/*******************************************************************************
*
* McStas, neutron ray-tracing package
*         Copyright 1997-2014, All rights reserved
*         Risoe National Laboratory, Roskilde, Denmark
*         Institut Laue Langevin, Grenoble, France
*
* Component: Monitor_Sqw
*
* %Identification
* Written by: <a href="mailto:farhi@ill.fr">Emmanuel Farhi</a>
* Date: 31 jan 2014.
* Origin: <a href="http://www.ill.fr">ILL</a>
*
* This component is a Sqw Monitor that records the dynamic structure factor S(q,w)
* from a scattering location, seen from a detector location.
*
* %Description
* This component is a specialized Monitor_nD variation, which records the S(q,w)
* scattering law. It accepts about the same parameters as the Monitor_nD, but makes
* use of the 'q' and 'w' user variables. The neutrons are restored in their previous
* state after neing detected (restore_neutron=1).
*
* The monitor records the intensity as a function of q=kf-ki and w=Ef-Ei were the
* 'f' refers to the component location, and the 'i' refers to the component located
* at 'index' relative to the component location.
*
* The component uses automatic limits, and is thus not recommended with MPI/multiprocessing.
* In this case, the limits should be set manually, e.g. user1=q and user2=w
*   options="user1 limits=[0 10] bins=100, user2 limits=[-50 50] bins=200"
*
* A usage example is for instance:
*   COMPONENT sample = Isotropic_Sqw(...)
*
*   COMPONENT sqw = Monitor_Sqw(index=-1, radius=2, yheight=2, bins=128)
*
* This component can be used to generate dynamic structure factors comvolved with
* the instrument response, and compare with molecular dynamics results (using e.g. nMoldyn).
* The incoming beam (e.g. at the sample) must be monochromatic.
*
* %Parameters
* INPUT PARAMETERS:
*
* xwidth: [m]      Width of detector.
* yheight: [m]     Height of detector.
* zdepth: [m]      Thickness of detector (z).
* radius: [m]      Radius of sphere/banana shape monitor
* options: [str]   String that specifies the configuration of the monitor The general syntax is "[x] options..." (see <b>Descr.</b>).
* index: [1]       Index of the component where scattering occurs with respect to the location of the Monitor_Sqw location in the instrument description. The index is usually negative, and should point to e.g. a  Isotropic_Sqw, , PowderN, or Single_crystal instance. index=-1 for the previous component.
*
* Optional input parameters (override xwidth yheight zdepth):
* xmin: [m]        Lower x bound of opening
* xmax: [m]        Upper x bound of opening
* ymin: [m]        Lower y bound of opening
* ymax: [m]        Upper y bound of opening
* zmin: [m]        Lower z bound of opening
* zmax: [m]        Upper z bound of opening
* filename: [str]  Output file name. If not set an automatic file name is used.
* bins: [1]        Number of bins to force for all variables. Use 'bins' keyword in 'options' for heterogeneous bins
* geometry: [str]  Name of an OFF file to specify a complex geometry detector
* nowritefile: [1]      If set, monitor will skip writing to disk
*
* OUTPUT PARAMETERS:
*
* DEFS: [struct]   structure containing Monitor_nD Defines
* Vars: [struct]   structure containing Monitor_nD variables
*
* %Link
* <a href="Monitor_nD.html">Monitor_nD</a>
* <a href="../examples/Test_Monitor_Sqw.html">Test_Monitor_Sqw</a>
* <a href="http://forge.ill.fr/projects/nmoldyn/">nMoldyn</a>
*
* %End
******************************************************************************/
DEFINE COMPONENT Monitor_Sqw
DEFINITION PARAMETERS ()
SETTING PARAMETERS (symbol user3=FLT_MAX,
  xwidth=0, yheight=0, zdepth=0,
  xmin=0, xmax=0, ymin=0, ymax=0, zmin=0, zmax=0, radius=0,
  bins=0, min=-1e40, max=1e40,
  int index=-1, string options=0, string filename=0, string geometry=0, int nowritefile=0,
  string username3=0)
/* these are protected C variables */
OUTPUT PARAMETERS ()

SHARE
%{
  %include "monitor_nd-lib"
%}

DECLARE
%{
  MonitornD_Defines_type DEFS;
  MonitornD_Variables_type Vars;
  MCDETECTOR detector;
  off_struct offdata;
  double mean_vx;
  double mean_vy;
  double mean_vz;
  double sum_p;
%}

