/* SPDX-License-Identifier: GPL-2.0-or-later */

/** \file
 * \ingroup freestyle
 * \brief Functions taking 0D input
 */

#include "Functions0D.h"
#include "ViewMap.h"

#include "BLI_sys_types.h"

#include "BKE_global.h"

using namespace std;

namespace Freestyle::Functions0D {

// Internal function
FEdge *getFEdge(Interface0D &it1, Interface0D &it2)
{
  return it1.getFEdge(it2);
}

void getFEdges(Interface0DIterator &it, FEdge *&fe1, FEdge *&fe2)
{
  // count number of vertices
  Interface0DIterator prev = it, next = it;
  ++next;
  int count = 1;
  if (!it.isBegin() && !next.isEnd()) {
    count = 3;
  }
  if (count < 3) {
    // if we only have 2 vertices
    FEdge *fe = nullptr;
    Interface0DIterator tmp = it;
    if (it.isBegin()) {
      ++tmp;
      fe = it->getFEdge(*tmp);
    }
    else {
      --tmp;
      fe = it->getFEdge(*tmp);
    }
    fe1 = fe;
    fe2 = nullptr;
  }
  else {
    // we have more than 2 vertices
    bool begin = false, last = false;
    Interface0DIterator previous = it;
    if (!previous.isBegin()) {
      --previous;
    }
    else {
      begin = true;
    }
    Interface0DIterator next = it;
    ++next;
    if (next.isEnd()) {
      last = true;
    }
    if (begin) {
      fe1 = it->getFEdge(*next);
      fe2 = nullptr;
    }
    else if (last) {
      fe1 = previous->getFEdge(*it);
      fe2 = nullptr;
    }
    else {
      fe1 = previous->getFEdge(*it);
      fe2 = it->getFEdge(*next);
    }
  }
}

void getViewEdges(Interface0DIterator &it, ViewEdge *&ve1, ViewEdge *&ve2)
{
  FEdge *fe1, *fe2;
  getFEdges(it, fe1, fe2);
  ve1 = fe1->viewedge();
  if (fe2 != nullptr) {
    ve2 = fe2->viewedge();
    if (ve2 == ve1) {
      ve2 = nullptr;
    }
  }
  else {
    ve2 = nullptr;
  }
}

ViewShape *getShapeF0D(Interface0DIterator &it)
{
  ViewEdge *ve1, *ve2;
  getViewEdges(it, ve1, ve2);
  return ve1->viewShape();
}

void getOccludersF0D(Interface0DIterator &it, set<ViewShape *> &oOccluders)
{
  ViewEdge *ve1, *ve2;
  getViewEdges(it, ve1, ve2);
  occluder_container::const_iterator oit = ve1->occluders_begin();
  occluder_container::const_iterator oitend = ve1->occluders_end();

  for (; oit != oitend; ++oit) {
    oOccluders.insert(*oit);
  }

  if (ve2 != nullptr) {
    oit = ve2->occluders_begin();
    oitend = ve2->occluders_end();
    for (; oit != oitend; ++oit) {
      oOccluders.insert(*oit);
    }
  }
}

ViewShape *getOccludeeF0D(Interface0DIterator &it)
{
  ViewEdge *ve1, *ve2;
  getViewEdges(it, ve1, ve2);
  ViewShape *aShape = ve1->aShape();
  return aShape;
}

//
int VertexOrientation2DF0D::operator()(Interface0DIterator &iter)
{
  Vec2f A, C;
  Vec2f B(iter->getProjectedX(), iter->getProjectedY());
  if (iter.isBegin()) {
    A = Vec2f(iter->getProjectedX(), iter->getProjectedY());
  }
  else {
    Interface0DIterator previous = iter;
    --previous;
    A = Vec2f(previous->getProjectedX(), previous->getProjectedY());
  }
  Interface0DIterator next = iter;
  ++next;
  if (next.isEnd()) {
    C = Vec2f(iter->getProjectedX(), iter->getProjectedY());
  }
  else {
    C = Vec2f(next->getProjectedX(), next->getProjectedY());
  }

  Vec2f AB(B - A);
  if (AB.norm() != 0) {
    AB.normalize();
  }
  Vec2f BC(C - B);
  if (BC.norm() != 0) {
    BC.normalize();
  }
  result = AB + BC;
  if (result.norm() != 0) {
    result.normalize();
  }
  return 0;
}

int VertexOrientation3DF0D::operator()(Interface0DIterator &iter)
{
  Vec3r A, C;
  Vec3r B(iter->getX(), iter->getY(), iter->getZ());
  if (iter.isBegin()) {
    A = Vec3r(iter->getX(), iter->getY(), iter->getZ());
  }
  else {
    Interface0DIterator previous = iter;
    --previous;
    A = Vec3r(previous->getX(), previous->getY(), previous->getZ());
  }
  Interface0DIterator next = iter;
  ++next;
  if (next.isEnd()) {
    C = Vec3r(iter->getX(), iter->getY(), iter->getZ());
  }
  else {
    C = Vec3r(next->getX(), next->getY(), next->getZ());
  }

