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/**
 * Height fusion logic
 */

#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 EkfHeightFusionTest : public ::testing::Test
{
public:

	EkfHeightFusionTest(): ::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);
		_ekf_wrapper.disableBaroHeightFusion();
		_ekf_wrapper.disableRangeHeightFusion();
		_sensor_simulator.runSeconds(0.1);
		_ekf->set_in_air_status(false);
		_ekf->set_vehicle_at_rest(true);

		_sensor_simulator.startGps();

		_sensor_simulator._rng.setData(1.f, 100);
		_sensor_simulator._rng.setLimits(0.1f, 9.f);
		_sensor_simulator.startRangeFinder();

		_sensor_simulator.startExternalVision();

		_sensor_simulator.runSeconds(15);

		_ekf->set_in_air_status(true);
		_ekf->set_vehicle_at_rest(false);
	}

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

TEST_F(EkfHeightFusionTest, noAiding)
{
	EXPECT_FALSE(_ekf_wrapper.isIntendingBaroHeightFusion());
	EXPECT_FALSE(_ekf_wrapper.isIntendingGpsHeightFusion());
	EXPECT_FALSE(_ekf_wrapper.isIntendingRangeHeightFusion());
	EXPECT_FALSE(_ekf_wrapper.isIntendingExternalVisionHeightFusion());
}

TEST_F(EkfHeightFusionTest, baroRef)
{
	// GIVEN: baro reference with GPS and range height fusion
	_ekf_wrapper.setBaroHeightRef();
	_ekf_wrapper.enableBaroHeightFusion();
	_sensor_simulator.runSeconds(0.1);

	_ekf_wrapper.enableGpsHeightFusion();
	_ekf_wrapper.enableRangeHeightFusion();
	/* _ekf_wrapper.enableExternalVisionHeightFusion(); */ //TODO: this currently sets the reference to EV
	_sensor_simulator.runSeconds(1);

	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::BARO);
	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingRangeHeightFusion());
	EXPECT_FALSE(_ekf_wrapper.isIntendingExternalVisionHeightFusion());

	// AND WHEN: the baro data increases
	const float baro_increment = 4.f;
	_sensor_simulator._baro.setData(_sensor_simulator._baro.getData() + baro_increment);
	_sensor_simulator.runSeconds(60);

	// THEN: the height estimate converges to the baro value
	// and the other height sources are getting their bias estimated
	EXPECT_NEAR(_ekf->getPosition()(2), -baro_increment, 0.1f);
	const BiasEstimator::status &baro_status = _ekf->getBaroBiasEstimatorStatus();
	/* EXPECT_EQ(status.bias, _sensor_simulator._baro.getData()); */ // This is the real bias, but the estimator isn't running so the status isn't updated
	EXPECT_EQ(baro_status.bias, 0.f);
	const BiasEstimator::status &gps_status = _ekf->getGpsHgtBiasEstimatorStatus();
	EXPECT_NEAR(gps_status.bias, _sensor_simulator._gps.getData().alt - _sensor_simulator._baro.getData(), 0.2f);

	const float terrain = _ekf->getTerrainVertPos();
	EXPECT_NEAR(terrain, -baro_increment, 1.2f);

	const BiasEstimator::status &ev_status = _ekf->getEvHgtBiasEstimatorStatus();
	EXPECT_EQ(ev_status.bias, 0.f);

	// BUT WHEN: the baro data jumps by a lot
	_sensor_simulator._baro.setData(_sensor_simulator._baro.getData() + 200.f);
	_sensor_simulator.runSeconds(10);

	// THEN: the baro is stopped and the GPS takes the role of the height reference
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::GNSS);
	EXPECT_FALSE(_ekf_wrapper.isIntendingBaroHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingRangeHeightFusion());

	// AND WHEN: the gps height increases
	const float gps_increment = 1.f;
	_sensor_simulator._gps.stepHeightByMeters(gps_increment);
	_sensor_simulator.runSeconds(60);

	// THEN: the GPS bias stays constant
	EXPECT_EQ(gps_status.bias, _ekf->getGpsHgtBiasEstimatorStatus().bias);
	// the estimated height follows the GPS height
	EXPECT_NEAR(_ekf->getPosition()(2), -(baro_increment + gps_increment), 0.3f);
	// and the range finder bias is adjusted to follow the new reference
	const float terrain2 = _ekf->getTerrainVertPos();
	EXPECT_NEAR(terrain2, -(baro_increment + gps_increment), 1.3f);
}

TEST_F(EkfHeightFusionTest, gpsRef)
{
	// GIVEN: GPS reference, baro and range height fusion
	_ekf_wrapper.setGpsHeightRef();
	_ekf_wrapper.enableBaroHeightFusion();
	_ekf_wrapper.enableGpsHeightFusion();
	_ekf_wrapper.enableRangeHeightFusion();
	_sensor_simulator.runSeconds(1);

