using SpaceGame.Simulation.Api.Contracts;
using SpaceGame.Simulation.Api.Simulation;
using System.Text.Json;

var builder = WebApplication.CreateBuilder(args);
var sseJsonOptions = new JsonSerializerOptions(JsonSerializerDefaults.Web);

builder.WebHost.UseUrls("http://127.0.0.1:5079");
builder.Services.AddCors((options) =>
{
  options.AddDefaultPolicy((policy) =>
  {
    policy
      .AllowAnyHeader()
      .AllowAnyMethod()
      .AllowAnyOrigin();
  });
});
builder.Services.AddSingleton<WorldService>();
builder.Services.AddHostedService<SimulationHostedService>();

var app = builder.Build();

app.UseCors();

app.MapGet("/", () => Results.Redirect("/api/world"));
app.MapGet("/api/world", (WorldService worldService) => Results.Ok(worldService.GetSnapshot()));
app.MapGet("/api/world/stream", async (HttpContext httpContext, WorldService worldService, CancellationToken cancellationToken) =>
{
  httpContext.Response.Headers.Append("Cache-Control", "no-cache");
  httpContext.Response.Headers.Append("Content-Type", "text/event-stream");

  var afterSequenceRaw = httpContext.Request.Query["afterSequence"].ToString();
  _ = long.TryParse(afterSequenceRaw, out var afterSequence);
  var scopeKind = httpContext.Request.Query["scopeKind"].ToString();
  if (string.IsNullOrWhiteSpace(scopeKind))
  {
    scopeKind = httpContext.Request.Query["scope"].ToString();
  }

  if (string.IsNullOrWhiteSpace(scopeKind))
  {
    scopeKind = "universe";
  }

  var systemId = httpContext.Request.Query["systemId"].ToString();
  var bubbleId = httpContext.Request.Query["bubbleId"].ToString();
  var scope = new ObserverScope(
    scopeKind,
    string.IsNullOrWhiteSpace(systemId) ? null : systemId,
    string.IsNullOrWhiteSpace(bubbleId) ? null : bubbleId);
  var stream = worldService.Subscribe(scope, afterSequence, cancellationToken);

  await httpContext.Response.WriteAsync(": connected\n\n", cancellationToken);
  await httpContext.Response.Body.FlushAsync(cancellationToken);

  await foreach (var delta in stream.ReadAllAsync(cancellationToken))
  {
    var payload = JsonSerializer.Serialize(delta, sseJsonOptions);
    await httpContext.Response.WriteAsync($"event: world-delta\ndata: {payload}\n\n", cancellationToken);
    await httpContext.Response.Body.FlushAsync(cancellationToken);
  }
});
app.MapGet("/api/world/health", (WorldService worldService) => Results.Ok(new
{
  ok = true,
  sequence = worldService.GetStatus().Sequence,
  generatedAtUtc = worldService.GetStatus().GeneratedAtUtc,
}));
app.MapPost("/api/world/reset", (WorldService worldService) =>
{
  var snapshot = worldService.Reset();
  return Results.Ok(snapshot);
});

app.Run();