// 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 <memory>

#include <string>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/run_loop.h"
#include "base/test/test_message_loop.h"
#include "cobalt/media/base/mock_media_log.h"
#include "cobalt/media/blink/watch_time_reporter.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace cobalt {
namespace media {

constexpr gfx::Size kSizeJustRight = gfx::Size(201, 201);

#define EXPECT_WATCH_TIME(key, value) \
  EXPECT_CALL(*media_log_, OnWatchTimeUpdate(key, value)).RetiresOnSaturation();

#define EXPECT_WATCH_TIME_FINALIZED() \
  EXPECT_CALL(*media_log_, OnWatchTimeFinalized()).RetiresOnSaturation();

#define EXPECT_POWER_WATCH_TIME_FINALIZED() \
  EXPECT_CALL(*media_log_, OnPowerWatchTimeFinalized()).RetiresOnSaturation();

class WatchTimeReporterTest : public testing::Test {
 public:
  WatchTimeReporterTest()
      : media_log_(new testing::StrictMock<WatchTimeLogMonitor>()) {}
  ~WatchTimeReporterTest() override {}

 protected:
  class WatchTimeLogMonitor : public MediaLog {
   public:
    WatchTimeLogMonitor() {}

    void AddEvent(std::unique_ptr<MediaLogEvent> event) override {
      ASSERT_EQ(event->type, MediaLogEvent::Type::WATCH_TIME_UPDATE);

      for (base::DictionaryValue::Iterator it(event->params); !it.IsAtEnd();
           it.Advance()) {
        bool finalize;
        if (it.value().GetAsBoolean(&finalize)) {
          if (it.key() == MediaLog::kWatchTimeFinalize)
            OnWatchTimeFinalized();
          else
            OnPowerWatchTimeFinalized();
          continue;
        }

        double in_seconds;
        ASSERT_TRUE(it.value().GetAsDouble(&in_seconds));
        OnWatchTimeUpdate(it.key(), base::TimeDelta::FromSecondsD(in_seconds));
      }
    }

    MOCK_METHOD0(OnWatchTimeFinalized, void(void));
    MOCK_METHOD0(OnPowerWatchTimeFinalized, void(void));
    MOCK_METHOD2(OnWatchTimeUpdate, void(const std::string&, base::TimeDelta));

   protected:
    ~WatchTimeLogMonitor() override {}

   private:
    DISALLOW_COPY_AND_ASSIGN(WatchTimeLogMonitor);
  };

  void Initialize(bool has_audio, bool has_video, bool is_mse,
                  bool is_encrypted, const gfx::Size& initial_video_size) {
    wtr_.reset(new WatchTimeReporter(
        has_audio, has_video, is_mse, is_encrypted, media_log_,
        initial_video_size,
        base::Bind(&WatchTimeReporterTest::GetCurrentMediaTime,
                   base::Unretained(this))));

    // Setup the reporting interval to be immediate to avoid spinning real time
    // within the unit test.
    wtr_->reporting_interval_ = base::TimeDelta();
  }

  void CycleReportingTimer() {
    base::RunLoop run_loop;
    message_loop_.task_runner()->PostTask(FROM_HERE, run_loop.QuitClosure());
    run_loop.Run();
  }

  bool IsMonitoring() { return wtr_->reporting_timer_.IsRunning(); }

  // We call directly into the reporter for this instead of using an actual
  // PowerMonitorTestSource since that results in a posted tasks which interfere
  // with our ability to test the timer.
  void SetOnBatteryPower(bool on_battery_power) {
    wtr_->is_on_battery_power_ = on_battery_power;
  }

  void OnPowerStateChange(bool on_battery_power) {
    wtr_->OnPowerStateChange(on_battery_power);
  }

  enum {
    // After |test_callback_func| is executed, should watch time continue to
    // accumulate?
    kAccumulationContinuesAfterTest = 1,

    // |test_callback_func| for hysteresis tests enters and exits finalize mode
    // for watch time, not all exits require a new current time update.
    kFinalizeExitDoesNotRequireCurrentTime = 2,

    // During finalize the watch time should not continue on the starting power
    // metric. By default this means the AC metric will be finalized, but if
    // used with |kStartOnBattery| it will be the battery metric.
    kFinalizePowerWatchTime = 4,

