// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2006-2010 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/.

#include "main.h"

template<typename MatrixType, typename Index, typename Scalar>
std::enable_if_t<!NumTraits<typename MatrixType::Scalar>::IsComplex,typename MatrixType::Scalar>
block_real_only(const MatrixType &m1, Index r1, Index r2, Index c1, Index c2, const Scalar& s1) {
  // check cwise-Functions:
  VERIFY_IS_APPROX(m1.row(r1).cwiseMax(s1), m1.cwiseMax(s1).row(r1));
  VERIFY_IS_APPROX(m1.col(c1).cwiseMin(s1), m1.cwiseMin(s1).col(c1));

  VERIFY_IS_APPROX(m1.block(r1,c1,r2-r1+1,c2-c1+1).cwiseMin(s1), m1.cwiseMin(s1).block(r1,c1,r2-r1+1,c2-c1+1));
  VERIFY_IS_APPROX(m1.block(r1,c1,r2-r1+1,c2-c1+1).cwiseMax(s1), m1.cwiseMax(s1).block(r1,c1,r2-r1+1,c2-c1+1));
  
  return Scalar(0);
}

template<typename MatrixType, typename Index, typename Scalar>
std::enable_if_t<NumTraits<typename MatrixType::Scalar>::IsComplex,typename MatrixType::Scalar>
block_real_only(const MatrixType &, Index, Index, Index, Index, const Scalar&) {
  return Scalar(0);
}

// Check at compile-time that T1==T2, and at runtime-time that a==b
template<typename T1,typename T2>
std::enable_if_t<internal::is_same<T1,T2>::value,bool>
is_same_block(const T1& a, const T2& b)
{
  return a.isApprox(b);
}

template <typename MatrixType>
std::enable_if_t<((MatrixType::Flags&RowMajorBit)==0),void>
check_left_top(const MatrixType& m, Index r, Index c,
               Index rows, Index /*unused*/) {
  if(c > 0) VERIFY_IS_EQUAL(m.leftCols(c).coeff(r+c*rows), m(r,c));
}

template <typename MatrixType>
std::enable_if_t<((MatrixType::Flags&RowMajorBit)!=0),void>
check_left_top(const MatrixType& m,  Index r, Index c,
               Index /*unused*/, Index cols) {
  if(r > 0) VERIFY_IS_EQUAL(m.topRows(r).coeff(c+r*cols), m(r,c));
}

template<typename MatrixType> void block(const MatrixType& m)
{
  typedef typename MatrixType::Scalar Scalar;
  typedef typename MatrixType::RealScalar RealScalar;
  typedef Matrix<Scalar, MatrixType::RowsAtCompileTime, 1> VectorType;
  typedef Matrix<Scalar, 1, MatrixType::ColsAtCompileTime> RowVectorType;
  typedef Matrix<Scalar, Dynamic, Dynamic, MatrixType::IsRowMajor?RowMajor:ColMajor> DynamicMatrixType;
  typedef Matrix<Scalar, Dynamic, 1> DynamicVectorType;
  
  Index rows = m.rows();
  Index cols = m.cols();

  MatrixType m1 = MatrixType::Random(rows, cols),
             m1_copy = m1,
             m2 = MatrixType::Random(rows, cols),
             m3(rows, cols),
             ones = MatrixType::Ones(rows, cols);
  VectorType v1 = VectorType::Random(rows);

  Scalar s1 = internal::random<Scalar>();

  Index r1 = internal::random<Index>(0,rows-1);
  Index r2 = internal::random<Index>(r1,rows-1);
  Index c1 = internal::random<Index>(0,cols-1);
  Index c2 = internal::random<Index>(c1,cols-1);

  block_real_only(m1, r1, r2, c1, c1, s1);

