//
//  matrix_test.cpp
//  matrix
//
//  Created by Sam Jaffe on 6/3/18.
//

#include <gmock/gmock.h>

#include "math/matrix/matrix.hpp"

using matr2i = math::matrix::matrix<int, 2, 2>;
using matr2 = math::matrix::matrix<double, 2, 2>;

matr2i identity2i() { return matr2i({{{1, 0}, {0, 1}}}); }
matr2 identity2() { return matr2({{{1, 0}, {0, 1}}}); }

TEST(Matrix, Equality) {
  EXPECT_THAT(identity2i(), matr2i({{{1, 0}, {0, 1}}}));
  EXPECT_THAT(identity2i(), ::testing::Ne(matr2i({{{0, 1}, {0, 1}}})));
}

TEST(Matrix, AtRowBeyondBoundaryThrowsException) {
  EXPECT_THROW(identity2i().at(2), std::out_of_range);
}

TEST(Matrix, ConstAtRowBeyondBoundaryThrowsException) {
  auto const iden = identity2i();
  EXPECT_THROW(iden.at(2), std::out_of_range);
}

TEST(Matrix, AtCoordBeyondBoundaryThrowsException) {
  EXPECT_THROW(identity2i().at(2, 1), std::out_of_range);
  EXPECT_THROW(identity2i().at(1, 2), std::out_of_range);
}

TEST(Matrix, ConstAtCoordBeyondBoundaryThrowsException) {
  auto const iden = identity2i();
  EXPECT_THROW(iden.at(2, 1), std::out_of_range);
  EXPECT_THROW(iden.at(1, 2), std::out_of_range);
}

TEST(Matrix, AtColumnBeyondBoundaryThrowsException) {
  auto iden = identity2i();
  auto row = iden[1];
  EXPECT_THROW(row.at(2), std::out_of_range);
}

TEST(Matrix, ConstAtColumnBeyondBoundaryThrowsException) {
  auto const iden = identity2i();
  auto const row = iden[1];
  EXPECT_THROW(row.at(2), std::out_of_range);
}

TEST(Matrix, TransposeOfSquareMatrixRotatesAroundDiagonal) {
  matr2i mat({{{1, 1}, {2, 2}}});
  EXPECT_THAT(mat.transpose(), matr2i({{{1, 2}, {1, 2}}}));
}

TEST(Matrix, TransposeOfMatrixFlipsDimension) {
  using matr3x2i = math::matrix::matrix<int, 3, 2>;
  using matr2x3i = math::matrix::matrix<int, 2, 3>;
  matr3x2i mat({{{1, 1}, {2, 2}, {3, 3}}});
  EXPECT_THAT(mat.transpose(), matr2x3i({{{1, 2, 3}, {1, 2, 3}}}));
}

TEST(Matrix, AdditionSumsAllElements) {
  auto iden = identity2i();
  auto result = matr2i({{{2, 0}, {0, 2}}});
  EXPECT_THAT(iden + iden, result);
}

TEST(Matrix, DefaultConstructorIsZeros) {
  auto zero = matr2i({{{0, 0}, {0, 0}}});
  EXPECT_THAT(matr2i{}, zero);
}

TEST(Matrix, SubtractionDiffsAllElements) {
  auto iden = identity2i();
  EXPECT_THAT(iden - iden, matr2i());
}

TEST(Matrix, NegationAltersAllElements) {
  EXPECT_THAT(-identity2i(), matr2i({{{-1, 0}, {0, -1}}}));
}

TEST(Matrix, MultiplicationAltersAllElements) {
  EXPECT_THAT(2 * identity2(), matr2({{{2.0, 0.0}, {0.0, 2.0}}}));
  EXPECT_THAT(identity2() * 2, matr2({{{2.0, 0.0}, {0.0, 2.0}}}));
}

TEST(Matrix, DivisionAltersAllElements) {
  EXPECT_THAT(identity2() / 2.0, matr2({{{0.5, 0.0}, {0.0, 0.5}}}));
}

