using System;
using System.Collections.Generic;

namespace FSO.Client.Utils
{
    public static class CollectionUtils
    {
        public static void Shuffle<T>(this IList<T> list)
        {
            Random rng = new Random();
            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;
            }
        }

        public static IEnumerable<TResult> Select<TSource, TResult>(this Array items, Func<TSource, TResult> converter)
        {
            var result = new List<TResult>();
            foreach (var item in items)
            {
                result.Add(converter((TSource)item));
            }
            return result;
        }


        public static Dictionary<TKey, TValue> Clone<TKey, TValue>(Dictionary<TKey, TValue> input)
        {
            var result = new Dictionary<TKey, TValue>();
            foreach (var val in input)
            {
                result.Add(val.Key, val.Value);
            }
            return result;
        }


        private static Random RAND = new Random();
        public static T RandomItem<T>(this T[] items)
        {
            var index = RAND.Next(items.Length);
            return items[index];
        }
    }
}