    // During finalize the watch time should continue on the metric opposite the
    // starting metric (by default it's AC, it's battery if |kStartOnBattery| is
    // specified.
    kTransitionPowerWatchTime = 8,

    // Indicates that power watch time should be reported to the battery metric.
    kStartOnBattery = 16,

    // Indicates an extra start event may be generated during test execution.
    kFinalizeInterleavedStartEvent = 32,
  };

  template <int TestFlags = 0, typename HysteresisTestCallback>
  void RunHysteresisTest(HysteresisTestCallback test_callback_func) {
    Initialize(true, true, false, false, kSizeJustRight);

    // Setup all current time expectations first since they need to use the
    // InSequence macro for ease of use, but we don't want the watch time
    // expectations to be in sequence (or expectations would depend on sorted
    // order of histogram names).
    constexpr base::TimeDelta kWatchTime1 = base::TimeDelta::FromSeconds(10);
    constexpr base::TimeDelta kWatchTime2 = base::TimeDelta::FromSeconds(12);
    constexpr base::TimeDelta kWatchTime3 = base::TimeDelta::FromSeconds(15);
    constexpr base::TimeDelta kWatchTime4 = base::TimeDelta::FromSeconds(30);
    {
      testing::InSequence s;
      EXPECT_CALL(*this, GetCurrentMediaTime())
          .WillOnce(testing::Return(base::TimeDelta()))
          .WillOnce(testing::Return(kWatchTime1));

      // Setup conditions depending on if the test will not resume watch time
      // accumulation or not; i.e. the finalize criteria will not be undone
      // within the hysteresis time.
      if (TestFlags & kAccumulationContinuesAfterTest) {
        EXPECT_CALL(*this, GetCurrentMediaTime())
            .Times(TestFlags & (kFinalizeExitDoesNotRequireCurrentTime |
                                kFinalizePowerWatchTime)
                       ? 1
                       : 2)
            .WillRepeatedly(testing::Return(kWatchTime2));
        EXPECT_CALL(*this, GetCurrentMediaTime())
            .WillOnce(testing::Return(kWatchTime3));
      } else {
        // Current time should be requested when entering the finalize state.
        EXPECT_CALL(*this, GetCurrentMediaTime())
            .Times(TestFlags & kFinalizeInterleavedStartEvent ? 2 : 1)
            .WillRepeatedly(testing::Return(kWatchTime2));
      }

      if (TestFlags & kTransitionPowerWatchTime) {
        EXPECT_CALL(*this, GetCurrentMediaTime())
            .WillOnce(testing::Return(kWatchTime4));
      }
    }

    wtr_->OnPlaying();
    EXPECT_TRUE(IsMonitoring());
    if (TestFlags & kStartOnBattery)
      SetOnBatteryPower(true);
    else
      ASSERT_FALSE(wtr_->is_on_battery_power_);

    EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kWatchTime1);
    EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoSrc, kWatchTime1);
    EXPECT_WATCH_TIME(TestFlags & kStartOnBattery
                          ? MediaLog::kWatchTimeAudioVideoBattery
                          : MediaLog::kWatchTimeAudioVideoAc,
                      kWatchTime1);
    CycleReportingTimer();

    // Invoke the test.
    test_callback_func();

    const base::TimeDelta kExpectedWatchTime =
        TestFlags & kAccumulationContinuesAfterTest ? kWatchTime3 : kWatchTime2;

    EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kExpectedWatchTime);
    EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoSrc, kExpectedWatchTime);
    EXPECT_WATCH_TIME(
        TestFlags & kStartOnBattery ? MediaLog::kWatchTimeAudioVideoBattery
                                    : MediaLog::kWatchTimeAudioVideoAc,
        TestFlags & kFinalizePowerWatchTime ? kWatchTime2 : kExpectedWatchTime);

    // If we're not testing battery watch time, this is the end of the test.
    if (!(TestFlags & kTransitionPowerWatchTime)) {
      EXPECT_WATCH_TIME_FINALIZED();
      wtr_.reset();
      return;
    }

    ASSERT_TRUE(TestFlags & kAccumulationContinuesAfterTest)
        << "kTransitionPowerWatchTime tests must be done with "
           "kAccumulationContinuesAfterTest";

