/**
 ******************************************************************************
 *
 * @file       pureprojection.cpp
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
 * @brief
 * @see        The GNU Public License (GPL) Version 3
 * @defgroup   OPMapWidget
 * @{
 *
 *****************************************************************************/
/*
 * 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; either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include "pureprojection.h"


namespace internals {
const double PureProjection::PI      = M_PI;
const double PureProjection::HALF_PI = (M_PI * 0.5);
const double PureProjection::TWO_PI  = (M_PI * 2.0);
const double PureProjection::EPSLoN  = 1.0e-10;
const double PureProjection::MAX_VAL = 4;
const double PureProjection::MAXLONG = 2147483647;
const double PureProjection::DBLLONG = 4.61168601e18;
const double PureProjection::R2D     = 180 / M_PI;
const double PureProjection::D2R     = M_PI / 180;

Point PureProjection::FromLatLngToPixel(const PointLatLng &p, const int &zoom)
{
    return FromLatLngToPixel(p.Lat(), p.Lng(), zoom);
}


PointLatLng PureProjection::FromPixelToLatLng(const Point &p, const int &zoom)
{
    return FromPixelToLatLng(p.X(), p.Y(), zoom);
}

Point PureProjection::FromPixelToTileXY(const Point &p)
{
    return Point((int)(p.X() / TileSize().Width()), (int)(p.Y() / TileSize().Height()));
}

Point PureProjection::FromTileXYToPixel(const Point &p)
{
    return Point((p.X() * TileSize().Width()), (p.Y() * TileSize().Height()));
}

Size PureProjection::GetTileMatrixSizeXY(const int &zoom)
{
    Size sMin = GetTileMatrixMinXY(zoom);
    Size sMax = GetTileMatrixMaxXY(zoom);

    return Size(sMax.Width() - sMin.Width() + 1, sMax.Height() - sMin.Height() + 1);
}
int PureProjection::GetTileMatrixItemCount(const int &zoom)
{
    Size s = GetTileMatrixSizeXY(zoom);

    return s.Width() * s.Height();
}
Size PureProjection::GetTileMatrixSizePixel(const int &zoom)
{
    Size s = GetTileMatrixSizeXY(zoom);

    return Size(s.Width() * TileSize().Width(), s.Height() * TileSize().Height());
}
QList<Point> PureProjection::GetAreaTileList(const RectLatLng &rect, const int &zoom, const int &padding)
{
    QList<Point> ret;

    Point topLeft     = FromPixelToTileXY(FromLatLngToPixel(rect.LocationTopLeft(), zoom));
    Point rightBottom = FromPixelToTileXY(FromLatLngToPixel(rect.Bottom(), rect.Right(), zoom));

    for (int x = (topLeft.X() - padding); x <= (rightBottom.X() + padding); x++) {
        for (int y = (topLeft.Y() - padding); y <= (rightBottom.Y() + padding); y++) {
            Point p = Point(x, y);
            if (!ret.contains(p) && p.X() >= 0 && p.Y() >= 0) {
                ret.append(p);
            }
        }
    }
    // ret.TrimExcess();

    return ret;
}
/*
 * Returns the conversion from pixels to meters
 */
double PureProjection::GetGroundResolution(const int &zoom, const double &latitude)
{
    return (cos(latitude * (PI / 180)) * 2 * PI * Axis()) / GetTileMatrixSizePixel(zoom).Width();
}

double PureProjection::Sign(const double &x)
{
    if (x < 0.0) {
        return -1;
    } else {
        return 1;
    }
}

double PureProjection::AdjustLongitude(double x)
{
    qlonglong count = 0;

    while (true) {
        if (qAbs(x) <= PI) {
            break;
        } else if (((qlonglong)qAbs(x / PI)) < 2) {
            x = x - (Sign(x) * TWO_PI);
        } else if (((qlonglong)qAbs(x / TWO_PI)) < MAXLONG) {
            x = x - (((qlonglong)(x / TWO_PI)) * TWO_PI);
        } else if (((qlonglong)qAbs(x / (MAXLONG * TWO_PI))) < MAXLONG) {
            x = x - (((qlonglong)(x / (MAXLONG * TWO_PI))) * (TWO_PI * MAXLONG));
        } else if (((qlonglong)qAbs(x / (DBLLONG * TWO_PI))) < MAXLONG) {
            x = x - (((qlonglong)(x / (DBLLONG * TWO_PI))) * (TWO_PI * DBLLONG));
        } else {
            x = x - (Sign(x) * TWO_PI);
        }
        count++;
        if (count > MAX_VAL) {
            break;
        }
    }
    return x;
}

void PureProjection::SinCos(const double &val, double &si, double &co)
{
    si = sin(val);
    co = cos(val);
}

