using System.Collections.ObjectModel;
using System.Linq;
using TeamAAS.Localization;
using Prism.Commands;

namespace TeamAAS.ViewModels
{
    /// <summary>
    /// 设置页 ViewModel - 语言设置部分
    /// </summary>
    public partial class SettingViewModel
    {
        #region 语言设置

        /// <summary>
        /// 可用语言列表
        /// </summary>
        public ObservableCollection<LanguageOption> AvailableLanguages { get; } = new ObservableCollection<LanguageOption>();

        private LanguageOption _selectedLanguage;
        /// <summary>
        /// 当前选中的语言
        /// </summary>
        public LanguageOption SelectedLanguage
        {
            get => _selectedLanguage;
            set
            {
                if (SetProperty(ref _selectedLanguage, value) && value != null)
                {
                    // 实时切换语言
                    GlobalLocalizationManager.Instance.CurrentLanguage = value.Code;
                    
                    // 保存到系统配置
                    App.SystemConfig.Language = value.Code;
                    App.SaveSystemConfig();
                }
            }
        }

        /// <summary>
        /// 刷新语言命令
        /// </summary>
        public DelegateCommand RefreshLanguagesCommand { get; }

        /// <summary>
        /// 初始化语言设置
        /// </summary>
        private void InitializeLanguageSettings()
        {
            LoadAvailableLanguages();
        }

        /// <summary>
        /// 加载可用语言列表（动态获取）
        /// </summary>
        private void LoadAvailableLanguages()
        {
            AvailableLanguages.Clear();

            // 从多语言管理器获取已加载的语言
            var languages = GlobalLocalizationManager.Instance.AvailableLanguages;
            // 添加已加载的语言
            foreach (var langCode in languages)
            {
                var displayName = GlobalLocalizationManager.Instance.GetLanguageName(langCode);
                AvailableLanguages.Add(new LanguageOption
                {
                    Code = langCode,
                    DisplayName = displayName
                });
            }

            // 如果没有加载任何语言，至少添加中文
            if (AvailableLanguages.Count == 0)
            {
                AvailableLanguages.Add(new LanguageOption
                {
                    Code = "zh-CN",
                    DisplayName = "简体中文"
                });
            }

            // 设置当前选中的语言
            var currentLang = GlobalLocalizationManager.Instance.CurrentLanguage;
            _selectedLanguage = AvailableLanguages.FirstOrDefault(l => l.Code == currentLang)
                             ?? AvailableLanguages.FirstOrDefault();
            
            RaisePropertyChanged(nameof(SelectedLanguage));
        }

        /// <summary>
        /// 刷新语言列表（用于动态添加新语言后刷新）
        /// </summary>
        private void RefreshLanguages()
        {
            var localizationPath = PathHelper.ResolveLocalizationDir();
            GlobalLocalizationManager.Instance.LoadLanguagePacks(localizationPath);
            LoadAvailableLanguages();
        }

        #endregion
    }

    /// <summary>
    /// 语言选项
    /// </summary>
    public class LanguageOption
    {
        /// <summary>
        /// 语言代码（如 "zh-CN", "en-US"）
        /// </summary>
        public string Code { get; set; }

        /// <summary>
        /// 显示名称（如 "简体中文", "English"）
        /// </summary>
        public string DisplayName { get; set; }

        public override string ToString() => DisplayName;
    }
}