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#include <gtest/gtest.h>
#include <AttitudeControl.hpp>
#include <mathlib/math/Functions.hpp>

using namespace matrix;

TEST(AttitudeControlTest, AllZeroCase)
{
	AttitudeControl attitude_control;
	Vector3f rate_setpoint = attitude_control.update(Quatf(), Quatf(), 0.f);
	EXPECT_EQ(rate_setpoint, Vector3f());
}

class AttitudeControlConvergenceTest : public ::testing::Test
{
public:
	AttitudeControlConvergenceTest()
	{
		_attitude_control.setProportionalGain(Vector3f(.5f, .6f, .3f));
		_attitude_control.setRateLimit(Vector3f(100, 100, 100));
	}

	void checkConvergence()
	{
		int i; // need function scope to check how many steps
		Vector3f rate_setpoint(1000, 1000, 1000);
		printf("Iterations: ");

		for (i = 100; i > 0; i--) {
			printf("%d ", i);
			// run attitude control to get rate setpoints
			const Vector3f rate_setpoint_new = _attitude_control.update(_quat_state, _quat_goal, 0.f);

			// expect the error and hence also the output to get smaller with each iteration
			if (rate_setpoint_new.norm() >= rate_setpoint.norm()) {
				break;
			}

			rate_setpoint = rate_setpoint_new;
			// rotate the simulated state quaternion according to the rate setpoint
			_quat_state = _quat_state * Quatf(AxisAnglef(rate_setpoint));
		}

		printf("\n");

		// it shouldn't have taken longer than an iteration timeout to converge
		EXPECT_GT(i, 0);
		// we need to have reached the goal attitude
		EXPECT_EQ(antipodal(_quat_state), antipodal(_quat_goal));
	}

	Quatf antipodal(const Quatf q)
	{
		return q * math::signNoZero(q(0));
	}

	AttitudeControl _attitude_control;
	Quatf _quat_state;
	Quatf _quat_goal;
};

TEST_F(AttitudeControlConvergenceTest, AttitudeControlConvergenceUnit)
{
	_quat_state = Quatf();
	checkConvergence();
}

TEST_F(AttitudeControlConvergenceTest, AttitudeControlConvergenceRoll180)
{
	_quat_state = Quatf(0, 1, 0, 0);
	checkConvergence();
}

TEST_F(AttitudeControlConvergenceTest, AttitudeControlConvergencePitch180)
{
	_quat_state = Quatf(0, 0, 1, 0);
	checkConvergence();
}

TEST_F(AttitudeControlConvergenceTest, AttitudeControlConvergenceYaw180)
{
	_quat_state = Quatf(0, 0, 0, 1);
	checkConvergence();
}

TEST_F(AttitudeControlConvergenceTest, AttitudeControlConvergenceRandom)
{
	const Quatf QRandom[] = {
		Quatf(0.698f, 0.024f, -0.681f, -0.220f),
		Quatf(-0.820f, -0.313f, 0.225f, -0.423f),
		Quatf(0.599f, -0.172f, 0.755f, -0.204f),
		Quatf(0.216f, -0.662f, 0.290f, -0.656f)
	};

	for (int i = 0; i < 4; i++) {
		for (int j = 0; j < 4; j++) {
			printf("Random combination: %d %d\n", i, j);
			_quat_state = QRandom[i];
			_quat_goal = QRandom[j];
			_quat_state.normalize();
			_quat_goal.normalize();
			checkConvergence();
		}
	}
}