#include "BoundingBox.hpp"
#include "ExPolygon.hpp"
#include "Geometry.hpp"
#include "Polygon.hpp"
#include "Line.hpp"
#include "ClipperUtils.hpp"
#include "polypartition.h"
#include "poly2tri/poly2tri.h"
#include <algorithm>
#include <cassert>
#include <list>

namespace Slic3r {

ExPolygon::operator Points() const
{
    Points points;
    Polygons pp = *this;
    for (Polygons::const_iterator poly = pp.begin(); poly != pp.end(); ++poly) {
        for (Points::const_iterator point = poly->points.begin(); point != poly->points.end(); ++point)
            points.push_back(*point);
    }
    return points;
}

ExPolygon::operator Polygons() const
{
    Polygons polygons;
    polygons.reserve(this->holes.size() + 1);
    polygons.push_back(this->contour);
    for (Polygons::const_iterator it = this->holes.begin(); it != this->holes.end(); ++it) {
        polygons.push_back(*it);
    }
    return polygons;
}

void
ExPolygon::scale(double factor)
{
    contour.scale(factor);
    for (Polygons::iterator it = holes.begin(); it != holes.end(); ++it) {
        (*it).scale(factor);
    }
}

void
ExPolygon::translate(double x, double y)
{
    contour.translate(x, y);
    for (Polygons::iterator it = holes.begin(); it != holes.end(); ++it) {
        (*it).translate(x, y);
    }
}

void
ExPolygon::rotate(double angle)
{
    contour.rotate(angle);
    for (Polygons::iterator it = holes.begin(); it != holes.end(); ++it) {
        (*it).rotate(angle);
    }
}

void
ExPolygon::rotate(double angle, const Point &center)
{
    contour.rotate(angle, center);
    for (Polygons::iterator it = holes.begin(); it != holes.end(); ++it) {
        (*it).rotate(angle, center);
    }
}

double
ExPolygon::area() const
{
    double a = this->contour.area();
    for (Polygons::const_iterator it = this->holes.begin(); it != this->holes.end(); ++it) {
        a -= -(*it).area();  // holes have negative area
    }
    return a;
}

bool
ExPolygon::is_valid() const
{
    if (!this->contour.is_valid() || !this->contour.is_counter_clockwise()) return false;
    for (Polygons::const_iterator it = this->holes.begin(); it != this->holes.end(); ++it) {
        if (!(*it).is_valid() || (*it).is_counter_clockwise()) return false;
    }
    return true;
}

bool
ExPolygon::contains(const Line &line) const
{
    return this->contains((Polyline)line);
}

bool
ExPolygon::contains(const Polyline &polyline) const
{
    Polylines pl_out;
    diff((Polylines)polyline, *this, &pl_out);
    return pl_out.empty();
}

bool
ExPolygon::contains(const Point &point) const
{
    if (!this->contour.contains(point)) return false;
    for (Polygons::const_iterator it = this->holes.begin(); it != this->holes.end(); ++it) {
        if (it->contains(point)) return false;
    }
    return true;
}

// inclusive version of contains() that also checks whether point is on boundaries
bool
ExPolygon::contains_b(const Point &point) const
{
    return this->contains(point) || this->has_boundary_point(point);
}

bool
ExPolygon::has_boundary_point(const Point &point) const
{
    if (this->contour.has_boundary_point(point)) return true;
    for (Polygons::const_iterator h = this->holes.begin(); h != this->holes.end(); ++h) {
        if (h->has_boundary_point(point)) return true;
    }
    return false;
}

void
ExPolygon::simplify_p(double tolerance, Polygons* polygons) const
{
    Polygons pp = this->simplify_p(tolerance);
    polygons->insert(polygons->end(), pp.begin(), pp.end());
}

Polygons
ExPolygon::simplify_p(double tolerance) const
{
    Polygons pp;
    pp.reserve(this->holes.size() + 1);
    
    // contour
    {
        Polygon p = this->contour;
        p.points.push_back(p.points.front());
        p.points = MultiPoint::_douglas_peucker(p.points, tolerance);
        p.points.pop_back();
        pp.push_back(p);
    }
    
