/*  smoothest.cc

    Mark Jenkinson, FMRIB Image Analysis Group

    Copyright (C) 2000-2004 University of Oxford  */

/*  Part of FSL - FMRIB's Software Library
    http://www.fmrib.ox.ac.uk/fsl
    fsl@fmrib.ox.ac.uk
    
    Developed at FMRIB (Oxford Centre for Functional Magnetic Resonance
    Imaging of the Brain), Department of Clinical Neurology, Oxford
    University, Oxford, UK
    
    
    LICENCE
    
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    University").
    
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    makes clear that no condition is made or to be implied, nor is any
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#include <cmath>
#include <iostream>
#include <string>
#include <map>

#include "smoothest.h"

#include "utils/options.h"

#define _GNU_SOURCE 1
#define POSIX_SOURCE 1

using namespace Utilities;
using namespace NEWIMAGE;

Option<bool> verbose(string("-V,--verbose"), false, 
		     string("switch on diagnostic messages"), 
		     false, no_argument);
Option<bool> help(string("-h,--help"), false,
		  string("display this message"),
		  false, no_argument);
Option<float> dof(string("-d,--dof"), 100.0,
		  string("number of degrees of freedom"),
		  true, requires_argument);
Option<string> maskname(string("-m,--mask"), "mask",
			string("brain mask volume"),
			true, requires_argument);
Option<string> zstatname(string("-z,--zstat"), "zstat",
			 string("filename of zstat image (not with -d)"),
			 true, requires_argument);
Option<string> residname(string("-r,--res"), "res4d",
			 string("filename of `residual-fit' image (use -d)"),
			 true, requires_argument);

namespace SMOOTHEST {

class Interpolate {
public:
  Interpolate() {
    lut[5]   = 1.5423138; lut[6]   = 1.3757105; lut[7]   = 1.2842680;
    lut[8]   = 1.2272151; lut[9]   = 1.1885232; lut[10]  = 1.1606988;
    lut[11]  = 1.1398000; lut[12]  = 1.1235677; lut[13]  = 1.1106196;
    lut[14]  = 1.1000651; lut[15]  = 1.0913060; lut[16]  = 1.0839261;
    lut[17]  = 1.0776276; lut[18]  = 1.0721920; lut[19]  = 1.0674553;
    lut[20]  = 1.0632924; lut[25]  = 1.0483053; lut[30]  = 1.0390117;
    lut[40]  = 1.0281339; lut[50]  = 1.0219834; lut[60]  = 1.0180339;
    lut[70]  = 1.0152850; lut[80]  = 1.0132621; lut[90]  = 1.0117115;
    lut[100] = 1.0104851; lut[150] = 1.0068808; lut[200] = 1.0051200;
    lut[300] = 1.0033865; lut[500] = 1.0020191;
  }

  inline float operator()(float v) {

    float retval = 0;

    if (v<6) return 1.1; // ?? no idea - steve ??

    map<int, float>::iterator i = lut.lower_bound(int(v));

    if(i != lut.end()) {
      if(i != lut.begin()) {
	map<int, float>::iterator j = i--;

	retval = (j->second - i->second)/(j->first - i->first)*(v - i->first)
	  + j->second;
      } 
    } else {
      retval = 1.0321/v + 1;
    }
    
    retval = pow(retval, 0.5);

    return retval;
  }

private:
  map<int, float> lut;
};

Interpolate interpolate;

}

//////////////////////////////////////////////////////////////////////////////
// Standardise the residual field (assuming gaussianity)
unsigned long standardise(volume<float>& mask, 
			  volume4D<float>& R)
{
  unsigned long count = 0;
  int M=R.tsize();

  for (int z=mask.minz(); z<=mask.maxz(); z++) {
    for (int y=mask.miny(); y<=mask.maxy(); y++) {
      for (int x=mask.minx(); x<=mask.maxx(); x++) {

	if( mask(x,y,z) > 0.5) {
	  
	  count ++;
	  
	  if( M > 2 ) {
	    
	    // For each voxel 
	    //    calculate mean and standard deviation...
	    double Sx = 0.0, SSx = 0.0;
	    
	    for ( int t = 0; t < M; t++ ) {
	      float R_it = R(x,y,z,t);
	      
	      Sx += R_it;
	      SSx += Sqr(R_it);
	    }
	    
	    float mean = Sx / M;
	    float sdsq = (SSx - (Sqr(Sx) / M)) / (M - 1) ;
	    
	    if (sdsq<=0) {
	      // trap for differences between mask and invalid data
	      mask(x,y,z)=0;
	      count--;
	    } else {
	      //    ... and use them to standardise to N(0, 1).
	      for ( unsigned short t = 0; t < M; t++ ) {
		R(x,y,z,t) = (R(x,y,z,t) - mean) / sqrt(sdsq);
	      }
	    } 
	  }
	}
      }
    }
  }  
  return count;
}


string title = "\
smoothest \nCopyright(c) 2000-2002, University of Oxford (Dave Flitney and Mark Jenkinson)";

string examples = "\
\tsmoothest -d <number> -r <filename> -m <filename>\n\
\tsmoothest -z <filename> -m <filename>";

int main(int argc, char **argv) {

  OptionParser options(title, examples);

  options.add(verbose);
  options.add(help);
  options.add(dof);
  options.add(maskname);
  options.add(residname);
  options.add(zstatname);

  options.parse_command_line(argc, argv);

