using NATS.Client.Core;

namespace NATS.Server.Benchmark.Tests.Infrastructure;

/// <summary>
/// Starts both a Go and .NET NATS server with WebSocket enabled for transport overhead benchmarks.
/// Shared across all tests in the "Benchmark-WebSocket" collection.
/// </summary>
public sealed class WebSocketServerFixture : IAsyncLifetime
{
    private GoServerProcess? _goServer;
    private DotNetServerProcess? _dotNetServer;

    public int GoNatsPort => _goServer?.Port ?? throw new InvalidOperationException("Go server not started");
    public int GoWsPort { get; private set; }
    public int DotNetNatsPort => _dotNetServer?.Port ?? throw new InvalidOperationException(".NET server not started");
    public int DotNetWsPort { get; private set; }
    public bool GoAvailable => _goServer is not null;

    public async Task InitializeAsync()
    {
        DotNetWsPort = PortAllocator.AllocateFreePort();

        var dotNetConfig = $$"""
            websocket {
                listen: 127.0.0.1:{{DotNetWsPort}}
                no_tls: true
            }
            """;

        _dotNetServer = new DotNetServerProcess(dotNetConfig);
        var dotNetTask = _dotNetServer.StartAsync();

        if (GoServerProcess.IsAvailable())
        {
            GoWsPort = PortAllocator.AllocateFreePort();

            var goConfig = $$"""
                websocket {
                    listen: 127.0.0.1:{{GoWsPort}}
                    no_tls: true
                }
                """;

            _goServer = new GoServerProcess(goConfig);
            await Task.WhenAll(dotNetTask, _goServer.StartAsync());
        }
        else
        {
            await dotNetTask;
        }
    }

    public async Task DisposeAsync()
    {
        if (_goServer is not null)
            await _goServer.DisposeAsync();
        if (_dotNetServer is not null)
            await _dotNetServer.DisposeAsync();
    }

    public NatsConnection CreateGoNatsClient()
        => new(new NatsOpts { Url = $"nats://127.0.0.1:{GoNatsPort}" });

    public NatsConnection CreateDotNetNatsClient()
        => new(new NatsOpts { Url = $"nats://127.0.0.1:{DotNetNatsPort}" });
}