using Omika.Core.Observability.Diagnostic;

namespace Omika.Tests.Observability.Correlation;

public class RequestDiagnosticContextTests
{
    [Fact]
    public void Begin_SetsContext_AndRestoresOnDispose()
    {
        var context = new RequestDiagnosticContext();
        Guid traceId = Guid.NewGuid();
        Guid sessionId = Guid.NewGuid();

        Assert.Null(context.TraceId);
        Assert.Null(context.SessionId);
        Assert.Null(context.StartedAtUtc);

        using (context.Begin(traceId, sessionId))
        {
            Assert.Equal(traceId, context.TraceId);
            Assert.Equal(sessionId, context.SessionId);
            Assert.NotNull(context.StartedAtUtc);
        }

        Assert.Null(context.TraceId);
        Assert.Null(context.SessionId);
        Assert.Null(context.StartedAtUtc);
    }

    [Fact]
    public void SetIdentity_WithinScope_SetsFields()
    {
        var context = new RequestDiagnosticContext();
        using (context.Begin(Guid.NewGuid()))
        {
            context.SetIdentity("device-1", "CLIENT01", "42", "7");

            Assert.Equal("device-1", context.DeviceId);
            Assert.Equal("CLIENT01", context.ClientId);
            Assert.Equal("42", context.UserId);
            Assert.Equal("7", context.CollaborateurId);
        }
    }

    [Fact]
    public void SetIdentity_OutsideScope_IsNoOp()
    {
        var context = new RequestDiagnosticContext();
        context.SetIdentity("device-1", "CLIENT01", "42", "7");

        Assert.Null(context.DeviceId);
        Assert.Null(context.ClientId);
        Assert.Null(context.UserId);
        Assert.Null(context.CollaborateurId);
    }

    [Fact]
    public async Task NestedScopes_AreIsolated_AndRestored()
    {
        var context = new RequestDiagnosticContext();
        Guid a = Guid.NewGuid();
        Guid b = Guid.NewGuid();

        using (context.Begin(a))
        {
            await Task.Yield();
            Assert.Equal(a, context.TraceId);

            using (context.Begin(b))
            {
                Assert.Equal(b, context.TraceId);
            }

            Assert.Equal(a, context.TraceId);
        }

        Assert.Null(context.TraceId);
    }
}