//  if(verbose.value()) options.check_compulsory_arguments(true);

  if(help.value()) {
    options.usage();
    exit(EXIT_SUCCESS);
  }

  if( !((zstatname.set() && residname.unset()) || (residname.set() && zstatname.unset())) ||
      (zstatname.set() && (residname.set() || dof.set())) || 
      (residname.set() && dof.unset()) ||
      (maskname.unset()) ) {
    options.usage();
    cerr << endl;
    cerr << "***************************************************************************" << endl;
    cerr << "You must specify either a zstat image OR a 4d residual image." << endl;
    cerr << "If processing a zstat image then you should not set degrees of freedom." << endl; 
    cerr << "You must specify a mask volume image filename" << endl; 
    cerr << "You must specify the degrees of freedom for processing a 4d residual image." << endl; 
    cerr << "***************************************************************************" << endl;
    cerr << endl;
    exit(EXIT_FAILURE);    
  }

  if(verbose.value()) {
    cout << "verbose = " << verbose.value() << endl;
    cout << "help = " << help.value() << endl;
    cout << "dof = " << dof.value() << endl;
    cout << "maskname = " << maskname.value() << endl;
    cout << "residname = " << residname.value() << endl;
    cout << "zstatname = " << zstatname.value() << endl;
  }

  // Read the AVW mask image (single volume)
  if(verbose.value()) cerr << "Reading mask....";
  volume<float> mask;
  read_volume(mask,maskname.value());
  if(verbose.value()) cerr << "done" << endl;
  if (verbose.value()) print_volume_info(mask,"mask");

  if(verbose.value()) cerr << "Reading datafile....";
  string datafilename;
  if(residname.set()) {
    // Read the AVW residual images (array of volumes)
    datafilename = residname.value();
  } else {
    // Read the AVW zstat image (array of one volume)
    datafilename = zstatname.value();
  }
  if(verbose.value()) cerr << "done" << endl;
  

  volume4D<float> R;
  read_volume4D(R,datafilename);
  if (verbose.value()) print_volume_info(R,"Data (residuals/zstat)");

  if (!samesize(R[0],mask)) {
    cerr << "Mask and Data (residuals/zstat) volumes MUST be the same size!"
	 << endl;
    exit(EXIT_FAILURE);
  }

  if(verbose.value()) cerr << "Standardising....";
  unsigned long mask_volume = standardise(mask, R);
  if(verbose.value()) cerr << "done" << endl;
  
  if(verbose.value()) cerr << "Masked-in voxels = " << mask_volume << endl;

  unsigned long N = 0;

  // MJ additions to make it cope with 2D images
  bool usez = true;
  if (R.zsize() <= 1) { usez = false; }
  if ((!usez) && verbose.value()) {
    cout << "Using 2D image mode." << endl;
  }

  // Estimate the smoothness of the normalised residual field
  // see TR00DF1 for mathematical description of the algorithm.
  enum {X = 0, Y, Z};
  float SSminus[3] = {0, 0, 0}, S2[3] = {0, 0, 0};

  int zstart=1;
  if (!usez) zstart=0;
  for ( unsigned short z = zstart; z < R.zsize() ; z++ )
    for ( unsigned short y = 1; y < R.ysize() ; y++ )
      for ( unsigned short x = 1; x < R.xsize() ; x++ )
	// Sum over N
	if( (mask(x, y, z)>0.5) &&
	    (mask(x-1, y, z)>0.5) && 
	    (mask(x, y-1, z)>0.5) && 
	    ( (!usez) || (mask(x, y, z-1)>0.5) ) ) {
	  
	  N++;
	  
	  for ( unsigned short t = 0; t < R.tsize(); t++ ) {
	    // Sum over M
	    SSminus[X] += R(x, y, z, t) * R(x-1, y, z, t);
	    SSminus[Y] += R(x, y, z, t) * R(x, y-1, z, t);
	    if (usez) SSminus[Z] += R(x, y, z, t) * R(x, y, z-1, t);

