/*********************************************************************/
/*                                                                   */
/* Copyright 2022-2023 Rémi Synave - remi.synave@univ-littoral.fr    */
/*                                                                   */
/* This file is part of DSL.                                         */
/* This software uses Qt to build the Graphical User Interface       */
/* https://www.qt.io/                                                */
/*                                                                   */
/* DSL 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.                            */
/*                                                                   */
/* DSL 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 DSL. If not, see <http://www.gnu.org/licenses/>.       */
/*                                                                   */
/*********************************************************************/

#include <cstdlib>
#include <ctime>
#include <stdexcept>
#include <QDebug>

#include "StrengthLine.hpp"

StrengthLine::StrengthLine (double ax, double ay, double bx, double by)
{
  if (ax == bx && ay ==  by)
    throw std::
      invalid_argument ("Points defining a strength line can't be equals.");

  this->p1 = new QPoint(ax, ay);
  this->p2 = new QPoint(bx, by);
}

StrengthLine::StrengthLine (QPoint * p1, QPoint * p2)
{
  if (p1 == NULL || p2 == NULL)
    throw std::
      invalid_argument ("Points defining a strength line can't be NULL.");
  if (p1->x () == p2->x () && p1->y () == p2->y ())
    throw std::
      invalid_argument ("Points defining a strength line can't be equals.");

  this->p1 = p1;
  this->p2 = p2;
}

QPoint*
StrengthLine::getP1() const
{
  return new QPoint(*p1);
}

QPoint*
StrengthLine::getP2() const
{
  return new QPoint(*p2);
}

std::pair < float, float >
StrengthLine::equation () const
{
  // This method can be called only if a and b are
  // not aligned into a vertical or horizontal line
  float a = ((p1->y () - p2->y ()) * 1.0) / (p1->x () - p2->x ());
  float b = p1->y () - a * p1->x ();
  return std::make_pair (a, b);
}

std::pair < QPoint *, QPoint * >StrengthLine::toDraw (QImage * img) const 
{
  return this->toDraw(img->width(), img->height());
}

std::pair < QPoint *, QPoint * >StrengthLine::toDraw (int imgWidth, int imgHeight) const
{
  // Methode qui va calculer les points pour l'affichage des droites
  // sur l'image passées en paramètre. Calcul rapide donc
  // les points peuvent sortir de l'image.

  // ligne verticale
  if (p1->x () == p2->x ())
    return std::make_pair (new QPoint (p1->x (), 0),
			   new QPoint (p1->x (), imgHeight));

  // ligne horizontale
  if (p1->y () == p2->y ())
    return std::make_pair (new QPoint (0, p1->y ()),
			   new QPoint (imgWidth, p1->y ()));

  // Equation de la droite et on prend les points gauche et droite de la ligne
  
  std::pair < float, float >
    eq = this->equation ();
  float
    a = std::get < 0 > (eq);
  float
    b = std::get < 1 > (eq);

  return std::make_pair (new QPoint (0, b),
			 new QPoint (imgWidth, imgWidth * a + b));
}

std::pair < QPoint *, QPoint * >StrengthLine::interpolateToEdge (QImage * img) const
{
  return this->interpolateToEdge(img->width(), img->height());
}

std::pair < QPoint *, QPoint * >StrengthLine::interpolateToEdge (int imgWidth, int imgHeight) const
{
  // Methode qui va calculer les points sur les bords des images
  // en fonction des deux points attributs qui définissent
  // la ligne.

  // ligne verticale
  if (p1->x () == p2->x ())
    return std::make_pair (new QPoint (p1->x (), 0),
			   new QPoint (p1->x (), imgHeight));

  // ligne horizontale
  if (p1->y () == p2->y ())
    return std::make_pair (new QPoint (0, p1->y ()),
			   new QPoint (imgWidth, p1->y ()));

  // Equation de la droite et on prend les points gauche et droite de la ligne
  std::pair < float, float >
    eq = this->equation ();
  float
    a = std::get < 0 > (eq);
  float
    b = std::get < 1 > (eq);

  QPoint *p1 = new QPoint(0, b);
  QPoint *p2 = new QPoint(imgWidth, imgWidth * a + b);

