// Copyright 2016 The Chromium 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 "mojo/services/media/common/cpp/timeline_function.h"
#include "services/media/common/test/test_base.h"

namespace mojo {
namespace media {
namespace {

class TimelineFunctionTest : public TestBase {
 public:
  // Verifies that a TimelineFunction instantiated in three different ways with
  // the given arguments has the expected properties.
  void VerifyBasics(int64_t reference_time,
                    int64_t subject_time,
                    uint32_t reference_delta,
                    uint32_t subject_delta) {
    TimelineFunction under_test_1(reference_time, subject_time, reference_delta,
                                  subject_delta);
    VerifyBasics(under_test_1, reference_time, subject_time, reference_delta,
                 subject_delta);

    TimelineFunction under_test_2(reference_time, subject_time,
                                  TimelineRate(subject_delta, reference_delta));
    VerifyBasics(under_test_2, reference_time, subject_time, reference_delta,
                 subject_delta);

    TimelineFunction under_test_3(TimelineRate(subject_delta, reference_delta));
    VerifyBasics(under_test_3, 0, 0, reference_delta, subject_delta);

    EXPECT_EQ(under_test_1, under_test_1);
    EXPECT_EQ(under_test_1, under_test_2);
    EXPECT_EQ(under_test_2, under_test_1);
    EXPECT_EQ(under_test_2, under_test_2);

    if (reference_time == 0 && subject_time == 0) {
      EXPECT_EQ(under_test_1, under_test_3);
      EXPECT_EQ(under_test_2, under_test_3);
      EXPECT_EQ(under_test_3, under_test_1);
      EXPECT_EQ(under_test_3, under_test_2);
    } else {
      EXPECT_NE(under_test_1, under_test_3);
      EXPECT_NE(under_test_2, under_test_3);
      EXPECT_NE(under_test_3, under_test_1);
      EXPECT_NE(under_test_3, under_test_2);
    }
  }

  // Verifies that the given TimelineFunction instantiated with the given
  // arguments has the expected properties.
  void VerifyBasics(const TimelineFunction& under_test,
                    int64_t reference_time,
                    int64_t subject_time,
                    uint32_t reference_delta,
                    uint32_t subject_delta) {
    TimelineRate::Reduce(&subject_delta, &reference_delta);
    EXPECT_EQ(reference_time, under_test.reference_time());
    EXPECT_EQ(subject_time, under_test.subject_time());
    EXPECT_EQ(reference_delta, under_test.reference_delta());
    EXPECT_EQ(subject_delta, under_test.subject_delta());
    EXPECT_EQ(reference_delta, under_test.rate().reference_delta());
    EXPECT_EQ(subject_delta, under_test.rate().subject_delta());
  }

  // Verifies that the inverse of a TimelineFunction instantiated in three
  // different ways with the given arguments has the expected properties.
  void VerifyInverse(int64_t reference_time,
                     int64_t subject_time,
                     uint32_t reference_delta,
                     uint32_t subject_delta) {
    TimelineFunction under_test_1(reference_time, subject_time, reference_delta,
                                  subject_delta);
    VerifyBasics(under_test_1.Inverse(), subject_time, reference_time,
                 subject_delta, reference_delta);

    TimelineFunction under_test_2(reference_time, subject_time,
                                  TimelineRate(subject_delta, reference_delta));
    VerifyBasics(under_test_2.Inverse(), subject_time, reference_time,
                 subject_delta, reference_delta);

    TimelineFunction under_test_3(TimelineRate(subject_delta, reference_delta));
    VerifyBasics(under_test_3.Inverse(), 0, 0, subject_delta, reference_delta);
  }

  // Verifies that TimelineFunction::Apply, in its various forms, works as
  // expected for the given arguments.
  void VerifyApply(int64_t reference_time,
                   int64_t subject_time,
                   uint32_t reference_delta,
                   uint32_t subject_delta,
                   int64_t reference_input,
                   int64_t expected_result) {
    // Verify the static method.
    EXPECT_EQ(expected_result, TimelineFunction::Apply(
                                   reference_time, subject_time,
                                   TimelineRate(subject_delta, reference_delta),
                                   reference_input));

    // Verify the instance method.
    TimelineFunction under_test(reference_time, subject_time, reference_delta,
                                subject_delta);
    EXPECT_EQ(expected_result, under_test.Apply(reference_input));

    // Verify the operator.
    EXPECT_EQ(expected_result, under_test(reference_input));
  }

  // Verifies that TimelineFunction::ApplyInverse, in its various forms, works
  // as
  // expected for the given arguments.
  void VerifyApplyInverse(int64_t reference_time,
                          int64_t subject_time,
                          uint32_t reference_delta,
                          uint32_t subject_delta,
                          int64_t subject_input,
                          int64_t expected_result) {
    // Verify the static method.
    EXPECT_EQ(expected_result,
              TimelineFunction::ApplyInverse(
                  reference_time, subject_time,
                  TimelineRate(subject_delta, reference_delta), subject_input));

    // Verify the instance method.
    TimelineFunction under_test(reference_time, subject_time, reference_delta,
                                subject_delta);
    EXPECT_EQ(expected_result, under_test.ApplyInverse(subject_input));
  }

  // Verifies that TimelineFunction::Compose works as expected with the given
  // inputs.
  void VerifyCompose(const TimelineFunction& a,
                     const TimelineFunction& b,
                     bool exact,
                     const TimelineFunction& expected_result) {
    // Verify the static method.
    EXPECT_EQ(expected_result, TimelineFunction::Compose(a, b, exact));
  }
};