    EXPECT_POWER_WATCH_TIME_FINALIZED();
    CycleReportingTimer();

    // Run one last cycle that is long enough to trigger a new watch time entry
    // on the opposite of the current power watch time graph; i.e. if we started
    // on battery we'll now record one for ac and vice versa.
    EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kWatchTime4);
    EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoSrc, kWatchTime4);
    EXPECT_WATCH_TIME(TestFlags & kStartOnBattery
                          ? MediaLog::kWatchTimeAudioVideoAc
                          : MediaLog::kWatchTimeAudioVideoBattery,
                      kWatchTime4 - kWatchTime2);
    EXPECT_WATCH_TIME_FINALIZED();
    wtr_.reset();
  }

  MOCK_METHOD0(GetCurrentMediaTime, base::TimeDelta());

  base::TestMessageLoop message_loop_;
  scoped_refptr<testing::StrictMock<WatchTimeLogMonitor>> media_log_;
  std::unique_ptr<WatchTimeReporter> wtr_;

 private:
  DISALLOW_COPY_AND_ASSIGN(WatchTimeReporterTest);
};

// Tests that watch time reporting is appropriately enabled or disabled.
TEST_F(WatchTimeReporterTest, WatchTimeReporter) {
  EXPECT_CALL(*this, GetCurrentMediaTime())
      .WillRepeatedly(testing::Return(base::TimeDelta()));

  Initialize(false, true, true, true, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_FALSE(IsMonitoring());

  Initialize(true, false, true, true, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_FALSE(IsMonitoring());

  constexpr gfx::Size kSizeTooSmall = gfx::Size(100, 100);
  Initialize(true, true, true, true, kSizeTooSmall);
  wtr_->OnPlaying();
  EXPECT_FALSE(IsMonitoring());

  Initialize(true, true, true, true, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_TRUE(IsMonitoring());

  Initialize(true, true, false, false, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_TRUE(IsMonitoring());

  Initialize(true, true, true, false, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_TRUE(IsMonitoring());
}

// Tests that basic reporting for the all category works.
TEST_F(WatchTimeReporterTest, WatchTimeReporterBasic) {
  constexpr base::TimeDelta kWatchTimeEarly = base::TimeDelta::FromSeconds(5);
  constexpr base::TimeDelta kWatchTimeLate = base::TimeDelta::FromSeconds(10);
  EXPECT_CALL(*this, GetCurrentMediaTime())
      .WillOnce(testing::Return(base::TimeDelta()))
      .WillOnce(testing::Return(kWatchTimeEarly))
      .WillRepeatedly(testing::Return(kWatchTimeLate));
  Initialize(true, true, true, true, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_TRUE(IsMonitoring());

  // No log should have been generated yet since the message loop has not had
  // any chance to pump.
  CycleReportingTimer();

  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAc, kWatchTimeLate);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kWatchTimeLate);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoEme, kWatchTimeLate);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoMse, kWatchTimeLate);
  CycleReportingTimer();
}
// Tests that starting from a non-zero base works.
TEST_F(WatchTimeReporterTest, WatchTimeReporterNonZeroStart) {
  constexpr base::TimeDelta kWatchTime1 = base::TimeDelta::FromSeconds(5);
  constexpr base::TimeDelta kWatchTime2 = base::TimeDelta::FromSeconds(15);
  EXPECT_CALL(*this, GetCurrentMediaTime())
      .WillOnce(testing::Return(kWatchTime1))
      .WillRepeatedly(testing::Return(kWatchTime2));
  Initialize(true, true, true, true, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_TRUE(IsMonitoring());

  const base::TimeDelta kWatchTime = kWatchTime2 - kWatchTime1;
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAc, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoEme, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoMse, kWatchTime);
  CycleReportingTimer();
}

// Tests that seeking causes an immediate finalization.
TEST_F(WatchTimeReporterTest, SeekFinalizes) {
  constexpr base::TimeDelta kWatchTime = base::TimeDelta::FromSeconds(10);
  EXPECT_CALL(*this, GetCurrentMediaTime())
      .WillOnce(testing::Return(base::TimeDelta()))
      .WillOnce(testing::Return(kWatchTime));
  Initialize(true, true, true, true, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_TRUE(IsMonitoring());

