// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008-2014 Gael Guennebaud <gael.guennebaud@inria.fr>
// Copyright (C) 2009 Benoit Jacob <jacob.benoit.1@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// SPDX-License-Identifier: MPL-2.0

// discard stack allocation as that too bypasses malloc
#define EIGEN_STACK_ALLOCATION_LIMIT 0
#define EIGEN_RUNTIME_NO_MALLOC
#include "main.h"
#include <Eigen/SVD>
#include <cfenv>
#include "fp_control.h"

#define SVD_DEFAULT(M) JacobiSVD<M>
#define SVD_FOR_MIN_NORM(M) JacobiSVD<M, ColPivHouseholderQRPreconditioner>
#define SVD_STATIC_OPTIONS(M, O) JacobiSVD<M, O>
#include "svd_common.h"

template <typename MatrixType>
void jacobisvd_method() {
  enum { Size = MatrixType::RowsAtCompileTime };
  typedef typename MatrixType::RealScalar RealScalar;
  typedef Matrix<RealScalar, Size, 1> RealVecType;
  MatrixType m = MatrixType::Identity();
  VERIFY_IS_APPROX(m.jacobiSvd().singularValues(), RealVecType::Ones());
  VERIFY_RAISES_ASSERT(m.jacobiSvd().matrixU());
  VERIFY_RAISES_ASSERT(m.jacobiSvd().matrixV());
  VERIFY_IS_APPROX(m.template jacobiSvd<ComputeFullU | ComputeFullV>().solve(m), m);
  VERIFY_IS_APPROX(m.template jacobiSvd<ComputeFullU | ComputeFullV>().transpose().solve(m), m);
  VERIFY_IS_APPROX(m.template jacobiSvd<ComputeFullU | ComputeFullV>().adjoint().solve(m), m);
}

template <typename MatrixType>
void jacobisvd_thin_full_options(const MatrixType& input = MatrixType()) {
  svd_thin_full_option_checks<MatrixType, 0>(input);
  svd_thin_full_option_checks<MatrixType, HouseholderQRPreconditioner>(input);
  svd_option_checks_full_only<MatrixType, FullPivHouseholderQRPreconditioner>(
      input);  // FullPiv only used when computing full unitaries
}

template <typename MatrixType>
void jacobisvd_vector_asserts(const MatrixType& input = MatrixType()) {
  MatrixType m(input.rows(), input.cols());
  svd_fill_random(m);

  svd_verify_assert<MatrixType>(m);
  svd_verify_assert<MatrixType, HouseholderQRPreconditioner>(m);
  svd_verify_assert_full_only<MatrixType, FullPivHouseholderQRPreconditioner>(m);
}

template <typename MatrixType>
void jacobisvd_verify_inputs(const MatrixType& input = MatrixType()) {
  // check defaults
  typedef JacobiSVD<MatrixType> DefaultSVD;
  MatrixType m(input.rows(), input.cols());
  svd_fill_random(m);
  DefaultSVD defaultSvd(m);
  VERIFY((int)DefaultSVD::QRPreconditioner == (int)ColPivHouseholderQRPreconditioner);
  VERIFY(!defaultSvd.computeU());
  VERIFY(!defaultSvd.computeV());

  // ColPivHouseholderQR is always default in presence of other options.
  VERIFY(((int)JacobiSVD<MatrixType, ComputeThinU>::QRPreconditioner == (int)ColPivHouseholderQRPreconditioner));
  VERIFY(((int)JacobiSVD<MatrixType, ComputeThinV>::QRPreconditioner == (int)ColPivHouseholderQRPreconditioner));
  VERIFY(((int)JacobiSVD<MatrixType, ComputeThinU | ComputeThinV>::QRPreconditioner ==
          (int)ColPivHouseholderQRPreconditioner));
  VERIFY(((int)JacobiSVD<MatrixType, ComputeFullU | ComputeFullV>::QRPreconditioner ==
          (int)ColPivHouseholderQRPreconditioner));
  VERIFY(((int)JacobiSVD<MatrixType, ComputeThinU | ComputeFullV>::QRPreconditioner ==
          (int)ColPivHouseholderQRPreconditioner));
  VERIFY(((int)JacobiSVD<MatrixType, ComputeFullU | ComputeThinV>::QRPreconditioner ==
          (int)ColPivHouseholderQRPreconditioner));
}

template <typename MatrixType>
void svd_triangular_matrix(const MatrixType& input = MatrixType()) {
  MatrixType matrix(input.rows(), input.cols());
  svd_fill_random(matrix);
  // Make sure that we only consider the 'Lower' part of the matrix.
  MatrixType matrix_self_adj = matrix.template selfadjointView<Lower>().toDenseMatrix();

