using System;

using AibisDream.Utility;

using Newtonsoft.Json;

using UnityEngine;



namespace AibisDream.SaveSystem

{

    /// <summary>

    /// <see cref="SaveSnapshot"/> 与 JSON 互转；写入时带上 <see cref="SaveSnapshotSchema.CurrentVersion"/>。

    /// 被 <see cref="SnapshotPersistence"/> 调用，业务层通常不直接使用。

    /// </summary>

    public static class SnapshotSerializer

    {

        private static readonly JsonSerializerSettings Settings = new()

        {

            TypeNameHandling = TypeNameHandling.None,

            ReferenceLoopHandling = ReferenceLoopHandling.Ignore,

            NullValueHandling = NullValueHandling.Ignore

        };



        public static string Serialize(SaveSnapshot snapshot)

        {

            snapshot.schemaVersion = SaveSnapshotSchema.CurrentVersion;

            return JsonConvert.SerializeObject(snapshot, Formatting.Indented, Settings);

        }



        public static SaveSnapshot Deserialize(string json)

        {

            var snapshot = JsonConvert.DeserializeObject<SaveSnapshot>(json, Settings);

            if (snapshot.schemaVersion != SaveSnapshotSchema.CurrentVersion)

            {

                Debug.LogWarning(

                    $"[SnapshotSerializer] schemaVersion {snapshot.schemaVersion} != {SaveSnapshotSchema.CurrentVersion}，按当前结构读取。");

            }



            return snapshot;

        }



        public static void SaveToFile(SaveSnapshot snapshot, string pathWithoutExtension)

        {

            var json = Serialize(snapshot);

            var dir = System.IO.Path.GetDirectoryName(JsonUtil.FormatAsJsonPath(pathWithoutExtension));

            if (!string.IsNullOrEmpty(dir))

            {

                System.IO.Directory.CreateDirectory(dir);

            }



            System.IO.File.WriteAllText(JsonUtil.FormatAsJsonPath(pathWithoutExtension), json);

        }



        public static SaveSnapshot LoadFromFile(string pathWithoutExtension)

        {

            var json = System.IO.File.ReadAllText(JsonUtil.FormatAsJsonPath(pathWithoutExtension));

            return Deserialize(json);

        }

    }

}