zedseven/Romanization.NET

using System;
using System.Globalization;

namespace Romanization.Internal
{
    internal static class CulturalOperations
    {
        /// <summary>
        /// Runs <paramref name="func"/> with a specified <paramref name="culture"/>, then reverts the thread culture
        /// back to what it was before.
        /// </summary>
        /// <param name="culture">The culture to run with.</param>
        /// <param name="func">The function to run. Note that this takes a culture as an argument: this is the culture
        /// the thread was using before.</param>
        /// <typeparam name="TRes">The type of the result of running <paramref name="func"/>.</typeparam>
        /// <returns>The result of <paramref name="func"/>.</returns>
        public static TRes RunWithCulture<TRes>(CultureInfo culture, Func<CultureInfo, TRes> func)
        {
            CultureInfo previousCulture = CultureInfo.CurrentCulture;
            if (Equals(previousCulture, culture))
                return func(previousCulture);

            TRes res;
            try
            {
                CultureInfo.CurrentCulture = culture;
                res = func(previousCulture);
            }
            finally
            {
                CultureInfo.CurrentCulture = previousCulture;
            }
            return res;
        }

        /// <summary>
        /// Runs <paramref name="func"/>, then reverts the thread culture back to what it was before.
        /// </summary>
        /// <param name="culture">The culture to run with.</param>
        /// <param name="func">The function to run.</param>
        /// <typeparam name="TRes">The type of the result of running <paramref name="func"/>.</typeparam>
        /// <returns>The result of <paramref name="func"/>.</returns>
        public static TRes RunWithCulture<TRes>(CultureInfo culture, Func<TRes> func)
        {
            CultureInfo previousCulture = CultureInfo.CurrentCulture;
            if (Equals(previousCulture, culture))
                return func();

            TRes res;
            try
            {
                CultureInfo.CurrentCulture = culture;
                res = func();
            }
            finally
            {
                CultureInfo.CurrentCulture = previousCulture;
            }
            return res;
        }

        /// <summary>
        /// Runs <paramref name="action"/>, then reverts the thread culture back to what it was before.
        /// </summary>
        /// <param name="culture">The culture to run with.</param>
        /// <param name="action">The action to run.</param>
        public static void RunWithCulture(CultureInfo culture, Action<CultureInfo> action)
        {
            CultureInfo previousCulture = CultureInfo.CurrentCulture;
            if (Equals(previousCulture, culture))
            {
                action(previousCulture);
                return;
            }

            try
            {
                CultureInfo.CurrentCulture = culture;
                action(previousCulture);
            }
            finally
            {
                CultureInfo.CurrentCulture = previousCulture;
            }
        }

        /// <summary>
        /// Runs <paramref name="action"/>, then reverts the thread culture back to what it was before.
        /// </summary>
        /// <param name="culture">The culture to run with.</param>
        /// <param name="action">The action to run.</param>
        public static void RunWithCulture(CultureInfo culture, Action action)
        {
            CultureInfo previousCulture = CultureInfo.CurrentCulture;
            if (Equals(previousCulture, culture))
            {
                action();
                return;
            }

            try
            {
                CultureInfo.CurrentCulture = culture;
                action();
            }
            finally
            {
                CultureInfo.CurrentCulture = previousCulture;
            }
        }
    }
}