using System;
using System.Text.RegularExpressions;

namespace Chernobyl.Utility
{
    /// <summary>
    /// This class defines extension methods for enumerations.
    /// </summary>
    public static class EnumExtensions
    {
        /// <summary>
        /// This extension method takes an item in an enumeration and turns it into
        /// a string with spaces inserted between words that are capitalized.
        /// i.e. the enum item "WhatTheHELL" becomes "What The HELL".
        /// 
        /// References: this method was taken and modified from 
        /// http://stackoverflow.com/questions/13599/convert-enums-to-human-readable-value-c
        /// </summary>
        /// <param name="theEnumItem">An enum item that is formatted using PascalCase.</param>
        /// <returns>The string formatted from <paramref name="theEnumItem"/>.</returns>
        public static string Wordify(this Enum theEnumItem)
        {
            return EnumWordifierRegex.Replace(theEnumItem.ToString(), " ${x}");
        }

        /// <summary>
        /// The <see cref="Regex"/> used in the <see cref="Wordify(Enum)"/> 
        /// method to turn an enum into a word with spaces.
        /// </summary>
        static readonly Regex EnumWordifierRegex = new Regex("(?<=[a-z])(?<x>[A-Z])|(?<=.)(?<x>[A-Z])(?=[a-z])", RegexOptions.Compiled);
    }
}