// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2015 Google Inc. All rights reserved.
// http://ceres-solver.org/
//
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// Author: keir@google.com (Keir Mierle)

#include "ceres/parameter_block.h"

#include "ceres/internal/eigen.h"
#include "gtest/gtest.h"

namespace ceres {
namespace internal {

TEST(ParameterBlock, SetParameterizationDiesOnSizeMismatch) {
  double x[3] = {1.0, 2.0, 3.0};
  ParameterBlock parameter_block(x, 3, -1);
  std::vector<int> indices;
  indices.push_back(1);
  SubsetParameterization subset_wrong_size(4, indices);
  EXPECT_DEATH_IF_SUPPORTED(
      parameter_block.SetParameterization(&subset_wrong_size), "global");
}

TEST(ParameterBlock, SetParameterizationWithSameExistingParameterization) {
  double x[3] = {1.0, 2.0, 3.0};
  ParameterBlock parameter_block(x, 3, -1);
  std::vector<int> indices;
  indices.push_back(1);
  SubsetParameterization subset(3, indices);
  parameter_block.SetParameterization(&subset);
  parameter_block.SetParameterization(&subset);
}

TEST(ParameterBlock, SetParameterizationAllowsResettingToNull) {
  double x[3] = {1.0, 2.0, 3.0};
  ParameterBlock parameter_block(x, 3, -1);
  std::vector<int> indices;
  indices.push_back(1);
  SubsetParameterization subset(3, indices);
  parameter_block.SetParameterization(&subset);
  EXPECT_EQ(parameter_block.local_parameterization(), &subset);
  parameter_block.SetParameterization(nullptr);
  EXPECT_EQ(parameter_block.local_parameterization(), nullptr);
}

TEST(ParameterBlock,
     SetParameterizationAllowsResettingToDifferentParameterization) {
  double x[3] = {1.0, 2.0, 3.0};
  ParameterBlock parameter_block(x, 3, -1);
  std::vector<int> indices;
  indices.push_back(1);
  SubsetParameterization subset(3, indices);
  parameter_block.SetParameterization(&subset);
  EXPECT_EQ(parameter_block.local_parameterization(), &subset);

  SubsetParameterization subset_different(3, indices);
  parameter_block.SetParameterization(&subset_different);
  EXPECT_EQ(parameter_block.local_parameterization(), &subset_different);
}

TEST(ParameterBlock, SetParameterizationAndNormalOperation) {
  double x[3] = {1.0, 2.0, 3.0};
  ParameterBlock parameter_block(x, 3, -1);
  std::vector<int> indices;
  indices.push_back(1);
  SubsetParameterization subset(3, indices);
  parameter_block.SetParameterization(&subset);

  // Ensure the local parameterization jacobian result is correctly computed.
  ConstMatrixRef local_parameterization_jacobian(
      parameter_block.LocalParameterizationJacobian(), 3, 2);
  ASSERT_EQ(1.0, local_parameterization_jacobian(0, 0));
  ASSERT_EQ(0.0, local_parameterization_jacobian(0, 1));
  ASSERT_EQ(0.0, local_parameterization_jacobian(1, 0));
  ASSERT_EQ(0.0, local_parameterization_jacobian(1, 1));
  ASSERT_EQ(0.0, local_parameterization_jacobian(2, 0));
  ASSERT_EQ(1.0, local_parameterization_jacobian(2, 1));

  // Check that updating works as expected.
  double x_plus_delta[3];
  double delta[2] = {0.5, 0.3};
  parameter_block.Plus(x, delta, x_plus_delta);
  ASSERT_EQ(1.5, x_plus_delta[0]);
  ASSERT_EQ(2.0, x_plus_delta[1]);
  ASSERT_EQ(3.3, x_plus_delta[2]);
}

struct TestParameterization : public LocalParameterization {
 public:
  virtual ~TestParameterization() {}
  bool Plus(const double* x,
            const double* delta,
            double* x_plus_delta) const final {
    LOG(FATAL) << "Shouldn't get called.";
    return true;
  }
  bool ComputeJacobian(const double* x, double* jacobian) const final {
    jacobian[0] = *x * 2;
    return true;
  }

  int GlobalSize() const final { return 1; }
  int LocalSize() const final { return 1; }
};

TEST(ParameterBlock, SetStateUpdatesLocalParameterizationJacobian) {
  TestParameterization test_parameterization;
  double x[1] = {1.0};
  ParameterBlock parameter_block(x, 1, -1, &test_parameterization);

  EXPECT_EQ(2.0, *parameter_block.LocalParameterizationJacobian());

  x[0] = 5.5;
  parameter_block.SetState(x);
  EXPECT_EQ(11.0, *parameter_block.LocalParameterizationJacobian());
}

