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/**
 * Test the flow fusion
 * @author Kamil Ritz <ka.ritz@hotmail.com>
 */

#include <gtest/gtest.h>
#include "EKF/ekf.h"
#include "sensor_simulator/sensor_simulator.h"
#include "sensor_simulator/ekf_wrapper.h"
#include "test_helper/reset_logging_checker.h"


class EkfFlowTest : public ::testing::Test {
 public:

	EkfFlowTest(): ::testing::Test(),
	_ekf{std::make_shared<Ekf>()},
	_sensor_simulator(_ekf),
	_ekf_wrapper(_ekf) {};

	std::shared_ptr<Ekf> _ekf;
	SensorSimulator _sensor_simulator;
	EkfWrapper _ekf_wrapper;

	// Setup the Ekf with synthetic measurements
	void SetUp() override
	{
		_ekf->init(0);
		_sensor_simulator.runSeconds(7);
	}

	// Use this method to clean up any memory, network etc. after each test
	void TearDown() override
	{
	}
};

TEST_F(EkfFlowTest, resetToFlowVelocityInAir)
{
	ResetLoggingChecker reset_logging_checker(_ekf);

	// WHEN: simulate being 5m above ground
	const float simulated_distance_to_ground = 5.f;
	_sensor_simulator._rng.setData(simulated_distance_to_ground, 100);
	_sensor_simulator._rng.setLimits(0.1f, 9.f);
	_sensor_simulator.startRangeFinder();
	_ekf->set_in_air_status(true);
	_sensor_simulator.runSeconds(5.f);

	const float estimated_distance_to_ground = _ekf->getTerrainVertPos();
	EXPECT_FLOAT_EQ(estimated_distance_to_ground, simulated_distance_to_ground);

	reset_logging_checker.capturePreResetState();

	// WHEN: start fusing flow data
	const Vector2f simulated_horz_velocity(0.5f, -0.2f);
	flowSample flow_sample = _sensor_simulator._flow.dataAtRest();
	flow_sample.flow_xy_rad =
		Vector2f( simulated_horz_velocity(1) * flow_sample.dt / estimated_distance_to_ground,
			 -simulated_horz_velocity(0) * flow_sample.dt / estimated_distance_to_ground);
	_sensor_simulator._flow.setData(flow_sample);
	_ekf_wrapper.enableFlowFusion();
	const float max_flow_rate = 5.f;
	const float min_ground_distance = 0.f;
	const float max_ground_distance = 50.f;
	_ekf->set_optical_flow_limits(max_flow_rate, min_ground_distance, max_ground_distance);
	_sensor_simulator.startFlow();
	_sensor_simulator.runSeconds(0.12); // Let it reset but not fuse more measurements

	// THEN: estimated velocity should match simulated velocity
	const Vector2f estimated_horz_velocity = Vector2f(_ekf->getVelocity());
	EXPECT_FALSE(isEqual(estimated_horz_velocity, simulated_horz_velocity))
		<< "estimated vel = " << estimated_horz_velocity(0) << ", "
		<< estimated_horz_velocity(1); // TODO: This needs to change (reset is always 0)

	// AND: the reset in velocity should be saved correctly
	reset_logging_checker.capturePostResetState();
	EXPECT_TRUE(reset_logging_checker.isHorizontalVelocityResetCounterIncreasedBy(1));
	EXPECT_TRUE(reset_logging_checker.isVerticalVelocityResetCounterIncreasedBy(0));
	EXPECT_TRUE(reset_logging_checker.isVelocityDeltaLoggedCorrectly(1e-9f));
}

TEST_F(EkfFlowTest, resetToFlowVelocityOnGround)
{
	ResetLoggingChecker reset_logging_checker(_ekf);

	// WHEN: being on ground
	const float estimated_distance_to_ground = _ekf->getTerrainVertPos();
	EXPECT_LT(estimated_distance_to_ground, 0.3f);

	reset_logging_checker.capturePreResetState();

	// WHEN: start fusing flow data
	_ekf_wrapper.enableFlowFusion();
	_sensor_simulator.startFlow();
	_sensor_simulator.runSeconds(1.0);

	// THEN: estimated velocity should match simulated velocity
	const Vector2f estimated_horz_velocity = Vector2f(_ekf->getVelocity());
	EXPECT_TRUE(isEqual(estimated_horz_velocity, Vector2f(0.f, 0.f)));

	// AND: the reset in velocity should be saved correctly
	reset_logging_checker.capturePostResetState();
	EXPECT_TRUE(reset_logging_checker.isHorizontalVelocityResetCounterIncreasedBy(1));
	EXPECT_TRUE(reset_logging_checker.isVerticalVelocityResetCounterIncreasedBy(0));
	EXPECT_TRUE(reset_logging_checker.isVelocityDeltaLoggedCorrectly(1e-9f));
}