using AibisDream.Kit;
using UnityEngine;
using UnityEngine.Localization;
using UnityEngine.Localization.Settings;
#if UNITY_EDITOR
using UnityEditor;
#endif

namespace AibisDream.Framework
{
    /// <summary>
    /// csv 本地化列类别。集中声明"哪些 Locale 归到哪一列"，csv 数据类按此枚举取字段。
    /// </summary>
    public enum LocaleKind
    {
        Cn,
        En,
        Ja
    }

    public static class LocalizationKit
    {
        private const string LocalizationPrefix = "l10n.";

        public static string CurrentLanguageCode { get; private set; } = "zh-Hans";
        public static Locale CurrentLocale => LocalizationSettings.SelectedLocale;

        /// <summary>
        /// 把 LocaleCode 映射到 csv 列类别。集中在此一处，便于扩展（加新语言时修改这里 + LocaleKind 枚举 + 数据类字段）。
        /// </summary>
        public static LocaleKind GetLocaleKind(string localeCode)
        {
            if (string.IsNullOrEmpty(localeCode)) return LocaleKind.Cn;
            if (localeCode.StartsWith("en")) return LocaleKind.En;
            if (localeCode.StartsWith("ja")) return LocaleKind.Ja;
            return LocaleKind.Cn;
        }

        public static LocaleKind CurrentLocaleKind => GetLocaleKind(CurrentLanguageCode);

        /// <summary>
        /// 解析 setting.json 中的 Language：空值表示跟随系统语言，否则使用用户保存的 code。
        /// </summary>
        public static string ResolveLanguage(string savedLanguage)
        {
            if (!string.IsNullOrWhiteSpace(savedLanguage))
            {
                return savedLanguage.Trim();
            }

            return MapSystemLanguage(Application.systemLanguage);
        }

        /// <summary>
        /// 将 Unity 系统语言映射到项目支持的 Locale code。
        /// </summary>
        public static string MapSystemLanguage(SystemLanguage lang) => lang switch
        {
            SystemLanguage.Chinese or SystemLanguage.ChineseSimplified or SystemLanguage.ChineseTraditional => "zh-Hans",
            SystemLanguage.Japanese => "ja-JP",
            SystemLanguage.English => "en",
            _ => "en",
        };

        static LocalizationKit()
        {
#if UNITY_EDITOR
            EditorApplication.playModeStateChanged += OnPlayModeChanged;
#else
            LocalizationSettings.SelectedLocaleChanged += OnLocaleChanged;
            RefreshCurrentLanguageCodeAsync();
#endif
        }

        private static void OnLocaleChanged(Locale locale)
        {
            UpdateCurrentLanguageCode(locale);
            EnumEventSystem.Global.Send(SettingChangeEvent.LocaleChanged, locale);
        }

        private static void UpdateCurrentLanguageCode(Locale locale)
        {
            if (locale != null)
            {
                CurrentLanguageCode = locale.Identifier.Code;
            }
        }

        private static async void RefreshCurrentLanguageCodeAsync()
        {
            await LocalizationSettings.InitializationOperation.Task;
            UpdateCurrentLanguageCode(LocalizationSettings.SelectedLocale);
        }

#if UNITY_EDITOR
        private static void OnPlayModeChanged(PlayModeStateChange playMode)
        {
            if (playMode == PlayModeStateChange.EnteredPlayMode)
            {
                LocalizationSettings.SelectedLocaleChanged += OnLocaleChanged;
                RefreshCurrentLanguageCodeAsync();
            }
            else if (playMode == PlayModeStateChange.ExitingPlayMode)
            {
                LocalizationSettings.SelectedLocaleChanged -= OnLocaleChanged;
            }
        }
#endif

        public static async void SwitchLanguage(string localeCode)
        {
            // 等待本地化系统初始化完成
            await LocalizationSettings.InitializationOperation.Task;

            var selectedLocale =
                LocalizationSettings.AvailableLocales.Locales.Find(locale => locale.Identifier.Code == localeCode);

            if (selectedLocale)
            {
                LocalizationSettings.SelectedLocale = selectedLocale;
            }
            else
            {
                Debug.LogWarning($"Locale with code {localeCode} not found.");
            }
        }

        /// <summary>
        /// 本地化参数
        /// </summary>
        /// <param name="param">参数名</param>
        /// <returns></returns>
        public static string LocalizeParam(string param)
        {
            // 非本地化参数直接返回
            if (string.IsNullOrEmpty(param)) return param;
            if (!param.StartsWith(LocalizationPrefix)) return param;

            var localizationKey = param[LocalizationPrefix.Length..];
            if (ConfigUtil.Instance.TryGetParam(localizationKey, out var value))
            {
                return value.LocalizeByKind(CurrentLocaleKind);
            }

            // 如果找不到，则使用原始值
            Debug.LogWarning($"Variable Key '{localizationKey}' not found in params csv.");
            return localizationKey;
        }

        public static string GetL10NParamKey(string key)
        {
            // 本地化参数则去除前缀，非本地化参数直接返回
            return key.StartsWith(LocalizationPrefix) ? key[LocalizationPrefix.Length..] : key;
        }

        /// <summary>
        /// 确保本地化系统已初始化
        /// </summary>
        /// <returns>初始化操作</returns>
        public static async void EnsureInitialized()
        {
            await LocalizationSettings.InitializationOperation.Task;
        }
    }
}