#region Copyright
// --------------------------------------------------------------------------------------------------------------------
// <copyright file="StringUtils.cs" company="Ian Horswill">
// Copyright (C) 2015 Ian Horswill
//  
// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in the
// Software without restriction, including without limitation the rights to use, copy,
// modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
// and to permit persons to whom the Software is furnished to do so, subject to the
// following conditions:
//  
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
// PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
// SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
// </copyright>
// --------------------------------------------------------------------------------------------------------------------
#endregion

using System.Linq;

namespace Prolog
{
    public static class StringUtils
    {
        static readonly char[] Vowels = { 'a', 'e', 'i', 'o', 'u' };

        public static string PluralForm(string singularForm)
        {
            switch (singularForm[singularForm.Length - 1])
            {
                case 's':
                case 'o':
                    return singularForm + "es";

                case 'f':
                    return singularForm.Substring(0, singularForm.Length - 1) + "ves";


                case 'y':
                    var secondToLast = singularForm[singularForm.Length - 2];
                    if (Vowels.Contains(secondToLast))
                    {
                        return singularForm + "s";
                    }
                    return singularForm.Substring(0, singularForm.Length - 1) + "ies";

                default:
                    return singularForm + "s";
            }
        }

        public static string LastWordOf(string phrase)
        {
            var space = phrase.LastIndexOf(' ');
            if (space < 0)
                return phrase;
            return phrase.Substring(space + 1);
        }

    }
}