using System.Collections.Generic;
using NUnit.Framework;

namespace Chernobyl.Collections.Generic.Hierarchy
{
    [TestFixture]
    [Description("Tests the following types: TreeEnumerator<T>, " +
        "DepthFirstEnumerator<T>, EnumeratorFactory<T>")]
    public class DepthFirstTreeEnumeratorTests : TreeEnumeratorTests
    {
        /// <summary>
        /// This method should return a new <see cref="IEnumerable{T}"/> that can
        /// be iterated over five times. The index will be requested from each
        /// item using <see cref="EnumerationTests{T}.GetIndex(T)"/>. The 
        /// items should return the following index values in exactly this order: 
        /// 1, 2, 3, 4, 5. This method should create a new <see cref="IEnumerable{T}"/> 
        /// every time it is invoked and not reuse instances.
        /// </summary>
        protected override IEnumerable<Foobar> CreateManyItemEnumerable()
        {
            // Setup the "ManyNodes" foobar, it should look like this:
            //        0
            //       /|\
            //      1 4 5
            //     /|   |
            //    2 3   6
            Foobar child0 = new Foobar(0);
            Foobar child1 = new Foobar(1);
            Foobar child2 = new Foobar(2);
            Foobar child3 = new Foobar(3);
            Foobar child4 = new Foobar(4);
            Foobar child5 = new Foobar(5);
            Foobar child6 = new Foobar(6);

            child1.Children.Add(child2);
            child1.Children.Add(child3);
            child5.Children.Add(child6);
            child0.Children.Add(child1);
            child0.Children.Add(child4);
            child0.Children.Add(child5);

            OrderedItemsValue = new[] { child0, child1, child2, child3, child4, child5, child6 };

            return child0.DepthFirst;
        }
    }
}