#include <UnitTest++.h>

#include <Timing/Timer.h>
#include <Timing/ManualClock.h>

using namespace Nuclex::Game::Timing;

class TestTimer : Timer {

  public: TestTimer(const std::shared_ptr<Clock> &clock) : Timer(clock) {}

  public: std::uint64_t GetElapsedMicroseconds() const {
    return Timer::GetElapsedMicroseconds();
  }

};

struct FastTimerTest {
  public: FastTimerTest() :
    manualClock(new ManualClock(1000001)) {
    this->testTimer.reset(new TestTimer(this->manualClock));
  }

  protected: std::shared_ptr<ManualClock> manualClock;
  protected: std::shared_ptr<TestTimer> testTimer;
};

struct SlowTimerTest {
  public: SlowTimerTest() :
    manualClock(new ManualClock(9)) {
    this->testTimer.reset(new TestTimer(this->manualClock));
  }

  protected: std::shared_ptr<ManualClock> manualClock;
  protected: std::shared_ptr<TestTimer> testTimer;
};

// --------------------------------------------------------------------------------------------- //

TEST_FIXTURE(SlowTimerTest, CompensatesForIndivisibleClockFrequency) {
  this->manualClock->AddTime(9);

  // After 9 ticks, the end result must be 1 second
  CHECK_EQUAL(1000000, this->testTimer->GetElapsedMicroseconds());
}

// --------------------------------------------------------------------------------------------- //

TEST_FIXTURE(SlowTimerTest, TicksAreConvertedToMicroseconds) {
  this->manualClock->AddTime(5);

  // An implementation could place the compensation tick at any point, so both
  // 555,555 or 555,556 are acceptable results
  if(this->testTimer->GetElapsedMicroseconds() == 555556) {
    CHECK_EQUAL(555556, this->testTimer->GetElapsedMicroseconds());
  } else {
    CHECK_EQUAL(555555, this->testTimer->GetElapsedMicroseconds());
  }
}

// --------------------------------------------------------------------------------------------- //

TEST_FIXTURE(FastTimerTest, CompensatesForIndivisibleClockFrequency) {
  this->manualClock->AddTime(1000001);

  // After 1000001 ticks, the end result must be 1 second
  CHECK_EQUAL(1000000, this->testTimer->GetElapsedMicroseconds());
}

// --------------------------------------------------------------------------------------------- //

TEST_FIXTURE(FastTimerTest, TicksAreConvertedToMicroseconds) {
  this->manualClock->AddTime(1000000);

  // After 1000000 ticks, the end result must be 0.999999 seconds,
  // no matter where the compensation microsecond is placed.
  CHECK_EQUAL(999999, this->testTimer->GetElapsedMicroseconds());
}

// --------------------------------------------------------------------------------------------- //