  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAc, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoEme, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoMse, kWatchTime);
  EXPECT_WATCH_TIME_FINALIZED();
  wtr_->OnSeeking();
}

// Tests that seeking causes an immediate finalization, but does not trample a
// previously set finalize time.
TEST_F(WatchTimeReporterTest, SeekFinalizeDoesNotTramplePreviousFinalize) {
  constexpr base::TimeDelta kWatchTime = base::TimeDelta::FromSeconds(10);
  EXPECT_CALL(*this, GetCurrentMediaTime())
      .WillOnce(testing::Return(base::TimeDelta()))
      .WillOnce(testing::Return(kWatchTime));
  Initialize(true, true, true, true, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_TRUE(IsMonitoring());

  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAc, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoEme, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoMse, kWatchTime);
  EXPECT_WATCH_TIME_FINALIZED();
  wtr_->OnPaused();
  wtr_->OnSeeking();
}

// Tests that watch time is finalized upon destruction.
TEST_F(WatchTimeReporterTest, WatchTimeReporterFinalizeOnDestruction) {
  constexpr base::TimeDelta kWatchTime = base::TimeDelta::FromSeconds(10);
  EXPECT_CALL(*this, GetCurrentMediaTime())
      .WillOnce(testing::Return(base::TimeDelta()))
      .WillOnce(testing::Return(kWatchTime));
  Initialize(true, true, true, true, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_TRUE(IsMonitoring());

  // Finalize the histogram before any cycles of the timer have run.
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAc, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoEme, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoMse, kWatchTime);
  EXPECT_WATCH_TIME_FINALIZED();
  wtr_.reset();
}

// Tests that watch time categories are mapped correctly.
TEST_F(WatchTimeReporterTest, WatchTimeCategoryMapping) {
  constexpr base::TimeDelta kWatchTime = base::TimeDelta::FromSeconds(10);

  // Verify ac, all, src
  EXPECT_CALL(*this, GetCurrentMediaTime())
      .WillOnce(testing::Return(base::TimeDelta()))
      .WillOnce(testing::Return(kWatchTime));
  Initialize(true, true, false, false, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_TRUE(IsMonitoring());
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAc, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoSrc, kWatchTime);
  EXPECT_WATCH_TIME_FINALIZED();
  wtr_.reset();

  // Verify ac, all, mse
  EXPECT_CALL(*this, GetCurrentMediaTime())
      .WillOnce(testing::Return(base::TimeDelta()))
      .WillOnce(testing::Return(kWatchTime));
  Initialize(true, true, true, false, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_TRUE(IsMonitoring());
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAc, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoMse, kWatchTime);
  EXPECT_WATCH_TIME_FINALIZED();
  wtr_.reset();

  // Verify ac, all, eme, src
  EXPECT_CALL(*this, GetCurrentMediaTime())
      .WillOnce(testing::Return(base::TimeDelta()))
      .WillOnce(testing::Return(kWatchTime));
  Initialize(true, true, false, true, kSizeJustRight);
  wtr_->OnPlaying();
  EXPECT_TRUE(IsMonitoring());
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAc, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoEme, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoSrc, kWatchTime);
  EXPECT_WATCH_TIME_FINALIZED();
  wtr_.reset();

  // Verify all, battery, src
  EXPECT_CALL(*this, GetCurrentMediaTime())
      .WillOnce(testing::Return(base::TimeDelta()))
      .WillOnce(testing::Return(kWatchTime));
  Initialize(true, true, false, false, kSizeJustRight);
  wtr_->OnPlaying();
  SetOnBatteryPower(true);
  EXPECT_TRUE(IsMonitoring());
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoAll, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoBattery, kWatchTime);
  EXPECT_WATCH_TIME(MediaLog::kWatchTimeAudioVideoSrc, kWatchTime);
  EXPECT_WATCH_TIME_FINALIZED();
  wtr_.reset();
}

TEST_F(WatchTimeReporterTest, PlayPauseHysteresisContinuation) {
  RunHysteresisTest<kAccumulationContinuesAfterTest>([this]() {
    wtr_->OnPaused();
    wtr_->OnPlaying();
  });
}

TEST_F(WatchTimeReporterTest, PlayPauseHysteresisFinalized) {
  RunHysteresisTest([this]() { wtr_->OnPaused(); });
}

