/*
 * (C) Copyright 1996-2016 ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 * In applying this licence, ECMWF does not waive the privileges and immunities
 * granted to it by virtue of its status as an intergovernmental organisation nor
 * does it submit to any jurisdiction.
 */

/*! \file AutomaticContourMethod.h
    \brief Definition of the Template class AutomaticContourMethod.

    Magics Team - ECMWF 2004

    Started: Mon 4-Oct-2004

    Changes:

*/

#ifndef AutomaticContourMethod_H
#define AutomaticContourMethod_H

#include "magics.h"

#include "Akima760Method.h"
#include "BasicSceneObject.h"
#include "ContourMethod.h"
#include "MatrixHandler.h"


namespace magics {


class AutomaticContourMethod : public ContourMethod {
public:
    AutomaticContourMethod() {}
    virtual ~AutomaticContourMethod() {}
    ContourMethod* clone() { return new AutomaticContourMethod(); }
    virtual bool accept(const string& node) { return magCompare(node, "automatic"); }

    virtual MatrixHandler* handler(const AbstractMatrix& matrix, const BasicGraphicsObjectContainer& owner) {
        // this is the ideal number of points per cm on the paper
        const double fDesiredPointsPerCm = 5.0;

        // do not allow the resolution to go beyond this
        const double fMinSensibleContourResolution = 0.01;

        // if the computed resolution is within this much of the native resolution,
        // then just use the native resolution
        const double fAutoContourRoundupProportion = 0.05;

        // we use this to reduce the aggressiveness of the subsampling calculation;
        // the higher the number, the less subsampling will be done.
        const double fSampleAdjustment = 1.7;

        MatrixHandler data(matrix);
        MatrixHandler* pMatrixHandler;
        if (matrix.akimaEnable() == false) {
            ContourMethod* pContourMethod = new ContourMethod();

            pMatrixHandler = pContourMethod->handler(matrix, owner);

            MagLog::debug() << "Linear contouring, "
                            << "\n";
            // return pMatrixHandler;
            return new DelegateMatrixHandler(matrix);
        }

        double fGeoAreaWidth;
        double fGeoAreaHeight;
        double fPaperAreaWidth;
        double fPaperAreaHeight;
        double fContourResolutionX;
        double fContourResolutionY;
        double fDataResolutionX;
        double fDataResolutionY;
        double fMinX, fMaxX;
        double fMinY, fMaxY;
        int nSampleX = 1, nSampleY = 1;


        // find the dimensions of the paper on which we will plot
        fPaperAreaWidth  = owner.absoluteWidth();
        fPaperAreaHeight = owner.absoluteHeight();

        // retrieve the data's resolution
        fDataResolutionX = fabs(data.XResolution());
        fDataResolutionY = fabs(data.YResolution());

        // retrieve the geographical area being used
        fMinX = data.minX();
        fMaxX = data.maxX();
        fMinY = data.minY();
        fMaxY = data.maxY();


        // if the points given are extreme values, then it means there are no
        // grid points - in this case, for the purposes of the algorithm, we will
        // pretend that there are 4 points

        if (fMinX == INT_MAX)  // yes, INT_MAX!
        {
            fMinX = 0.0;
            fMaxX = fMinX + fDataResolutionX;
            fMinY = 0.0;
            fMaxY = fMinY + fDataResolutionY;
        }
        else {
            // if only one grid point is in the area, then we may get min and max the same,
            // which causes problems because their difference is then 0 and it forces the
            // maximum possible Akima interpolation.

            if (fMinX == fMaxX)
                fMaxX = fMinX + fDataResolutionX;  // pretend that we have 2 points!
            if (fMinY == fMaxY)
                fMaxY = fMinY + fDataResolutionY;  // pretend that we have 2 points!
        }


        fGeoAreaWidth  = fMaxX - fMinX;
        fGeoAreaHeight = fMaxY - fMinY;

        // calculate the resolutions we need in order to fulfil our
        // 'desired points per cm' criteria
        fContourResolutionX = fGeoAreaWidth / (fDesiredPointsPerCm * fPaperAreaWidth);
        fContourResolutionY = fGeoAreaHeight / (fDesiredPointsPerCm * fPaperAreaHeight);

        // clip it to sensible limits so that we don't go overboard on the Akima interpolation
        // XXX we may need to revise this, given that we're not always in geo projection

        if (fContourResolutionX < fMinSensibleContourResolution) {
            fContourResolutionX = fMinSensibleContourResolution;
        }

        // otherwise, if we don't need every data point, then we maybe need to subsample.
        // for example, if our desired contouring resolution (fContourResolutionX) is to
        // have one point every 1.0 degree, but our data (fDataResolutionX) is one point
        // every 0.5 degrees, then we only need to take every second point.
        // But on top of that, we want to be a little bit cautious about removing data points,
        // so we make an adjustment to the computation so that we don't subsample too aggressively.

