using Xunit;

namespace Robotico.Nexus.Client.Tests;

[Collection("NexusTlsEnvironment")]
public class NexusTlsMaterialTests : IDisposable
{
    private const string CaVar = "NEXUS_TLS_CA_FILE";
    private const string CertVar = "NEXUS_TLS_CLIENT_CERT_FILE";
    private const string KeyVar = "NEXUS_TLS_CLIENT_KEY_FILE";
    private const string ModeVar = "NEXUS_TLS_MODE";

    public void Dispose()
    {
        Environment.SetEnvironmentVariable(CaVar, null);
        Environment.SetEnvironmentVariable(CertVar, null);
        Environment.SetEnvironmentVariable(KeyVar, null);
        Environment.SetEnvironmentVariable(ModeVar, null);
    }

    [Fact]
    public void Constructor_ThrowsOnBlankArguments()
    {
        Assert.Throws<ArgumentException>(() => new NexusTlsMaterial(string.Empty, "cert", "key"));
        Assert.Throws<ArgumentException>(() => new NexusTlsMaterial("ca", string.Empty, "key"));
        Assert.Throws<ArgumentException>(() => new NexusTlsMaterial("ca", "cert", string.Empty));
    }

    [Fact]
    public void Constructor_ResolvesFullPaths_AndDefaultsToHttps()
    {
        NexusTlsMaterial material = new("ca.pem", "cert.pem", "key.pem");

        Assert.EndsWith("ca.pem", material.CaCertificateFile, StringComparison.Ordinal);
        Assert.True(Path.IsPathRooted(material.CaCertificateFile));
        Assert.True(material.UseHttps);
    }

    [Fact]
    public void TryFromEnvironment_ReturnsNull_WhenVariablesUnset()
    {
        Assert.Null(NexusTlsMaterial.TryFromEnvironment());
    }

    [Fact]
    public void TryFromEnvironment_ReturnsNull_WhenFilesDoNotExist()
    {
        Environment.SetEnvironmentVariable(CaVar, "/nonexistent/ca.pem");
        Environment.SetEnvironmentVariable(CertVar, "/nonexistent/cert.pem");
        Environment.SetEnvironmentVariable(KeyVar, "/nonexistent/key.pem");

        Assert.Null(NexusTlsMaterial.TryFromEnvironment());
    }

    [Fact]
    public void TryFromEnvironment_ReturnsMaterial_WhenFilesExist()
    {
        string dir = Directory.CreateTempSubdirectory("nexus-tls-test-").FullName;
        try
        {
            string ca = Path.Combine(dir, "ca.pem");
            string cert = Path.Combine(dir, "cert.pem");
            string key = Path.Combine(dir, "key.pem");
            File.WriteAllText(ca, "ca");
            File.WriteAllText(cert, "cert");
            File.WriteAllText(key, "key");

            Environment.SetEnvironmentVariable(CaVar, ca);
            Environment.SetEnvironmentVariable(CertVar, cert);
            Environment.SetEnvironmentVariable(KeyVar, key);
            Environment.SetEnvironmentVariable(ModeVar, "insecure");

            NexusTlsMaterial? material = NexusTlsMaterial.TryFromEnvironment();

            Assert.NotNull(material);
            Assert.False(material!.UseHttps);
        }
        finally
        {
            Directory.Delete(dir, recursive: true);
        }
    }

    [Fact]
    public void EnsureFilesExist_Throws_WhenAnyFileMissing()
    {
        NexusTlsMaterial material = new("/nonexistent/ca.pem", "/nonexistent/cert.pem", "/nonexistent/key.pem");

        Assert.Throws<InvalidOperationException>(material.EnsureFilesExist);
    }

    [Fact]
    public void EnsureFilesExist_Succeeds_WhenAllFilesPresent()
    {
        string dir = Directory.CreateTempSubdirectory("nexus-tls-test-").FullName;
        try
        {
            string ca = Path.Combine(dir, "ca.pem");
            string cert = Path.Combine(dir, "cert.pem");
            string key = Path.Combine(dir, "key.pem");
            File.WriteAllText(ca, "ca");
            File.WriteAllText(cert, "cert");
            File.WriteAllText(key, "key");

            NexusTlsMaterial material = new(ca, cert, key);
            material.EnsureFilesExist();
        }
        finally
        {
            Directory.Delete(dir, recursive: true);
        }
    }
}