#include <vector>
#include <map>
#include <assert.h>
#include <math.h>
#include <iostream>

#include <TSystem.h>
#include <TGeoManager.h>
#include <TGeoXtru.h>
#include <TGeoMatrix.h>
#include <TEveManager.h>
#include <TEveGeoNode.h>



void computeCorners( int symmetryOrder, double closestDistanceToIp, double phi0, std::vector<std::pair<Double_t,Double_t> > &coordinates )
{
    if (symmetryOrder > 2)
    {
        const Double_t pi(3.1415927);
        const Double_t x0(-1. * closestDistanceToIp * tan(pi / Double_t(symmetryOrder)));
        const Double_t y0(closestDistanceToIp);

        for (int i = 0; i <= symmetryOrder; ++i)
        {
            Double_t theta = 0.f; 
            theta = phi0 + (2 * pi * Double_t(i) / Double_t(symmetryOrder));

            Double_t x = x0 * cos(theta) + y0 * sin(theta);
            Double_t y = y0 * cos(theta) - x0 * sin(theta);
            coordinates.push_back( std::pair<double,double>( x, y ) );
        }
    }
}



TGeoVolume* makePolygoneTube( std::string name, int symmetryOrder, double closestDistanceToIp, double phi0, double halfLength, TGeoMedium* medium = 0 )
{
    std::vector<std::pair<Double_t,Double_t> > vertices;

    computeCorners( symmetryOrder, closestDistanceToIp, phi0, vertices );
   
    const Int_t nvertices = vertices.size();
   
    Double_t* x = new Double_t[nvertices];
    Double_t* y = new Double_t[nvertices];

    int index = 0;
    for( std::vector< std::pair<Double_t,Double_t> >::iterator itCoord = vertices.begin(), itCoordEnd = vertices.end(); itCoord != itCoordEnd; ++itCoord )
    {
        x[index] = (*itCoord).first;
        y[index] = (*itCoord).second;

        ++index;
    }

    Int_t nz = 2;
    TGeoXtru *xtru = new TGeoXtru(2);
//     TGeoXtru *xtru = new TGeoXtru(5);

    xtru->DefinePolygon(nvertices,x,y);
    Double_t z0 = -halfLength, x0 = 0, y0 = 0;
    Double_t z1 = halfLength,   x1 = 0, y1 = 0;

    Double_t scale0 = 1.0, scale1 = 0.99;
    xtru->DefineSection(0, z0, x0, y0, scale0); // Z position, offset and scale for first section
    xtru->DefineSection(1, z1, x1, y1, scale0); // -''- go forward
//     xtru->DefineSection(2, z1, x1, y1, scale1); // -''- go inward
//     xtru->DefineSection(3, z0, x0, y0, scale1); // -''- go backward
//     xtru->DefineSection(4, z0, x0, y0, scale0); // -''- go outward

    TGeoVolume* xtruVol = new TGeoVolume( name.c_str(), xtru, medium);

    delete[] x;
    delete[] y;
    

    return xtruVol;
}



void myGeoEve()
{
//--- Definition of a simple geometry
   gSystem->Load("libGeom");
   TGeoManager *geom = new TGeoManager("GeomTest", "test drawing simple detector");
   Int_t i;




//    //--- define some materials
   TGeoMaterial *matVacuum = new TGeoMaterial("Vacuum", 0,0,0);
   TGeoMaterial *matAl = new TGeoMaterial("Al", 26.98,13,2.7);

// //   //--- define some media
   TGeoMedium *Vacuum = new TGeoMedium("Vacuum",1, matVacuum);
   TGeoMedium *Al = new TGeoMedium("Aluminium",2, matAl);


   //--- make the top container volume
   TGeoVolume *top = geom->MakeBox("TOP", Vacuum, 1000., 1000., 100.);

   geom->SetTopVolume(top);


   Int_t symInner = 8;
   Int_t symOuter = 12;



   TGeoVolume* plate = geom->MakeBox( "box", Al, 20, 40, 5 );


   TGeoVolume* xtruVolInner = makePolygoneTube( "inner", symInner, 30., 0.0, 70., Al );
   TGeoVolume* xtruVolOuter = makePolygoneTube( "outer", symOuter, 50., 0.3, 70., Al );
   TGeoVolume* tube = geom->MakeTube("tube", Al, 60, 70, 50 );


   xtruVolInner->SetLineColor(kRed);
   xtruVolOuter->SetLineColor(kBlue);


   xtruVolInner->SetTransparency(0);
   xtruVolOuter->SetTransparency(0);



   top->AddNode( xtruVolInner, 0, new TGeoTranslation(0,0,0));
   top->AddNode( xtruVolOuter, 1, new TGeoTranslation(0,0,0));
   top->AddNode( tube, 2, new TGeoTranslation(0,0,0));
//   top->AddNode( plate, 2, new TGeoTranslation(30,20,-20));





   //--- close the geometry
   geom->CloseGeometry();

   TEveManager::Create();

   TGeoNode* node = gGeoManager->GetTopNode();
   TEveGeoTopNode* en = new TEveGeoTopNode(gGeoManager, node);
   en->SetVisLevel(4);
   en->GetNode()->GetVolume()->SetVisibility(kFALSE);

   gEve->AddGlobalElement(en);

   gEve->Redraw3D(kTRUE);
}