#include "../ClipperUtils.hpp"
#include "../PolylineCollection.hpp"
#include "../Surface.hpp"
#include <cmath>
#include <algorithm>
#include <iostream>

#include "FillGyroid.hpp"

namespace Slic3r {

Polyline FillGyroid::makeLineVert(double xPos, double yPos, double width, double height, double currentXBegin, double segmentSize, coord_t scaleFactor, 
        double zCs, double zSn, bool flip, double decal){
    double maxSlope = abs(abs(zCs)-abs(zSn));
    Polyline polyline;
    polyline.points.push_back(Point(coord_t((std::max(std::min(currentXBegin, xPos+width),xPos) + decal) * scaleFactor), coord_t(yPos * scaleFactor)));
    for(double y=yPos;y<yPos+height+segmentSize;y+=segmentSize){
        if(y>yPos+height) y = yPos+height;
        double ySn = sin(y +(zCs<0?3.14:0) + 3.14);
        double yCs = cos(y +(zCs<0?3.14:0) + 3.14+(!flip?0:3.14));

        double a = ySn;
        double b = -zCs;
        double res = zSn*yCs;
        double r = sqrt(a*a + b*b);
        double x = asin(a/r) + asin(res/r) +3.14;
        x += currentXBegin;
        
        double ydeviation = 0.5*(flip?-1:1)*(zSn>0?-1:1)*decal*(1-maxSlope)*(res/r - a/r);
        polyline.points.push_back(Point(coord_t((std::max(std::min(x, xPos+width),xPos)+decal-ydeviation/2) * scaleFactor), coord_t((y + ydeviation) * scaleFactor)));
    }
    
    return polyline;
}

Polyline FillGyroid::makeLineHori(double xPos, double yPos, double width, double height, double currentYBegin, double segmentSize, coord_t scaleFactor, 
        double zCs, double zSn, bool flip, double decal){
    double maxSlope = abs(abs(zCs)-abs(zSn));
    Polyline polyline;
    polyline.points.push_back(Point(coord_t(xPos * scaleFactor), coord_t((std::max(std::min(currentYBegin, yPos+height),yPos)+decal) * scaleFactor)));
    for(double x=xPos;x<xPos+width+segmentSize;x+=segmentSize){
        if(x>xPos+width) x = xPos+width;
        double xSn = sin(x +(zSn<0?3.14:0) +(flip?0:3.14));
        double xCs = cos(x +(zSn<0?3.14:0) );
        
        double a = xCs;
        double b = -zSn;
        double res = zCs*xSn;
        double r = sqrt(a*a + b*b);
        double y = asin(a/r) + asin(res/r) +3.14/2;
        y += currentYBegin;
        
        double xdeviation = 0.5*(flip?-1:1)*(zCs>0?-1:1)*decal*(1-maxSlope)*(res/r - a/r);
        polyline.points.push_back(Point(coord_t((x + xdeviation) * scaleFactor), coord_t((std::max(std::min(y, yPos+height),yPos)+decal-xdeviation/2) * scaleFactor)));
    }
    
    return polyline;
}

inline void FillGyroid::correctOrderAndAdd(const int num, Polyline poly, Polylines &array){
    if(num%2==0){
        Points temp(poly.points.rbegin(), poly.points.rend());
        poly.points.assign(temp.begin(),temp.end());
    }
    array.push_back(poly);
}

// Generate a set of curves (array of array of 2d points) that describe a
// horizontal slice of a truncated regular octahedron with a specified
// grid square size.
Polylines FillGyroid::makeGrid(coord_t gridZ, double density, double layer_width, size_t gridWidth, size_t gridHeight, size_t curveType)
{
    coord_t  scaleFactor = coord_t(scale_(layer_width) / density);
    Polylines result;
    Polyline *polyline2;
    double segmentSize = density/2;
    double decal = layer_width*density;
    double xPos = 0, yPos=0, width=gridWidth, height=gridHeight;
     //scale factor for 5% : 8 712 388
     // 1z = 10^-6 mm ?
    double z = gridZ/(1.0 * scaleFactor);
    double zSn = sin(z);
    double zCs = cos(z);
    

    int numLine = 0;
    
    if(abs(zSn)<=abs(zCs)){
        //vertical
        //begin to first one
        int iter = 1;
        double currentXBegin = xPos - PI/2;
        currentXBegin = PI*(int)(currentXBegin/PI -1);
        iter = (int)(currentXBegin/PI +1)%2;
        bool flip = iter%2==1;
        // bool needNewLine =false;
        while(currentXBegin<xPos+width-PI/2){
            
            correctOrderAndAdd(numLine, makeLineVert(xPos, yPos, width, height, currentXBegin, segmentSize, scaleFactor, zCs, zSn, flip, 0), result);
            numLine++;
            
