namespace AtlasUtility
{
    using System;
    using System.Collections.Generic;

    public static class ExtList
    {
        public static T Back<T>(this List<T> list, int index, bool remove = false)
        {
            T t = list[list.Count - 1 - index];

            if (remove)
            {
                list.RemoveAt(list.Count - 1 - index);
            }

            return t;
        }


        public static void MySort<T>(this List<T> list, Func<T, T, bool> func)
        {
            bool finish = false;
            
            for (int i = 0; i < list.Count; i++)
            {
                finish = true;

                for (int j = 0; j < list.Count - i - 1; j++)
                {
                    if (func(list[j], list[j + 1]))
                    {
                        finish = false;

                        T t = list[j];

                        list[j] = list[j + 1];
                        list[j + 1] = t;
                    }
                }

                if (finish)
                {
                    break;
                }
            }
        }

        public static float MyMax<T>(this List<T> list, Func<T, float> func)
        {
            float result = func(list[0]);

            for (int i = 1; i < list.Count; i++)
            {
                if (result < func(list[i]))
                {
                    result = func(list[i]);
                }
            }

            return result;
        }

        public static float MySum<T>(this List<T> list, Func<T, float> func)
        {
            float result = 0;

            for (int i = 0; i < list.Count; i++)
            {
                result += func(list[i]);
            }

            return result;
        }
    }
}