  JacobiSVD<MatrixType, ComputeFullV> svd_triangular(matrix.template selfadjointView<Lower>());
  JacobiSVD<MatrixType, ComputeFullV> svd_full(matrix_self_adj);

  VERIFY_IS_APPROX(svd_triangular.singularValues(), svd_full.singularValues());
}

namespace Foo {
class Bar {
 public:
  Bar() {}
};
bool operator<(const Bar&, const Bar&) { return true; }
}  // namespace Foo
// regression test for a very strange MSVC issue for which simply
// including SVDBase.h messes up with std::max and custom scalar type
void msvc_workaround() {
  const Foo::Bar a;
  const Foo::Bar b;
  const Foo::Bar c = std::max EIGEN_NOT_A_MACRO(a, b);
  EIGEN_UNUSED_VARIABLE(c);
}

void jacobisvd_mixed_option_enum_regression() {
  using NoQrFullSVD = JacobiSVD<MatrixXd, NoQRPreconditioner | ComputeFullU | ComputeFullV>;
  using ReversedMixedSVD = JacobiSVD<MatrixXd, ComputeThinU | HouseholderQRPreconditioner | ComputeFullV>;

  STATIC_CHECK((int(NoQrFullSVD::QRPreconditioner) == int(NoQRPreconditioner)));
  STATIC_CHECK(((int(NoQrFullSVD::Options) & ComputeFullU) != 0));
  STATIC_CHECK(((int(NoQrFullSVD::Options) & ComputeFullV) != 0));
  STATIC_CHECK(((int(NoQrFullSVD::Options) & ComputeThinU) == 0));
  STATIC_CHECK(((int(NoQrFullSVD::Options) & ComputeThinV) == 0));

  STATIC_CHECK((int(ReversedMixedSVD::QRPreconditioner) == int(HouseholderQRPreconditioner)));
  STATIC_CHECK(((int(ReversedMixedSVD::Options) & ComputeThinU) != 0));
  STATIC_CHECK(((int(ReversedMixedSVD::Options) & ComputeFullV) != 0));
  STATIC_CHECK(((int(ReversedMixedSVD::Options) & ComputeFullU) == 0));
  STATIC_CHECK(((int(ReversedMixedSVD::Options) & ComputeThinV) == 0));
}

void jacobisvd_large_tau_regression() {
  Matrix3f m;
  m << 3.7855173218304116745e-07f, 0.0f, 500.0f, -4.9999995231628417969f, -0.0f, -1.9106853686029490191e-12f,
      -8.6602544784545898438f, 0.0f, 2.1855694285477511585f;

#ifdef FE_OVERFLOW
  std::fenv_t environment;
  const bool check_overflow = std::feholdexcept(&environment) == 0;
  if (!check_overflow) std::cout << "SKIP: JacobiSVD overflow flag check: feholdexcept failed.\n";
#else
  std::cout << "SKIP: JacobiSVD overflow flag check: FE_OVERFLOW is unavailable.\n";
#endif
  JacobiSVD<Matrix3f> svd(m, ComputeFullU | ComputeFullV);
#ifdef FE_OVERFLOW
  if (check_overflow) {
    const int overflow = std::fetestexcept(FE_OVERFLOW);
    const int restored = std::fesetenv(&environment);
    VERIFY_IS_EQUAL(restored, 0);
    VERIFY_IS_EQUAL(overflow, 0);
  }
#endif
  svd_check_full(m, svd);
}

void jacobisvd_power_of_two_scaling() {
  // Reciprocal scaling rounds the smaller singular value up by one ULP.
  Matrix2f matrix = Matrix2f::Zero();
  matrix(0, 0) = numext::bit_cast<float>(numext::uint32_t(0x58f6aaed));
  matrix(1, 1) = numext::bit_cast<float>(numext::uint32_t(0x537dcf0e));

  const JacobiSVD<Matrix2f> svd(matrix);
  VERIFY_IS_EQUAL(svd.singularValues()(0), matrix(0, 0));
  VERIFY_IS_EQUAL(svd.singularValues()(1), matrix(1, 1));