    // holes
    for (Polygons::const_iterator it = this->holes.begin(); it != this->holes.end(); ++it) {
        Polygon p = *it;
        p.points.push_back(p.points.front());
        p.points = MultiPoint::_douglas_peucker(p.points, tolerance);
        p.points.pop_back();
        pp.push_back(p);
    }
    simplify_polygons(pp, &pp);
    return pp;
}

ExPolygons
ExPolygon::simplify(double tolerance) const
{
    Polygons pp = this->simplify_p(tolerance);
    return union_ex(pp);
}

void
ExPolygon::simplify(double tolerance, ExPolygons* expolygons) const
{
    ExPolygons ep = this->simplify(tolerance);
    expolygons->insert(expolygons->end(), ep.begin(), ep.end());
}

void
ExPolygon::medial_axis(double max_width, double min_width, ThickPolylines* polylines) const
{
    // init helper object
    Slic3r::Geometry::MedialAxis ma(max_width, min_width);
    ma.expolygon = this;
    
    // populate list of segments for the Voronoi diagram
    ma.lines = this->contour.lines();
    for (Polygons::const_iterator hole = this->holes.begin(); hole != this->holes.end(); ++hole) {
        Lines lines = hole->lines();
        ma.lines.insert(ma.lines.end(), lines.begin(), lines.end());
    }
    
    // compute the Voronoi diagram
    ThickPolylines pp;
    ma.build(&pp);
    
    /*
    SVG svg("medial_axis.svg");
    svg.draw(*this);
    svg.draw(pp);
    svg.Close();
    */
    
    // find the maximum width returned
    double max_w = 0;
    if (!pp.empty()) {
        std::vector<double> widths;
        for (ThickPolylines::const_iterator it = pp.begin(); it != pp.end(); ++it)
            widths.insert(widths.end(), it->width.begin(), it->width.end());
        max_w = *std::max_element(widths.begin(), widths.end());
    }
    
    bool removed = false;
    for (size_t i = 0; i < pp.size(); ++i) {
        ThickPolyline& polyline = pp[i];
        
        // extend initial and final segments of each polyline if they're actual endpoints
        /* We assign new endpoints to temporary variables because in case of a single-line
           polyline, after we extend the start point it will be caught by the intersection()
           call, so we keep the inner point until we perform the second intersection() as well */
        Point new_front = polyline.points.front();
        Point new_back  = polyline.points.back();
        if (polyline.endpoints.first && !this->has_boundary_point(new_front)) {
            Line line(polyline.points.front(), polyline.points[1]);
            
            // prevent the line from touching on the other side, otherwise intersection() might return that solution
            if (polyline.points.size() == 2) line.b = line.midpoint();
            
            line.extend_start(max_width);
            (void)this->contour.intersection(line, &new_front);
        }
        if (polyline.endpoints.second && !this->has_boundary_point(new_back)) {
            Line line(
                *(polyline.points.end() - 2),
                polyline.points.back()
            );
            
            // prevent the line from touching on the other side, otherwise intersection() might return that solution
            if (polyline.points.size() == 2) line.a = line.midpoint();
            line.extend_end(max_width);
            
            (void)this->contour.intersection(line, &new_back);
        }
        polyline.points.front() = new_front;
        polyline.points.back()  = new_back;
        
        /*  remove too short polylines
            (we can't do this check before endpoints extension and clipping because we don't
            know how long will the endpoints be extended since it depends on polygon thickness
            which is variable - extension will be <= max_width/2 on each side)  */
        if ((polyline.endpoints.first || polyline.endpoints.second)
            && polyline.length() < max_w*2) {
            pp.erase(pp.begin() + i);
            --i;
            removed = true;
            continue;
        }
    }
    
    /*  If we removed any short polylines we now try to connect consecutive polylines
        in order to allow loop detection. Note that this algorithm is greedier than 
        MedialAxis::process_edge_neighbors() as it will connect random pairs of 
        polylines even when more than two start from the same point. This has no 
        drawbacks since we optimize later using nearest-neighbor which would do the 
        same, but should we use a more sophisticated optimization algorithm we should
        not connect polylines when more than two meet.  */
    if (removed) {
        for (size_t i = 0; i < pp.size(); ++i) {
            ThickPolyline& polyline = pp[i];
            if (polyline.endpoints.first && polyline.endpoints.second) continue; // optimization
            
