PKHeX/PKHeX.Core/Util/Localization/LocalizeUtil.cs

using System.Threading.Tasks;

namespace PKHeX.Core
{
    public static class LocalizeUtil
    {
        /// <summary>
        /// Initializes PKHeX's runtime strings to the specified language.
        /// </summary>
        /// <param name="lang">2-char language ID</param>
        /// <param name="sav">Save data (optional)</param>
        /// <param name="hax">Permit illegal things (items, only)</param>
        public static void InitializeStrings(string lang, SaveFile? sav = null, bool hax = false)
        {
            var str = GameInfo.Strings = GameInfo.GetStrings(lang);
            if (sav != null)
                GameInfo.FilteredSources = new FilteredGameDataSource(sav, GameInfo.Sources, hax);

            // Update Legality Analysis strings
            ParseSettings.ChangeLocalizationStrings(str.movelist, str.specieslist);

            // Update Legality Strings
            Task.Run(() =>
            {
                RibbonStrings.ResetDictionary(str.ribbons);
                LocalizationUtil.SetLocalization(typeof(LegalityCheckStrings), lang);
                LocalizationUtil.SetLocalization(typeof(MessageStrings), lang);
            });
        }
    }
}