// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "gtest/gtest.h"

#include "flutter/impeller/geometry/matrix.h"

#include "flutter/impeller/geometry/geometry_asserts.h"
#include "impeller/geometry/constants.h"

namespace impeller {
namespace testing {

TEST(MatrixTest, Multiply) {
  Matrix x(0.0, 0.0, 0.0, 1.0,  //
           1.0, 0.0, 0.0, 1.0,  //
           0.0, 1.0, 0.0, 1.0,  //
           1.0, 1.0, 0.0, 1.0);
  Matrix translate = Matrix::MakeTranslation({10, 20, 0});
  Matrix result = translate * x;
  EXPECT_TRUE(MatrixNear(result, Matrix(10.0, 20.0, 0.0, 1.0,  //
                                        11.0, 20.0, 0.0, 1.0,  //
                                        10.0, 21.0, 0.0, 1.0,  //
                                        11.0, 21.0, 0.0, 1.0)));
}

TEST(MatrixTest, Equals) {
  Matrix x;
  Matrix y = x;
  EXPECT_TRUE(x.Equals(y));
}

TEST(MatrixTest, NotEquals) {
  Matrix x;
  Matrix y = x.Translate({1, 0, 0});
  EXPECT_FALSE(x.Equals(y));
}

TEST(MatrixTest, HasPerspective2D) {
  EXPECT_FALSE(Matrix().HasPerspective2D());

  auto test = [](int index, bool expect) {
    Matrix matrix;
    EXPECT_FALSE(matrix.HasPerspective2D());
    matrix.m[index] = 0.5f;
    EXPECT_EQ(matrix.HasPerspective2D(), expect) << "index: " << index;
  };

  // clang-format off
  test( 0, false);  test( 1, false);  test( 2, false);  test( 3, true);
  test( 4, false);  test( 5, false);  test( 6, false);  test( 7, true);
  test( 8, false);  test( 9, false);  test(10, false);  test(11, false);
  test(12, false);  test(13, false);  test(14, false);  test(15, true);
  // clang-format on
}

TEST(MatrixTest, HasPerspective) {
  EXPECT_FALSE(Matrix().HasPerspective());

  auto test = [](int index, bool expect) {
    Matrix matrix;
    EXPECT_FALSE(matrix.HasPerspective());
    matrix.m[index] = 0.5f;
    EXPECT_EQ(matrix.HasPerspective(), expect) << "index: " << index;
  };

  // clang-format off
  test( 0, false);  test( 1, false);  test( 2, false);  test( 3, true);
  test( 4, false);  test( 5, false);  test( 6, false);  test( 7, true);
  test( 8, false);  test( 9, false);  test(10, false);  test(11, true);
  test(12, false);  test(13, false);  test(14, false);  test(15, true);
  // clang-format on
}

TEST(MatrixTest, HasTranslation) {
  EXPECT_TRUE(Matrix::MakeTranslation({100, 100, 0}).HasTranslation());
  EXPECT_TRUE(Matrix::MakeTranslation({0, 100, 0}).HasTranslation());
  EXPECT_TRUE(Matrix::MakeTranslation({100, 0, 0}).HasTranslation());
  EXPECT_FALSE(Matrix().HasTranslation());
}

TEST(MatrixTest, IsAligned2D) {
  EXPECT_TRUE(Matrix().IsAligned2D());
  EXPECT_TRUE(Matrix::MakeScale({1.0f, 1.0f, 2.0f}).IsAligned2D());

  auto test = [](int index, bool expect) {
    Matrix matrix;
    EXPECT_TRUE(matrix.IsAligned2D());
    matrix.m[index] = 0.5f;
    EXPECT_EQ(matrix.IsAligned2D(), expect) << "index: " << index;
  };

  // clang-format off
  test( 0, true);   test( 1, false);  test( 2, true);   test( 3, false);
  test( 4, false);  test( 5, true);   test( 6, true);   test( 7, false);
  test( 8, true);   test( 9, true);   test(10, true);   test(11, true);
  test(12, true);   test(13, true);   test(14, true);   test(15, false);
  // clang-format on

  // True for quadrant rotations from -250 to +250 full circles
  for (int i = -1000; i < 1000; i++) {
    Degrees d = Degrees(i * 90);
    Matrix matrix = Matrix::MakeRotationZ(Degrees(d));
    EXPECT_TRUE(matrix.IsAligned2D()) << "degrees: " << d.degrees;
  }

  // False for half degree rotations from -999.5 to +1000.5 degrees
  for (int i = -1000; i < 1000; i++) {
    Degrees d = Degrees(i + 0.5f);
    Matrix matrix = Matrix::MakeRotationZ(Degrees(d));
    EXPECT_FALSE(matrix.IsAligned2D()) << "degrees: " << d.degrees;
  }
}