        else if (fContourResolutionX > fDataResolutionX - (fDataResolutionX * fAutoContourRoundupProportion)) {
            nSampleX = static_cast<int>(fContourResolutionX / (fDataResolutionX * fSampleAdjustment));
            if (nSampleX < 1)
                nSampleX = 1;
            fContourResolutionX = fDataResolutionX;  // only needed if we end up with linear contouring
        }


        // do all the same again for the Y direction

        if (fContourResolutionY < fMinSensibleContourResolution) {
            fContourResolutionY = fMinSensibleContourResolution;
        }

        else if (fContourResolutionY > fDataResolutionY - (fDataResolutionY * fAutoContourRoundupProportion)) {
            nSampleY = static_cast<int>(fContourResolutionY / (fDataResolutionY * fSampleAdjustment));
            if (nSampleY < 1)
                nSampleY = 1;
            fContourResolutionY = fDataResolutionY;  // only needed if we end up with linear contouring
        }


        // compute some values for debug output, including some safety checking

        int nNumColumns = matrix.columns();
        int nNumRows    = matrix.rows();
        double fCol0    = (nNumColumns == 0) ? 0.0 : matrix.column(0, 0);
        double fColN    = (nNumColumns == 0) ? 0.0 : matrix.column(0, matrix.columns() - 1);
        double fRow0    = (nNumRows == 0) ? 0.0 : matrix.row(0, 0);
        double fRowN    = (nNumRows == 0) ? 0.0 : matrix.row(matrix.rows() - 1, 0);

        MagLog::debug() << "\n*************************************************************\n"
                        << "Automatic contour method\n"
                        << "Points per cm (desired): " << fDesiredPointsPerCm << "\n"
                        << "Your data X: " << fMaxX << " to " << fMinX << "\n"
                        << "Your data Y: " << fMaxY << " to " << fMinY << "\n"
                        << "Resolution:[ " << fDataResolutionX << ", " << fDataResolutionY << "]\n"
                        << "Cols: " << nNumColumns << "  Rows: " << nNumRows << "\n"
                        << "Col 0: " << fCol0 << " Col n: " << fColN << "\n"
                        << "Row 0: " << fRow0 << " Row n: " << fRowN << "\n"
                        << "Paper dimension: [" << fPaperAreaWidth << ", " << fPaperAreaHeight << "]\n";


        // Check for the linear case (contour resolution == data resolution).
        // Also need to use linear contouring if we have missing values, because Akima will
        // incorrectly interpolate them. Missing data is also handled correctly if we have high-res
        // data, because the sub-sampling method (above) uses no interpolation.
        if ((nSampleX > 1) && (nSampleY > 1)) {
            ContourMethod* cm = MagTranslator<string, ContourMethod>()("linear");
            unique_ptr<ContourMethod> pContourMethod(cm);

            pMatrixHandler = pContourMethod->handler(matrix, owner);

            MagLog::debug() << "Linear contouring, Res: " << fContourResolutionX << "x" << fContourResolutionY << "\n";
        }
        else if (((fContourResolutionX == fDataResolutionX) && (fContourResolutionY == fDataResolutionY)) ||
                 data.hasMissingValues()) {
            ContourMethod* cm = MagTranslator<string, ContourMethod>()("linear");
            unique_ptr<ContourMethod> pContourMethod(cm);

            pMatrixHandler = pContourMethod->handler(matrix, owner);

            MagLog::debug() << "Linear contouring, Res: " << fContourResolutionX << "x" << fContourResolutionY << "\n";
        }

        // otherwise we use the Akima760 method
        else {
            Akima760Method* am = static_cast<Akima760Method*>(MagTranslator<string, ContourMethod>()("akima760"));
            unique_ptr<Akima760Method> pAkima760Method(am);

            pAkima760Method->resolutionX_ = (fContourResolutionX);
            pAkima760Method->resolutionY_ = (fContourResolutionY);

            pMatrixHandler = pAkima760Method->handler(matrix, owner);

            MagLog::debug() << "Akima 760, Res: " << fContourResolutionX << "x" << fContourResolutionY << "\n";
        }

        MagLog::debug() << "\n*************************************************************\n";

        return pMatrixHandler;
    }

protected:
    //! Method to print string about this class on to a stream of type ostream (virtual).
    virtual void print(ostream& out) const {
        out << "AutomaticContourMethod"
            << "\n";
    }

private:
    //! Copy constructor - No copy allowed
    AutomaticContourMethod(const AutomaticContourMethod&);
    //! Overloaded << operator to copy - No copy allowed
    AutomaticContourMethod& operator=(const AutomaticContourMethod&);

    // -- Friends
    //! Overloaded << operator to call print().
    friend ostream& operator<<(ostream& s, const AutomaticContourMethod& p) {
        p.print(s);
        return s;
    }
};


}  // namespace magics

#endif