TEST(ParameterBlock, PlusWithNoLocalParameterization) {
  double x[2] = {1.0, 2.0};
  ParameterBlock parameter_block(x, 2, -1);

  double delta[2] = {0.2, 0.3};
  double x_plus_delta[2];
  parameter_block.Plus(x, delta, x_plus_delta);
  EXPECT_EQ(1.2, x_plus_delta[0]);
  EXPECT_EQ(2.3, x_plus_delta[1]);
}

// Stops computing the jacobian after the first time.
class BadLocalParameterization : public LocalParameterization {
 public:
  BadLocalParameterization() : calls_(0) {}

  virtual ~BadLocalParameterization() {}
  bool Plus(const double* x,
            const double* delta,
            double* x_plus_delta) const final {
    *x_plus_delta = *x + *delta;
    return true;
  }

  bool ComputeJacobian(const double* x, double* jacobian) const final {
    if (calls_ == 0) {
      jacobian[0] = 0;
    }
    ++calls_;
    return true;
  }

  int GlobalSize() const final { return 1; }
  int LocalSize() const final { return 1; }

 private:
  mutable int calls_;
};

TEST(ParameterBlock, DetectBadLocalParameterization) {
  double x = 1;
  BadLocalParameterization bad_parameterization;
  ParameterBlock parameter_block(&x, 1, -1, &bad_parameterization);
  double y = 2;
  EXPECT_FALSE(parameter_block.SetState(&y));
}

TEST(ParameterBlock, DefaultBounds) {
  double x[2];
  ParameterBlock parameter_block(x, 2, -1, nullptr);
  EXPECT_EQ(parameter_block.UpperBoundForParameter(0),
            std::numeric_limits<double>::max());
  EXPECT_EQ(parameter_block.UpperBoundForParameter(1),
            std::numeric_limits<double>::max());
  EXPECT_EQ(parameter_block.LowerBoundForParameter(0),
            -std::numeric_limits<double>::max());
  EXPECT_EQ(parameter_block.LowerBoundForParameter(1),
            -std::numeric_limits<double>::max());
}

TEST(ParameterBlock, SetBounds) {
  double x[2];
  ParameterBlock parameter_block(x, 2, -1, nullptr);
  parameter_block.SetLowerBound(0, 1);
  parameter_block.SetUpperBound(1, 1);

  EXPECT_EQ(parameter_block.LowerBoundForParameter(0), 1.0);
  EXPECT_EQ(parameter_block.LowerBoundForParameter(1),
            -std::numeric_limits<double>::max());

  EXPECT_EQ(parameter_block.UpperBoundForParameter(0),
            std::numeric_limits<double>::max());
  EXPECT_EQ(parameter_block.UpperBoundForParameter(1), 1.0);
}

TEST(ParameterBlock, PlusWithBoundsConstraints) {
  double x[] = {1.0, 0.0};
  double delta[] = {2.0, -10.0};
  ParameterBlock parameter_block(x, 2, -1, nullptr);
  parameter_block.SetUpperBound(0, 2.0);
  parameter_block.SetLowerBound(1, -1.0);
  double x_plus_delta[2];
  parameter_block.Plus(x, delta, x_plus_delta);
  EXPECT_EQ(x_plus_delta[0], 2.0);
  EXPECT_EQ(x_plus_delta[1], -1.0);
}

TEST(ParameterBlock, ResetLocalParameterizationToNull) {
  double x[3] = {1.0, 2.0, 3.0};
  ParameterBlock parameter_block(x, 3, -1);
  std::vector<int> indices;
  indices.push_back(1);
  SubsetParameterization subset(3, indices);
  parameter_block.SetParameterization(&subset);
  EXPECT_EQ(parameter_block.local_parameterization(), &subset);
  parameter_block.SetParameterization(nullptr);
  EXPECT_EQ(parameter_block.local_parameterization(), nullptr);
}

TEST(ParameterBlock, ResetLocalParameterizationToNotNull) {
  double x[3] = {1.0, 2.0, 3.0};
  ParameterBlock parameter_block(x, 3, -1);
  std::vector<int> indices;
  indices.push_back(1);
  SubsetParameterization subset(3, indices);
  parameter_block.SetParameterization(&subset);
  EXPECT_EQ(parameter_block.local_parameterization(), &subset);

  SubsetParameterization subset_different(3, indices);
  parameter_block.SetParameterization(&subset_different);
  EXPECT_EQ(parameter_block.local_parameterization(), &subset_different);
}

TEST(ParameterBlock, SetNullLocalParameterization) {
  double x[3] = {1.0, 2.0, 3.0};
  ParameterBlock parameter_block(x, 3, -1);
  EXPECT_EQ(parameter_block.local_parameterization(), nullptr);

  parameter_block.SetParameterization(nullptr);
  EXPECT_EQ(parameter_block.local_parameterization(), nullptr);
}

}  // namespace internal
}  // namespace ceres