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#include <gtest/gtest.h>
#include "EKF/ekf.h"
#include "test_helper/comparison_helper.h"

#include "../EKF/python/ekf_derivation/generated/compute_mag_declination_pred_innov_var_and_h.h"
#include "../EKF/python/ekf_derivation/generated/state.h"

using namespace matrix;

TEST(MagDeclinationGenerated, declination90deg)
{
	// GIVEN: an estimated mag declination of 90 degrees
	StateSample state{};
	state.mag_I(0) = 0.f; // North mag field
	state.mag_I(1) = 0.2f; // East mag field

	const float R = sq(radians(sq(0.5f)));
	SquareMatrixState P = createRandomCovarianceMatrix();

	VectorState H;
	float decl_pred;
	float innov_var;

	const float decl = radians(90.f);
	sym::ComputeMagDeclinationPredInnovVarAndH(state.vector(), P, R, FLT_EPSILON, &decl_pred, &innov_var, &H);

	// THEN: Even at the singularity point, atan2 is still defined
	EXPECT_TRUE(innov_var < 5000.f && innov_var > R) << "innov_var = " << innov_var;
	EXPECT_LT(fabsf(wrap_pi(decl_pred - decl)), 1e-6f);
}

TEST(MagDeclinationGenerated, declinationUndefined)
{
	// GIVEN: an undefined declination
	StateSample state{};
	state.mag_I(0) = 0.f; // North mag field
	state.mag_I(1) = 0.f; // East mag field

	const float R = sq(radians(sq(0.5f)));
	SquareMatrixState P = createRandomCovarianceMatrix();

	VectorState H;
	float decl_pred;
	float innov_var;

	const float decl = radians(0.f);
	sym::ComputeMagDeclinationPredInnovVarAndH(state.vector(), P, R, FLT_EPSILON, &decl_pred, &innov_var, &H);

	// THEN: the innovation variance is gigantic but finite
	EXPECT_TRUE(PX4_ISFINITE(innov_var) && innov_var > R && innov_var > 1e9f) << "innov_var = " << innov_var;
	EXPECT_LT(fabsf(wrap_pi(decl_pred - decl)), 1e-6f);
}