PKHeX/PKHeX.Core/Util/Localization/LocalizationUtil.cs

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;

namespace PKHeX.Core;

public static class LocalizationUtil
{
    private const string TranslationSplitter = " = ";

    /// <summary>
    /// Gets the names of the properties defined in the given input
    /// </summary>
    /// <param name="input">Enumerable of translation definitions in the form "Property = Value".</param>
    private static string[] GetProperties(IEnumerable<string> input)
    {
        static string AfterSplit(string l)
        {
            var split = l.IndexOf(TranslationSplitter, StringComparison.Ordinal);
            return l[..split];
        }
        return input.Select(AfterSplit).ToArray();
    }

    private static IEnumerable<string> DumpStrings(Type t)
    {
        var props = ReflectUtil.GetPropertiesStartWithPrefix(t, string.Empty);
        return props.Select(p => $"{p}{TranslationSplitter}{ReflectUtil.GetValue(t, p)}");
    }

    /// <summary>
    /// Gets the current localization in a static class containing language-specific strings
    /// </summary>
    /// <param name="t"></param>
    public static string[] GetLocalization(Type t) => DumpStrings(t).ToArray();

    /// <summary>
    /// Gets the current localization in a static class containing language-specific strings
    /// </summary>
    /// <param name="t"></param>
    /// <param name="existingLines">Existing localization lines (if provided)</param>
    public static string[] GetLocalization(Type t, string[] existingLines)
    {
        var currentLines = GetLocalization(t);
        var existing = GetProperties(existingLines);
        var current = GetProperties(currentLines);

        var result = new string[currentLines.Length];
        for (int i = 0; i < current.Length; i++)
        {
            int index = Array.IndexOf(existing, current[i]);
            result[i] = index < 0 ? currentLines[i] : existingLines[index];
        }
        return result;
    }

    /// <summary>
    /// Applies localization to a static class containing language-specific strings.
    /// </summary>
    /// <param name="t">Type of the static class containing the desired strings.</param>
    /// <param name="lines">Lines containing the localized strings</param>
    private static void SetLocalization(Type t, IReadOnlyCollection<string> lines)
    {
        if (lines.Count == 0)
            return;
        foreach (var line in lines)
        {
            var index = line.IndexOf(TranslationSplitter, StringComparison.Ordinal);
            if (index < 0)
                continue;
            var prop = line[..index];
            var value = line[(index + TranslationSplitter.Length)..];

            try
            {
                ReflectUtil.SetValue(t, prop, value);
            }
            // Malformed translation files, log
            catch (Exception e)
            {
                Debug.WriteLine($"Property not present: {prop} || Value written: {value}");
                Debug.WriteLine(e.Message);
            }
        }
    }

    /// <summary>
    /// Applies localization to a static class containing language-specific strings.
    /// </summary>
    /// <param name="t">Type of the static class containing the desired strings.</param>
    /// <param name="languageFilePrefix">Prefix of the language file to use.  Example: if the target is legality_en.txt, <paramref name="languageFilePrefix"/> should be "legality".</param>
    /// <param name="currentCultureCode">Culture information</param>
    private static void SetLocalization(Type t, string languageFilePrefix, string currentCultureCode)
    {
        var lines = Util.GetStringList($"{languageFilePrefix}_{currentCultureCode}");
        SetLocalization(t, lines);
    }

    /// <summary>
    /// Applies localization to a static class containing language-specific strings.
    /// </summary>
    /// <param name="t">Type of the static class containing the desired strings.</param>
    /// <remarks>The values used to translate the given static class are retrieved from [TypeName]_[CurrentLangCode2].txt in the resource manager of PKHeX.Core.</remarks>
    /// <param name="currentCultureCode">Culture information</param>
    public static void SetLocalization(Type t, string currentCultureCode)
    {
        SetLocalization(t, t.Name, currentCultureCode);
    }
}