using FluentAssertions;
using PerfectNumbers.Core.Gpu.Accelerators;
using Xunit;

namespace PerfectNumbers.Core.Tests;

public class MersenneDivisorCyclesTests
{
	public static IEnumerable<object[]> Divisors() =>
		new[]
		{
			new object[] {3UL, 2UL},
			new object[] {7UL, 3UL},
			new object[] {11UL, 10UL},
		};

	[Theory]
	[Trait("Category", "Fast")]
	[MemberData(nameof(Divisors))]
	public void CalculateCycleLength_returns_expected_value(ulong divisor, ulong expected)
	{
		var gpu = PrimeOrderCalculatorAccelerator.Rent(1);
		try
		{
			MontgomeryDivisorData divisorData = MontgomeryDivisorData.FromModulus(divisor);
			MersenneDivisorCyclesCpu.CalculateCycleLength(divisor, divisorData).Should().Be(expected);
			MersenneDivisorCyclesGpu.CalculateCycleLength(gpu, divisor, divisorData).Should().Be(expected);
		}
		finally
		{
			PrimeOrderCalculatorAccelerator.Return(gpu);
		}
	}
}