using System.Collections.Generic;

namespace Hallucinate.GameSetup.Maze.Extensions
{
    /// <summary>
    /// Provides utility extension methods for maze generation algorithms.
    /// </summary>
    public static class Extensions
    {
        private static System.Random _rng = new System.Random();

        /// <summary>
        /// Shuffles the elements of an <see cref="IList{T}"/> using the Fisher-Yates algorithm.
        /// This is used to randomize directions for maze generation.
        /// </summary>
        /// <typeparam name="T">The type of elements in the list.</typeparam>
        /// <param name="list">The list to shuffle.</param>
        public static void Shuffle<T>(this IList<T> list)
        {
            int n = list.Count;
            while (n > 1)
            {
                n--;
                int k = _rng.Next(n + 1);
                T value = list[k];
                list[k] = list[n];
                list[n] = value;
            }
        }
    }
}