	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::GNSS);
	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingRangeHeightFusion());
	EXPECT_FALSE(_ekf_wrapper.isIntendingExternalVisionHeightFusion());

	const float baro_initial = _sensor_simulator._baro.getData();

	const BiasEstimator::status &baro_status_initial = _ekf->getBaroBiasEstimatorStatus();
	const float baro_rel_initial = baro_initial - _sensor_simulator._gps.getData().alt;
	EXPECT_NEAR(baro_status_initial.bias, baro_rel_initial, 0.6f);

	// AND WHEN: the baro data increases
	const float baro_increment = 5.f;
	_sensor_simulator._baro.setData(baro_initial + baro_increment);
	_sensor_simulator.runSeconds(100);

	// THEN: the height estimate is temporarily biased but then converges back to
	// the GPS height value and the baro gets its bias estimated
	EXPECT_NEAR(_ekf->getPosition()(2), 0.f, 1.f);
	const BiasEstimator::status &baro_status = _ekf->getBaroBiasEstimatorStatus();
	EXPECT_NEAR(baro_status.bias, baro_rel_initial + baro_increment, 1.3f);

	const float terrain = _ekf->getTerrainVertPos();
	EXPECT_NEAR(terrain, 0.f, 1.1f); // TODO: why?

	// BUT WHEN: the GPS jumps by a lot
	const float gps_step = 100.f;
	_sensor_simulator._gps.stepHeightByMeters(gps_step);
	_sensor_simulator.runSeconds(10);

	// THEN: the height is reset to the new GPS altitude and all the bias estimates are updated accordingly
	EXPECT_NEAR(_ekf->getPosition()(2), -gps_step, 1.f);
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::GNSS);
	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingRangeHeightFusion());
	EXPECT_NEAR(_ekf->getBaroBiasEstimatorStatus().bias, baro_rel_initial + baro_increment - gps_step, 0.2f);

	// and the innovations are close to zero
	EXPECT_NEAR(_ekf->aid_src_baro_hgt().innovation, 0.f, 0.2f);
	EXPECT_NEAR(_ekf->aid_src_rng_hgt().innovation, 0.f, 0.2f);
}

TEST_F(EkfHeightFusionTest, baroRefFailOver)
{
	// GIVEN: baro reference with GPS and range height fusion
	_ekf_wrapper.setBaroHeightRef();
	_ekf_wrapper.enableBaroHeightFusion();
	_ekf_wrapper.enableGpsHeightFusion();
	_ekf_wrapper.enableRangeHeightFusion();

	_sensor_simulator.runSeconds(0.1);

	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::BARO);

	_sensor_simulator.stopBaro();
	_sensor_simulator.runSeconds(10);
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::GNSS);

	_sensor_simulator.stopGps();
	_sensor_simulator.runSeconds(10);
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::RANGE);

	_sensor_simulator.stopRangeFinder();
	_sensor_simulator.runSeconds(10);
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::UNKNOWN);
}

TEST_F(EkfHeightFusionTest, gpsRefFailOver)
{
	// GIVEN: baro reference with GPS and range height fusion
	_sensor_simulator.startBaro();
	_sensor_simulator.startGps();
	_sensor_simulator.startRangeFinder();
	_ekf_wrapper.setGpsHeightRef();
	_ekf_wrapper.enableBaroHeightFusion();
	_ekf_wrapper.enableGpsHeightFusion();
	_ekf_wrapper.enableRangeHeightFusion();

	// The GPS takes time to start, use baro at first
	_sensor_simulator.runSeconds(0.1);
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::BARO);

	// Then switch to reference height source
	_sensor_simulator.runSeconds(10);
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::GNSS);

	// And switch to the fallback sources once the current reference fails
	_sensor_simulator.stopGps();
	_sensor_simulator.runSeconds(10);
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::BARO);

	_sensor_simulator.stopBaro();
	_sensor_simulator.runSeconds(10);
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::RANGE);

	_sensor_simulator.stopRangeFinder();
	_sensor_simulator.runSeconds(10);
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::UNKNOWN);
}

TEST_F(EkfHeightFusionTest, gpsRefAllHgtFailReset)
{
	// GIVEN: EKF that fuses GNSS (reference) and baro
	_sensor_simulator.startBaro();
	_sensor_simulator.startGps();
	_ekf_wrapper.setGpsHeightRef();
	_ekf_wrapper.enableBaroHeightFusion();
	_ekf_wrapper.enableGpsHeightFusion();

	_sensor_simulator.runSeconds(11);
	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::GNSS);

	const Vector3f previous_position = _ekf->getPosition();

