#include <iostream>
#include <cmath>

#include <TPad.h>

#include "IMesh.hxx"

COMET::IMesh::IMesh() : fUnitXLength(1), fUnitYLength(1) { }

// This routine is a little weird since COMET::IMeshPoint and COMET::IMeshEdge objects have
// cross pointers and will try to delete each other.  COMET::IMesh is going to delete
// all of the pointers and we don't want this complicated inter-delete stuff.
// For that reason, it does some internal clearing and NULL pointer setting
// before actually deleting stuff.
COMET::IMesh::~IMesh() {
    // Delete the each COMET::IMeshPoint by first clearing the edges that connect it
    // to other points, and then doing the delete.  After this loop is
    // finished, the end point pointers in fEdges are invalid and so must be
    // reset before deleting the edges.
    for (TMeshPointSet::iterator p = fPoints.begin();
         p!=fPoints.end();
         ++p) {
        (*p)->fEdges.clear(); // invalidate the edge set...
        delete *p;
    }
    // Now delete the edges by first clearing the head and tail pointers so
    // that the COMET::IMeshEdge destructor won't try to remove the edge from the end
    // point edge sets.
    for (TMeshEdgeSet::iterator e = fEdges.begin();
         e!=fEdges.end();
         ++e) {
        (*e)->fHead = NULL;
        (*e)->fTail = NULL;
        delete *e;
    }
}

COMET::IMeshPoint* COMET::IMesh::AddPoint(COMET::IMeshPoint* point) {
    TMeshPointSet::iterator p = fPoints.find(point);
    if (p != fPoints.end()) {
        if (*p != point) delete point;
        return *p;
    }
    fPoints.insert(point);
    return point;
}

COMET::IMeshEdge* COMET::IMesh::AddEdge(COMET::IMeshEdge* edge) {
    TMeshEdgeSet::iterator e = fEdges.find(edge);
    if (e != fEdges.end()) {
        if (*e != edge) delete edge;
        edge = *e;
    }
    COMET::IMeshPoint* h = COMET::IMesh::AddPoint(edge->GetHead());
    h->AddEdge(edge);
    COMET::IMeshPoint* t = COMET::IMesh::AddPoint(edge->GetTail());
    t->AddEdge(edge);
    fEdges.insert(edge);
    return edge;
}

void COMET::IMesh::RemoveEdge(COMET::IMeshEdge* edge) {
    TMeshEdgeSet::iterator e = fEdges.find(edge);
    fEdges.erase(e);
    delete edge;
}

void COMET::IMesh::Paint(Option_t* opt) {
    TAttMarker::Modify();
    TAttLine::Modify();

    for (TMeshPointSet::iterator p = BeginPoints(); p!=EndPoints(); ++p) {
        double x1 = gPad->XtoPad((*p)->X()/fUnitXLength);
        double y1 = gPad->YtoPad((*p)->Y()/fUnitYLength);
        gPad->PaintPolyMarker(-1,&x1,&y1,"");
    }

    for (TMeshEdgeSet::iterator e = BeginEdges(); e != EndEdges(); ++e) {
        double x1 = gPad->XtoPad((*e)->GetHead()->X()/fUnitXLength);
        double y1 = gPad->YtoPad((*e)->GetHead()->Y()/fUnitYLength);
        double x2 = gPad->XtoPad((*e)->GetTail()->X()/fUnitXLength);
        double y2 = gPad->YtoPad((*e)->GetTail()->Y()/fUnitYLength);
        gPad->PaintLine(x1,y1,x2,y2);
    }
}