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#include <pcl/kdtree/impl/kdtree_flann.hpp>

#include <pcl/point_cloud.h>
#include <pcl/point_types.h>
#include <pcl/common/distances.h>
#include <pcl/common/point_tests.h> // for pcl::isFinite
#include <pcl/common/time.h>
#include <pcl/io/pcd_io.h>
#include <pcl/test/gtest.h>

#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/xml_parser.hpp>

#include <algorithm>
#include <iostream>  // For debug
#include <map>

using namespace pcl;

boost::property_tree::ptree xml_property_tree;


PointCloud<PointXYZ>::Ptr cloud_in (new PointCloud<PointXYZ> ());

struct MyPoint : public PointXYZ 
{
    MyPoint (float x, float y, float z) {this->x=x; this->y=y; this->z=z;}
};

PointCloud<MyPoint> cloud, cloud_big;

void 
init ()
{
  float resolution = 0.1f;
  for (float z = -0.5f; z <= 0.5f; z += resolution)
    for (float y = -0.5f; y <= 0.5f; y += resolution)
      for (float x = -0.5f; x <= 0.5f; x += resolution)
        cloud.emplace_back(x, y, z);
  cloud.width  = cloud.size ();
  cloud.height = 1;

  cloud_big.width  = 640;
  cloud_big.height = 480;
  srand (static_cast<unsigned int> (time (nullptr)));
  // Randomly create a new point cloud
  for (std::size_t i = 0; i < cloud_big.width * cloud_big.height; ++i)
    cloud_big.emplace_back(static_cast<float> (1024 * rand () / (RAND_MAX + 1.0)),
                                         static_cast<float> (1024 * rand () / (RAND_MAX + 1.0)),
                                         static_cast<float> (1024 * rand () / (RAND_MAX + 1.0)));
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
TEST (PCL, KdTreeFLANN_radiusSearch)
{
  KdTreeFLANN<MyPoint> kdtree;
  kdtree.setInputCloud (cloud.makeShared ());
  MyPoint test_point(0.0f, 0.0f, 0.0f);
  double max_dist = 0.15;
  std::set<int> brute_force_result;
  for (std::size_t i=0; i < cloud.size(); ++i)
    if (euclideanDistance(cloud[i], test_point) < max_dist)
      brute_force_result.insert(i);
  pcl::Indices k_indices;
  std::vector<float> k_distances;
  kdtree.radiusSearch (test_point, max_dist, k_indices, k_distances, 100);
  
  //std::cout << k_indices.size()<<"=="<<brute_force_result.size()<<"?\n";
  
  for (const auto &k_index : k_indices)
  {
    auto brute_force_result_it = brute_force_result.find (k_index);
    bool ok = brute_force_result_it != brute_force_result.end ();
    //if (!ok)  std::cerr << k_indices[i] << " is not correct...\n";
    //else      std::cerr << k_indices[i] << " is correct...\n";
    EXPECT_TRUE (ok);
    if (ok)
      brute_force_result.erase (brute_force_result_it);
  }
  //for (set<int>::const_iterator it=brute_force_result.begin(); it!=brute_force_result.end(); ++it)
  //std::cerr << "FLANN missed "<<*it<<"\n";
  
  bool error = !brute_force_result.empty ();
  //if (error)  std::cerr << "Missed too many neighbors!\n";
  EXPECT_FALSE (error);

  {
    KdTreeFLANN<MyPoint> kdtree;
    kdtree.setInputCloud (cloud_big.makeShared ());

    ScopeTime scopeTime ("FLANN radiusSearch");
    {
      for (const auto &point : cloud_big.points)
        kdtree.radiusSearch (point, 0.1, k_indices, k_distances);
    }
  }
  
  {
    KdTreeFLANN<MyPoint> kdtree;
    kdtree.setInputCloud (cloud_big.makeShared ());

    ScopeTime scopeTime ("FLANN radiusSearch (max neighbors in radius)");
    {
      for (const auto &point : cloud_big.points)
        kdtree.radiusSearch (point, 0.1, k_indices, k_distances, 10);
    }
  }
  
  
  {
    KdTreeFLANN<MyPoint> kdtree (false);
    kdtree.setInputCloud (cloud_big.makeShared ());

