using System;
using System.Collections.Generic;
using System.Linq;
using Chernobyl.Event;
using NUnit.Framework;

namespace Chernobyl.Collections.Generic.Event
{
    [TestFixture, Description("Tests for the SelectEventEnumerable<TSource, TResult> type.")]
    public class SelectEventEnumerableTests : EnumerationTests<string>
    {
        public SelectEventEnumerableTests()
            : base(true)
        { }

        #region Overridables

        /// <summary>
        /// Creates the <see cref="SelectEventEnumerable{TSource,TResult}"/>
        /// instance that is to be tested.
        /// </summary>
        /// <param name="source">The sequence that is to be treated as the source.</param>
        /// <returns>The instance to be tested.</returns>
        protected virtual SelectEventEnumerable<int, string> CreateSelectEventEnumerable(IEventEnumerable<int> source)
        {
            return new SelectEventEnumerable<int, string>(source,
                (value, index, handler) => handler(null, new ValueChangedEventArgs<string>(string.Empty, Convert.ToString(value))),
                (value, index, handler) => { /* no-op */ });
        }

        protected override IEnumerable<string> CreateSingleItemEnumerable()
        {
            return CreateSelectEventEnumerable(new DecoratingEventList<int>(new[] {1}));
        }

        protected override IEnumerable<string> CreateManyItemEnumerable()
        {
            return CreateSelectEventEnumerable(new DecoratingEventList<int>(_items));
        }

        protected override IEnumerable<string> OrderedItems
        {
            get { return _items.Select(i => Convert.ToString(i)); }
        }

        #endregion

        readonly IList<int> _items = new List<int>(new[] { 1, 2, 3, 4, 5, 6 });
    }
}