using System;
using System.Collections.Generic;

namespace Chronos.Extensions
{
    /// <summary>
    /// Extension methods for all kind of Collections implementing the ICollection&lt;T&gt; interface
    /// </summary>
    public static class CollectionExtensions
    {
        #region · Extensions ·

        /// <summary>
        /// Adds a value uniquely to to a collection and returns a value whether the value was added or not.
        /// </summary>
        /// <typeparam name="T">The generic collection value type</typeparam>
        /// <param name="collection">The collection.</param>
        /// <param name="value">The value to be added.</param>
        /// <returns>Indicates whether the value was added or not</returns>
        /// <example><code>
        /// list.AddUnique(1); // returns true;
        /// list.AddUnique(1); // returns false the second time;
        /// </code></example>
        public static bool AddUnique<T>(this ICollection<T> collection, T value)
        {
            if (!collection.Contains(value))
            {
                collection.Add(value);
                return true;
            }

            return false;
        }

        /// <summary>
        /// Adds a range of value uniquely to a collection and returns the amount of values added.
        /// </summary>
        /// <typeparam name="T">The generic collection value type.</typeparam>
        /// <param name="collection">The collection.</param>
        /// <param name="values">The values to be added.</param>
        /// <returns>The amount if values that were added.</returns>
        public static int AddRangeUnique<T>(this ICollection<T> collection, IEnumerable<T> values)
        {
            var count = 0;

            foreach (var value in values)
            {
                if (collection.AddUnique(value))
                {
                    count++;
                }
            }

            return count;
        }

        public static void AddRange<T>(this ICollection<T> collection, IEnumerable<T> values)
        {
            foreach (T value in values)
            {
                collection.Add(value);
            }
        }

        #endregion
    }
}