    ScopeTime scopeTime ("FLANN radiusSearch (unsorted results)");
    {
      for (const auto &point : cloud_big.points)
        kdtree.radiusSearch (point, 0.1, k_indices, k_distances);
    }
  }
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
TEST (PCL, KdTreeFLANN_nearestKSearch)
{
  KdTreeFLANN<MyPoint> kdtree;
  kdtree.setInputCloud (cloud.makeShared ());
  MyPoint test_point (0.01f, 0.01f, 0.01f);
  unsigned int no_of_neighbors = 20;
  std::multimap<float, int> sorted_brute_force_result;
  for (std::size_t i = 0; i < cloud.size (); ++i)
  {
    float distance = euclideanDistance (cloud[i], test_point);
    sorted_brute_force_result.insert (std::make_pair (distance, static_cast<int> (i)));
  }
  float max_dist = 0.0f;
  unsigned int counter = 0;
  for (auto it = sorted_brute_force_result.begin (); it != sorted_brute_force_result.end () && counter < no_of_neighbors; ++it)
  {
    max_dist = std::max (max_dist, it->first);
    ++counter;
  }

  pcl::Indices k_indices;
  k_indices.resize (no_of_neighbors);
  std::vector<float> k_distances;
  k_distances.resize (no_of_neighbors);
  kdtree.nearestKSearch (test_point, no_of_neighbors, k_indices, k_distances);
  //if (k_indices.size() != no_of_neighbors)  std::cerr << "Found "<<k_indices.size()<<" instead of "<<no_of_neighbors<<" neighbors.\n";
  EXPECT_EQ (k_indices.size (), no_of_neighbors);

  // Check if all found neighbors have distance smaller than max_dist
  for (const auto &k_index : k_indices)
  {
    const MyPoint& point = cloud[k_index];
    bool ok = euclideanDistance (test_point, point) <= max_dist;
    if (!ok)
      ok = (std::abs (euclideanDistance (test_point, point)) - max_dist) <= 1e-6;
    //if (!ok)  std::cerr << k_index << " is not correct...\n";
    //else      std::cerr << k_index << " is correct...\n";
    EXPECT_TRUE (ok);
  }

  ScopeTime scopeTime ("FLANN nearestKSearch");
  {
    KdTreeFLANN<MyPoint> kdtree;
    kdtree.setInputCloud (cloud_big.makeShared ());
    for (const auto &point : cloud_big.points)
      kdtree.nearestKSearch (point, no_of_neighbors, k_indices, k_distances);
  }
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
class MyPointRepresentationXY : public PointRepresentation<MyPoint>
{
  public:
    MyPointRepresentationXY ()
    {
      this->nr_dimensions_ = 2;
    }

    void copyToFloatArray (const MyPoint &p, float *out) const override
    {
      out[0] = p.x;
      out[1] = p.y;
    }
};

TEST (PCL, KdTreeFLANN_setPointRepresentation)
{
  PointCloud<MyPoint>::Ptr random_cloud (new PointCloud<MyPoint> ());
  random_cloud->points.emplace_back(86.6f, 42.1f, 92.4f);
  random_cloud->points.emplace_back(63.1f, 18.4f, 22.3f);
  random_cloud->points.emplace_back(35.5f, 72.5f, 37.3f);
  random_cloud->points.emplace_back(99.7f, 37.0f,  8.7f);
  random_cloud->points.emplace_back(22.4f, 84.1f, 64.0f);
  random_cloud->points.emplace_back(65.2f, 73.4f, 18.0f);
  random_cloud->points.emplace_back(60.4f, 57.1f,  4.5f);
  random_cloud->points.emplace_back(38.7f, 17.6f, 72.3f);
  random_cloud->points.emplace_back(14.2f, 95.7f, 34.7f);
  random_cloud->points.emplace_back( 2.5f, 26.5f, 66.0f);

  KdTreeFLANN<MyPoint> kdtree;
  kdtree.setInputCloud (random_cloud);
  MyPoint p (50.0f, 50.0f, 50.0f);
  
  // Find k nearest neighbors
  constexpr int k = 10;
  pcl::Indices k_indices (k);
  std::vector<float> k_distances (k);
  kdtree.nearestKSearch (p, k, k_indices, k_distances);
  for (int i = 0; i < k; ++i)
  {
    // Compare to ground truth values, computed independently
    static const int gt_indices[10] = {2, 7, 5, 1, 4, 6, 9, 0, 8, 3};
    static const float gt_distances[10] =
    {877.8f, 1674.7f, 1802.6f, 1937.5f, 2120.6f, 2228.8f, 3064.5f, 3199.7f, 3604.2f, 4344.8f};
    EXPECT_EQ (k_indices[i], gt_indices[i]);
    EXPECT_NEAR (k_distances[i], gt_distances[i], 0.1);
  }
  