  //check row() and col()
  VERIFY_IS_EQUAL(m1.col(c1).transpose(), m1.transpose().row(c1));
  //check operator(), both constant and non-constant, on row() and col()
  m1 = m1_copy;
  m1.row(r1) += s1 * m1_copy.row(r2);
  VERIFY_IS_APPROX(m1.row(r1), m1_copy.row(r1) + s1 * m1_copy.row(r2));
  // check nested block xpr on lhs
  m1.row(r1).row(0) += s1 * m1_copy.row(r2);
  VERIFY_IS_APPROX(m1.row(r1), m1_copy.row(r1) + Scalar(2) * s1 * m1_copy.row(r2));
  m1 = m1_copy;
  m1.col(c1) += s1 * m1_copy.col(c2);
  VERIFY_IS_APPROX(m1.col(c1), m1_copy.col(c1) + s1 * m1_copy.col(c2));
  m1.col(c1).col(0) += s1 * m1_copy.col(c2);
  VERIFY_IS_APPROX(m1.col(c1), m1_copy.col(c1) + Scalar(2) * s1 * m1_copy.col(c2));

  check_left_top(m1,r1,c1,rows,cols);
  
  //check block()
  Matrix<Scalar,Dynamic,Dynamic> b1(1,1); b1(0,0) = m1(r1,c1);

  RowVectorType br1(m1.block(r1,0,1,cols));
  VectorType bc1(m1.block(0,c1,rows,1));
  VERIFY_IS_EQUAL(b1, m1.block(r1,c1,1,1));
  VERIFY_IS_EQUAL(m1.row(r1), br1);
  VERIFY_IS_EQUAL(m1.col(c1), bc1);
  //check operator(), both constant and non-constant, on block()
  m1.block(r1,c1,r2-r1+1,c2-c1+1) = s1 * m2.block(0, 0, r2-r1+1,c2-c1+1);
  m1.block(r1,c1,r2-r1+1,c2-c1+1)(r2-r1,c2-c1) = m2.block(0, 0, r2-r1+1,c2-c1+1)(0,0);

  const Index BlockRows = 2;
  const Index BlockCols = 5;

  if (rows>=5 && cols>=8)
  {
    // test fixed block() as lvalue
    m1.template block<BlockRows,BlockCols>(1,1) *= s1;
    // test operator() on fixed block() both as constant and non-constant
    m1.template block<BlockRows,BlockCols>(1,1)(0, 3) = m1.template block<2,5>(1,1)(1,2);
    // check that fixed block() and block() agree
    Matrix<Scalar,Dynamic,Dynamic> b = m1.template block<BlockRows,BlockCols>(3,3);
    VERIFY_IS_EQUAL(b, m1.block(3,3,BlockRows,BlockCols));

    // same tests with mixed fixed/dynamic size
    m1.template block<BlockRows,Dynamic>(1,1,BlockRows,BlockCols) *= s1;
    m1.template block<BlockRows,Dynamic>(1,1,BlockRows,BlockCols)(0,3) = m1.template block<2,5>(1,1)(1,2);
    Matrix<Scalar,Dynamic,Dynamic> b2 = m1.template block<Dynamic,BlockCols>(3,3,2,5);
    VERIFY_IS_EQUAL(b2, m1.block(3,3,BlockRows,BlockCols));

    VERIFY(is_same_block(m1.block(3,3,BlockRows,BlockCols), m1.block(3,3,fix<Dynamic>(BlockRows),fix<Dynamic>(BlockCols))));
    VERIFY(is_same_block(m1.template block<BlockRows,Dynamic>(1,1,BlockRows,BlockCols), m1.block(1,1,fix<BlockRows>,BlockCols)));
    VERIFY(is_same_block(m1.template block<BlockRows,BlockCols>(1,1,BlockRows,BlockCols), m1.block(1,1,fix<BlockRows>(),fix<BlockCols>)));
    VERIFY(is_same_block(m1.template block<BlockRows,BlockCols>(1,1,BlockRows,BlockCols), m1.block(1,1,fix<BlockRows>,fix<BlockCols>(BlockCols))));
  }

