/*************************************************************************/
/*  test_curve.h                                                         */
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#ifndef TEST_CURVE_H
#define TEST_CURVE_H

#include "scene/resources/curve.h"

#include "thirdparty/doctest/doctest.h"

namespace TestCurve {

TEST_CASE("[Curve] Default curve") {
	const Ref<Curve> curve = memnew(Curve);

	CHECK_MESSAGE(
			curve->get_point_count() == 0,
			"Default curve should contain the expected number of points.");
	CHECK_MESSAGE(
			Math::is_zero_approx(curve->interpolate(0)),
			"Default curve should return the expected value at offset 0.0.");
	CHECK_MESSAGE(
			Math::is_zero_approx(curve->interpolate(0.5)),
			"Default curve should return the expected value at offset 0.5.");
	CHECK_MESSAGE(
			Math::is_zero_approx(curve->interpolate(1)),
			"Default curve should return the expected value at offset 1.0.");
}

TEST_CASE("[Curve] Custom curve with free tangents") {
	Ref<Curve> curve = memnew(Curve);
	// "Sawtooth" curve with an open ending towards the 1.0 offset.
	curve->add_point(Vector2(0, 0));
	curve->add_point(Vector2(0.25, 1));
	curve->add_point(Vector2(0.5, 0));
	curve->add_point(Vector2(0.75, 1));

	CHECK_MESSAGE(
			Math::is_zero_approx(curve->get_point_left_tangent(0)),
			"get_point_left_tangent() should return the expected value for point index 0.");
	CHECK_MESSAGE(
			Math::is_zero_approx(curve->get_point_right_tangent(0)),
			"get_point_right_tangent() should return the expected value for point index 0.");
	CHECK_MESSAGE(
			curve->get_point_left_mode(0) == Curve::TangentMode::TANGENT_FREE,
			"get_point_left_mode() should return the expected value for point index 0.");
	CHECK_MESSAGE(
			curve->get_point_right_mode(0) == Curve::TangentMode::TANGENT_FREE,
			"get_point_right_mode() should return the expected value for point index 0.");

	CHECK_MESSAGE(
			curve->get_point_count() == 4,
			"Custom free curve should contain the expected number of points.");

	CHECK_MESSAGE(
			Math::is_zero_approx(curve->interpolate(-0.1)),
			"Custom free curve should return the expected value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(0.1), (real_t)0.352),
			"Custom free curve should return the expected value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(0.4), (real_t)0.352),
			"Custom free curve should return the expected value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(0.7), (real_t)0.896),
			"Custom free curve should return the expected value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(1), 1),
			"Custom free curve should return the expected value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(2), 1),
			"Custom free curve should return the expected value at offset 0.1.");

	CHECK_MESSAGE(
			Math::is_zero_approx(curve->interpolate_baked(-0.1)),
			"Custom free curve should return the expected baked value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(0.1), (real_t)0.352),
			"Custom free curve should return the expected baked value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(0.4), (real_t)0.352),
			"Custom free curve should return the expected baked value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(0.7), (real_t)0.896),
			"Custom free curve should return the expected baked value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(1), 1),
			"Custom free curve should return the expected baked value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(2), 1),
			"Custom free curve should return the expected baked value at offset 0.1.");

	curve->remove_point(1);
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(0.1), 0),
			"Custom free curve should return the expected value at offset 0.1 after removing point at index 1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(0.1), 0),
			"Custom free curve should return the expected baked value at offset 0.1 after removing point at index 1.");

	curve->clear_points();
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(0.6), 0),
			"Custom free curve should return the expected value at offset 0.6 after clearing all points.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(0.6), 0),
			"Custom free curve should return the expected baked value at offset 0.6 after clearing all points.");
}

TEST_CASE("[Curve] Custom curve with linear tangents") {
	Ref<Curve> curve = memnew(Curve);
	// "Sawtooth" curve with an open ending towards the 1.0 offset.
	curve->add_point(Vector2(0, 0), 0, 0, Curve::TangentMode::TANGENT_LINEAR, Curve::TangentMode::TANGENT_LINEAR);
	curve->add_point(Vector2(0.25, 1), 0, 0, Curve::TangentMode::TANGENT_LINEAR, Curve::TangentMode::TANGENT_LINEAR);
	curve->add_point(Vector2(0.5, 0), 0, 0, Curve::TangentMode::TANGENT_LINEAR, Curve::TangentMode::TANGENT_LINEAR);
	curve->add_point(Vector2(0.75, 1), 0, 0, Curve::TangentMode::TANGENT_LINEAR, Curve::TangentMode::TANGENT_LINEAR);