TEST_F(WatchTimeReporterTest, OnVolumeChangeHysteresisContinuation) {
  RunHysteresisTest<kAccumulationContinuesAfterTest>([this]() {
    wtr_->OnVolumeChange(0);
    wtr_->OnVolumeChange(1);
  });
}

TEST_F(WatchTimeReporterTest, OnVolumeChangeHysteresisFinalized) {
  RunHysteresisTest([this]() { wtr_->OnVolumeChange(0); });
}

TEST_F(WatchTimeReporterTest, OnShownHiddenHysteresisContinuation) {
  RunHysteresisTest<kAccumulationContinuesAfterTest>([this]() {
    wtr_->OnHidden();
    wtr_->OnShown();
  });
}

TEST_F(WatchTimeReporterTest, OnShownHiddenHysteresisFinalized) {
  RunHysteresisTest([this]() { wtr_->OnHidden(); });
}

TEST_F(WatchTimeReporterTest, OnPowerStateChangeHysteresisBatteryContinuation) {
  RunHysteresisTest<kAccumulationContinuesAfterTest |
                    kFinalizeExitDoesNotRequireCurrentTime | kStartOnBattery>(
      [this]() {
        OnPowerStateChange(false);
        OnPowerStateChange(true);
      });
}

TEST_F(WatchTimeReporterTest, OnPowerStateChangeHysteresisBatteryFinalized) {
  RunHysteresisTest<kAccumulationContinuesAfterTest | kFinalizePowerWatchTime |
                    kStartOnBattery>([this]() { OnPowerStateChange(false); });
}

TEST_F(WatchTimeReporterTest, OnPowerStateChangeHysteresisAcContinuation) {
  RunHysteresisTest<kAccumulationContinuesAfterTest |
                    kFinalizeExitDoesNotRequireCurrentTime>([this]() {
    OnPowerStateChange(true);
    OnPowerStateChange(false);
  });
}

TEST_F(WatchTimeReporterTest, OnPowerStateChangeHysteresisAcFinalized) {
  RunHysteresisTest<kAccumulationContinuesAfterTest | kFinalizePowerWatchTime>(
      [this]() { OnPowerStateChange(true); });
}

TEST_F(WatchTimeReporterTest, OnPowerStateChangeBatteryTransitions) {
  RunHysteresisTest<kAccumulationContinuesAfterTest | kFinalizePowerWatchTime |
                    kStartOnBattery | kTransitionPowerWatchTime>(
      [this]() { OnPowerStateChange(false); });
}

TEST_F(WatchTimeReporterTest, OnPowerStateChangeAcTransitions) {
  RunHysteresisTest<kAccumulationContinuesAfterTest | kFinalizePowerWatchTime |
                    kTransitionPowerWatchTime>(
      [this]() { OnPowerStateChange(true); });
}

// Tests that the first finalize is the only one that matters.
TEST_F(WatchTimeReporterTest, HysteresisFinalizedWithEarliest) {
  RunHysteresisTest([this]() {
    wtr_->OnPaused();

    // These subsequent "stop events" should do nothing since a finalize time
    // has already been selected.
    wtr_->OnHidden();
    wtr_->OnVolumeChange(0);
  });
}

// Tests that if a stop, stop, start sequence occurs, the middle stop is not
// undone and thus finalize still occurs.
TEST_F(WatchTimeReporterTest, HysteresisPartialExitStillFinalizes) {
  auto stop_event = [this](size_t i) {
    if (i == 0)
      wtr_->OnPaused();
    else if (i == 1)
      wtr_->OnHidden();
    else
      wtr_->OnVolumeChange(0);
  };

  auto start_event = [this](size_t i) {
    if (i == 0)
      wtr_->OnPlaying();
    else if (i == 1)
      wtr_->OnShown();
    else
      wtr_->OnVolumeChange(1);
  };

  for (size_t i = 0; i < 3; ++i) {
    for (size_t j = 0; j < 3; ++j) {
      if (i == j) continue;

      RunHysteresisTest<kFinalizeInterleavedStartEvent>(
          [i, j, start_event, stop_event]() {
            stop_event(i);
            stop_event(j);
            start_event(i);
          });
    }
  }
}

}  // namespace media
}  // namespace cobalt