using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Windows;
using LocalizationTool.Models;

namespace LocalizationTool.ViewModels
{
    /// <summary>单个语言的译文输入字段。</summary>
    public class EntryField
    {
        public string LanguageCode { get; set; }
        public string Label { get; set; }
        public string Value { get; set; }
    }

    /// <summary>新增词条窗口：中文 key + 各语言译文（可留空 = 缺译）。</summary>
    public class AddEntryViewModel : ViewModelBase
    {
        private string _key;

        public string Key
        {
            get => _key;
            set
            {
                if (Set(ref _key, value)) OnPropertyChanged(nameof(CanConfirm));
            }
        }

        /// <summary>各目标语言译文输入字段。</summary>
        public ObservableCollection<EntryField> Fields { get; } = new ObservableCollection<EntryField>();

        public bool CanConfirm => !string.IsNullOrWhiteSpace(Key);
        public bool HasNoFields => Fields.Count == 0;

        /// <summary>请求关闭窗口（true = 确认）。</summary>
        public event Action<bool> RequestClose;

        public RelayCommand ConfirmCommand { get; }
        public RelayCommand CancelCommand { get; }

        /// <summary>确认后按语言代码收集的译文（留空的语言不收录）。</summary>
        public Dictionary<string, string> CollectTranslations() =>
            Fields.Where(f => !string.IsNullOrWhiteSpace(f.Value))
                  .ToDictionary(f => f.LanguageCode, f => f.Value.Trim());

        public AddEntryViewModel(IEnumerable<PackFile> langs)
        {
            foreach (var lang in langs ?? Enumerable.Empty<PackFile>())
                Fields.Add(new EntryField
                {
                    LanguageCode = lang.LanguageCode,
                    Label = $"{lang.LanguageName} ({lang.LanguageCode}) —— 可留空待翻译",
                });

            ConfirmCommand = new RelayCommand(() =>
            {
                if (!CanConfirm)
                {
                    MessageBox.Show("请输入中文原文（key）。", "提示");
                    return;
                }
                RequestClose?.Invoke(true);
            });
            CancelCommand = new RelayCommand(() => RequestClose?.Invoke(false));
        }
    }
}