/******************************************************************************
 * $Id$
 *
 * Project:  GDAL Warp API
 * Purpose:  Declarations for 2D Thin Plate Spline transformer.
 * Author:   VIZRT Development Team.
 *
 * This code was provided by Gilad Ronnen (gro at visrt dot com) with
 * permission to reuse under the following license.
 *
 ******************************************************************************
 * Copyright (c) 2004, VIZRT Inc.
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#ifndef THINPLATESPLINE_H_INCLUDED
#define THINPLATESPLINE_H_INCLUDED

#ifndef DOXYGEN_SKIP

#include "gdal_alg.h"
#include "cpl_conv.h"

typedef enum
{
    VIZ_GEOREF_SPLINE_ZERO_POINTS,
    VIZ_GEOREF_SPLINE_ONE_POINT,
    VIZ_GEOREF_SPLINE_TWO_POINTS,
    VIZ_GEOREF_SPLINE_ONE_DIMENSIONAL,
    VIZ_GEOREF_SPLINE_FULL,

    VIZ_GEOREF_SPLINE_POINT_WAS_ADDED,
    VIZ_GEOREF_SPLINE_POINT_WAS_DELETED
} vizGeorefInterType;

// #define VIZ_GEOREF_SPLINE_MAX_POINTS 40
#define VIZGEOREF_MAX_VARS 2

class VizGeorefSpline2D
{
    bool grow_points();

  public:
    explicit VizGeorefSpline2D(int nof_vars = 1)
        : type(VIZ_GEOREF_SPLINE_ZERO_POINTS), _nof_vars(nof_vars),
          _nof_points(0), _max_nof_points(0), _nof_eqs(0),
#if 0
        _tx(0.0),
        _ty(0.0),
        _ta(10.0),
#endif
          _dx(0.0), _dy(0.0), x(nullptr), y(nullptr), u(nullptr),
          unused(nullptr), index(nullptr), x_mean(0), y_mean(0)
    {
        for (int i = 0; i < VIZGEOREF_MAX_VARS; i++)
        {
            rhs[i] = nullptr;
            coef[i] = nullptr;
        }

        grow_points();
    }

    ~VizGeorefSpline2D()
    {
        CPLFree(x);
        CPLFree(y);
        CPLFree(u);
        CPLFree(unused);
        CPLFree(index);
        for (int i = 0; i < _nof_vars; i++)
        {
            CPLFree(rhs[i]);
            CPLFree(coef[i]);
        }
    }

#if 0
    int get_nof_points(){
        return _nof_points;
    }

    void set_toler( double tx, double ty ){
        _tx = tx;
        _ty = ty;
    }

    void get_toler( double& tx, double& ty) {
        tx = _tx;
        ty = _ty;
    }

    vizGeorefInterType get_interpolation_type ( ){
        return type;
    }

    void dump_data_points()
    {
        for ( int i = 0; i < _nof_points; i++ )
        {
            fprintf(stderr, "X = %f Y = %f Vars = ", x[i], y[i]);
            for ( int v = 0; v < _nof_vars; v++ )
                fprintf(stderr, "%f ", rhs[v][i+3]);
            fprintf(stderr, "\n");
        }
    }

    int delete_list()
    {
        _nof_points = 0;
        type = VIZ_GEOREF_SPLINE_ZERO_POINTS;
        if ( _AA )
        {
            CPLFree(_AA);
            _AA = NULL;
        }
        if ( _Ainv )
        {
            CPLFree(_Ainv);
            _Ainv = NULL;
        }
        return _nof_points;
    }
#endif

    bool add_point(const double Px, const double Py, const double *Pvars);
    int get_point(const double Px, const double Py, double *Pvars);
#if 0
    int delete_point(const double Px, const double Py );
    bool get_xy(int index, double& x, double& y);
    bool change_point(int index, double x, double y, double* Pvars);
    void reset(void) { _nof_points = 0; }
#endif
    int solve(void);

  private:
    vizGeorefInterType type;

    const int _nof_vars;
    int _nof_points;
    int _max_nof_points;
    int _nof_eqs;

#if 0
    // Disabled because the methods that use there is disabled.
    double _tx, _ty;
    double _ta;
#endif

    double _dx, _dy;

    double *x;  // [VIZ_GEOREF_SPLINE_MAX_POINTS+3];
    double *y;  // [VIZ_GEOREF_SPLINE_MAX_POINTS+3];

    //    double rhs[VIZ_GEOREF_SPLINE_MAX_POINTS+3][VIZGEOREF_MAX_VARS];
    //    double coef[VIZ_GEOREF_SPLINE_MAX_POINTS+3][VIZGEOREF_MAX_VARS];
    double *rhs[VIZGEOREF_MAX_VARS];
    double *coef[VIZGEOREF_MAX_VARS];

    double *u;    // [VIZ_GEOREF_SPLINE_MAX_POINTS];
    int *unused;  // [VIZ_GEOREF_SPLINE_MAX_POINTS];
    int *index;   // [VIZ_GEOREF_SPLINE_MAX_POINTS];

    double x_mean;
    double y_mean;

  private:
    CPL_DISALLOW_COPY_ASSIGN(VizGeorefSpline2D)
};

#endif /* #ifndef DOXYGEN_SKIP */

#endif /* THINPLATESPLINE_H_INCLUDED */