            // find another polyline starting here
            for (size_t j = i+1; j < pp.size(); ++j) {
                ThickPolyline& other = pp[j];
                if (polyline.last_point().coincides_with(other.last_point())) {
                    other.reverse();
                } else if (polyline.first_point().coincides_with(other.last_point())) {
                    polyline.reverse();
                    other.reverse();
                } else if (polyline.first_point().coincides_with(other.first_point())) {
                    polyline.reverse();
                } else if (!polyline.last_point().coincides_with(other.first_point())) {
                    continue;
                }
                
                polyline.points.insert(polyline.points.end(), other.points.begin() + 1, other.points.end());
                polyline.width.insert(polyline.width.end(), other.width.begin(), other.width.end());
                polyline.endpoints.second = other.endpoints.second;
                assert(polyline.width.size() == polyline.points.size()*2 - 2);
                
                pp.erase(pp.begin() + j);
                j = i;  // restart search from i+1
            }
        }
    }
    
    polylines->insert(polylines->end(), pp.begin(), pp.end());
}

void
ExPolygon::medial_axis(double max_width, double min_width, Polylines* polylines) const
{
    ThickPolylines tp;
    this->medial_axis(max_width, min_width, &tp);
    polylines->insert(polylines->end(), tp.begin(), tp.end());
}

void
ExPolygon::get_trapezoids(Polygons* polygons) const
{
    ExPolygons expp;
    expp.push_back(*this);
    boost::polygon::get_trapezoids(*polygons, expp);
}

void
ExPolygon::get_trapezoids(Polygons* polygons, double angle) const
{
    ExPolygon clone = *this;
    clone.rotate(PI/2 - angle, Point(0,0));
    clone.get_trapezoids(polygons);
    for (Polygons::iterator polygon = polygons->begin(); polygon != polygons->end(); ++polygon)
        polygon->rotate(-(PI/2 - angle), Point(0,0));
}

// This algorithm may return more trapezoids than necessary
// (i.e. it may break a single trapezoid in several because
// other parts of the object have x coordinates in the middle)
void
ExPolygon::get_trapezoids2(Polygons* polygons) const
{
    // get all points of this ExPolygon
    Points pp = *this;
    
    // build our bounding box
    BoundingBox bb(pp);
    
    // get all x coordinates
    std::vector<coord_t> xx;
    xx.reserve(pp.size());
    for (Points::const_iterator p = pp.begin(); p != pp.end(); ++p)
        xx.push_back(p->x);
    std::sort(xx.begin(), xx.end());
    
    // find trapezoids by looping from first to next-to-last coordinate
    for (std::vector<coord_t>::const_iterator x = xx.begin(); x != xx.end()-1; ++x) {
        coord_t next_x = *(x + 1);
        if (*x == next_x) continue;
        
        // build rectangle
        Polygon poly;
        poly.points.resize(4);
        poly[0].x = *x;
        poly[0].y = bb.min.y;
        poly[1].x = next_x;
        poly[1].y = bb.min.y;
        poly[2].x = next_x;
        poly[2].y = bb.max.y;
        poly[3].x = *x;
        poly[3].y = bb.max.y;
        
        // intersect with this expolygon
        Polygons trapezoids;
        intersection<Polygons,Polygons>(poly, *this, &trapezoids);
        
        // append results to return value
        polygons->insert(polygons->end(), trapezoids.begin(), trapezoids.end());
    }
}

void
ExPolygon::get_trapezoids2(Polygons* polygons, double angle) const
{
    ExPolygon clone = *this;
    clone.rotate(PI/2 - angle, Point(0,0));
    clone.get_trapezoids2(polygons);
    for (Polygons::iterator polygon = polygons->begin(); polygon != polygons->end(); ++polygon)
        polygon->rotate(-(PI/2 - angle), Point(0,0));
}

// While this triangulates successfully, it's NOT a constrained triangulation
// as it will create more vertices on the boundaries than the ones supplied.
void
ExPolygon::triangulate(Polygons* polygons) const
{
    // first make trapezoids
    Polygons trapezoids;
    this->get_trapezoids2(&trapezoids);
    
    // then triangulate each trapezoid
    for (Polygons::iterator polygon = trapezoids.begin(); polygon != trapezoids.end(); ++polygon)
        polygon->triangulate_convex(polygons);
}

void
ExPolygon::triangulate_pp(Polygons* polygons) const
{
    // convert polygons
    std::list<TPPLPoly> input;
    
