#nullable enable

using System;
using Demo2.Domain;
using UnityEngine;

namespace Demo2.Runtime
{
    public sealed class Demo2HeadlessBootstrap : MonoBehaviour
    {
        private Demo2GameService? _service;
        private Demo2LanRuntime? _lan;

        private void Awake()
        {
            var args = Environment.GetCommandLineArgs();
            if (!Application.isBatchMode && Array.IndexOf(args, "-demo2-headless") < 0) { enabled = false; return; }
            var port = ReadInt(args, "-demo2-port", 27320);
            var mode = ReadString(args, "-demo2-transport", "tcp").Equals("kcp", StringComparison.OrdinalIgnoreCase) ? Demo2TransportMode.Kcp : Demo2TransportMode.Tcp;
            var seed = (ulong)ReadInt(args, "-demo2-seed", 20260817);
            _service = Demo2GameService.Current ?? new Demo2GameService();
            _service.StartNewGame(seed);
            _lan = new Demo2LanRuntime(_service);
            _lan.Host(port, mode, "headless");
            Debug.Log($"[Demo2] Headless server ready. transport={mode} port={port} seed={seed}");
        }

        private void Update()
        {
            _lan?.Pump();
            _service?.AdvanceFrame(Time.unscaledDeltaTime);
        }

        private void OnDestroy() => _lan?.Dispose();

        private static int ReadInt(string[] args, string key, int fallback)
        {
            var index = Array.IndexOf(args, key);
            return index >= 0 && index + 1 < args.Length && int.TryParse(args[index + 1], out var value) ? value : fallback;
        }

        private static string ReadString(string[] args, string key, string fallback)
        {
            var index = Array.IndexOf(args, key);
            return index >= 0 && index + 1 < args.Length ? args[index + 1] : fallback;
        }
    }
}