using System;
using System.IO;
using System.Security.Cryptography;
using Ashfall.Core;
using UnityEngine;

namespace Ashfall.Runtime
{
    public sealed class UnityWorldCodec : IWorldCodec
    {
        public string Encode(WorldState world) => JsonUtility.ToJson(world);
        public WorldState Decode(string json) => JsonUtility.FromJson<WorldState>(json);
    }
    [Serializable]
    public sealed class JoinIdentity
    {
        public string playerId, token, name;
        public Species species;
        public const string Protocol = "ashfall-prototype-1";
        public string protocol = Protocol;
    }
    [Serializable]
    public sealed class WorldPacket
    {
        public bool full;
        public WorldState world;
        public string recipient;
    }
    [Serializable]
    public sealed class CommandReply { public long sequence; public bool success; public string message; }

    public static class LocalProfile
    {
        public static JoinIdentity Load(string profile)
        {
            string safe = "";
            foreach (char c in profile) if (char.IsLetterOrDigit(c) || c == '-') safe += c;
            if (safe == "") safe = "default";
            string directory = Path.Combine(Application.persistentDataPath, "Profiles"); Directory.CreateDirectory(directory);
            string path = Path.Combine(directory, safe + ".json");
            if (File.Exists(path))
            {
                var identity = JsonUtility.FromJson<JoinIdentity>(File.ReadAllText(path));
                if (identity != null && Guid.TryParse(identity.playerId, out _) && identity.token?.Length == 64) return identity;
                throw new InvalidDataException("本地身份文件无效；请备份 Profiles 目录后使用新的 --profile 名称。");
            }
            byte[] secret = new byte[32]; using (var rng = RandomNumberGenerator.Create()) rng.GetBytes(secret);
            var value = new JoinIdentity { playerId = Guid.NewGuid().ToString("N"), token = BitConverter.ToString(secret).Replace("-", ""), name = "幸存者" };
            File.WriteAllText(path, JsonUtility.ToJson(value)); return value;
        }
        public static string TokenHash(string token)
        { using (var hash = SHA256.Create()) return Convert.ToBase64String(hash.ComputeHash(System.Text.Encoding.UTF8.GetBytes(token ?? ""))); }
    }
}