	    S2[X] += 0.5 * (Sqr(R(x, y, z, t)) + Sqr(R(x-1, y, z, t)));
	    S2[Y] += 0.5 * (Sqr(R(x, y, z, t)) + Sqr(R(x, y-1, z, t)));
	    if (usez) S2[Z] += 0.5 * (Sqr(R(x, y, z, t)) + Sqr(R(x, y, z-1, t)));
	  }
	}

  float norm = 1.0/(float) N;
  float v = dof.value();	// v - degrees of freedom (nu)  
  if(R.tsize() > 1) {
    if(verbose.value()) {
      cerr << "Non-edge voxels = " << N << endl;
      cerr << "(v - 2)/(v - 1) = " << (v - 2)/(v - 1) << endl;
    }
    norm = (v - 2) / ((v - 1) * N * R.tsize());
  }
 
//    SSminus[X] *= norm;
//    SSminus[Y] *= norm;
//    SSminus[Z] *= norm;
  
//    S2[X] *= norm;
//    S2[Y] *= norm;
//    S2[Z] *= norm;

  if(verbose.value()) {
    cout << "SSminus[X] = " << SSminus[X] << ", SSminus[Y] = " << SSminus[Y] << ", SSminus[Z] = " << SSminus[Z] 
	 << ", S2[X] = " << S2[X] << ", S2[Y] = " << S2[Y] << ", S2[Z] = " << S2[Z]
	 << endl;
  }

  // for extreme smoothness 
  if (SSminus[X]>=0.99999999*S2[X]) {
    SSminus[X]=0.99999*S2[X];  
    cerr << "WARNING: Extreme smoothness detected in X - possibly biased"
	 << " global estimate." << endl; } 
  if (SSminus[Y]>=0.99999999*S2[Y]) {
    SSminus[Y]=0.99999*S2[Y];
    cerr << "WARNING: Extreme smoothness detected in Y - possibly biased"
	 << " global estimate." << endl; } 
  if (usez) {
    if (SSminus[Z]>=0.99999999*S2[Z]) {
      SSminus[Z]=0.99999*S2[Z];
      cerr << "WARNING: Extreme smoothness detected in Z - possibly biased"
	   << " global estimate." << endl; } 
  }

  // Convert to sigma squared
  float sigmasq[3];

  sigmasq[X] = -1.0 / (4 * log(fabs(SSminus[X]/S2[X])));
  sigmasq[Y] = -1.0 / (4 * log(fabs(SSminus[Y]/S2[Y])));
  if (usez) { sigmasq[Z] = -1.0 / (4 * log(fabs(SSminus[Z]/S2[Z]))); }
  else { sigmasq[Z]=0; }
  // the following is determininant of Lambda to the half 
  //   i.e. dLh = | Lambda |^(1/2)
  // Furthermore, W_i = 1/(2.lambda_i) = sigma_i^2 => 
  //   det(Lambda) = det( lambda_i ) = det ( (2 W_i)^-1 ) = (2^D det(W))^-1
  //   where D = number of dimensions (2 or 3)
  float dLh;
  if (usez) { dLh=pow(sigmasq[X]*sigmasq[Y]*sigmasq[Z], -0.5)*pow(8, -0.5); }
  else { dLh = pow(sigmasq[X]*sigmasq[Y], -0.5)*pow(4, -0.5); }

  if(verbose.value()) {
    cout << "DLH " << dLh << " voxels^-3 before correcting for temporal DOF" << endl;
  }
  if(R.tsize() > 1) dLh *= SMOOTHEST::interpolate(v);

  // Convert to full width half maximum
  float FWHM[3];
  FWHM[X] = sqrt(8 * log(2) * sigmasq[X]);
  FWHM[Y] = sqrt(8 * log(2) * sigmasq[Y]);
  if (usez) { FWHM[Z] = sqrt(8 * log(2) * sigmasq[Z]); }
  else { FWHM[Z]=0; }
  float resels = FWHM[X] * FWHM[Y];
  if (usez) resels *= FWHM[Z];

  if(verbose.value()) {
    cout << "FWHMx = " << FWHM[X] << " voxels, " 
	 << "FWHMy = " << FWHM[Y] << " voxels"; 
    if (usez) cout << ", FWHMz = " << FWHM[Z] << " voxels";
    cout << endl;
  }
  
  FWHM[X] *= R.xdim(); FWHM[Y] *= R.ydim(); if (usez) FWHM[Z] *= R.zdim(); 

  if(verbose.value()) {
    cout << "FWHMx = " << FWHM[X] << " mm, "
	 << "FWHMy = " << FWHM[Y] << " mm";
    if (usez) cout << ", FWHMz = " << FWHM[Z] << " mm";
    cout << endl;
    cout << "DLH " << dLh << " voxels^-3" << endl;
    cout << "VOLUME " << mask_volume << " voxels" << endl;
    cout << "RESELS " << resels << " voxels per resel" << endl;
  }
  
  cout << "DLH " << dLh << endl;
  cout << "VOLUME " << mask_volume << endl;
  cout << "RESELS " << resels << endl;

  return EXIT_SUCCESS;
}