using System.Collections.Generic;

namespace Plane.Collections
{
    public static class CollectionExtensions
    {
        /// <summary>
        /// Calls ICollection<T>.Add internally, but returns the original collection for chain programming.
        /// </summary>
        /// <typeparam name="T">The item type.</typeparam>
        /// <param name="origin">The original collection.</param>
        /// <param name="itemToAdd">The item to add.</param>
        /// <returns>The original collection.</returns>
        public static ICollection<T> AddEx<T>(this ICollection<T> origin, T itemToAdd)
        {
            origin.Add(itemToAdd);
            return origin;
        }

        /// <summary>
        /// Add items to the collection.
        /// </summary>
        /// <typeparam name="T">The item type.</typeparam>
        /// <param name="origin">The original collection.</param>
        /// <param name="itemToAdd">The items to add.</param>
        /// <returns>The original collection.</returns>
        public static ICollection<T> AddEx<T>(this ICollection<T> origin, IEnumerable<T> itemsToAdd)
        {
            foreach (var item in itemsToAdd)
            {
                origin.Add(item);
            }
            return origin;
        }

        /// <summary>
        /// Calls ICollection<T>.Clear internally, but returns the original collection for chain programming.
        /// </summary>
        /// <typeparam name="T">The item type.</typeparam>
        /// <param name="origin">The original collection.</param>
        /// <returns>The original collection.</returns>
        public static ICollection<T> ClearEx<T>(this ICollection<T> origin)
        {
            origin.Clear();
            return origin;
        }
    }
}