MARKUS

using System;

using System.Collections.Generic;

using System.Linq;

using System.Linq.Expressions;

using System.Text;

using System.Threading.Tasks;

namespace Markus.Service.Extensions

{

    public static class CollectionExtensions

    {

        //public static void Update<T>(this IList<T> source,IList<T> Target,IList<string> Keys)

        //{

        //    for (int i = source.Count; i == 0 ; --i)

        //    {

        //        var item = source[i];

        //         Target.Where(f=>)

        //        item.GetType().GetProperty()

        //    }

        //}

        /// <summary>

        /// Changes all elements of IEnumerable by the change function

        /// </summary>

        /// <param name="enumerable">The enumerable where you want to change stuff</param>

        /// <param name="change">The way you want to change the stuff</param>

        /// <returns>An IEnumerable with all changes applied</returns>

        public static IEnumerable<T> Change<T>(this IEnumerable<T> enumerable, Func<T, T> change)

        {

            ArgumentCheck.IsNullorWhiteSpace(enumerable, "enumerable");

            ArgumentCheck.IsNullorWhiteSpace(change, "change");

            foreach (var item in enumerable)

            {

                yield return change(item);

            }

        }

        /// <summary>

        /// Changes all elements of IEnumerable by the change function, that fullfill the where function

        /// </summary>

        /// <param name="enumerable">The enumerable where you want to change stuff</param>

        /// <param name="change">The way you want to change the stuff</param>

        /// <param name="where">The function to check where changes should be made</param>

        /// <returns>

        /// An IEnumerable with all changes applied

        /// </returns>

        public static IEnumerable<T> ChangeWhere<T>(this IEnumerable<T> enumerable,

                                                    Func<T, T> change,

                                                    Func<T, bool> @where)

        {

            ArgumentCheck.IsNullorWhiteSpace(enumerable, "enumerable");

            ArgumentCheck.IsNullorWhiteSpace(change, "change");

            ArgumentCheck.IsNullorWhiteSpace(@where, "where");

            foreach (var item in enumerable)

            {

                if (@where(item))

                {

                    yield return change(item);

                }

                else

                {

                    yield return item;

                }

            }

        }

        public static class ArgumentCheck

        {

            /// <summary>

            /// Checks if a value is string or any other object if it is string

            /// it checks for nullorwhitespace otherwhise it checks for null only

            /// </summary>

            /// <typeparam name="T">Type of the item you want to check</typeparam>

            /// <param name="item">The item you want to check</param>

            /// <param name="nameOfTheArgument">Name of the argument</param>

            public static void IsNullorWhiteSpace<T>(T item, string nameOfTheArgument = "")

            {

                Type type = typeof(T);

                if (type == typeof(string) ||

                    type == typeof(String))

                {

                    if (string.IsNullOrWhiteSpace(item as string))

                    {

                        throw new ArgumentException(nameOfTheArgument + " is null or Whitespace");

                    }

                }

                else

                {

                    if (item == null)

                    {

                        throw new ArgumentException(nameOfTheArgument + " is null");

                    }

                }

            }

        }

        /// <summary>

        /// Changes all elements of IEnumerable by the change function that do not fullfill the except function

        /// </summary>

        /// <param name="enumerable">The enumerable where you want to change stuff</param>

        /// <param name="change">The way you want to change the stuff</param>

        /// <param name="where">The function to check where changes should not be made</param>

        /// <returns>

        /// An IEnumerable with all changes applied

        /// </returns>

        public static IEnumerable<T> ChangeExcept<T>(this IEnumerable<T> enumerable,

                                                     Func<T, T> change,

                                                     Func<T, bool> @where)

        {

            ArgumentCheck.IsNullorWhiteSpace(enumerable, "enumerable");

            ArgumentCheck.IsNullorWhiteSpace(change, "change");

            ArgumentCheck.IsNullorWhiteSpace(@where, "where");

            foreach (var item in enumerable)

            {

                if (!@where(item))

                {

                    yield return change(item);

                }

                else

                {

                    yield return item;

                }

            }

        }

        /// <summary>

        /// Update all elements of IEnumerable by the update function (only works with reference types)

        /// </summary>

        /// <param name="enumerable">The enumerable where you want to change stuff</param>

        /// <param name="update">The way you want to change the stuff</param>

        /// <returns>

        /// The same enumerable you passed in

        /// </returns>

        public static IEnumerable<T> Update<T>(this IEnumerable<T> enumerable,

                                               Action<T> update) where T : class

        {

            ArgumentCheck.IsNullorWhiteSpace(enumerable, "enumerable");

            ArgumentCheck.IsNullorWhiteSpace(update, "update");

            foreach (var item in enumerable)

            {

                update(item);

            }

            return enumerable;

        }

        /// <summary>

        /// Update all elements of IEnumerable by the update function (only works with reference types)

        /// where the where function returns true

        /// </summary>

        /// <param name="enumerable">The enumerable where you want to change stuff</param>

        /// <param name="update">The way you want to change the stuff</param>

        /// <param name="where">The function to check where updates should be made</param>

        /// <returns>

        /// The same enumerable you passed in

        /// </returns>

        public static IEnumerable<T> UpdateWhere<T>(this IEnumerable<T> enumerable,

                                               Action<T> update, Func<T, bool> where) where T : class

        {

            ArgumentCheck.IsNullorWhiteSpace(enumerable, "enumerable");

            ArgumentCheck.IsNullorWhiteSpace(update, "update");

            foreach (var item in enumerable)

            {

                if (where(item))//UpdateWhere에서 맨마지막 조건

                {

                    update(item);

                }

            }

            return enumerable;

        }

        /// <summary>

        /// Update all elements of IEnumerable by the update function (only works with reference types)

        /// Except the elements from the where function

        /// </summary>

        /// <param name="enumerable">The enumerable where you want to change stuff</param>

        /// <param name="update">The way you want to change the stuff</param>

        /// <param name="where">The function to check where changes should not be made</param>

        /// <returns>

        /// The same enumerable you passed in

        /// </returns>

        public static IEnumerable<T> UpdateExcept<T>(this IEnumerable<T> enumerable,

                                               Action<T> update, Func<T, bool> where) where T : class

        {

            ArgumentCheck.IsNullorWhiteSpace(enumerable, "enumerable");

            ArgumentCheck.IsNullorWhiteSpace(update, "update");

            foreach (var item in enumerable)

            {

                if (!where(item))

                {

                    update(item);

                }

            }

            return enumerable;

        }

    }

}