            //then, return by the other side
            iter++;
            currentXBegin = currentXBegin + PI;
            flip = iter%2==1;
            
            if(currentXBegin < xPos+width-PI/2){
                
                correctOrderAndAdd(numLine, makeLineVert(xPos, yPos, width, height, currentXBegin, segmentSize, scaleFactor, zCs, zSn, flip, 0), result);
                numLine++;

                // relance
                iter++;
                currentXBegin = currentXBegin + PI;
                flip = iter%2==1;
            }
        }
    }else{
        //horizontal
        

        //begin to first one
        int iter = 1;
        //search first line output
        double currentYBegin = yPos ;
        currentYBegin = PI*(int)(currentYBegin/PI -0);
        iter = (int)(currentYBegin/PI +1)%2;
        
        bool flip = iter%2==1;
        
        
        while(currentYBegin < yPos+width){

            correctOrderAndAdd(numLine, makeLineHori(xPos, yPos, width, height, currentYBegin, segmentSize, scaleFactor, zCs, zSn, flip, 0), result);
            numLine++;
        
            //then, return by the other side
            iter++;
            currentYBegin = currentYBegin + PI;
            flip = iter%2==1;
            
            if(currentYBegin<yPos+width){
                
                correctOrderAndAdd(numLine, makeLineHori(xPos, yPos, width, height, currentYBegin, segmentSize, scaleFactor, zCs, zSn, flip, 0), result);
                numLine++;
                
                //relance
                iter++;
                currentYBegin = currentYBegin + PI;
                flip = iter%2==1;
            }
        }
    }
    
    return result;
}

void FillGyroid::_fill_surface_single(
    const FillParams                &params, 
    unsigned int                     thickness_layers,
    const std::pair<float, Point>   &direction, 
    ExPolygon                       &expolygon, 
    Polylines                       &polylines_out)
{
    // no rotation is supported for this infill pattern
    BoundingBox bb = expolygon.contour.bounding_box();
    coord_t     distance = coord_t(scale_(this->spacing) / (params.density*this->scaling));

    // align bounding box to a multiple of our grid module
    bb.merge(_align_to_grid(bb.min, Point(2*M_PI*distance, 2*M_PI*distance)));
    
    // generate pattern
    Polylines   polylines = makeGrid(
        (coord_t)scale_(this->z),
        params.density*this->scaling,
        this->spacing,
        (size_t)(ceil(bb.size().x / distance) + 1),
        (size_t)(ceil(bb.size().y / distance) + 1),
        (size_t)(((this->layer_id/thickness_layers) % 2) + 1) );
    
    // move pattern in place
    for (Polylines::iterator it = polylines.begin(); it != polylines.end(); ++ it)
        it->translate(bb.min.x, bb.min.y);
    

    // clip pattern to boundaries
    polylines = intersection_pl(polylines, (Polygons)expolygon);

    // connect lines
    if (! params.dont_connect && ! polylines.empty()) { // prevent calling leftmost_point() on empty collections
        ExPolygon expolygon_off;
        {
            ExPolygons expolygons_off = offset_ex(expolygon, (float)SCALED_EPSILON);
            if (! expolygons_off.empty()) {
                // When expanding a polygon, the number of islands could only shrink. Therefore the offset_ex shall generate exactly one expanded island for one input island.
                assert(expolygons_off.size() == 1);
                std::swap(expolygon_off, expolygons_off.front());
            }
        }
        Polylines chained = PolylineCollection::chained_path_from(
#if SLIC3R_CPPVER >= 11
            std::move(polylines), 
#else
            polylines,
#endif
            PolylineCollection::leftmost_point(polylines), false); // reverse allowed
        bool first = true;
        for (Polylines::iterator it_polyline = chained.begin(); it_polyline != chained.end(); ++ it_polyline) {
            if (! first) {
                // Try to connect the lines.
                Points &pts_end = polylines_out.back().points;
                const Point &first_point = it_polyline->points.front();
                const Point &last_point = pts_end.back();
                // TODO: we should also check that both points are on a fill_boundary to avoid 
                // connecting paths on the boundaries of internal regions
                // TODO: avoid crossing current infill path
                if (first_point.distance_to(last_point) <= 5 * distance && 
                    expolygon_off.contains(Line(last_point, first_point))) {
                    // Append the polyline.
                    pts_end.insert(pts_end.end(), it_polyline->points.begin(), it_polyline->points.end());
                    continue;
                }
            }
            // The lines cannot be connected.
#if SLIC3R_CPPVER >= 11
            polylines_out.push_back(std::move(*it_polyline));
#else
            polylines_out.push_back(Polyline());
            std::swap(polylines_out.back(), *it_polyline);
#endif
            first = false;
        }
    }
}

} // namespace Slic3r