  Matrix<float, 3, 2> rectangular = Matrix<float, 3, 2>::Zero();
  rectangular.template topRows<2>() = matrix;
  const JacobiSVD<Matrix<float, 3, 2>> rectangularSvd(rectangular);
  VERIFY_IS_EQUAL(rectangularSvd.singularValues(), matrix.diagonal());

  const auto checkSubnormalScaling = [] {
    volatile float normalMinInput = (std::numeric_limits<float>::min)();
    const float inputScale = 256.0f * normalMinInput;
    Matrix2cf normalized = Matrix2cf::Identity();
    normalized(1, 0) = std::complex<float>(1.0f / 512.0f, -1.0f / 1024.0f);
    Matrix2cf tiny = Matrix2cf::Identity() * inputScale;
    // Narrowing an arithmetic product to float would flush the fixture before the solver sees it.
    tiny(1, 0) = std::complex<float>(numext::bit_cast<float>(numext::uint32_t(0x00400000)),
                                     numext::bit_cast<float>(numext::uint32_t(0x80200000)));
    const JacobiSVD<Matrix2cf> normalizedSvd(normalized);
    const JacobiSVD<Matrix2cf> tinySvd(tiny);
    // These well-conditioned, nearly identity problems should agree to a few rounding errors.
    const float tolerance = 8 * NumTraits<float>::epsilon();
    VERIFY((tinySvd.singularValues() / inputScale - normalizedSvd.singularValues()).norm() <= tolerance);

    Matrix<std::complex<float>, 3, 2> tinyTall = Matrix<std::complex<float>, 3, 2>::Zero();
    tinyTall.template topRows<2>() = tiny;
    const JacobiSVD<Matrix<std::complex<float>, 3, 2>> tinyTallSvd(tinyTall);
    VERIFY((tinyTallSvd.singularValues() / inputScale - normalizedSvd.singularValues()).norm() <= tolerance);

    const Matrix<std::complex<float>, 2, 3> tinyWide = tinyTall.adjoint();
    const JacobiSVD<Matrix<std::complex<float>, 2, 3>> tinyWideSvd(tinyWide);
    VERIFY((tinyWideSvd.singularValues() / inputScale - normalizedSvd.singularValues()).norm() <= tolerance);
  };
  checkSubnormalScaling();
  {
    ScopedFlushToZero flushToZero;
    checkSubnormalScaling();
  }

  volatile float denormMinInput = std::numeric_limits<float>::denorm_min();
  const float denormMin = denormMinInput;
  if (!(denormMin > 0.0f)) return;
  matrix.diagonal() << 1.5f, denormMin;
  const JacobiSVD<Matrix2f> tailSvd(matrix);
  VERIFY_IS_EQUAL(tailSvd.singularValues()(1), denormMin);
}

EIGEN_DECLARE_TEST(jacobisvd) {
  CALL_SUBTEST_60((svd_normal_equation_roundoff<float, ColMajor>()));
  CALL_SUBTEST_60((svd_normal_equation_roundoff<double, RowMajor>()));
  CALL_SUBTEST_61((svd_normal_equation_roundoff<std::complex<float>, RowMajor>()));
  CALL_SUBTEST_61((svd_normal_equation_roundoff<std::complex<double>, ColMajor>()));

  CALL_SUBTEST_1((jacobisvd_verify_inputs<Matrix4d>()));
  CALL_SUBTEST_2((jacobisvd_verify_inputs(Matrix<float, 5, Dynamic>(5, 6))));
  CALL_SUBTEST_3((jacobisvd_verify_inputs<Matrix<std::complex<double>, 7, 5>>()));
  CALL_SUBTEST_4((jacobisvd_mixed_option_enum_regression()));
  CALL_SUBTEST_4((jacobisvd_large_tau_regression()));

  CALL_SUBTEST_11((jacobisvd_thin_full_options<Matrix2cd>()));
  CALL_SUBTEST_12((jacobisvd_thin_full_options<Matrix2d>()));

  for (int i = 0; i < g_repeat; i++) {
    int r = internal::random<int>(1, 30), c = internal::random<int>(1, 30);

    TEST_SET_BUT_UNUSED_VARIABLE(r);
    TEST_SET_BUT_UNUSED_VARIABLE(c);

