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#include "colmap/estimators/generalized_absolute_pose.h"

#include "colmap/geometry/pose.h"
#include "colmap/geometry/rigid3.h"
#include "colmap/optim/ransac.h"
#include "colmap/util/eigen_alignment.h"

#include <array>

#include <Eigen/Core>
#include <gtest/gtest.h>

namespace colmap {
namespace {

TEST(GeneralizedAbsolutePose, Estimate) {
  std::vector<Eigen::Vector3d> points3D;
  points3D.emplace_back(1, 1, 1);
  points3D.emplace_back(0, 1, 1);
  points3D.emplace_back(3, 1.0, 4);
  points3D.emplace_back(3, 1.1, 4);
  points3D.emplace_back(3, 1.2, 4);
  points3D.emplace_back(3, 1.3, 4);
  points3D.emplace_back(3, 1.4, 4);
  points3D.emplace_back(2, 1, 7);

  auto points3D_faulty = points3D;
  for (size_t i = 0; i < points3D.size(); ++i) {
    points3D_faulty[i](0) = 20;
  }

  // NOLINTNEXTLINE(clang-analyzer-security.FloatLoopCounter)
  for (double qx = 0; qx < 1; qx += 0.2) {
    // NOLINTNEXTLINE(clang-analyzer-security.FloatLoopCounter)
    for (double tx = 0; tx < 1; tx += 0.1) {
      const int kRefCamIdx = 1;
      const int kNumCams = 3;

      const std::array<Rigid3d, kNumCams> cams_from_world = {{
          Rigid3d(Eigen::Quaterniond(1, qx, 0, 0).normalized(),
                  Eigen::Vector3d(tx, -0.1, 0)),
          Rigid3d(Eigen::Quaterniond(1, qx, 0, 0).normalized(),
                  Eigen::Vector3d(tx, 0, 0)),
          Rigid3d(Eigen::Quaterniond(1, qx, 0, 0).normalized(),
                  Eigen::Vector3d(tx, 0.1, 0)),
      }};

      const Rigid3d& rig_from_world = cams_from_world[kRefCamIdx];

      std::array<Rigid3d, kNumCams> cams_from_rig;
      for (size_t i = 0; i < kNumCams; ++i) {
        cams_from_rig[i] = cams_from_world[i] * Inverse(rig_from_world);
      }

      // Project points to camera coordinate system.
      std::vector<GP3PEstimator::X_t> points2D;
      for (size_t i = 0; i < points3D.size(); ++i) {
        points2D.emplace_back();
        points2D.back().cam_from_rig = cams_from_rig[i % kNumCams];
        points2D.back().ray_in_cam =
            (cams_from_world[i % kNumCams] * points3D[i]).normalized();
      }

      RANSACOptions options;
      options.max_error = 1e-5;
      RANSAC<GP3PEstimator> ransac(options);
      const auto report = ransac.Estimate(points2D, points3D);

      EXPECT_TRUE(report.success);
      EXPECT_LT((rig_from_world.ToMatrix() - report.model.ToMatrix()).norm(),
                1e-2)
          << report.model.ToMatrix() << "\n\n"
          << rig_from_world.ToMatrix();

      // Test residuals of exact points.
      std::vector<double> residuals;
      ransac.estimator.Residuals(points2D, points3D, report.model, &residuals);
      for (size_t i = 0; i < residuals.size(); ++i) {
        EXPECT_LT(residuals[i], 1e-10);
      }

      // Test residuals of faulty points.
      ransac.estimator.Residuals(
          points2D, points3D_faulty, report.model, &residuals);
      for (size_t i = 0; i < residuals.size(); ++i) {
        EXPECT_GT(residuals[i], 1e-10);
      }
    }
  }
}

}  // namespace
}  // namespace colmap