INITIALIZE
%{
  char tmp[CHAR_BUF_LENGTH];
  strcpy(Vars.compcurname, NAME_CURRENT_COMP);
  if (options != NULL)
    strncpy(Vars.option, options, CHAR_BUF_LENGTH);
  if (!strstr(Vars.option, "user1"))
    strncat(Vars.option," user1", CHAR_BUF_LENGTH);
  if (!strstr(Vars.option, "user2"))
    strncat(Vars.option," user2", CHAR_BUF_LENGTH);
  if (!strstr(Vars.option, "limits") && !strstr(Vars.option, "auto"))
    strncat(Vars.option," all auto", CHAR_BUF_LENGTH);
  strncat(Vars.option," borders", CHAR_BUF_LENGTH);
  Vars.compcurpos = POS_A_CURRENT_COMP;

  if (bins && !strstr(Vars.option, "bins")) {
    sprintf(tmp, " all bins=%ld ", (long)bins); strncat(Vars.option, tmp, CHAR_BUF_LENGTH);
  }
  if (min > -FLT_MAX && max < FLT_MAX && !strstr(Vars.option, "limits")) {
    sprintf(tmp, " all limits=[%g %g]", min, max); strncat(Vars.option, tmp, CHAR_BUF_LENGTH);
  }
  else if (min > -FLT_MAX) {
    sprintf(tmp, " all min=%g", min); strncat(Vars.option, tmp, CHAR_BUF_LENGTH);
  }
  else if (max <  FLT_MAX) {
    sprintf(tmp, " all max=%g", max); strncat(Vars.option, tmp, CHAR_BUF_LENGTH);
  }

  strcpy(Vars.UserName1, "Momentum transfer Q [Angs-1]");
  strcpy(Vars.UserName2, "Energy transfer w [meV]");
  strncpy(Vars.UserName3, username3 && strlen(username3) ? username3 : "", 128);
  if (radius) {
    xwidth = zdepth = 2*radius;
    if (yheight && !strstr(Vars.option, "cylinder") && !strstr(Vars.option, "banana"))
      strncat(Vars.option, " banana", CHAR_BUF_LENGTH);
    else if (!yheight && !strstr(Vars.option ,"sphere")) {
      strncat(Vars.option, " sphere", CHAR_BUF_LENGTH);
      yheight=2*radius;
    }
  }
  int offflag=0;
  if (geometry && strlen(geometry) && strcmp(geometry,"NULL") && strcmp(geometry,"0"))
    if (!off_init(  geometry, xwidth, yheight, zdepth, 0, &offdata )) {
      printf("Monitor_Sqw: %s could not initiate the OFF geometry. \n"
             "            Defaulting to normal Monitor dimensions.\n", NAME_CURRENT_COMP);
      strcpy(geometry, "");
    } else {
      offflag=1;
    }

  if (!radius && !xwidth && !yheight && !zdepth && !xmin && !xmax && !ymin && !ymax && !strstr(Vars.option, "previous") && (!geometry || !strlen(geometry)))
    exit(printf("Monitor_Sqw: %s has no dimension specified. Aborting (radius, xwidth, yheight, zdepth, previous, geometry).\n", NAME_CURRENT_COMP));

  Monitor_nD_Init(&DEFS, &Vars, xwidth, yheight, zdepth, xmin,xmax,ymin,ymax,zmin,zmax,offflag);

  if (filename && strlen(filename) && strcmp(filename,"NULL") && strcmp(filename,"0"))
    strncpy(Vars.Mon_File, filename, 128);

  Vars.Flag_parallel=1;
  detector.m = 0;

  mean_vx=0; mean_vy=0; mean_vz=0; sum_p=0;
%}

TRACE
%{
  double  XY=0;
  double  t0 = 0;
  double  t1 = 0;
  double  pp;
  int     intersect   = 0;

  Vars.UserVariable3 = user3;

  if (geometry && strlen(geometry) && strcmp(geometry,"NULL") && strcmp(geometry,"0"))
  {
    /* determine intersections with object */
    intersect = off_intersect(&t0, &t1, NULL, NULL,
       x,y,z, vx, vy, vz, 0, 0, 0, offdata );
  }
  else if (abs(Vars.Flag_Shape) == DEFS.SHAPE_SQUARE) /* square xy */
  {
    PROP_Z0;
    intersect = (x>=Vars.mxmin && x<=Vars.mxmax && y>=Vars.mymin && y<=Vars.mymax);
  }
  else if (abs(Vars.Flag_Shape) == DEFS.SHAPE_DISK)   /* disk xy */
  {
    PROP_Z0;
    intersect = ((x*x + y*y) <= Vars.Sphere_Radius*Vars.Sphere_Radius);
  }
  else if (abs(Vars.Flag_Shape) == DEFS.SHAPE_SPHERE) /* sphere */
  {
    intersect = sphere_intersect(&t0, &t1, x, y, z, vx, vy, vz, Vars.Sphere_Radius);
  /*      intersect = (intersect && t0 > 0); */
  }
  else if ((abs(Vars.Flag_Shape) == DEFS.SHAPE_CYLIND) || (abs(Vars.Flag_Shape) == DEFS.SHAPE_BANANA)) /* cylinder */
  {
    intersect = cylinder_intersect(&t0, &t1, x, y, z, vx, vy, vz, Vars.Sphere_Radius, Vars.Cylinder_Height);
  }
  else if (abs(Vars.Flag_Shape) == DEFS.SHAPE_BOX) /* box */
  {
    intersect = box_intersect(&t0, &t1, x, y, z, vx, vy, vz, fabs(Vars.mxmax-Vars.mxmin), fabs(Vars.mymax-Vars.mymin), fabs(Vars.mzmax-Vars.mzmin));
  }
  else if (abs(Vars.Flag_Shape) == DEFS.SHAPE_PREVIOUS) /* previous comp */
  { intersect = 1; }



