//===========================================================================
// Copyright (C) 1998, 2000-2007, 2010, 2011, 2012 SINTEF ICT, Applied
// Mathematics, Norway.
//
// This file is part of GoTools
//
// This program is free software; you can redistribute it and/or          
// modify it under the terms of the GNU General Public License            
// as published by the Free Software Foundation version 2 of the License. 
//
// This program is distributed in the hope that it will be useful,        
// but WITHOUT ANY WARRANTY; without even the implied warranty of         
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the          
// GNU General Public License for more details.                           
//
// You should have received a copy of the GNU General Public License      
// along with this program; if not, see <http://www.gnu.org/licenses>
//
// Contact information: E-mail: tor.dokken@sintef.no                      
// SINTEF ICT, Department of Applied Mathematics,                         
// P.O. Box 124 Blindern,                                                 
// 0314 Oslo, Norway.                                                     
//
// Other licenses are also available for this software, notably licenses
// for:
// - Building commercial software.                                        
// - Building software whose source code you wish to keep private.        
//===========================================================================

#include <iostream>
#include <fstream>
#include <string>
#include <stdexcept>
#include <cstdlib>

#include "sisl.h"
#include "GoReadWrite.h"

using namespace std;

namespace {
    string OUT_FILE_CURVE_1 = "example8_curve_1.g2";
    string OUT_FILE_CURVE_2 = "example8_curve_2.g2";
    string OUT_FILE_POINT   = "example8_closestpoints.g2";

    string DESCRIPTION = 
    //==========================================================
    "This program generates two non-intersecting curves (from \n"
    "internal data), and computes their mutual closest points, \n"
    "using SISL routine s1955.  The curves will be saved to the \n"
    "two files '" + OUT_FILE_CURVE_1 + "' and '" + OUT_FILE_CURVE_2 + "'\n"
    "The closest points will be saved to the file '" + OUT_FILE_POINT + "'\n\n";


    const int dim = 3;

    const int c1_number = 4;
    const int c1_order = 4;
    
    double c1_coef[] = {0, 0, 0,
			0, 1, 0,
			1, 1, 0,
			1, 0, 0};

    double c1_knots[] = {0, 0, 0, 0, 1, 1, 1, 1};

    const int c2_number = 4;
    const int c2_order = 4;
    
    double c2_coef[] = {-2,   0, 0,
                         0, 1.2, 0,
                         1, 1.2, 0,
			 3,   0, 0};
			
    double c2_knots[] = {0, 0, 0, 0, 1, 1, 1, 1};

}; // end anonymous namespace 

//===========================================================================
int main(int avnum, char** vararg)
//===========================================================================
{
    cout << '\n' << vararg[0] << ":\n" << DESCRIPTION << endl;
    cout << "To proceed, press enter, or ^C to quit." << endl;
    getchar();

    try {
	ofstream os_cv1(OUT_FILE_CURVE_1.c_str());
	ofstream os_cv2(OUT_FILE_CURVE_2.c_str());
	ofstream os_pts(OUT_FILE_POINT.c_str());
	if (!os_cv1 || !os_cv2 || !os_pts) {
	    throw runtime_error("Unable to open output file.");
	}

	// generating curves from internal data
	SISLCurve* c1 = newCurve(c1_number, // num. of control points
				 c1_order,  // spline order
				 c1_knots,  // knotvector
				 c1_coef,   // control points
				 1,         // kind = polynomial B-spline curve
				 dim,       // dimension of space (3D)
				 1);        // copy input arrays

	SISLCurve* c2 = newCurve(c2_number, // num. of control points
				 c2_order,  // spline order
				 c2_knots,  // knotvector
				 c2_coef,   // control points
				 1,         // kind = polynomial B-spline curve
				 dim,       // dimension of space (3D)
				 1);        // copy input arrays
		 
	if(!c1 || !c2) {
	    throw runtime_error("Error occured while generating curves.");
	}

	// calculating closest point

 	double epsco = 1.0e-15; // computational epsilon
 	double epsge = 1.0e-5; // geometric tolerance
 	int num_cl_points = 0; // number of found intersection points
 	double* intpar1 = 0; // parameter values for the first curve in the intersections
 	double* intpar2 = 0; // parameter values for the second curve in the intersections
 	int num_int_curves = 0;   // number of intersection curves
 	SISLIntcurve** intcurve = 0; // pointer to array of detected intersection curves
 	int jstat; // status variable

	s1955(c1,              // first curve 
	      c2,              // second curve
	      epsco,           // computational resolution
	      epsge,           // geometry resolution
	      &num_cl_points,  // number of single closest points
	      &intpar1,        // pointer to array of parameter values for curve 1
	      &intpar2,        //               "                      for curve 2
	      &num_int_curves, // number of detected intersection curves
	      &intcurve,       // pointer to array of detected intersection curves.
	      &jstat);
	
	if (jstat < 0) {
	    throw runtime_error("Error occured inside call to SISL routine s1955.");
	} else if (jstat > 0) {
	    cerr << "WARNING: warning occured inside call to SISL routine s1955. \n" 
		 << endl;
	}

 	// In this example, we do not expect to find intersection curves, since the
 	// input curves do not intersect at all.

 	cout << "Number of pairs of closest points detected: " << num_cl_points << endl;
 	cout << "Number of intersection curves detected: " << num_int_curves << endl;
	
	// evaluating closest points and writing them to file
	vector<double> point_coords_3D(3 * num_cl_points * 2);
	int i;
	for (i = 0; i < num_cl_points; ++i) {
	    // calculating closest point on curve 1
	    int temp, jstat1, jstat2;
	    s1227(c1,         // we evaluate on the first curve
		  0,          // calculate no derivatives
		  intpar1[i], // parameter value on which to evaluate
		  &temp,      // not used for our purposes (gives parameter interval)
		  &point_coords_3D[3 * 2 * i], // result written here
		  &jstat1);

	    // calculating closest point on curve 2
	    s1227(c2,
		  0,
		  intpar2[i],
		  &temp,
		  &point_coords_3D[3 * 2 * i + 3],
		  &jstat2);

	    if (jstat1 < 0 || jstat2 < 0) {
		throw runtime_error("Error occured inside call to SISL routine s1227.");
	    } else if (jstat1 > 0 || jstat2 > 0) {
		cerr << "WARNING: warning occured inside call to SISL routine s1227. \n" 
		     << endl;
	    }
	}

	// writing curves and intersections to file
	writeGoCurve(c1, os_cv1);
	writeGoCurve(c2, os_cv2);
 	writeGoPoints(num_cl_points * 2, &point_coords_3D[0], os_pts);

	// cleaning up
	freeCurve(c1);
	freeCurve(c2);
	os_cv1.close();
	os_cv2.close();
	os_pts.close();
	free(intpar1);
	free(intpar2);
	for (i = 0; i < num_int_curves; ++i) {
	    freeIntcurve(intcurve[i]);
	}
	free(intcurve);

    } catch (exception& e) {
	cerr << "Exception thrown: " << e.what() << endl;
	return 0;
    }

    return 1;
};
