using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using LocalizationTool.Models;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace LocalizationTool.Services
{
    /// <summary>
    /// 语言包仓库（JSON 格式，人类可读，与主程序 TeamAAS 共用同一份 .json 文件）。
    /// </summary>
    public static class PackRepository
    {
        /// <summary>加载目录下所有语言包；zh-CN 识别为源（IsSource）。</summary>
        public static List<PackFile> Load(string dir)
        {
            var packs = new List<PackFile>();

            foreach (var file in Directory.GetFiles(dir, "*.json"))
            {
                try
                {
                    var pack = LanguagePackIO.LoadJson(file);
                    var code = pack.LanguageCode;
                    packs.Add(new PackFile
                    {
                        FilePath = file,
                        LanguageCode = code,
                        LanguageName = pack.LanguageName ?? code,
                        Version = pack.Version,
                        Author = pack.Author,
                        IsSource = code == "zh-CN",
                        Translations = pack.Translations ?? new Dictionary<string, string>(),
                    });
                }
                catch { /* 解析失败的文件跳过 */ }
            }

            return packs.OrderBy(p => p.LanguageCode).ToList();
        }

        /// <summary>
        /// 构建全部行：Key = 应翻译的中文源文集合。
        /// 来源= 所有语言 translations 键的并集 ∪ zh-CN 分节结构的叶子中文值（捕获新属性）。
        /// </summary>
        public static List<RowVm> BuildRows(List<PackFile> packs, out List<PackFile> targetLangs)
        {
            var source = packs.FirstOrDefault(p => p.IsSource);
            targetLangs = packs.Where(p => !p.IsSource).ToList();

            var keys = new HashSet<string>(StringComparer.Ordinal);
            foreach (var p in packs)
                foreach (var k in p.Translations.Keys)
                    keys.Add(k);
            if (source != null)
                foreach (var cv in EnumerateChineseValues(source))
                    keys.Add(cv);

            // 排序：优先按 zh-CN 源的枚举顺序——新增词条自然排在末尾，不再"随机"插入
            List<string> orderedKeys;
            if (source != null)
            {
                orderedKeys = new List<string>();
                var seen = new HashSet<string>(StringComparer.Ordinal);
                foreach (var k in source.Translations.Keys)
                    if (keys.Contains(k) && seen.Add(k))
                        orderedKeys.Add(k);
                // 仅存在于其他语言包的 key 追加在后（字母序）
                foreach (var k in keys.OrderBy(k => k, StringComparer.Ordinal))
                    if (seen.Add(k))
                        orderedKeys.Add(k);
            }
            else
            {
                orderedKeys = keys.OrderBy(k => k, StringComparer.Ordinal).ToList();
            }

            var rows = new List<RowVm>();
            int index = 1;
            foreach (var key in orderedKeys)
            {
                var row = new RowVm { Index = index++, Key = key };
                foreach (var lang in targetLangs)
                {
                    lang.Translations.TryGetValue(key, out var val);
                    row.Cells[lang.LanguageCode] = new CellVm { LangCode = lang.LanguageCode, Value = val ?? "" };
                }
                rows.Add(row);
            }
            return rows;
        }

        /// <summary>保存语言包为 .json（人类可读）。</summary>
        public static void Save(PackFile pack)
        {
            LanguagePackIO.SaveJson(new LanguagePack
            {
                LanguageCode = pack.LanguageCode,
                LanguageName = pack.LanguageName,
                Version = string.IsNullOrWhiteSpace(pack.Version) ? "1.0.0" : pack.Version,
                Author = pack.Author ?? "TeamAAS",
                Translations = pack.Translations
            }, pack.FilePath);
        }

        /// <summary>新增语言：以 zh-CN 中文源为 Key 集生成空模板（值留空）。</summary>
        public static bool CreateFromTemplate(string langCode, string langName, List<PackFile> packs, string dir, out PackFile result)
        {
            result = null;
            if (string.IsNullOrWhiteSpace(langCode)) return false;
            var path = Path.Combine(dir, langCode + ".json");
            if (File.Exists(path)) return false;

            var source = packs.FirstOrDefault(p => p.IsSource);
            var pack = new PackFile
            {
                FilePath = path,
                LanguageCode = langCode,
                LanguageName = langName,
                Version = "1.0.0",
                Author = "TeamAAS",
                IsSource = false,
            };
            foreach (var kv in EnumerateKeysFromSource(packs, source))
                pack.Translations[kv] = "";

