using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using UnityEditor;
using UnityEditor.AddressableAssets;
using UnityEditor.AddressableAssets.Settings;
using UnityEngine;
using BaseGames.Localization;

namespace BaseGames.Editor.Localization
{
    /// <summary>
    /// 本地化 JSON 表的编辑器侧磁盘读写门面（唯一入口）。
    ///
    /// 所有编辑器工具（表格编辑器、CSV 工具、审计模块、各 Inspector）读写本地化文件
    /// 都必须经此类，统一：路径（<see cref="LocalizationPaths"/>）、格式
    /// （<see cref="LocalizationSerializer"/>）、Addressable 注册、编辑器缓存刷新。
    ///
    /// 这样运行时加载与编辑器写盘永不脱节——杜绝"编辑器看着正常、Play 加载不到"的隐藏 bug。
    /// </summary>
    public static class LocalizationFileIO
    {
        /// <summary>所有受支持语言（枚举顺序）。</summary>
        public static readonly Language[] AllLanguages =
            (Language[])Enum.GetValues(typeof(Language));

        // ── 读 ───────────────────────────────────────────────────────────────

        /// <summary>
        /// 读取指定语言 + 表的 key→value 字典（返回可安全修改的副本，不存在时返回空字典）。
        /// 内部走 <see cref="LocalizationManager.GetEditorTable"/> 复用其静态缓存。
        /// </summary>
        public static Dictionary<string, string> Read(Language language, string table)
        {
            var src = LocalizationManager.GetEditorTable(language, table);
            return src == null
                ? new Dictionary<string, string>(StringComparer.Ordinal)
                : new Dictionary<string, string>(src, StringComparer.Ordinal);
        }

        /// <summary>该表的 JSON 文件是否已存在于磁盘。</summary>
        public static bool TableExists(Language language, string table)
            => AssetDatabase.LoadAssetAtPath<TextAsset>(LocalizationPaths.AssetPath(language, table)) != null;

        /// <summary>扫描数据根目录，返回磁盘上实际存在子目录的语言。</summary>
        public static List<Language> DiscoverLanguages()
        {
            var result = new List<Language>();
            if (!AssetDatabase.IsValidFolder(LocalizationPaths.DataRoot)) return result;

            foreach (var langFolder in AssetDatabase.GetSubFolders(LocalizationPaths.DataRoot))
            {
                string langName = Path.GetFileName(langFolder);
                if (Enum.TryParse<Language>(langName, out var lang))
                    result.Add(lang);
            }
            return result;
        }

        // ── 写 ───────────────────────────────────────────────────────────────

        /// <summary>
        /// 将字典写回指定语言 + 表的 JSON 文件（正确的 <c>{entries:[…]}</c> 格式 + 正确目录）。
        /// 新文件会自动注册到 Addressables（地址 <see cref="LocalizationPaths.Address"/>），
        /// 写盘后清除编辑器预览缓存。
        /// </summary>
        /// <param name="language">目标语言。</param>
        /// <param name="table">目标表名（<see cref="LocalizationTable"/> 常量）。</param>
        /// <param name="dict">key→value 字典。</param>
        /// <param name="registerAddressable">是否确保 Addressable 注册（默认 true）。</param>
        public static void Write(Language language, string table,
            IReadOnlyDictionary<string, string> dict, bool registerAddressable = true)
        {
            string assetPath = LocalizationPaths.AssetPath(language, table);
            EditorScaffoldUtils.EnsureFolder(LocalizationPaths.LanguageFolder(language));

            // JSON 文件不写 BOM（Addressables/TextAsset 解析期望纯 UTF-8）。
            string json = LocalizationSerializer.Serialize(dict, sortKeys: true);
            string fullPath = ToFullPath(assetPath);
            File.WriteAllText(fullPath, json, new UTF8Encoding(encoderShouldEmitUTF8Identifier: false));

            AssetDatabase.ImportAsset(assetPath, ImportAssetOptions.ForceUpdate);

            if (registerAddressable)
                EnsureAddressable(language, table, assetPath);

            LocalizationManager.ClearEditorPreviewCache();
        }

        // ── Ping ───────────────────────────────────────────────────────────────

        /// <summary>在 Project 窗口中定位指定语言 + 表的 JSON 文件。</summary>
        public static TextAsset Ping(Language language, string table)
        {
            var asset = AssetDatabase.LoadAssetAtPath<TextAsset>(LocalizationPaths.AssetPath(language, table));
            if (asset != null) EditorScaffoldUtils.PingAndSelect(asset);
            return asset;
        }

        /// <summary>在 Project 窗口中定位指定表的任一存在语言文件（优先简体中文 → 英文 → 其余）。</summary>
        public static TextAsset PingAny(string table)
        {
            foreach (var lang in OrderedForPing())
            {
                var asset = AssetDatabase.LoadAssetAtPath<TextAsset>(LocalizationPaths.AssetPath(lang, table));
                if (asset != null) { EditorScaffoldUtils.PingAndSelect(asset); return asset; }
            }
            Debug.LogWarning($"[LocalizationFileIO] 未找到本地化表文件：{LocalizationPaths.DataRoot}/…/{table}.json");
            return null;
        }

        // ── 内部 ───────────────────────────────────────────────────────────────

        private static IEnumerable<Language> OrderedForPing()
        {
            yield return Language.ChineseSimplified;
            yield return Language.English;
            foreach (var lang in AllLanguages)
                if (lang != Language.ChineseSimplified && lang != Language.English)
                    yield return lang;
        }

        /// <summary>
        /// 确保该 JSON 文件已注册为对应 Addressable 地址。
        /// 复用 <see cref="BaseGames.Editor.Addressables.CoreSceneRegistrar"/> 的 FindEntry-or-Create 幂等范式。
        /// </summary>
        private static void EnsureAddressable(Language language, string table, string assetPath)
        {
            var settings = AddressableAssetSettingsDefaultObject.Settings;
            if (settings == null)
            {
                Debug.LogWarning(
                    $"[LocalizationFileIO] Addressable Settings 未初始化，未能注册 " +
                    $"{LocalizationPaths.Address(language, table)}。运行时可能加载不到该表。");
                return;
            }

            string guid = AssetDatabase.AssetPathToGUID(assetPath);
            if (string.IsNullOrEmpty(guid)) return;

            string address = LocalizationPaths.Address(language, table);
            var entry = settings.FindAssetEntry(guid)
                        ?? settings.CreateOrMoveEntry(guid, settings.DefaultGroup, false, false);

            // 已注册且地址正确则无需改动（避免无意义的 SetDirty）。
            if (entry.address == address) return;

            entry.address = address;
            EditorUtility.SetDirty(settings);
            AssetDatabase.SaveAssets();
        }

        private static string ToFullPath(string assetPath)
        {
            string projectRoot = Path.GetDirectoryName(Application.dataPath)!;
            return Path.Combine(projectRoot, assetPath.Replace('/', Path.DirectorySeparatorChar));
        }
    }
}