  if (rows>2)
  {
    // test sub vectors
    VERIFY_IS_EQUAL(v1.template head<2>(), v1.block(0,0,2,1));
    VERIFY_IS_EQUAL(v1.template head<2>(), v1.head(2));
    VERIFY_IS_EQUAL(v1.template head<2>(), v1.segment(0,2));
    VERIFY_IS_EQUAL(v1.template head<2>(), v1.template segment<2>(0));
    Index i = rows-2;
    VERIFY_IS_EQUAL(v1.template tail<2>(), v1.block(i,0,2,1));
    VERIFY_IS_EQUAL(v1.template tail<2>(), v1.tail(2));
    VERIFY_IS_EQUAL(v1.template tail<2>(), v1.segment(i,2));
    VERIFY_IS_EQUAL(v1.template tail<2>(), v1.template segment<2>(i));
    i = internal::random<Index>(0,rows-2);
    VERIFY_IS_EQUAL(v1.segment(i,2), v1.template segment<2>(i));
  }

  // stress some basic stuffs with block matrices
  VERIFY_IS_EQUAL(numext::real(ones.col(c1).sum()), RealScalar(rows));
  VERIFY_IS_EQUAL(numext::real(ones.row(r1).sum()), RealScalar(cols));

  VERIFY_IS_EQUAL(numext::real(ones.col(c1).dot(ones.col(c2))), RealScalar(rows));
  VERIFY_IS_EQUAL(numext::real(ones.row(r1).dot(ones.row(r2))), RealScalar(cols));
  
  // check that linear acccessors works on blocks
  m1 = m1_copy;

  // now test some block-inside-of-block.
  
  // expressions with direct access
  VERIFY_IS_EQUAL( (m1.block(r1,c1,rows-r1,cols-c1).block(r2-r1,c2-c1,rows-r2,cols-c2)) , (m1.block(r2,c2,rows-r2,cols-c2)) );
  VERIFY_IS_EQUAL( (m1.block(r1,c1,r2-r1+1,c2-c1+1).row(0)) , (m1.row(r1).segment(c1,c2-c1+1)) );
  VERIFY_IS_EQUAL( (m1.block(r1,c1,r2-r1+1,c2-c1+1).col(0)) , (m1.col(c1).segment(r1,r2-r1+1)) );
  VERIFY_IS_EQUAL( (m1.block(r1,c1,r2-r1+1,c2-c1+1).transpose().col(0)) , (m1.row(r1).segment(c1,c2-c1+1)).transpose() );
  VERIFY_IS_EQUAL( (m1.transpose().block(c1,r1,c2-c1+1,r2-r1+1).col(0)) , (m1.row(r1).segment(c1,c2-c1+1)).transpose() );

  // expressions without direct access
  VERIFY_IS_APPROX( ((m1+m2).block(r1,c1,rows-r1,cols-c1).block(r2-r1,c2-c1,rows-r2,cols-c2)) , ((m1+m2).block(r2,c2,rows-r2,cols-c2)) );
  VERIFY_IS_APPROX( ((m1+m2).block(r1,c1,r2-r1+1,c2-c1+1).row(0)) , ((m1+m2).row(r1).segment(c1,c2-c1+1)) );
  VERIFY_IS_APPROX( ((m1+m2).block(r1,c1,r2-r1+1,c2-c1+1).row(0)) , ((m1+m2).eval().row(r1).segment(c1,c2-c1+1)) );
  VERIFY_IS_APPROX( ((m1+m2).block(r1,c1,r2-r1+1,c2-c1+1).col(0)) , ((m1+m2).col(c1).segment(r1,r2-r1+1)) );
  VERIFY_IS_APPROX( ((m1+m2).block(r1,c1,r2-r1+1,c2-c1+1).transpose().col(0)) , ((m1+m2).row(r1).segment(c1,c2-c1+1)).transpose() );
  VERIFY_IS_APPROX( ((m1+m2).transpose().block(c1,r1,c2-c1+1,r2-r1+1).col(0)) , ((m1+m2).row(r1).segment(c1,c2-c1+1)).transpose() );
  VERIFY_IS_APPROX( ((m1+m2).template block<Dynamic,1>(r1,c1,r2-r1+1,1)) , ((m1+m2).eval().col(c1).eval().segment(r1,r2-r1+1)) );
  VERIFY_IS_APPROX( ((m1+m2).template block<1,Dynamic>(r1,c1,1,c2-c1+1)) , ((m1+m2).eval().row(r1).eval().segment(c1,c2-c1+1)) );
  VERIFY_IS_APPROX( ((m1+m2).transpose().template block<1,Dynamic>(c1,r1,1,r2-r1+1)) , ((m1+m2).eval().col(c1).eval().segment(r1,r2-r1+1)).transpose() );
  VERIFY_IS_APPROX( (m1+m2).row(r1).eval(), (m1+m2).eval().row(r1) );
  VERIFY_IS_APPROX( (m1+m2).adjoint().col(r1).eval(), (m1+m2).adjoint().eval().col(r1) );
  VERIFY_IS_APPROX( (m1+m2).adjoint().row(c1).eval(), (m1+m2).adjoint().eval().row(c1) );
  VERIFY_IS_APPROX( (m1*1).row(r1).segment(c1,c2-c1+1).eval(), m1.row(r1).eval().segment(c1,c2-c1+1).eval() );
  VERIFY_IS_APPROX( m1.col(c1).reverse().segment(r1,r2-r1+1).eval(),m1.col(c1).reverse().eval().segment(r1,r2-r1+1).eval() );