// Tests TimelineFunction basics for various instantiation arguments.
TEST_F(TimelineFunctionTest, Basics) {
  VerifyBasics(0, 0, 1, 0);
  VerifyBasics(0, 0, 1, 1);
  VerifyBasics(1, 1, 10, 10);
  VerifyBasics(1234, 5678, 4321, 8765);
  VerifyBasics(-1234, 5678, 4321, 8765);
  VerifyBasics(-1234, -5678, 4321, 8765);
  VerifyBasics(1234, -5678, 4321, 8765);
}

// Tests TimelineFunction::Inverse.
TEST_F(TimelineFunctionTest, Inverse) {
  VerifyInverse(0, 0, 1, 1);
  VerifyInverse(1, 1, 10, 10);
  VerifyInverse(1234, 5678, 4321, 8765);
  VerifyInverse(-1234, 5678, 4321, 8765);
  VerifyInverse(-1234, -5678, 4321, 8765);
  VerifyInverse(1234, -5678, 4321, 8765);
}

// Tests TimelineFunction::Apply in its variations.
TEST_F(TimelineFunctionTest, Apply) {
  VerifyApply(0, 0, 1, 0, 0, 0);
  VerifyApply(0, 0, 1, 0, 1000, 0);
  VerifyApply(0, 1234, 1, 0, 0, 1234);
  VerifyApply(0, 1234, 1, 0, 1000, 1234);
  VerifyApply(0, 1234, 1, 0, -1000, 1234);
  VerifyApply(0, -1234, 1, 0, 0, -1234);
  VerifyApply(0, -1234, 1, 0, 1000, -1234);
  VerifyApply(0, -1234, 1, 0, -1000, -1234);
  VerifyApply(0, 0, 1, 1, 0, 0);
  VerifyApply(0, 0, 1, 1, 1000, 1000);
  VerifyApply(0, 1234, 1, 1, 0, 1234);
  VerifyApply(0, 1234, 1, 1, 1000, 2234);
  VerifyApply(0, 1234, 1, 1, -1000, 234);
  VerifyApply(0, -1234, 1, 1, 0, -1234);
  VerifyApply(0, -1234, 1, 1, 1000, -234);
  VerifyApply(0, -1234, 1, 1, -1000, -2234);
  VerifyApply(10, 0, 1, 0, 0, 0);
  VerifyApply(10, 0, 1, 1, 0, -10);
  VerifyApply(-10, 0, 1, 0, 0, 0);
  VerifyApply(-10, 0, 1, 1, 0, 10);
  VerifyApply(0, 1234, 2, 1, 0, 1234);
  VerifyApply(0, 1234, 2, 1, 1234, 1234 + 1234 / 2);
  VerifyApply(0, 1234, 1, 2, 1234, 1234 + 1234 * 2);
}

// Tests TimelineFunction::Apply in its variations.
TEST_F(TimelineFunctionTest, ApplyInverse) {
  VerifyApplyInverse(0, 0, 1, 1, 0, 0);
  VerifyApplyInverse(0, 0, 1, 1, 1000, 1000);
  VerifyApplyInverse(0, 1234, 1, 1, 1234, 0);
  VerifyApplyInverse(0, 1234, 1, 1, 2234, 1000);
  VerifyApplyInverse(0, 1234, 1, 1, 234, -1000);
  VerifyApplyInverse(0, -1234, 1, 1, -1234, 0);
  VerifyApplyInverse(0, -1234, 1, 1, -234, 1000);
  VerifyApplyInverse(0, -1234, 1, 1, -2234, -1000);
  VerifyApplyInverse(10, 0, 1, 1, -10, 0);
  VerifyApplyInverse(-10, 0, 1, 1, 10, 0);
  VerifyApplyInverse(0, 1234, 2, 1, 1234, 0);
  VerifyApplyInverse(0, 1234, 2, 1, 1234 + 1234 / 2, 1234);
  VerifyApplyInverse(0, 1234, 1, 2, 1234 + 1234 * 2, 1234);
}

// Tests TimelineFunction::Compose.
TEST_F(TimelineFunctionTest, Compose) {
  VerifyCompose(TimelineFunction(0, 0, 1, 0), TimelineFunction(0, 0, 1, 0),
                true, TimelineFunction(0, 0, 1, 0));
  VerifyCompose(TimelineFunction(0, 0, 1, 1), TimelineFunction(0, 0, 1, 1),
                true, TimelineFunction(0, 0, 1, 1));
  VerifyCompose(TimelineFunction(1, 0, 1, 1), TimelineFunction(0, 0, 1, 1),
                true, TimelineFunction(0, -1, 1, 1));
  VerifyCompose(TimelineFunction(10, 10, 1, 1), TimelineFunction(0, 0, 1, 1),
                true, TimelineFunction(0, 0, 1, 1));
  VerifyCompose(TimelineFunction(0, 0, 1, 2), TimelineFunction(0, 0, 1, 2),
                true, TimelineFunction(0, 0, 1, 4));
  VerifyCompose(TimelineFunction(0, 0, 2, 1), TimelineFunction(0, 0, 2, 1),
                true, TimelineFunction(0, 0, 4, 1));
  VerifyCompose(TimelineFunction(0, 0, 2, 1), TimelineFunction(0, 0, 1, 2),
                true, TimelineFunction(0, 0, 1, 1));
}

}  // namespace
}  // namespace media
}  // namespace mojo