	CHECK_MESSAGE(
			Math::is_equal_approx(curve->get_point_left_tangent(3), 4),
			"get_point_left_tangent() should return the expected value for point index 3.");
	CHECK_MESSAGE(
			Math::is_zero_approx(curve->get_point_right_tangent(3)),
			"get_point_right_tangent() should return the expected value for point index 3.");
	CHECK_MESSAGE(
			curve->get_point_left_mode(3) == Curve::TangentMode::TANGENT_LINEAR,
			"get_point_left_mode() should return the expected value for point index 3.");
	CHECK_MESSAGE(
			curve->get_point_right_mode(3) == Curve::TangentMode::TANGENT_LINEAR,
			"get_point_right_mode() should return the expected value for point index 3.");

	ERR_PRINT_OFF;
	CHECK_MESSAGE(
			Math::is_zero_approx(curve->get_point_right_tangent(300)),
			"get_point_right_tangent() should return the expected value for invalid point index 300.");
	CHECK_MESSAGE(
			curve->get_point_left_mode(-12345) == Curve::TangentMode::TANGENT_FREE,
			"get_point_left_mode() should return the expected value for invalid point index -12345.");
	ERR_PRINT_ON;

	CHECK_MESSAGE(
			curve->get_point_count() == 4,
			"Custom linear curve should contain the expected number of points.");

	CHECK_MESSAGE(
			Math::is_zero_approx(curve->interpolate(-0.1)),
			"Custom linear curve should return the expected value at offset -0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(0.1), (real_t)0.4),
			"Custom linear curve should return the expected value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(0.4), (real_t)0.4),
			"Custom linear curve should return the expected value at offset 0.4.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(0.7), (real_t)0.8),
			"Custom linear curve should return the expected value at offset 0.7.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(1), 1),
			"Custom linear curve should return the expected value at offset 1.0.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(2), 1),
			"Custom linear curve should return the expected value at offset 2.0.");

	CHECK_MESSAGE(
			Math::is_zero_approx(curve->interpolate_baked(-0.1)),
			"Custom linear curve should return the expected baked value at offset -0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(0.1), (real_t)0.4),
			"Custom linear curve should return the expected baked value at offset 0.1.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(0.4), (real_t)0.4),
			"Custom linear curve should return the expected baked value at offset 0.4.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(0.7), (real_t)0.8),
			"Custom linear curve should return the expected baked value at offset 0.7.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(1), 1),
			"Custom linear curve should return the expected baked value at offset 1.0.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(2), 1),
			"Custom linear curve should return the expected baked value at offset 2.0.");

	ERR_PRINT_OFF;
	curve->remove_point(10);
	ERR_PRINT_ON;
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate(0.7), (real_t)0.8),
			"Custom free curve should return the expected value at offset 0.7 after removing point at invalid index 10.");
	CHECK_MESSAGE(
			Math::is_equal_approx(curve->interpolate_baked(0.7), (real_t)0.8),
			"Custom free curve should return the expected baked value at offset 0.7 after removing point at invalid index 10.");
}

TEST_CASE("[Curve2D] Linear sampling should return exact value") {
	Ref<Curve2D> curve = memnew(Curve2D);
	int len = 2048;

	curve->add_point(Vector2(0, 0));
	curve->add_point(Vector2((float)len, 0));

	float baked_length = curve->get_baked_length();
	CHECK((float)len == baked_length);

	for (int i = 0; i < len; i++) {
		float expected = (float)i;
		Vector2 pos = curve->interpolate_baked(expected);
		CHECK_MESSAGE(pos.x == expected, "interpolate_baked should return exact value");
	}
}

TEST_CASE("[Curve3D] Linear sampling should return exact value") {
	Ref<Curve3D> curve = memnew(Curve3D);
	int len = 2048;

	curve->add_point(Vector3(0, 0, 0));
	curve->add_point(Vector3((float)len, 0, 0));

	float baked_length = curve->get_baked_length();
	CHECK((float)len == baked_length);

	for (int i = 0; i < len; i++) {
		float expected = (float)i;
		Vector3 pos = curve->interpolate_baked(expected);
		CHECK_MESSAGE(pos.x == expected, "interpolate_baked should return exact value");
	}
}

} // namespace TestCurve

#endif // TEST_CURVE_H