    CALL_SUBTEST_13((jacobisvd_thin_full_options<Matrix3f>()));
    CALL_SUBTEST_15((jacobisvd_thin_full_options<Matrix4d>()));
    CALL_SUBTEST_17((jacobisvd_thin_full_options<Matrix<float, 2, 3>>()));
    CALL_SUBTEST_19((jacobisvd_thin_full_options<Matrix<double, 4, 7>>()));
    CALL_SUBTEST_21((jacobisvd_thin_full_options<Matrix<double, 7, 4>>()));
    CALL_SUBTEST_23((jacobisvd_thin_full_options<Matrix<double, Dynamic, 5>>(Matrix<double, Dynamic, 5>(r, 5))));
    CALL_SUBTEST_25((jacobisvd_thin_full_options<Matrix<double, 5, Dynamic>>(Matrix<double, 5, Dynamic>(5, c))));
    CALL_SUBTEST_27((jacobisvd_thin_full_options<MatrixXf>(MatrixXf(r, c))));
    CALL_SUBTEST_29((jacobisvd_thin_full_options<MatrixXcd>(MatrixXcd(r, c))));
    CALL_SUBTEST_31((jacobisvd_thin_full_options<MatrixXd>(MatrixXd(r, c))));
    CALL_SUBTEST_33((jacobisvd_thin_full_options<Matrix<double, 5, 7, RowMajor>>()));
    CALL_SUBTEST_35((jacobisvd_thin_full_options<Matrix<double, 7, 5, RowMajor>>()));

    MatrixXcd noQRTest = MatrixXcd(r, r);
    CALL_SUBTEST_37((svd_thin_full_option_checks<MatrixXcd, NoQRPreconditioner>(noQRTest)));

    CALL_SUBTEST_38((
        svd_check_max_size_matrix<Matrix<float, Dynamic, Dynamic, ColMajor, 13, 15>, ColPivHouseholderQRPreconditioner>(
            r, c)));
    CALL_SUBTEST_39(
        (svd_check_max_size_matrix<Matrix<float, Dynamic, Dynamic, ColMajor, 15, 13>, HouseholderQRPreconditioner>(r,
                                                                                                                   c)));
    CALL_SUBTEST_40((
        svd_check_max_size_matrix<Matrix<float, Dynamic, Dynamic, RowMajor, 13, 15>, ColPivHouseholderQRPreconditioner>(
            r, c)));
    CALL_SUBTEST_41(
        (svd_check_max_size_matrix<Matrix<float, Dynamic, Dynamic, RowMajor, 15, 13>, HouseholderQRPreconditioner>(r,
                                                                                                                   c)));

    // Test on inf/nan matrix
    CALL_SUBTEST_42((svd_inf_nan<MatrixXf>()));
    CALL_SUBTEST_43((svd_inf_nan<MatrixXd>()));

    CALL_SUBTEST_44((jacobisvd_vector_asserts<Matrix<double, 6, 1>>()));
    CALL_SUBTEST_45((jacobisvd_vector_asserts<Matrix<double, 1, 6>>()));
    CALL_SUBTEST_46((jacobisvd_vector_asserts<Matrix<double, Dynamic, 1>>(Matrix<double, Dynamic, 1>(r))));
    CALL_SUBTEST_47((jacobisvd_vector_asserts<Matrix<double, 1, Dynamic>>(Matrix<double, 1, Dynamic>(c))));
  }

  CALL_SUBTEST_48((jacobisvd_thin_full_options<MatrixXd>(
      MatrixXd(internal::random<int>(EIGEN_TEST_MAX_SIZE / 4, EIGEN_TEST_MAX_SIZE / 2),
               internal::random<int>(EIGEN_TEST_MAX_SIZE / 4, EIGEN_TEST_MAX_SIZE / 2)))));
  CALL_SUBTEST_50((jacobisvd_thin_full_options<MatrixXcd>(
      MatrixXcd(internal::random<int>(EIGEN_TEST_MAX_SIZE / 4, EIGEN_TEST_MAX_SIZE / 3),
                internal::random<int>(EIGEN_TEST_MAX_SIZE / 4, EIGEN_TEST_MAX_SIZE / 3)))));

  // test matrixbase method
  CALL_SUBTEST_52((jacobisvd_method<Matrix2cd>()));
  CALL_SUBTEST_53((jacobisvd_method<Matrix3f>()));

  // Test problem size constructors
  CALL_SUBTEST_54(JacobiSVD<MatrixXf>(10, 10));

  // Check that preallocation avoids subsequent mallocs
  CALL_SUBTEST_55(svd_preallocate<void>());

  CALL_SUBTEST_56(svd_underoverflow<void>());
  CALL_SUBTEST_56(jacobisvd_power_of_two_scaling());

  // Check that the TriangularBase constructor works
  CALL_SUBTEST_57((svd_triangular_matrix<Matrix3d>()));
  CALL_SUBTEST_58((svd_triangular_matrix<Matrix4f>()));
  CALL_SUBTEST_59((svd_triangular_matrix<Matrix<double, 10, 10>>()));

  msvc_workaround();
}