  // Si le point de gauche est trop bas
  if(b < 0)
    {
      p1->setX(-b/a);
      p1->setY(0);
    }
  // Si le point de gauche est trop haut
  if(b > imgHeight)
    {
      p1->setX((imgHeight-b)/a);
      p1->setY(imgHeight);
    }
  // Si le point de droite est trop bas
  if((imgWidth * a + b) < 0)
    {
      p2->setX(-b/a);
      p2->setY(0);
    }
  // Si le point de droite est trop haut
  if((imgWidth * a + b) > imgHeight)
    {
      p2->setX((imgHeight-b)/a);
      p2->setY(imgHeight);
    }
  
  return std::make_pair (p1, p2);
}


float StrengthLine::ea_score(const StrengthLine *sl, double imgWidth, double imgHeight) const
{
  std::pair < QPoint*, QPoint* > pointsSL1 = this->interpolateToEdge (imgWidth, imgHeight);
  std::pair < QPoint*, QPoint* > pointsSL2 = sl->interpolateToEdge (imgWidth, imgHeight);
  QPoint* p1SL1 = std::get < 0 > (pointsSL1);
  QPoint* p2SL1 = std::get < 1 > (pointsSL1);
  QPoint* p1SL2 = std::get < 0 > (pointsSL2);
  QPoint* p2SL2 = std::get < 1 > (pointsSL2);

  float u[2] = {p2SL1->x()-p1SL1->x(), p2SL1->y()-p1SL1->y()};
  float v[2] = {p2SL2->x()-p1SL2->x(), p2SL2->y()-p1SL2->y()};
  float normU = sqrt(u[0]*u[0]+u[1]*u[1]);
  float normV = sqrt(v[0]*v[0]+v[1]*v[1]);
  u[0]=u[0]/normU;
  u[1]=u[1]/normU;
  v[0]=v[0]/normV;
  v[1]=v[1]/normV;
  float angle = 0;
  
  if((u[0]!=v[0]) || (u[1]!=v[1]))
    {
      float prodScal=u[0]*v[0]+u[1]*v[1];
	
      // In case of number approximation...
      if(prodScal>1)
	prodScal=1;
      if(prodScal<-1)
	prodScal=-1;
	     			     
      angle = acos(prodScal);
    }

  float sT = 1 - (angle/(M_PI/2));

  float midSL1X = ((p1SL1->x() + p2SL1->x())/2.0)/(imgWidth*1.0);
  float midSL1Y = ((p1SL1->y() + p2SL1->y())/2.0)/(imgHeight*1.0);
  float midSL2X = ((p1SL2->x() + p2SL2->x())/2.0)/(imgWidth*1.0);
  float midSL2Y = ((p1SL2->y() + p2SL2->y())/2.0)/(imgHeight*1.0);

  float sd = 1 - sqrt(((midSL1X-midSL2X)*(midSL1X-midSL2X))+((midSL1Y-midSL2Y)*(midSL1Y-midSL2Y)));


  return ((sT*sd)*(sT*sd));
}

float StrengthLine::distance(const StrengthLine *sl, double imgWidth, double imgHeight) const
{
  return (1 - ea_score(sl, imgWidth, imgHeight));
}
  
StrengthLine* StrengthLine::getRandomLine (QImage * img)
{
  std::srand(static_cast<unsigned int>(std::time(nullptr)+std::rand())); 
  
  int x1rand = std::rand() % img->width();
  int x2rand = std::rand() % img->width();
  int y1rand = std::rand() % img->height();
  int y2rand = std::rand() % img->height();
  while ( x1rand == x2rand && y1rand==y2rand )
    {
      x2rand = std::rand() % img->width();
      y2rand = std::rand() % img->height();
    }
  return new StrengthLine( new QPoint(x1rand, y1rand), new QPoint(x2rand, y2rand) );
}

StrengthLine* StrengthLine::getRandomLine (int width, int height)
{
  std::srand(static_cast<unsigned int>(std::time(nullptr)+std::rand())); 
  
  int x1rand = std::rand() % width;
  int x2rand = std::rand() % width;
  int y1rand = std::rand() % height;
  int y2rand = std::rand() % height;
  while ( x1rand == x2rand && y1rand==y2rand )
    {
      x2rand = std::rand() % width;
      y2rand = std::rand() % height;
    }
  return new StrengthLine( new QPoint(x1rand, y1rand), new QPoint(x2rand, y2rand) );
}

std::ostream& operator<<(std::ostream &o, const StrengthLine sl) {
  return o << "(" << sl.p1->x() << " , " << sl.p1->y() << ") - (" << sl.p2->x() << " , " << sl.p2->y() << ")";
}