    Polygons pp = *this;
    simplify_polygons(pp, &pp, true);
    ExPolygons expp;
    union_(pp, &expp);
    
    for (ExPolygons::const_iterator ex = expp.begin(); ex != expp.end(); ++ex) {
        // contour
        {
            TPPLPoly p;
            p.Init(ex->contour.points.size());
            //printf("%zu\n0\n", ex->contour.points.size());
            for (Points::const_iterator point = ex->contour.points.begin(); point != ex->contour.points.end(); ++point) {
                p[ point-ex->contour.points.begin() ].x = point->x;
                p[ point-ex->contour.points.begin() ].y = point->y;
                //printf("%ld %ld\n", point->x, point->y);
            }
            p.SetHole(false);
            input.push_back(p);
        }
    
        // holes
        for (Polygons::const_iterator hole = ex->holes.begin(); hole != ex->holes.end(); ++hole) {
            TPPLPoly p;
            p.Init(hole->points.size());
            //printf("%zu\n1\n", hole->points.size());
            for (Points::const_iterator point = hole->points.begin(); point != hole->points.end(); ++point) {
                p[ point-hole->points.begin() ].x = point->x;
                p[ point-hole->points.begin() ].y = point->y;
                //printf("%ld %ld\n", point->x, point->y);
            }
            p.SetHole(true);
            input.push_back(p);
        }
    }
    
    // perform triangulation
    std::list<TPPLPoly> output;
    int res = TPPLPartition().Triangulate_MONO(&input, &output);
    if (res != 1) CONFESS("Triangulation failed");
    
    // convert output polygons
    for (std::list<TPPLPoly>::iterator poly = output.begin(); poly != output.end(); ++poly) {
        long num_points = poly->GetNumPoints();
        Polygon p;
        p.points.resize(num_points);
        for (long i = 0; i < num_points; ++i) {
            p.points[i].x = (*poly)[i].x;
            p.points[i].y = (*poly)[i].y;
        }
        polygons->push_back(p);
    }
}

void
ExPolygon::triangulate_p2t(Polygons* polygons) const
{
    ExPolygons expp;
    simplify_polygons(*this, &expp, true);
    
    for (ExPolygons::const_iterator ex = expp.begin(); ex != expp.end(); ++ex) {
        // TODO: prevent duplicate points

        // contour
        std::vector<p2t::Point*> ContourPoints;
        for (Points::const_iterator point = ex->contour.points.begin(); point != ex->contour.points.end(); ++point) {
            // We should delete each p2t::Point object
            ContourPoints.push_back(new p2t::Point(point->x, point->y));
        }
        p2t::CDT cdt(ContourPoints);

        // holes
        for (Polygons::const_iterator hole = ex->holes.begin(); hole != ex->holes.end(); ++hole) {
            std::vector<p2t::Point*> points;
            for (Points::const_iterator point = hole->points.begin(); point != hole->points.end(); ++point) {
                // will be destructed in SweepContext::~SweepContext
                points.push_back(new p2t::Point(point->x, point->y));
            }
            cdt.AddHole(points);
        }
        
        // perform triangulation
        cdt.Triangulate();
        std::vector<p2t::Triangle*> triangles = cdt.GetTriangles();
        
        for (std::vector<p2t::Triangle*>::const_iterator triangle = triangles.begin(); triangle != triangles.end(); ++triangle) {
            Polygon p;
            for (int i = 0; i <= 2; ++i) {
                p2t::Point* point = (*triangle)->GetPoint(i);
                p.points.push_back(Point(point->x, point->y));
            }
            polygons->push_back(p);
        }

        for(std::vector<p2t::Point*>::iterator it = ContourPoints.begin(); it != ContourPoints.end(); ++it) {
            delete *it;
        }
    }
}

Lines
ExPolygon::lines() const
{
    Lines lines = this->contour.lines();
    for (Polygons::const_iterator h = this->holes.begin(); h != this->holes.end(); ++h) {
        Lines hole_lines = h->lines();
        lines.insert(lines.end(), hole_lines.begin(), hole_lines.end());
    }
    return lines;
}

}
