using System;
using Chernobyl.Readiness;
using NUnit.Framework;

namespace Chernobyl.Values
{
    [TestFixture, Description("Tests for the NotReady<T> type.")]
    public class NotNullTests : ValueTests<IValue<string>, string>
    {
        //----------------------------------------------------------------------
        // NotNull(IValue<T>)
        //----------------------------------------------------------------------

        [Test, Description("Ensures NotNull(IValue<T>) throws an ArgumentNullException " +
                           "when it is given a null argument.")]
        public void ConstructorIValueArgumentNullException()
        {
            // ReSharper disable ObjectCreationAsStatement
            Assert.Throws<ArgumentNullException>(() => new NotNull<string>(null));
            // ReSharper restore ObjectCreationAsStatement
        }

        //----------------------------------------------------------------------
        // Change Tests
        //----------------------------------------------------------------------

        [Test, Description("A test to ensure that setting the internal value of " +
                           "IValue<T> to the value it is already set at raises the " +
                           "IValue<T>.Provide event if the IValue<T> is not ready. " +
                           "Override this test if it is not applicable.")]
        [Ignore("NotNull is only ready when the value is not null.")]
        public override void ProvideRaisedWhenValueIsNotChangedButIsMadeReady()
        {}

        //----------------------------------------------------------------------
        // Utility
        //----------------------------------------------------------------------

        protected override ValueTests<IValue<string>, string>.Wrapper CreateValue()
        {
            return new Wrapper();
        }

        protected new class Wrapper : ValueTests<IValue<string>, string>.Wrapper
        {
            public Wrapper()
                : base(null, "hola", "hello" )
            {
                TestInstance = new NotNull<string>(_container);
            }

            public override void MakeReady()
            {
                _container.Value = "hola";
            }

            public override void ChangeValue()
            {
                _container.Value = FinalValue;
            }

            public override void FakeChangeValue()
            {
                _container.Value = _container.Value;
            }

            readonly DynamicContainer<string> _container = new DynamicContainer<string>();
        }
    }
}