using System.IO;
using System.Text.Json;

namespace XWorld.Server.Host
{
    public sealed class GameManifest
    {
        public string GameId { get; set; }
        public int Version { get; set; }
        public string ServerAssembly { get; set; }   // 例如 "RPS.Server.dll"
        public string ServerEntryType { get; set; }  // 例如 "RPS.Server.RpsServerRoom"
        public int MinFrameworkVersion { get; set; }
        public int PlayerCount { get; set; }
        public int TickRateHz { get; set; }

        public static GameManifest Parse(string json)
        {
            var opts = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
            GameManifest m;
            try { m = JsonSerializer.Deserialize<GameManifest>(json, opts); }
            catch (JsonException ex) { throw new InvalidDataException("game.json: 无法解析", ex); }

            if (m == null) throw new InvalidDataException("game.json: 内容为空");
            if (string.IsNullOrEmpty(m.GameId)) throw new InvalidDataException("game.json: 缺少 gameId");
            if (string.IsNullOrEmpty(m.ServerEntryType)) throw new InvalidDataException("game.json: 缺少 serverEntryType");
            if (string.IsNullOrEmpty(m.ServerAssembly)) throw new InvalidDataException("game.json: 缺少 serverAssembly");
            if (m.Version <= 0) throw new InvalidDataException("game.json: version 必须为正");
            return m;
        }

        public static GameManifest Load(string path) => Parse(File.ReadAllText(path));
    }
}