  VERIFY_IS_APPROX( (m1*1).topRows(r1),  m1.topRows(r1) );
  VERIFY_IS_APPROX( (m1*1).leftCols(c1), m1.leftCols(c1) );
  VERIFY_IS_APPROX( (m1*1).transpose().topRows(c1), m1.transpose().topRows(c1) );
  VERIFY_IS_APPROX( (m1*1).transpose().leftCols(r1), m1.transpose().leftCols(r1) );
  VERIFY_IS_APPROX( (m1*1).transpose().middleRows(c1,c2-c1+1), m1.transpose().middleRows(c1,c2-c1+1) );
  VERIFY_IS_APPROX( (m1*1).transpose().middleCols(r1,r2-r1+1), m1.transpose().middleCols(r1,r2-r1+1) );

  // evaluation into plain matrices from expressions with direct access (stress MapBase)
  DynamicMatrixType dm;
  DynamicVectorType dv;
  dm.setZero();
  dm = m1.block(r1,c1,rows-r1,cols-c1).block(r2-r1,c2-c1,rows-r2,cols-c2);
  VERIFY_IS_EQUAL(dm, (m1.block(r2,c2,rows-r2,cols-c2)));
  dm.setZero();
  dv.setZero();
  dm = m1.block(r1,c1,r2-r1+1,c2-c1+1).row(0).transpose();
  dv = m1.row(r1).segment(c1,c2-c1+1);
  VERIFY_IS_EQUAL(dv, dm);
  dm.setZero();
  dv.setZero();
  dm = m1.col(c1).segment(r1,r2-r1+1);
  dv = m1.block(r1,c1,r2-r1+1,c2-c1+1).col(0);
  VERIFY_IS_EQUAL(dv, dm);
  dm.setZero();
  dv.setZero();
  dm = m1.block(r1,c1,r2-r1+1,c2-c1+1).transpose().col(0);
  dv = m1.row(r1).segment(c1,c2-c1+1);
  VERIFY_IS_EQUAL(dv, dm);
  dm.setZero();
  dv.setZero();
  dm = m1.row(r1).segment(c1,c2-c1+1).transpose();
  dv = m1.transpose().block(c1,r1,c2-c1+1,r2-r1+1).col(0);
  VERIFY_IS_EQUAL(dv, dm);

  VERIFY_IS_EQUAL( (m1.template block<Dynamic,1>(1,0,0,1)), m1.block(1,0,0,1));
  VERIFY_IS_EQUAL( (m1.template block<1,Dynamic>(0,1,1,0)), m1.block(0,1,1,0));
  VERIFY_IS_EQUAL( ((m1*1).template block<Dynamic,1>(1,0,0,1)), m1.block(1,0,0,1));
  VERIFY_IS_EQUAL( ((m1*1).template block<1,Dynamic>(0,1,1,0)), m1.block(0,1,1,0));