            Save(pack);
            result = pack;
            return true;
        }

        /// <summary>由各语言 translations 键并集 + zh 源值生成"应翻译 Key 集"（供模板/新增语言用）。</summary>
        private static IEnumerable<string> EnumerateKeysFromSource(List<PackFile> packs, PackFile source)
        {
            var keys = new HashSet<string>(StringComparer.Ordinal);
            foreach (var p in packs)
                foreach (var k in p.Translations.Keys)
                    keys.Add(k);
            if (source != null)
                foreach (var cv in EnumerateChineseValues(source))
                    keys.Add(cv);
            return keys;
        }

        /// <summary>zh-CN 分节结构的所有叶子中文值（properties/plugins/pluginCategories/enums/uiTexts）。</summary>
        private static IEnumerable<string> EnumerateChineseValues(PackFile source)
        {
            var result = new List<string>();
            try
            {
                var root = JObject.Parse(File.ReadAllText(source.FilePath, Encoding.UTF8));
                foreach (var leaf in EnumerateLeaves(root))
                    if (leaf.Value is JValue jv && jv.Value is string s && !string.IsNullOrWhiteSpace(s))
                        result.Add(s);
            }
            catch { }
            return result;
        }

        /// <summary>校验：JSON 可解析、UTF-8、含 languageCode。</summary>
        public static List<string> Validate(string dir)
        {
            var errors = new List<string>();
            foreach (var file in Directory.GetFiles(dir, "*.json"))
            {
                var bytes = HandleBom(File.ReadAllBytes(file));
                try { new UTF8Encoding(false, true).GetString(bytes); }
                catch (Exception) { errors.Add($"{Path.GetFileName(file)}: 不是合法 UTF-8"); }

                try
                {
                    var root = JObject.Parse(Encoding.UTF8.GetString(bytes));
                    if (root["languageCode"] == null)
                        errors.Add($"{Path.GetFileName(file)}: 缺少 languageCode");
                }
                catch (Exception) { errors.Add($"{Path.GetFileName(file)}: JSON 解析失败"); }
            }
            return errors;
        }

        private static byte[] HandleBom(byte[] bytes)
        {
            if (bytes.Length >= 3 && bytes[0] == 0xEF && bytes[1] == 0xBB && bytes[2] == 0xBF)
                return bytes.Skip(3).ToArray();
            return bytes;
        }

        // ---------- 通用叶子枚举（供 zh-CN 分节结构取值） ----------
        public class Leaf { public string Section; public string Path; public JToken Value; public List<string> ValuePath; }

        public static IEnumerable<Leaf> EnumerateLeaves(JObject root)
        {
            var list = new List<Leaf>();
            WalkSection(root, "properties", list, 4);
            WalkSection(root, "plugins", list, 3);
            WalkSection(root, "pluginCategories", list, 2);
            WalkSection(root, "enums", list, 3);
            WalkSection(root, "uiTexts", list, 2);
            return list;
        }

        private static void WalkSection(JObject root, string section, List<Leaf> list, int depth)
        {
            var seg = root[section];
            if (seg == null) return;
            Collect(seg, new List<string> { section }, section, depth, list);
        }

        private static void Collect(JToken token, List<string> prefix, string section, int depth, List<Leaf> list)
        {
            if (token is JObject obj)
            {
                foreach (var prop in obj.Properties())
                {
                    var next = new List<string>(prefix) { prop.Name };
                    if (next.Count == depth && prop.Value is JValue v)
                        list.Add(new Leaf { Section = section, Path = string.Join(".", next), Value = v, ValuePath = next });
                    else
                        Collect(prop.Value, next, section, depth, list);
                }
            }
        }
    }
}