TEST(MatrixTest, IsAligned) {
  EXPECT_TRUE(Matrix().IsAligned());
  EXPECT_TRUE(Matrix::MakeScale({1.0f, 1.0f, 2.0f}).IsAligned());

  // Begin Legacy tests transferred over from geometry_unittests.cc
  {
    auto m = Matrix::MakeTranslation({1, 2, 3});
    bool result = m.IsAligned();
    ASSERT_TRUE(result);
  }

  {
    auto m = Matrix::MakeRotationZ(Degrees{123});
    bool result = m.IsAligned();
    ASSERT_FALSE(result);
  }
  // End Legacy tests transferred over from geometry_unittests.cc

  auto test = [](int index, bool expect) {
    Matrix matrix;
    EXPECT_TRUE(matrix.IsAligned());
    matrix.m[index] = 0.5f;
    EXPECT_EQ(matrix.IsAligned(), expect) << "index: " << index;
  };

  // clang-format off
  test( 0, true);   test( 1, false);  test( 2, false);  test( 3, false);
  test( 4, false);  test( 5, true);   test( 6, false);  test( 7, false);
  test( 8, false);  test( 9, false);  test(10, true);   test(11, false);
  test(12, true);   test(13, true);   test(14, true);   test(15, false);
  // clang-format on

  // True for quadrant rotations from -250 to +250 full circles
  for (int i = -1000; i < 1000; i++) {
    Degrees d = Degrees(i * 90);
    Matrix matrix = Matrix::MakeRotationZ(Degrees(d));
    EXPECT_TRUE(matrix.IsAligned()) << "degrees: " << d.degrees;
  }

  // False for half degree rotations from -999.5 to +1000.5 degrees
  for (int i = -1000; i < 1000; i++) {
    Degrees d = Degrees(i + 0.5f);
    Matrix matrix = Matrix::MakeRotationZ(Degrees(d));
    EXPECT_FALSE(matrix.IsAligned()) << "degrees: " << d.degrees;
  }
}

TEST(MatrixTest, TransformHomogenous) {
  Matrix matrix = Matrix::MakeColumn(
      // clang-format off
       2.0f,  3.0f,  5.0f,  7.0f,
      11.0f, 13.0f, 17.0f, 19.0f,
      23.0f, 29.0f, 31.0f, 37.0f,
      41.0f, 43.0f, 47.0f, 53.0f
      // clang-format on
  );
  EXPECT_EQ(matrix.TransformHomogenous({1.0f, -1.0f}),
            Vector3(32.0f, 33.0f, 41.0f));
}

TEST(MatrixTest, GetMaxBasisXYNegativeScale) {
  Matrix m = Matrix::MakeScale({-2, 1, 1});

  EXPECT_EQ(m.GetMaxBasisLengthXY(), 2);

  m = Matrix::MakeScale({1, -3, 1});

  EXPECT_EQ(m.GetMaxBasisLengthXY(), 3);
}

// Verifies a translate scale matrix doesn't need to compute sqrt(pow(scale, 2))
TEST(MatrixTest, GetMaxBasisXYWithLargeAndSmallScalingFactor) {
  Matrix m = Matrix::MakeScale({2.625e+20, 2.625e+20, 1});
  EXPECT_NEAR(m.GetMaxBasisLengthXY(), 2.625e+20, 1e+20);

  m = Matrix::MakeScale({2.625e-20, 2.625e-20, 1});
  EXPECT_NEAR(m.GetMaxBasisLengthXY(), 2.625e-20, 1e-20);
}

TEST(MatrixTest, GetMaxBasisXYWithLargeAndSmallScalingFactorNonScaleTranslate) {
  Matrix m = Matrix::MakeScale({2.625e+20, 2.625e+20, 1});
  m.e[0][1] = 2;

  EXPECT_TRUE(std::isinf(m.GetMaxBasisLengthXY()));
}

TEST(MatrixTest, TranslateWithPerspective) {
  Matrix m = Matrix::MakeRow(1.0, 0.0, 0.0, 10.0,  //
                             0.0, 1.0, 0.0, 20.0,  //
                             0.0, 0.0, 1.0, 0.0,   //
                             0.0, 2.0, 0.0, 30.0);
  Matrix result = m.Translate({100, 200});
  EXPECT_TRUE(MatrixNear(result, Matrix::MakeRow(1.0, 0.0, 0.0, 110.0,  //
                                                 0.0, 1.0, 0.0, 220.0,  //
                                                 0.0, 0.0, 1.0, 0.0,    //
                                                 0.0, 2.0, 0.0, 430.0)));
}

}  // namespace testing
}  // namespace impeller