  VERIFY_IS_EQUAL( m1.template subVector<Horizontal>(r1), m1.row(r1) );
  VERIFY_IS_APPROX( (m1+m1).template subVector<Horizontal>(r1), (m1+m1).row(r1) );
  VERIFY_IS_EQUAL( m1.template subVector<Vertical>(c1), m1.col(c1) );
  VERIFY_IS_APPROX( (m1+m1).template subVector<Vertical>(c1), (m1+m1).col(c1) );
  VERIFY_IS_EQUAL( m1.template subVectors<Horizontal>(), m1.rows() );
  VERIFY_IS_EQUAL( m1.template subVectors<Vertical>(), m1.cols() );

  if (rows>=2 || cols>=2) {
    VERIFY_IS_EQUAL( int(m1.middleCols(0,0).IsRowMajor), int(m1.IsRowMajor) );
    VERIFY_IS_EQUAL( m1.middleCols(0,0).outerSize(), m1.IsRowMajor ? rows : 0);
    VERIFY_IS_EQUAL( m1.middleCols(0,0).innerSize(), m1.IsRowMajor ? 0 : rows);

    VERIFY_IS_EQUAL( int(m1.middleRows(0,0).IsRowMajor), int(m1.IsRowMajor) );
    VERIFY_IS_EQUAL( m1.middleRows(0,0).outerSize(), m1.IsRowMajor ? 0 : cols);
    VERIFY_IS_EQUAL( m1.middleRows(0,0).innerSize(), m1.IsRowMajor ? cols : 0);
  }
}


template<typename MatrixType>
std::enable_if_t<MatrixType::IsVectorAtCompileTime,void>
compare_using_data_and_stride(const MatrixType& m)
{
  Index rows = m.rows();
  Index cols = m.cols();
  Index size = m.size();
  Index innerStride = m.innerStride();
  Index rowStride = m.rowStride();
  Index colStride = m.colStride();
  const typename MatrixType::Scalar* data = m.data();

  for(int j=0;j<cols;++j)
    for(int i=0;i<rows;++i)
      VERIFY(m.coeff(i,j) == data[i*rowStride + j*colStride]);

  VERIFY(innerStride == int((&m.coeff(1))-(&m.coeff(0))));
  for (int i=0;i<size;++i)
    VERIFY(m.coeff(i) == data[i*innerStride]);
}

template<typename MatrixType>
std::enable_if_t<!MatrixType::IsVectorAtCompileTime,void>
compare_using_data_and_stride(const MatrixType& m)
{
  Index rows = m.rows();
  Index cols = m.cols();
  Index innerStride = m.innerStride();
  Index outerStride = m.outerStride();
  Index rowStride = m.rowStride();
  Index colStride = m.colStride();
  const typename MatrixType::Scalar* data = m.data();

  for(int j=0;j<cols;++j)
    for(int i=0;i<rows;++i)
      VERIFY(m.coeff(i,j) == data[i*rowStride + j*colStride]);

  for(int j=0;j<cols;++j)
    for(int i=0;i<rows;++i)
      VERIFY(m.coeff(i,j) == data[(MatrixType::Flags&RowMajorBit)
                                  ? i*outerStride + j*innerStride
                                  : j*outerStride + i*innerStride]);
}

template<typename MatrixType>
void data_and_stride(const MatrixType& m)
{
  Index rows = m.rows();
  Index cols = m.cols();

  Index r1 = internal::random<Index>(0,rows-1);
  Index r2 = internal::random<Index>(r1,rows-1);
  Index c1 = internal::random<Index>(0,cols-1);
  Index c2 = internal::random<Index>(c1,cols-1);