	ResetLoggingChecker reset_logging_checker(_ekf);
	reset_logging_checker.capturePreResetState();

	// WHEN:
	const float gnss_height_step = 10.f;
	_sensor_simulator._gps.stepHeightByMeters(gnss_height_step);

	const float baro_height_step = 5.f;
	_sensor_simulator._baro.setData(_sensor_simulator._baro.getData() + baro_height_step);
	_sensor_simulator.runSeconds(15);

	// THEN: then the fusion of both sensors starts to fail and the height is reset to the
	// reference sensor (GNSS)
	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());

	const Vector3f new_position = _ekf->getPosition();
	EXPECT_NEAR(new_position(2), previous_position(2) - gnss_height_step, 0.2f);

	// Also check the reset counters to make sure the reset logic triggered
	reset_logging_checker.capturePostResetState();
	EXPECT_TRUE(reset_logging_checker.isVerticalVelocityResetCounterIncreasedBy(1));
	EXPECT_TRUE(reset_logging_checker.isVerticalPositionResetCounterIncreasedBy(1));
}

TEST_F(EkfHeightFusionTest, baroRefAllHgtFailReset)
{
	// GIVEN: EKF that fuses GNSS and baro (reference)
	_sensor_simulator.startBaro();
	_sensor_simulator.startGps();
	_ekf_wrapper.setBaroHeightRef();
	_ekf_wrapper.enableBaroHeightFusion();
	_ekf_wrapper.enableGpsHeightFusion();

	_sensor_simulator.runSeconds(11);
	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());
	EXPECT_TRUE(_ekf->getHeightSensorRef() == HeightSensor::BARO);

	const Vector3f previous_position = _ekf->getPosition();

	ResetLoggingChecker reset_logging_checker(_ekf);
	reset_logging_checker.capturePreResetState();

	// WHEN:
	const float gnss_height_step = 10.f;
	_sensor_simulator._gps.stepHeightByMeters(gnss_height_step);

	const float baro_height_step = 5.f;
	_sensor_simulator._baro.setData(_sensor_simulator._baro.getData() + baro_height_step);
	_sensor_simulator.runSeconds(20);

	// THEN: then the fusion of both sensors starts to fail and the height is reset to the
	// reference sensor (baro)
	EXPECT_TRUE(_ekf_wrapper.isIntendingGpsHeightFusion());
	EXPECT_TRUE(_ekf_wrapper.isIntendingBaroHeightFusion());

	const Vector3f new_position = _ekf->getPosition();
	EXPECT_NEAR(new_position(2), previous_position(2) - baro_height_step, 0.2f);

	// Also check the reset counters to make sure the reset logic triggered
	reset_logging_checker.capturePostResetState();

	EXPECT_TRUE(reset_logging_checker.isVerticalPositionResetCounterIncreasedBy(1));

	// The velocity does not reset as baro only provides height measurement
	EXPECT_TRUE(reset_logging_checker.isVerticalVelocityResetCounterIncreasedBy(0));
}

TEST_F(EkfHeightFusionTest, changeEkfOriginAlt)
{
	_sensor_simulator.startBaro();
	_sensor_simulator.startGps();
	_sensor_simulator.startRangeFinder();
	_ekf_wrapper.setGpsHeightRef();
	_ekf_wrapper.enableBaroHeightFusion();
	_ekf_wrapper.enableGpsHeightFusion();
	_ekf_wrapper.enableRangeHeightFusion();
	_sensor_simulator.runSeconds(10);

	uint64_t origin_time;
	double lat;
	double lon;
	float alt;
	_ekf->getEkfGlobalOrigin(origin_time, lat, lon, alt);

	ResetLoggingChecker reset_logging_checker(_ekf);
	reset_logging_checker.capturePreResetState();
	const float baro_bias_prev = _ekf->getBaroBiasEstimatorStatus().bias;

	const float alt_increment = 4478.f;
	_ekf->setEkfGlobalOrigin(lat, lon, alt + alt_increment);
	_sensor_simulator.runSeconds(10);

	// The origin moves up by some altitude, the current position (down) is then higher
	EXPECT_NEAR(_ekf->getPosition()(2), alt_increment, 1.f);

	reset_logging_checker.capturePostResetState();

	// An origin reset doesn't change the baro bias as it is relative to the height reference (GNSS)
	EXPECT_NEAR(_ekf->getBaroBiasEstimatorStatus().bias, baro_bias_prev, 0.3f);

	EXPECT_NEAR(_ekf->getTerrainVertPos(), alt_increment, 1.f);

	EXPECT_TRUE(reset_logging_checker.isVerticalVelocityResetCounterIncreasedBy(0));
	EXPECT_TRUE(reset_logging_checker.isVerticalPositionResetCounterIncreasedBy(1));
}