using System;
using System.Collections.Generic;
using AMWD.Common.Cli;

namespace AMWD.Common.Tests.Cli
{
	[TestClass]
	public class EnumerableWalkerTest
	{
		private List<string> _list;

		[TestInitialize]
		public void Initialize()
		{
			_list = ["one", "two", "three", "four"];
		}

		[TestMethod]
		public void ShouldThrowExceptionOnNullReference()
		{
			// arrange

			// act & assert
			Assert.ThrowsExactly<ArgumentNullException>(() => new EnumerableWalker<string>(null));
		}

		[TestMethod]
		public void ShouldReturnEnumerator()
		{
			// arrange
			var walker = new EnumerableWalker<string>(_list);

			// act
			var enumerator = walker.GetEnumerator();

			// assert
			Assert.IsNotNull(enumerator);
		}

		[TestMethod]
		public void ShouldReturnGenericEnumerator()
		{
			// arrange
			var walker = new EnumerableWalker<string>(_list);

			// act
			var enumerator = ((IEnumerable<string>)walker).GetEnumerator();

			// assert
			Assert.IsNotNull(enumerator);
		}

		[TestMethod]
		public void ShouldReturnItems()
		{
			// arrange
			var walker = new EnumerableWalker<string>(_list);
			_ = walker.GetEnumerator();

			string[] items = new string[_list.Count];

			// act
			for (int i = 0; i < _list.Count; i++)
				items[i] = walker.GetNext();

			// assert
			for (int i = 0; i < _list.Count; i++)
				Assert.AreEqual(_list[i], items[i], $"Position {i} failed");
		}

		[TestMethod]
		public void ShouldReturnDefaultWhenNothingLeft()
		{
			// arrange
			var walker = new EnumerableWalker<string>([]);
			_ = walker.GetEnumerator();

			// act
			string item = walker.GetNext();

			// assert
			Assert.AreEqual(default, item);
		}
	}
}