  if (intersect)
  {
    double rx,ry,rz,rvx,rvy,rvz,rt,rsx,rsy,rsz,rp;
    double Ei, Ef;

    if ((abs(Vars.Flag_Shape) == DEFS.SHAPE_SPHERE) || (abs(Vars.Flag_Shape) == DEFS.SHAPE_CYLIND)
     || (abs(Vars.Flag_Shape) == DEFS.SHAPE_BOX) || (abs(Vars.Flag_Shape) == DEFS.SHAPE_BANANA)
     || (geometry && strlen(geometry) && strcmp(geometry,"NULL") && strcmp(geometry,"0")) )
    {
      /* check if we have to remove the top/bottom with BANANA shape */
      if ((abs(Vars.Flag_Shape) == DEFS.SHAPE_BANANA) && (intersect != 1)) {
        double y0,y1;
        /* propagate to intersection point as temporary variable to check top/bottom */
        y0 = y+t0*vy;
        y1 = y+t1*vy;
        if (fabs(y0) >= Vars.Cylinder_Height/2*0.99) t0 = t1;
        if (fabs(y1) >= Vars.Cylinder_Height/2*0.99) t1 = t0;
      }
      if (t0 < 0 && t1 > 0)
        t0 = t;  /* neutron was already inside ! */
      if (t1 < 0 && t0 > 0) /* neutron exit before entering !! */
        t1 = t;
      /* t0 is now time of incoming intersection with the detection area */
      if ((Vars.Flag_Shape < 0) && (t1 > 0))
        PROP_DT(t1); /* t1 outgoing beam */
      else
        PROP_DT(t0); /* t0 incoming beam */
      /* Final test if we are on lid / bottom of banana */
      if (abs(Vars.Flag_Shape) == DEFS.SHAPE_BANANA) {
        if (fabs(y) >= Vars.Cylinder_Height/2*0.99) ABSORB;
      }
    }
    SCATTER;

    Ef = VS2E*(vx*vx+vy*vy+vz*vz);

    /* get incoming beam velocity in 'initial' coordinate frame */
    RESTORE_NEUTRON(INDEX_CURRENT_COMP+index,
      rx,ry,rz,rvx,rvy,rvz,rt,rsx,rsy,rsz,rp);
    mean_vx += rvx*rp; mean_vy += rvy*rp; mean_vz += rvz*rp;
    sum_p   += rp;

    /* compute mean incoming energy and mean beam direction */
    rvx = mean_vx/sum_p; rvy = mean_vy/sum_p; rvz = mean_vz/sum_p;
    Ei  =  VS2E*(rvx*rvx+rvy*rvy+rvz*rvz);

    Vars.UserVariable1=V2K*sqrt( (vx-rvx)*(vx-rvx)
                                +(vy-rvy)*(vy-rvy)
                                +(vz-rvz)*(vz-rvz) ); // Q = |Kf - Ki| with left/right sign
    Vars.UserVariable1 *= (x >= 0 ? 1 : -1);
    Vars.UserVariable2  = Ef-Ei;                      // E = Ef-Ei

    /* send current neutron state to Monitor_nD_Trace */
    /* Vars.cp  = p;
    Vars.cx  = x;
    Vars.cvx = vx;
    Vars.csx = sx;
    Vars.cy  = y;
    Vars.cvy = vy;
    Vars.csy = sy;
    Vars.cz  = z;
    Vars.cvz = vz;
    Vars.csz = sz;
    Vars.ct  = t; */

    pp = Monitor_nD_Trace(&DEFS, &Vars, _particle);
    SCATTER;

  } /* end if intersection */

  RESTORE_NEUTRON(INDEX_CURRENT_COMP, x, y, z, vx, vy, vz, t, sx, sy, sz, p);
%}

SAVE COPY Monitor_nD

FINALLY COPY Monitor_nD

MCDISPLAY COPY Monitor_nD

END
