using System;
using FluentAssertions;
using StellaOps.TestKit.Evidence;
using Xunit;

namespace StellaOps.TestKit.Tests;

public sealed partial class EvidenceChainTests
{
    [Fact]
    public void ArtifactHashStable_PassesWithCorrectHash()
    {
        var content = "test artifact";
        var expectedHash = EvidenceChainAssert.ComputeSha256(content);

        var act = () => EvidenceChainAssert.ArtifactHashStable(content, expectedHash);
        act.Should().NotThrow();
    }

    [Fact]
    public void ArtifactHashStable_ThrowsWithIncorrectHash()
    {
        var content = "test artifact";
        var wrongHash = new string('0', 64);

        var act = () => EvidenceChainAssert.ArtifactHashStable(content, wrongHash);
        act.Should().Throw<EvidenceTraceabilityException>()
            .WithMessage("*Artifact hash mismatch*");
    }

    [Fact]
    public void ArtifactHashStable_ThrowsOnNullArtifact()
    {
        var act = () => EvidenceChainAssert.ArtifactHashStable((byte[])null!, "hash");
        act.Should().Throw<ArgumentNullException>();
    }

    [Fact]
    public void ArtifactImmutable_PassesWithDeterministicGenerator()
    {
        var counter = 0;
        Func<string> generator = () =>
        {
            counter++;
            return "immutable content";
        };

        var act = () => EvidenceChainAssert.ArtifactImmutable(generator, iterations: 5);
        act.Should().NotThrow();
        counter.Should().Be(5);
    }

    [Fact]
    public void ArtifactImmutable_ThrowsWithNonDeterministicGenerator()
    {
        var counter = 0;
        Func<string> generator = () =>
        {
            counter++;
            return $"non-deterministic content {counter}";
        };

        var act = () => EvidenceChainAssert.ArtifactImmutable(generator, iterations: 5);
        act.Should().Throw<EvidenceTraceabilityException>()
            .WithMessage("*Artifact not immutable*");
    }

    [Fact]
    public void ArtifactImmutable_ThrowsWithLessThanTwoIterations()
    {
        var act = () => EvidenceChainAssert.ArtifactImmutable(() => "content", iterations: 1);
        act.Should().Throw<ArgumentOutOfRangeException>();
    }
}