_static != 0.0 || pd_cor_length_dynamic != 0.0) {
      trace_cor_length_static = (randnorm () * pd_cor_length_static + 1.0) * cor_length_static;
      trace_cor_length_dynamic = (randnorm () * pd_cor_length_dynamic + 1.0) * cor_length_dynamic;
    }

    // Sample dependent. Retrieved from SasView./////////////////////
    float Iq_out;
    Iq_out = 1;

    Iq_out = Iq_gauss_lorentz_gel (q, gauss_scale, trace_cor_length_static, lorentz_scale, trace_cor_length_dynamic);

    float vol;
    vol = 1;

    // Scale by 1.0E2 [SasView: 1/cm  ->   McXtrace: 1/m]
    Iq_out = model_scale * Iq_out / vol * 1.0E2;

    p *= l_full * solid_angle / (4 * PI) * Iq_out * exp (-my_a_k * (l + l1));

    SCATTER;
  }
%}

MCDISPLAY
%{

  if (shape == 0) { /* cylinder */
    circle ("xz", 0, yheight / 2.0, 0, R);
    circle ("xz", 0, -yheight / 2.0, 0, R);
    line (-R, -yheight / 2.0, 0, -R, +yheight / 2.0, 0);
    line (+R, -yheight / 2.0, 0, +R, +yheight / 2.0, 0);
    line (0, -yheight / 2.0, -R, 0, +yheight / 2.0, -R);
    line (0, -yheight / 2.0, +R, 0, +yheight / 2.0, +R);
  } else if (shape == 1) { /* box */
    double xmin = -0.5 * xwidth;
    double xmax = 0.5 * xwidth;
    double ymin = -0.5 * yheight;
    double ymax = 0.5 * yheight;
    double zmin = -0.5 * zdepth;
    double zmax = 0.5 * zdepth;
    multiline (5, xmin, ymin, zmin, xmax, ymin, zmin, xmax, ymax, zmin, xmin, ymax, zmin, xmin, ymin, zmin);
    multiline (5, xmin, ymin, zmax, xmax, ymin, zmax, xmax, ymax, zmax, xmin, ymax, zmax, xmin, ymin, zmax);
    line (xmin, ymin, zmin, xmin, ymin, zmax);
    line (xmax, ymin, zmin, xmax, ymin, zmax);
    line (xmin, ymax, zmin, xmin, ymax, zmax);
    line (xmax, ymax, zmin, xmax, ymax, zmax);
  } else if (shape == 2) { /* sphere */
    circle ("xy", 0, 0.0, 0, R);
    circle ("xz", 0, 0.0, 0, R);
    circle ("yz", 0, 0.0, 0, R);
  }
%}
END