  Vec3r AB(B - A);
  if (AB.norm() != 0) {
    AB.normalize();
  }
  Vec3r BC(C - B);
  if (BC.norm() != 0) {
    BC.normalize();
  }
  result = AB + BC;
  if (result.norm() != 0) {
    result.normalize();
  }
  return 0;
}

int Curvature2DAngleF0D::operator()(Interface0DIterator &iter)
{
  Interface0DIterator tmp1 = iter, tmp2 = iter;
  ++tmp2;
  uint count = 1;
  while (!tmp1.isBegin() && (count < 3)) {
    --tmp1;
    ++count;
  }
  while (!tmp2.isEnd() && (count < 3)) {
    ++tmp2;
    ++count;
  }
  if (count < 3) {
    // if we only have 2 vertices
    result = 0;
    return 0;
  }

  Interface0DIterator v = iter;
  if (iter.isBegin()) {
    ++v;
  }
  Interface0DIterator next = v;
  ++next;
  if (next.isEnd()) {
    next = v;
    --v;
  }
  Interface0DIterator prev = v;
  --prev;

  Vec2r A(prev->getProjectedX(), prev->getProjectedY());
  Vec2r B(v->getProjectedX(), v->getProjectedY());
  Vec2r C(next->getProjectedX(), next->getProjectedY());
  Vec2r AB(B - A);
  Vec2r BC(C - B);
  Vec2r N1(-AB[1], AB[0]);
  if (N1.norm() != 0) {
    N1.normalize();
  }
  Vec2r N2(-BC[1], BC[0]);
  if (N2.norm() != 0) {
    N2.normalize();
  }
  if ((N1.norm() == 0) && (N2.norm() == 0)) {
    Exception::raiseException();
    result = 0;
    return -1;
  }
  double cosin = N1 * N2;
  if (cosin > 1) {
    cosin = 1;
  }
  if (cosin < -1) {
    cosin = -1;
  }
  result = acos(cosin);
  return 0;
}

int ZDiscontinuityF0D::operator()(Interface0DIterator &iter)
{
  FEdge *fe1, *fe2;
  getFEdges(iter, fe1, fe2);
  result = fe1->z_discontinuity();
  if (fe2 != nullptr) {
    result += fe2->z_discontinuity();
    result /= 2.0f;
  }
  return 0;
}

int Normal2DF0D::operator()(Interface0DIterator &iter)
{
  FEdge *fe1, *fe2;
  getFEdges(iter, fe1, fe2);
  Vec3f e1(fe1->orientation2d());
  Vec2f n1(e1[1], -e1[0]);
  Vec2f n(n1);
  if (fe2 != nullptr) {
    Vec3f e2(fe2->orientation2d());
    Vec2f n2(e2[1], -e2[0]);
    n += n2;
  }
  n.normalize();
  result = n;
  return 0;
}

int MaterialF0D::operator()(Interface0DIterator &iter)
{
  FEdge *fe1, *fe2;
  getFEdges(iter, fe1, fe2);
  if (fe1 == nullptr) {
    return -1;
  }
  if (fe1->isSmooth()) {
    result = ((FEdgeSmooth *)fe1)->frs_material();
  }
  else {
    result = ((FEdgeSharp *)fe1)->bFrsMaterial();
  }
#if 0
  const SShape *sshape = getShapeF0D(iter);
  return sshape->material();
#endif
  return 0;
}

int ShapeIdF0D::operator()(Interface0DIterator &iter)
{
  ViewShape *vshape = getShapeF0D(iter);
  result = vshape->getId();
  return 0;
}

int QuantitativeInvisibilityF0D::operator()(Interface0DIterator &iter)
{
  ViewEdge *ve1, *ve2;
  getViewEdges(iter, ve1, ve2);
  uint qi1, qi2;
  qi1 = ve1->qi();
  if (ve2 != nullptr) {
    qi2 = ve2->qi();
    if (qi2 != qi1) {
      if (G.debug & G_DEBUG_FREESTYLE) {
        cout << "QuantitativeInvisibilityF0D: ambiguous evaluation for point " << iter->getId()
             << endl;
      }
    }
  }
  result = qi1;
  return 0;
}

int CurveNatureF0D::operator()(Interface0DIterator &iter)
{
  Nature::EdgeNature nat = 0;
  ViewEdge *ve1, *ve2;
  getViewEdges(iter, ve1, ve2);
  nat |= ve1->getNature();
  if (ve2 != nullptr) {
    nat |= ve2->getNature();
  }
  result = nat;
  return 0;
}

int GetOccludersF0D::operator()(Interface0DIterator &iter)
{
  set<ViewShape *> occluders;
  getOccludersF0D(iter, occluders);
  result.clear();
  // vsOccluders.insert(vsOccluders.begin(), occluders.begin(), occluders.end());
  for (set<ViewShape *>::iterator it = occluders.begin(), itend = occluders.end(); it != itend;
       ++it) {
    result.push_back(*it);
  }
  return 0;
}

int GetShapeF0D::operator()(Interface0DIterator &iter)
{
  result = getShapeF0D(iter);
  return 0;
}

int GetOccludeeF0D::operator()(Interface0DIterator &iter)
{
  result = getOccludeeF0D(iter);
  return 0;
}

}  // namespace Freestyle::Functions0D