#include "occ_libstl.h"

#include <cstring>
#include <StlMesh_Mesh.hxx>
#include <StlMesh_MeshTriangle.hxx>
#include <StlMesh_SequenceOfMeshTriangle.hxx>
#include <TColgp_SequenceOfXYZ.hxx>

/* Common */

static void occ_mesh_stl_add_triangle(Handle_StlMesh_Mesh* mesh, const foug_stl_triangle_t* tri)
{
  const int uId = (*mesh)->AddOnlyNewVertex(tri->v1.x, tri->v1.y, tri->v1.z);
  const int vId = (*mesh)->AddOnlyNewVertex(tri->v2.x, tri->v2.y, tri->v2.z);
  const int wId = (*mesh)->AddOnlyNewVertex(tri->v3.x, tri->v3.y, tri->v3.z);
  (*mesh)->AddTriangle(uId, vId, wId, tri->normal.x, tri->normal.y, tri->normal.z);
}

/* ASCII STL */

static void occ_mesh_stla_igeom_begin_solid(foug_stla_geom_input_t* geom, const char* /*name*/)
{
  Handle_StlMesh_Mesh* mesh = static_cast<Handle_StlMesh_Mesh*>(geom->cookie);
  if (mesh->IsNull())
    *mesh = new StlMesh_Mesh;
  (*mesh)->AddDomain();
}

static void occ_mesh_stla_igeom_process_next_triangle(foug_stla_geom_input_t* geom,
                                                      const foug_stl_triangle_t* tri)
{
  Handle_StlMesh_Mesh* mesh = static_cast<Handle_StlMesh_Mesh*>(geom->cookie);
  occ_mesh_stl_add_triangle(mesh, tri);
}

void foug_stla_geom_input_set_occmesh(foug_stla_geom_input_t* input, Handle_StlMesh_Mesh* mesh)
{
  input->cookie = mesh;
  input->begin_solid_func = occ_mesh_stla_igeom_begin_solid;
  input->process_next_triangle_func = occ_mesh_stla_igeom_process_next_triangle;
  input->end_solid_func = NULL;
}

/* Binary STL */

static void occ_mesh_stlb_igeom_begin_triangles(foug_stlb_geom_input_t* geom, uint32_t /*count*/)
{
  Handle_StlMesh_Mesh* mesh = static_cast<Handle_StlMesh_Mesh*>(geom->cookie);
  *mesh = new StlMesh_Mesh;
  (*mesh)->AddDomain();
}

static void occ_mesh_stlb_igeom_process_next_triangle(foug_stlb_geom_input_t* geom,
                                                      const foug_stlb_triangle_t* face)
{
  Handle_StlMesh_Mesh* mesh = static_cast<Handle_StlMesh_Mesh*>(geom->cookie);
  occ_mesh_stl_add_triangle(mesh, &(face->data));
}

void foug_stlb_geom_input_set_occmesh(foug_stlb_geom_input_t* input, Handle_StlMesh_Mesh* mesh)
{
  input->cookie = mesh;
  input->process_header_func = NULL;
  input->begin_triangles_func = occ_mesh_stlb_igeom_begin_triangles;
  input->process_next_triangle_func = occ_mesh_stlb_igeom_process_next_triangle;
  input->end_triangles_func = NULL;
}

static void occ_mesh_stlb_ogeom_get_header(const foug_stlb_geom_output_t* /*geom*/, uint8_t* header)
{
  std::memcpy(header, "Generated by libfougdatax-c", FOUG_STLB_HEADER_SIZE);
}

static uint32_t occ_mesh_stlb_ogeom_get_triangle_count(const foug_stlb_geom_output_t* geom)
{
  Handle_StlMesh_Mesh* mesh = static_cast<Handle_StlMesh_Mesh*>(geom->cookie);
  if ((*mesh)->NbDomains() >= 1)
    return (*mesh)->NbTriangles(1);
  return 0;
}

static void occ_mesh_stlb_ogeom_get_triangle(const foug_stlb_geom_output_t* geom,
                                             uint32_t index,
                                             foug_stlb_triangle_t* facet)
{
  Handle_StlMesh_Mesh* mesh = static_cast<Handle_StlMesh_Mesh*>(geom->cookie);

  const StlMesh_SequenceOfMeshTriangle& meshTriangles = (*mesh)->Triangles(1);
  const Handle_StlMesh_MeshTriangle tri = meshTriangles.Value(index + 1);
  Standard_Integer v1;
  Standard_Integer v2;
  Standard_Integer v3;
  Standard_Real xN;
  Standard_Real yN;
  Standard_Real zN;
  tri->GetVertexAndOrientation(v1, v2, v3, xN, yN, zN);
  facet->data.normal.x = xN;
  facet->data.normal.y = yN;
  facet->data.normal.z = zN;

  const TColgp_SequenceOfXYZ& vertices = (*mesh)->Vertices(1);
  const gp_XYZ& coordsV1 = vertices.Value(v1);
  const gp_XYZ& coordsV2 = vertices.Value(v2);
  const gp_XYZ& coordsV3 = vertices.Value(v3);
  facet->data.v1.x = coordsV1.X();
  facet->data.v2.x = coordsV2.X();
  facet->data.v3.x = coordsV3.X();

  facet->data.v1.y = coordsV1.Y();
  facet->data.v2.y = coordsV2.Y();
  facet->data.v3.y = coordsV3.Y();

  facet->data.v1.z = coordsV1.Z();
  facet->data.v2.z = coordsV2.Z();
  facet->data.v3.z = coordsV3.Z();

  facet->attribute_byte_count = 0;
}

void foug_stlb_geom_output_set_occmesh(foug_stlb_geom_output_t* output, Handle_StlMesh_Mesh* mesh)
{
  output->cookie = mesh;
  output->get_header_func = occ_mesh_stlb_ogeom_get_header;
  output->get_triangle_count_func = occ_mesh_stlb_ogeom_get_triangle_count;
  output->get_triangle_func = occ_mesh_stlb_ogeom_get_triangle;
}