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 * OPC Foundation MIT License 1.00
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using System;
using System.Security.Cryptography;
using System.Threading.Tasks;
using NUnit.Framework;
using Opc.Ua.Identity;

namespace Opc.Ua.Core.Tests.Security.Identity
{
    [TestFixture]
    [Category("Identity")]
    [Parallelizable]
    public class StaticIssuerKeyResolverTests
    {
        [Test]
        public async Task GetKeysAsyncReturnsKnownKid()
        {
            using IssuerVerificationKey key1 = CreateKey("kid-1");
            using IssuerVerificationKey key2 = CreateKey("kid-2");
            using var resolver = new StaticIssuerKeyResolver(
                "https://issuer.example.test",
                [key1, key2]);

            System.Collections.Generic.IReadOnlyList<IIssuerVerificationKey> keys = await resolver
                .GetKeysAsync("kid-1")
                .ConfigureAwait(false);

            Assert.That(keys, Has.Count.EqualTo(1));
            Assert.That(keys[0].KeyId, Is.EqualTo("kid-1"));
        }

        [Test]
        public async Task GetKeysAsyncReturnsEmptyForUnknownKid()
        {
            using IssuerVerificationKey key1 = CreateKey("kid-1");
            using var resolver = new StaticIssuerKeyResolver(
                "https://issuer.example.test",
                [key1]);

            System.Collections.Generic.IReadOnlyList<IIssuerVerificationKey> keys = await resolver
                .GetKeysAsync("KID-1")
                .ConfigureAwait(false);

            Assert.That(keys, Is.Empty);
        }

        [Test]
        public async Task GetKeysAsyncReturnsAllKeysForNullKid()
        {
            using IssuerVerificationKey key1 = CreateKey("kid-1");
            using IssuerVerificationKey key2 = CreateKey("kid-2");
            using var resolver = new StaticIssuerKeyResolver(
                "https://issuer.example.test",
                [key1, key2]);

            System.Collections.Generic.IReadOnlyList<IIssuerVerificationKey> keys = await resolver
                .GetKeysAsync(null)
                .ConfigureAwait(false);

            Assert.That(keys, Has.Count.EqualTo(2));
        }

        [Test]
        public void DisposeDisposesContainedKeys()
        {
            using IssuerVerificationKey key = CreateKey("kid-1");
            var resolver = new StaticIssuerKeyResolver(
                "https://issuer.example.test",
                [key]);

            resolver.Dispose();

            Assert.That(
                () => key.VerifySignature([1], [1]),
                Throws.TypeOf<ObjectDisposedException>());
        }

        private static IssuerVerificationKey CreateKey(string kid)
        {
            RSA? rsa = null;
            try
            {
                rsa = RSA.Create(2048);
                var key = new IssuerVerificationKey(kid, rsa, "RS256");
                // Ownership of the RSA instance has transferred to the key.
                rsa = null!;
                return key;
            }
            finally
            {
                rsa?.Dispose();
            }
        }
    }
}