TEST(Matrix, MultiplyingSameSizeMatricesProducesSameSize) {
  auto A = matr2i({{{1, 2}, {2, 3}}});
  auto B = matr2i({{{1, 0}, {1, 1}}});
  EXPECT_THAT(A * B, matr2i({{{3, 2}, {5, 3}}}));
  EXPECT_THAT(B * A, matr2i({{{1, 2}, {3, 5}}}));
}

TEST(Matrix, MultiplyingDifferentSizeMatricesChangesSize) {
  using matr2x2i = math::matrix::matrix<int, 2, 2>;
  using matr2x3i = math::matrix::matrix<int, 2, 3>;
  using matr3x2i = math::matrix::matrix<int, 3, 2>;
  using matr3x3i = math::matrix::matrix<int, 3, 3>;
  auto A = matr3x2i({{{1, 0}, {0, 1}, {1, 1}}});
  auto B = matr2x3i({{{0, 1, 0}, {1, 0, 1}}});
  EXPECT_THAT(A * B, matr3x3i({{{0, 1, 0}, {1, 0, 1}, {1, 1, 1}}}));
  EXPECT_THAT(B * A, matr2x2i({{{0, 1}, {2, 1}}}));
}

TEST(Matrix, VectorMultiplicationProducesVector) {
  using vec2i = math::vector::vector<int, 2>;
  auto A = matr2i({{{1, 0}, {1, 2}}});
  auto x = vec2i({1, 2});
  EXPECT_THAT(A * x, vec2i({1, 5}));
}

TEST(Matrix, ConcatenationExtends) {
  using namespace math::matrix;
  auto A = matr2i({{{1, 2}, {2, 3}}});
  auto B = matr2i({{{1, 0}, {1, 1}}});
  EXPECT_THAT(A.concat(B, concat_strategy::horizontal),
              (matrix<int, 2, 4>({{{1, 2, 1, 0}, {2, 3, 1, 1}}})));
  EXPECT_THAT(A.concat(B, concat_strategy::vertical),
              (matrix<int, 4, 2>({{{1, 2}, {2, 3}, {1, 0}, {1, 1}}})));
  EXPECT_THAT(A.concat(B, concat_strategy::diagonal),
              (matrix<int, 4, 4>(
                  {{{1, 2, 0, 0}, {2, 3, 0, 0}, {0, 0, 1, 0}, {0, 0, 1, 1}}})));
}

// TEST(Matrix, Composition) {
//  using namespace math::matrix;
//  using vec4 = math::vector::vector<double, 4>;
//  using vec3 = math::vector::vector<double, 3>;
//  auto rot = rotation<4>(math::degree{90}, rotate::X_AXIS);
//  auto mov = translation(vec3({2.0, 2.5, 1.5}));
//  auto scl = scalar(vec3(2.0, math::vector::fill));
//  vec4 epsilon{0.00001, math::vector::fill};
//  TS_ASSERT_DELTA((mov * scl * rot * vec4({1,2,3,1})),
//                  (vec4({4.0,-1.5,-4.5,1.0})),
//                  epsilon);
//}

TEST(Matrix, MatrixConstructableFromVector) {
  using vec3 = math::vector::vector<double, 3>;
  vec3 v = vec3({1, 2, 3});
  math::matrix::matrix<double, 3, 1> m{v};
  EXPECT_THAT(m(0, 0), v[0]);
  EXPECT_THAT(m(1, 0), v[1]);
  EXPECT_THAT(m(2, 0), v[2]);
}

TEST(Matrix, RowAllowsMutation) {
  matr2i A = identity2i();
  A[0][0] = 2;
  EXPECT_THAT(A, matr2i({{{2, 0}, {0, 1}}}));
}

TEST(Matrix, CanAlterEntireRowInOneExpression) {
  matr2i A = identity2i();
  matr2i const B = 2 * A;
  A[0] = B[0];
  EXPECT_THAT(A, matr2i({{{2, 0}, {0, 1}}}));
}