#include <string>
#include <iostream>
#include <fstream>
#include <iomanip>
#include <set>
#include <map>
#include <cmath>

#include "JTools/JFunction1D_t.hh"
#include "JTools/JFunctionalMap_t.hh"
#include "JTools/JQuadrature.hh"
#include "JPhysics/JPDF.hh"
#include "JPhysics/JPDFTable.hh"
#include "JPhysics/Antares.hh"
#include "JPhysics/KM3NeT.hh"

#include "Jeep/JParser.hh"
#include "Jeep/JMessage.hh"


/**
 * Scaling of absorption and scattering length.
 */
double  absorptionLengthFactor;
double  scatteringLengthFactor;


inline double getAbsorptionLength(const double lambda)
{
  return absorptionLengthFactor * NAMESPACE::getAbsorptionLength(lambda);
}


inline double getScatteringLength(const double lambda)
{
  return scatteringLengthFactor * NAMESPACE::getScatteringLength(lambda);
}


/**
 * \file
 *
 * Program to create interpolation tables of the PDF of the arrival time of the Cherenkov light from a shower.
 *
 * The PDFs are tabulated as a function of <tt>(D, cos(theta), theta, phi, t)</tt>, where:
 * - <tt>D</tt> is the distance between the vertex and the PMT;
 * - <tt>cos(theta)</tt> the cosine of the photon emission angle;
 * - <tt>(theta, phi)</tt> the orientation of the PMT; and
 * - <tt>t</tt> the arrival time of the light with respect to the Cherenkov hypothesis.
 *
 * The orientation of the PMT is defined in the coordinate system in which
 * the shower developes along the z-axis and the PMT is located in the x-z plane.
 * \author mdejong
 */
int main(int argc, char **argv)
{
  using namespace std;
  using namespace JPP;

  string              outputFile;
  int                 numberOfPoints;
  double              epsilon;
  int                 function;
  set<double>         D;                          // distance [m]
  int                 debug;
  
  try {

    JParser<> zap("Program to create interpolation tables of the PDF of the arrival time of the Cherenkov light from a shower.");

    zap['o'] = make_field(outputFile);
    zap['n'] = make_field(numberOfPoints,         "points for integration")     = 25;
    zap['e'] = make_field(epsilon,                "precision for integration")  = 1.0e-10;
    zap['A'] = make_field(absorptionLengthFactor, "scaling factor")             = 1.0;
    zap['S'] = make_field(scatteringLengthFactor, "scaling factor")             = 1.0;
    zap['F'] = make_field(function,               "PDF type")                   =
      SCATTERED_LIGHT_FROM_MUON_5D,
      DIRECT_LIGHT_FROM_EMSHOWER,
      SCATTERED_LIGHT_FROM_EMSHOWER;
    zap['D'] = make_field(D,                      "distance [m]")               = JPARSER::initialised();
    zap['d'] = make_field(debug)                  = 0;

    zap['F'] = JPARSER::not_initialised();

    zap(argc, argv);
  }
  catch(const exception &error) {
    FATAL(error.what() << endl);
  }


  typedef double (JPDF::*fcn)(const double,
			      const double,
			      const double,
			      const double,
			      const double) const;


  // set global parameters

  const double P_atm = NAMESPACE::getAmbientPressure();
  const double wmin  = getMinimalWavelength();
  const double wmax  = getMaximalWavelength();
  

  const JPDF_C
    pdf_c(NAMESPACE::getPhotocathodeArea(),
	  NAMESPACE::getQE,
	  NAMESPACE::getAngularAcceptance,
	  getAbsorptionLength,
	  getScatteringLength,
	  NAMESPACE::getScatteringProbability,
	  P_atm,
          wmin,
	  wmax,
	  numberOfPoints,
	  epsilon);


  typedef JSplineFunction1D_t                                     JFunction1D_t;
  typedef JMAPLIST<JPolint1FunctionalMap,
		   JPolint1FunctionalMap,
		   JPolint1FunctionalGridMap,
		   JPolint1FunctionalGridMap>::maplist            JMapList_t;
  typedef JPDFTable<JFunction1D_t, JMapList_t>                    JPDF_t;

  typedef JPDFTransformer<4, JFunction1D_t::argument_type>        JFunction4DTransformer_t;
  typedef JArray<4, JFunction1D_t::argument_type>                 JArray_t;

