using System.Net;
using System.Net.Sockets;
using Microsoft.Extensions.Logging.Abstractions;
using NUnit.Framework;
using RhMcp.Router;

namespace RhMcp.Router.Tests;

// Locks in the single-source-of-truth seam both spawn callers (SpawnSlotTool and
// ProxyDispatcher) now share. If the spawn-pipeline exception->code map drifts,
// these break, they previously couldn't, because each caller had its own copy.
[TestFixture]
public class SpawnDiagnosticsTests
{
    private static RhinoCrashReportFinder Finder => new(NullLogger<RhinoCrashReportFinder>.Instance);

    [Test]
    public void FileNotFound_classifies_as_rhino_not_installed()
    {
        bool ok = SpawnDiagnostics.TryClassify(
            new FileNotFoundException("Rhino 9 is not installed."), Finder, out SpawnDiagnostics.SpawnDiagnosis d);

        Assert.That(ok, Is.True);
        Assert.That(d.Code, Is.EqualTo("rhino_not_installed"));
        // Base message carries the diagnosis; the next-action suffix is the caller's.
        Assert.That(d.BaseMessage, Is.EqualTo("Rhino 9 is not installed."));
    }

    [Test]
    public void PluginNotInstalled_classifies_with_versions_and_setup_link()
    {
        bool ok = SpawnDiagnostics.TryClassify(
            new PluginNotInstalledException("8", ["9"]), Finder, out SpawnDiagnostics.SpawnDiagnosis d);

        Assert.That(ok, Is.True);
        Assert.That(d.Code, Is.EqualTo("plugin_not_installed"));
        Assert.That(d.BaseMessage, Does.Contain("Rhino 8"));
        Assert.That(d.BaseMessage, Does.Contain("installed for: 9"));
        Assert.That(d.BaseMessage, Does.Contain("getting-started"));
    }

    [Test]
    public void Timeout_classifies_as_startup_timeout_with_shared_advice()
    {
        bool ok = SpawnDiagnostics.TryClassify(
            new TimeoutException("Rhino didn't start in time."), Finder, out SpawnDiagnostics.SpawnDiagnosis d);

        Assert.That(ok, Is.True);
        Assert.That(d.Code, Is.EqualTo("startup_timeout"));
        Assert.That(d.BaseMessage, Does.Contain("license, EULA, or update dialog"));
    }

    [Test]
    public void PlatformNotSupported_classifies_as_unsupported_platform()
    {
        bool ok = SpawnDiagnostics.TryClassify(
            new PlatformNotSupportedException("WIP not on this OS."), Finder, out SpawnDiagnostics.SpawnDiagnosis d);

        Assert.That(ok, Is.True);
        Assert.That(d.Code, Is.EqualTo("unsupported_platform"));
        Assert.That(d.BaseMessage, Is.EqualTo("WIP not on this OS."));
    }

    [Test]
    public void Connection_level_http_failure_classifies_as_existing_rhino_unreachable()
    {
        HttpRequestException hre = new(
            HttpRequestError.ConnectionError, "connection refused", inner: new SocketException());

        bool ok = SpawnDiagnostics.TryClassify(hre, Finder, out SpawnDiagnostics.SpawnDiagnosis d);

        Assert.That(ok, Is.True);
        Assert.That(d.Code, Is.EqualTo("existing_rhino_unreachable"));
        Assert.That(d.BaseMessage, Does.Contain("stale slot has been pruned"));
    }

    [Test]
    public void Non_connection_http_failure_is_not_a_shared_shape()
    {
        // HTTP 5xx from the plugin: Rhino is alive, the request failed. Each caller
        // handles this itself, so the shared classifier must decline it.
        HttpRequestException hre = new("Child Rhino returned HTTP 500");

        bool ok = SpawnDiagnostics.TryClassify(hre, Finder, out _);

        Assert.That(ok, Is.False);
    }

    [TestCase(typeof(InvalidOperationException))]
    [TestCase(typeof(OperationCanceledException))]
    [TestCase(typeof(Exception))]
    public void Caller_specific_shapes_are_declined(Type exceptionType)
    {
        Exception ex = (Exception)Activator.CreateInstance(exceptionType)!;

        bool ok = SpawnDiagnostics.TryClassify(ex, Finder, out _);

        Assert.That(ok, Is.False);
    }
}