using System.Net.WebSockets;
using Backend;

var builder = WebApplication.CreateBuilder(args);

// -------- Config --------
builder.Services.Configure<LanderConfig>(builder.Configuration.GetSection("Lander"));

// -------- Singletons --------
builder.Services.AddSingleton<PolicyRunner>(sp =>
{
    var cfg = sp.GetRequiredService<Microsoft.Extensions.Options.IOptions<LanderConfig>>().Value;
    var absolute = PathResolver.Resolve(cfg.ModelPath);
    return new PolicyRunner(absolute);
});

builder.Services.AddLogging();

var app = builder.Build();

// Fail-fast: eagerly resolve PolicyRunner so a missing ONNX file surfaces at
// startup rather than on the first WebSocket connect.
var startupLogger = app.Services.GetRequiredService<ILoggerFactory>().CreateLogger("Startup");
var policy = app.Services.GetRequiredService<PolicyRunner>();
var modelPath = PathResolver.Resolve(
    app.Services.GetRequiredService<Microsoft.Extensions.Options.IOptions<LanderConfig>>().Value.ModelPath);
startupLogger.LogInformation("Loaded PPO policy from {ModelPath}", modelPath);

app.UseWebSockets();

// -------- Health --------
app.MapGet("/", () => "GameCli Backend");

// -------- WebSocket endpoint --------
app.Map("/ws/game", async (HttpContext ctx,
                          PolicyRunner policy,
                          Microsoft.Extensions.Options.IOptions<LanderConfig> cfg,
                          ILoggerFactory loggerFactory) =>
{
    if (!ctx.WebSockets.IsWebSocketRequest)
    {
        ctx.Response.StatusCode = 400;
        return;
    }
    using var socket = await ctx.WebSockets.AcceptWebSocketAsync();
    var cliPath = PathResolver.Resolve(cfg.Value.CliPath);
    var proc = new GameProcess(cliPath);
    var logger = loggerFactory.CreateLogger<GameSession>();
    await using var session = new GameSession(socket, proc, policy, logger);
    try
    {
        await session.RunAsync(ctx.RequestAborted);
    }
    catch (WebSocketException) { /* client disconnected */ }
    catch (OperationCanceledException) { /* shutdown */ }
});

app.Run();

// -------- Public program class so Backend.Tests can use WebApplicationFactory --------
public partial class Program { }