double PureProjection::e0fn(const double &x)
{
    return 1.0 - 0.25 * x * (1.0 + x / 16.0 * (3.0 + 1.25 * x));
}

double PureProjection::e1fn(const double &x)
{
    return 0.375 * x * (1.0 + 0.25 * x * (1.0 + 0.46875 * x));
}

double PureProjection::e2fn(const double &x)
{
    return 0.05859375 * x * x * (1.0 + 0.75 * x);
}

double PureProjection::e3fn(const double &x)
{
    return x * x * x * (35.0 / 3072.0);
}

double PureProjection::mlfn(const double &e0, const double &e1, const double &e2, const double &e3, const double &phi)
{
    return e0 * phi - e1 * sin(2.0 * phi) + e2 * sin(4.0 * phi) - e3 * sin(6.0 * phi);
}

qlonglong PureProjection::GetUTMzone(const double &lon)
{
    return (qlonglong)(((lon + 180.0) / 6.0) + 1.0);
}


void PureProjection::FromGeodeticToCartesian(double Lat, double Lng, double Height, double &X, double &Y, double &Z)
{
    Lat = (PI / 180) * Lat;
    Lng = (PI / 180) * Lng;

    double B  = Axis() * (1.0 - Flattening());
    double ee = 1.0 - (B / Axis()) * (B / Axis());
    double N  = (Axis() / sqrt(1.0 - ee * sin(Lat) * sin(Lat)));

    X = (N + Height) * cos(Lat) * cos(Lng);
    Y = (N + Height) * cos(Lat) * sin(Lng);
    Z = (N * (B / Axis()) * (B / Axis()) + Height) * sin(Lat);
}
void PureProjection::FromCartesianTGeodetic(const double &X, const double &Y, const double &Z, double &Lat, double &Lng)
{
    double E = Flattening() * (2.0 - Flattening());

    Lng = atan2(Y, X);

    double P     = sqrt(X * X + Y * Y);
    double Theta = atan2(Z, (P * (1.0 - Flattening())));
    double st    = sin(Theta);
    double ct    = cos(Theta);
    Lat  = atan2(Z + E / (1.0 - Flattening()) * Axis() * st * st * st, P - E * Axis() * ct * ct * ct);

    Lat /= (PI / 180);
    Lng /= (PI / 180);
}
double PureProjection::courseBetweenLatLng(PointLatLng const & p1, PointLatLng const & p2)
{
    double lon1 = p1.Lng() * (M_PI / 180);
    double lat1 = p1.Lat() * (M_PI / 180);
    double lon2 = p2.Lng() * (M_PI / 180);
    double lat2 = p2.Lat() * (M_PI / 180);

    return 2 * M_PI - myfmod(atan2(sin(lon1 - lon2) * cos(lat2),
                                   cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(lon1 - lon2)), 2 * M_PI);
}

double PureProjection::DistanceBetweenLatLng(PointLatLng const & p1, PointLatLng const & p2)
{
    double R    = 6371; // km
    double lat1 = p1.Lat();
    double lat2 = p2.Lat();
    double lon1 = p1.Lng();
    double lon2 = p2.Lng();
    double dLat = (lat2 - lat1) * (PI / 180);
    double dLon = (lon2 - lon1) * (PI / 180);
    double a    = sin(dLat / 2) * sin(dLat / 2) + cos(lat1 * (PI / 180)) * cos(lat2 * (PI / 180)) * sin(dLon / 2) * sin(dLon / 2);
    double c    = 2 * atan2(sqrt(a), sqrt(1 - a));
    double d    = R * c;

    return d;
}

void PureProjection::offSetFromLatLngs(PointLatLng p1, PointLatLng p2, double &distance, double &bearing)
{
    distance = DistanceBetweenLatLng(p1, p2) * 1000;
    bearing  = courseBetweenLatLng(p1, p2);
}

double PureProjection::myfmod(double x, double y)
{
    return x - y * floor(x / y);
}

PointLatLng PureProjection::translate(PointLatLng p1, double distance, double bearing)
{
    PointLatLng ret;
    double d    = distance;
    double tc   = bearing;
    double lat1 = p1.Lat() * M_PI / 180;
    double lon1 = p1.Lng() * M_PI / 180;
    double R    = 6378137;
    double lat2 = asin(sin(lat1) * cos(d / R) + cos(lat1) * sin(d / R) * cos(tc));
    double lon2 = lon1 + atan2(sin(tc) * sin(d / R) * cos(lat1),
                               cos(d / R) - sin(lat1) * sin(lat2));

    lat2 = lat2 * 180 / M_PI;
    lon2 = lon2 * 180 / M_PI;
    ret.SetLat(lat2);
    ret.SetLng(lon2);
    return ret;
}
}