  JPDF_t pdf;


  NOTICE("building multi-dimensional function object <" << function << ">... " << flush);
  
  const double ng[] = { pdf_c.getIndexOfRefractionGroup(wmax),
			pdf_c.getIndexOfRefractionGroup(wmin) };
  
  map<int, pair<fcn,JFunction4DTransformer_t> > zmap;

  zmap[SCATTERED_LIGHT_FROM_MUON_5D]  = make_pair((fcn) &JPDF::getScatteredLightFromMuon,     JFunction4DTransformer_t(21.5, 2, ng[0], 0.0,   JGeant(JGeanx(0.33, -9.5)), 6e-4, NAMESPACE::getAngularAcceptance, 0.06));
  zmap[DIRECT_LIGHT_FROM_EMSHOWER]    = make_pair((fcn) &JPDF::getDirectLightFromEMshower,    JFunction4DTransformer_t(21.5, 2, ng[0], ng[1], JGeant(JGeanx(0.35, -5.4)), 1e-5, NAMESPACE::getAngularAcceptance, 0.001));
  zmap[SCATTERED_LIGHT_FROM_EMSHOWER] = make_pair((fcn) &JPDF::getScatteredLightFromEMshower, JFunction4DTransformer_t(21.5, 2, ng[0], 0.0,   JGeant(JGeanx(0.55, -4.5)), 1e-2, NAMESPACE::getAngularAcceptance, 0.05));

  if (zmap.find(function) == zmap.end()) {
    FATAL("illegal function specifier" << endl);
  }

  fcn                      f           = zmap[function].first;    // PDF
  JFunction4DTransformer_t transformer = zmap[function].second;   // transformer


  if (D.empty()) {
    D.insert(  0.10);
    D.insert(  0.50);
    D.insert(  1.00);
    D.insert(  5.00);
    D.insert( 10.00);
    D.insert( 20.00);
    D.insert( 30.00);
    D.insert( 40.00);
    D.insert( 50.00);
    D.insert( 60.00);
    D.insert( 70.00);
    D.insert( 80.00);
    D.insert( 90.00);
    D.insert(100.00);
    D.insert(120.00);
    D.insert(150.00);
    D.insert(170.00);
    D.insert(190.00);
    D.insert(210.00);
    D.insert(230.00);
    D.insert(250.00);
    D.insert(270.00);
    D.insert(290.00);
    D.insert(310.00);
  }

  set<double> C;        // cosine emission angle

  JQuadrature qeant(-1.0, +1.0, 60, geanx);

  for (JQuadrature::const_iterator i = qeant.begin(); i != qeant.end(); ++i)
    C.insert(i->getX());

  C.insert(-1.00);
  C.insert(+1.00);


  set<double> X;        // time [ns]

  if (function == DIRECT_LIGHT_FROM_EMSHOWER) {

    for (double buffer[] = { 0.0, 0.005, 0.01, 0.015, -1 }, *x = buffer; *x >= 0; ++x) {
      X.insert(0.0 + *x);
      X.insert(1.0 - *x);
    }

    for (double x = 0.02; x < 0.99; x += 0.01)
      X.insert(x);

