using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Globalization;
using System.IO;
using System.Text.Json;
using ClosedXML.Excel;

namespace Deckungsbeitrag.AA_Klassen
{
  public class TranslationService
  {
    private static Dictionary<string, Dictionary<string, string>> _data = new Dictionary<string, Dictionary<string, string>>();
    public static string CurrentLanguage { get; set; } = "de";
    public static string FallbackLanguage { get; set; } = "de";

    public static IReadOnlyList<string> AvailableLanguages =>
        _data.Values
             .SelectMany(d => d.Keys)
             .Distinct(StringComparer.OrdinalIgnoreCase)
             .OrderBy(x => x)
             .ToList();

    public static void Load(string filePath = @"N:\TECHNIK\Software\Wirl-Verwaltung\Test\translations.json")
    {
      var json = File.ReadAllText(filePath);
      _data = JsonSerializer.Deserialize<Dictionary<string, Dictionary<string, string>>>(json)
              ?? new Dictionary<string, Dictionary<string, string>>();
    }

    public static void SetLanguage(string languageCode)
    {
      //CultureInfo.CurrentUICulture = new CultureInfo(languageCode);
      //CultureInfo.CurrentCulture = new CultureInfo(languageCode);
      CurrentLanguage = languageCode.Substring(0,2);
    }

    /// <summary>
    /// Verwenden um die Strings zu erhalten.
    /// </summary>
    /// <param name="key"></param>
    /// <param name="args"></param>
    /// <returns>Einen String in der gewünschten Sprache</returns>
    public static string T(string key, params object[] args)
    {
      if (_data.TryGetValue(key, out var translations))
      {
        if (translations.TryGetValue(CurrentLanguage, out var text))
          return Format(text, args);

        if (!string.IsNullOrWhiteSpace(FallbackLanguage) &&
            translations.TryGetValue(FallbackLanguage, out text))
          return Format(text, args);
      }

      int i = key.IndexOf('.');
      return $"{key.Substring(i + 1)}";
    }

    private static string Format(string text, object[] args)
        => args != null && args.Length > 0 ? string.Format(text, args) : text;

    public static void Convert(string excelFile, string jsonFile, string sheetName = "Translation01")
    {
      var result = new Dictionary<string, Dictionary<string, string>>();

      var workbook = new XLWorkbook(excelFile);
      var ws = workbook.Worksheet(sheetName);

      var usedRange = ws.RangeUsed();
      if (usedRange == null)
        throw new InvalidOperationException("Excel sheet is empty.");

      var headerRow = usedRange.FirstRow();
      var headers = headerRow.Cells().Select(c => c.GetString().Trim()).ToList();

      int keyCol = headers.FindIndex(h => h.Equals("Key", StringComparison.OrdinalIgnoreCase)) + 1;
      if (keyCol <= 0)
        throw new InvalidOperationException("No 'Key' column found.");

      for (int row = 2; row <= usedRange.RowCount(); row++)
      {
        var excelRow = usedRange.Row(row);
        var key = excelRow.Cell(keyCol).GetString().Trim();
        if (string.IsNullOrWhiteSpace(key))
          continue;

        var translations = new Dictionary<string, string>();

        for (int col = 1; col <= headers.Count; col++)
        {
          if (col == keyCol)
            continue;

          var lang = headers[col - 1];
          if (string.IsNullOrWhiteSpace(lang))
            continue;

          var value = excelRow.Cell(col).GetString();
          if (!string.IsNullOrWhiteSpace(value))
            translations[lang] = value;
        }

        result[key] = translations;
      }

      var json = JsonSerializer.Serialize(result, new JsonSerializerOptions
      {
        WriteIndented = true
      });

      File.WriteAllText(jsonFile, json, new UTF8Encoding(false));
    }
  }
}