  // Find k nearest neighbors with a different point representation
  KdTreeFLANN<MyPoint>::PointRepresentationConstPtr ptrep (new MyPointRepresentationXY);
  kdtree.setPointRepresentation (ptrep);
  kdtree.nearestKSearch (p, k, k_indices, k_distances);
  for (int i = 0; i < k; ++i)
  {
    // Compare to ground truth values, computed independently
    static const int gt_indices[10] = {6, 2, 5, 1, 7, 0, 4, 3, 9, 8};
    static const float gt_distances[10] =
    {158.6f, 716.5f, 778.6f, 1170.2f, 1177.5f, 1402.0f, 1924.6f, 2639.1f, 2808.5f, 3370.1f};
    EXPECT_EQ (k_indices[i], gt_indices[i]);
    EXPECT_NEAR (k_distances[i], gt_distances[i], 0.1);
  }

  // Go back to the default, this time with the values rescaled
  DefaultPointRepresentation<MyPoint> point_rep;
  float alpha[3] = {1.0f, 2.0f, 3.0f};
  point_rep.setRescaleValues(alpha);
  kdtree.setPointRepresentation (point_rep.makeShared ());
  kdtree.nearestKSearch (p, k, k_indices, k_distances);
  for (int i = 0; i < k; ++i)
  {
    // Compare to ground truth values, computed independently
    static const int gt_indices[10] =  {2, 9, 4, 7, 1, 5, 8, 0, 3, 6};
    static const float gt_distances[10] =
    {3686.9f, 6769.2f, 7177.0f, 8802.3f, 11071.5f, 11637.3f, 11742.4f, 17769.0f, 18497.3f, 18942.0f};
    EXPECT_EQ (k_indices[i], gt_indices[i]);
    EXPECT_NEAR (k_distances[i], gt_distances[i], 0.1);
  }
}


//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
TEST (PCL, KdTreeFLANN_32_vs_64_bit)
{
  KdTreeFLANN<PointXYZ> tree;
  tree.setInputCloud (cloud_in);

  std::vector<pcl::Indices > nn_indices_vector;
  for (std::size_t i = 0; i < cloud_in->size (); ++i)
    if (isFinite ((*cloud_in)[i]))
    {
      pcl::Indices nn_indices;
      std::vector<float> nn_dists;
      tree.radiusSearch ((*cloud_in)[i], 0.02, nn_indices, nn_dists);

      nn_indices_vector.push_back (nn_indices);
    }



  for (std::size_t vec_i = 0; vec_i < nn_indices_vector.size (); ++vec_i)
  {
    char str[512];
    sprintf (str, "point_%d", static_cast<int>(vec_i));
    boost::optional<boost::property_tree::ptree&> tree = xml_property_tree.get_child_optional (str);
    if (!tree)
      FAIL ();

    int vec_size = tree.get ().get<int> ("size");
    EXPECT_EQ (vec_size, nn_indices_vector[vec_i].size ());

    for (std::size_t n_i = 0; n_i < nn_indices_vector[vec_i].size (); ++n_i)
    {
      sprintf (str, "nn_%d", static_cast<int>(n_i));
      int neighbor_index = tree.get ().get<int> (str);
      EXPECT_EQ (neighbor_index, nn_indices_vector[vec_i][n_i]);
    }
  }
}

/* ---[ */
int
main (int argc, char** argv)
{
  // Load the standard PCD file from disk
  if (argc < 3)
  {
    std::cerr << "No test file given. Please download `sac_plane_test.pcd` and 'kdtree_unit_test_results.xml' pass them path to the test." << std::endl;
    return (-1);
  }

  // Load in the point clouds
  io::loadPCDFile (argv[1], *cloud_in);

  std::ifstream xml_file_input_stream (argv[2], std::ifstream::in);
  read_xml (xml_file_input_stream, xml_property_tree, boost::property_tree::xml_parser::trim_whitespace);

  testing::InitGoogleTest (&argc, argv);

  init ();
  return (RUN_ALL_TESTS ());
}
/* ]--- */