  MatrixType m1 = MatrixType::Random(rows, cols);
  compare_using_data_and_stride(m1.block(r1, c1, r2-r1+1, c2-c1+1));
  compare_using_data_and_stride(m1.transpose().block(c1, r1, c2-c1+1, r2-r1+1));
  compare_using_data_and_stride(m1.row(r1));
  compare_using_data_and_stride(m1.col(c1));
  compare_using_data_and_stride(m1.row(r1).transpose());
  compare_using_data_and_stride(m1.col(c1).transpose());
}


template <typename BaseXpr, typename Xpr = BaseXpr, int Depth = 0>
struct unwind_test_impl {
  static void run(Xpr& xpr) {
    Index startRow = internal::random<Index>(0, xpr.rows() / 5);
    Index startCol = internal::random<Index>(0, xpr.cols() / 6);
    Index rows = xpr.rows() / 3;
    Index cols = xpr.cols() / 2;
    // test equivalence of const expressions
    const Block<const Xpr> constNestedBlock(xpr, startRow, startCol, rows, cols);
    const Block<const BaseXpr> constUnwoundBlock = constNestedBlock.unwind();
    VERIFY_IS_CWISE_EQUAL(constNestedBlock, constUnwoundBlock);
    // modify a random element in each representation and test equivalence of non-const expressions
    Block<Xpr> nestedBlock(xpr, startRow, startCol, rows, cols);
    Block<BaseXpr> unwoundBlock = nestedBlock.unwind();
    Index r1 = internal::random<Index>(0, rows - 1);
    Index c1 = internal::random<Index>(0, cols - 1);
    Index r2 = internal::random<Index>(0, rows - 1);
    Index c2 = internal::random<Index>(0, cols - 1);
    nestedBlock.coeffRef(r1, c1) = internal::random<typename DenseBase<Xpr>::Scalar>();
    unwoundBlock.coeffRef(r2, c2) = internal::random<typename DenseBase<Xpr>::Scalar>();
    VERIFY_IS_CWISE_EQUAL(nestedBlock, unwoundBlock);
    unwind_test_impl<BaseXpr, Block<Xpr>, Depth + 1>::run(nestedBlock);
  }
};

template <typename BaseXpr, typename Xpr>
struct unwind_test_impl<BaseXpr, Xpr, 4> {
  static void run(const Xpr&) {}
};

template <typename BaseXpr>
void unwind_test(const BaseXpr&) {
  BaseXpr xpr = BaseXpr::Random(100, 100);
  unwind_test_impl<BaseXpr>::run(xpr);
}

EIGEN_DECLARE_TEST(block)
{
  for(int i = 0; i < g_repeat; i++) {
    CALL_SUBTEST_1( block(Matrix<float, 1, 1>()) );
    CALL_SUBTEST_1( block(Matrix<float, 1, Dynamic>(internal::random(2,50))) );
    CALL_SUBTEST_1( block(Matrix<float, Dynamic, 1>(internal::random(2,50))) );
    CALL_SUBTEST_2( block(Matrix4d()) );
    CALL_SUBTEST_3( block(MatrixXcf(internal::random(2,50), internal::random(2,50))) );
    CALL_SUBTEST_4( block(MatrixXi(internal::random(2,50), internal::random(2,50))) );
    CALL_SUBTEST_5( block(MatrixXcd(internal::random(2,50), internal::random(2,50))) );
    CALL_SUBTEST_6( block(MatrixXf(internal::random(2,50), internal::random(2,50))) );
    CALL_SUBTEST_7( block(Matrix<int,Dynamic,Dynamic,RowMajor>(internal::random(2,50), internal::random(2,50))) );

    CALL_SUBTEST_8( block(Matrix<float,Dynamic,4>(3, 4)) );
    CALL_SUBTEST_9( unwind_test(MatrixXf()));

#ifndef EIGEN_DEFAULT_TO_ROW_MAJOR
    CALL_SUBTEST_6( data_and_stride(MatrixXf(internal::random(5,50), internal::random(5,50))) );
    CALL_SUBTEST_7( data_and_stride(Matrix<int,Dynamic,Dynamic,RowMajor>(internal::random(5,50), internal::random(5,50))) );
#endif
  }
}