  } else {

    X.insert(  0.00);
    X.insert(  0.10);
    X.insert(  0.20);
    X.insert(  0.30);
    X.insert(  0.40);
    X.insert(  0.50);
    X.insert(  0.60);
    X.insert(  0.70);
    X.insert(  0.80);
    X.insert(  0.90);
    X.insert(  1.00);
    X.insert(  1.00);
    X.insert(  1.10);
    X.insert(  1.20);
    X.insert(  1.30);
    X.insert(  1.40);
    X.insert(  1.50);
    X.insert(  1.60);
    X.insert(  1.70);
    X.insert(  1.80);
    X.insert(  1.90);
    X.insert(  2.00);
    X.insert(  2.20);
    X.insert(  2.40);
    X.insert(  2.60);
    X.insert(  2.80);
    X.insert(  3.00);
    X.insert(  3.25);
    X.insert(  3.50);
    X.insert(  3.75);
    X.insert(  4.00);
    X.insert(  4.25);
    X.insert(  4.50);
    X.insert(  4.75);
    X.insert(  5.0);
    X.insert(  6.0);
    X.insert(  7.0);
    X.insert(  8.0);
    X.insert(  9.0);
    X.insert( 10.0);
    X.insert( 15.0);
    X.insert( 20.0);
    X.insert( 25.0);
    X.insert( 30.0);
    X.insert( 40.0);
    X.insert( 50.0);
    X.insert( 60.0);
    X.insert( 70.0);
    X.insert( 80.0);
    X.insert( 90.0);
    X.insert(100.0);
    X.insert(120.0);
    X.insert(140.0);
    X.insert(160.0);
    X.insert(180.0);
    X.insert(200.0);
    X.insert(250.0);
    X.insert(300.0);
    X.insert(350.0);
    X.insert(400.0);
    X.insert(450.0);
    X.insert(500.0);
    X.insert(600.0);
    X.insert(700.0);
    X.insert(800.0);
    X.insert(900.0);
    X.insert(1200.0);
    X.insert(1500.0);
  }
    
  const double grid  =  7.0;                                      // [deg]
      
  const double alpha = 2.0 * sqrt(1.0 - cos(grid * PI / 180.0));  // azimuth angle unit step size


  for (set<double>::const_iterator d = D.begin(); d != D.end(); ++d) {

    const double D_m = *d;

    for (set<double>::const_iterator c = C.begin(); c != C.end(); ++c) {

      const double cd  = *c;

      const unsigned int number_of_theta_points = max(2u, (unsigned int) (180.0/(1.4 * grid)));

      for (double theta = 0.0; theta <= PI + epsilon; theta += PI/number_of_theta_points) {

	const unsigned int number_of_phi_points = max(2u, (unsigned int) (PI * sin(theta) / alpha));
      
	for (double phi = 0.0; phi <= PI + epsilon; phi += PI/number_of_phi_points) {

	  JFunction1D_t& f1 = pdf[D_m][cd][theta][phi];

	  const JArray_t array(D_m, cd, theta, phi);

	  double t_old = transformer.getXn(array, *X.begin());
	  double y_old = 0.0;

	  for (set<double>::const_iterator x = X.begin(); x != X.end(); ++x) {
	  
	    const double t = transformer.getXn(array, *x);
	    const double y = (pdf_c.*f)(D_m, cd, theta, phi, t);

	    if (y != 0.0) {

	      if (*x < 0.0) {
		WARNING("dt < 0 " << *x << ' ' << D_m << ' ' << t << ' ' << y << endl);
	      }

	      if (y_old == 0.0) {
		f1[t_old] = y_old;
	      }

	      f1[t] = y;
	      
	    } else {
	      
	      if (y_old != 0.0) {
		f1[t] = y;
	      }
	    }
	    
	    t_old = t;
	    y_old = y;
	  }
	}
      }
    }
  }

  pdf.transform(transformer);
  pdf.compile();

  NOTICE("OK" << endl);

  try {

    NOTICE("storing output to file " << outputFile << "... " << flush);

    pdf.store(outputFile.c_str());

    NOTICE("OK" << endl);
  }
  catch(const JException& error) {
    FATAL(error.what() << endl);
  }
}