using System;
using System.Reflection;
using Chernobyl.Creation;
using NUnit.Framework;

namespace Chernobyl.Event
{
    [TestFixture, Description("Tests for the CreationEventArgs<TCreated> type.")]
    public class CreationEventArgsTest
    {
        [Test, Description("Test to ensure " +
            "CreationEventArgs<TCreated>.CreationEventArgs(TCreated) " +
            "constructor sets the CreationEventArgs<TCreated>.CreatedInstance " +
            "to a proper value.")]
        public void ConstructorTCreatedTest()
        {
            CreationEventArgs<int> args = new CreationEventArgs<int>(2);

            Assert.AreEqual(2, args.CreatedInstance,
                "CreationEventArgs<TCreated>.CreatedInstance was not the " +
                "expected value.");
        }

        [Test, Description("Test to ensure " +
            "CreationEventArgs<TCreated>.CreationEventArgs(TCreated, Object) " +
            "constructor sets the CreationEventArgs<TCreated>.CreatedInstance " +
            "and CreationEventArgs<TCreated>.UserState to proper values.")]
        public void ConstructorTCreatedObjectTest()
        {
            String userState = new string('A', 1);
            CreationEventArgs<int> args = new CreationEventArgs<int>(2, userState);

            Assert.AreEqual(2, args.CreatedInstance,
                "CreationEventArgs<TCreated>.CreatedInstance was not the " +
                "expected value.");
            Assert.AreEqual(userState, args.UserState,
                "CreationEventArgs<TCreated>.UserState was not the " +
                "expected value.");
        }

        [Test, Description("Test to ensure " +
            "CreationEventArgs<TCreated>.CreationEventArgs(TCreated) " +
            "constructor sets the CreationEventArgs<TCreated>.Canceled " +
            "to a the proper value.")]
        public void ConstructorBoolTest()
        {
            CreationEventArgs<int> args = new CreationEventArgs<int>(true);

            Assert.AreEqual(true, args.Cancelled,
                "CreationEventArgs<TCreated>.Canceled was not the " +
                "expected value.");
        }

        [Test, Description("Test to ensure " +
            "CreationEventArgs<TCreated>.CreationEventArgs(TCreated) " +
            "constructor sets the CreationEventArgs<TCreated>.Canceled " +
            "and CreationEventArgs<TCreated>.UserState to proper values.")]
        public void ConstructorBoolObjectTest()
        {
            String userState = new string('A', 1);
            CreationEventArgs<int> args = new CreationEventArgs<int>(true, userState);

            Assert.AreEqual(true, args.Cancelled,
                "CreationEventArgs<TCreated>.Canceled was not the " +
                "expected value.");
            Assert.AreEqual(userState, args.UserState,
                "CreationEventArgs<TCreated>.UserState was not the " +
                "expected value.");
        }

        [Test, Description("Test to ensure " +
            "CreationEventArgs<TCreated>.CreationEventArgs(Exception) " +
            "constructor sets the CreationEventArgs<TCreated>.Error " +
            "to a the proper value.")]
        public void ConstructorExceptionTest()
        {
            Exception exception = new Exception();
            CreationEventArgs<int> args = new CreationEventArgs<int>(exception);

            Assert.AreEqual(exception, args.Error,
                "CreationEventArgs<TCreated>.Error was not the " +
                "expected value.");
        }

        [Test, Description("Test to ensure " +
            "CreationEventArgs<TCreated>.CreationEventArgs(Exception) " +
            "constructor sets the CreationEventArgs<TCreated>.Error " +
            "and CreationEventArgs<TCreated>.UserState to proper values.")]
        public void ConstructorExceptionObjectTest()
        {
            Exception exception = new Exception();
            String userState = new string('A', 1);
            CreationEventArgs<int> args = new CreationEventArgs<int>(exception, userState);

            Assert.AreEqual(exception, args.Error,
                "CreationEventArgs<TCreated>.Error was not the " +
                "expected value.");
            Assert.AreEqual(userState, args.UserState,
                "CreationEventArgs<TCreated>.UserState was not the " +
                "expected value.");
        }

        [Test, Description("Test to ensure " +
            "CreationEventArgs<TCreated>.CreatedInstance " +
            "throws an exception when CreationEventArgs<TCreated>.Error is set " +
            "to a non-null value.")]
        public void CreatedInstanceErrorExceptionTest()
        {
            ArgumentException exception = new ArgumentException();
            CreationEventArgs<int> args = new CreationEventArgs<int>(exception);
            Assert.Throws<TargetInvocationException>(() => Console.Write(args.CreatedInstance));
        }

        [Test, Description("Test to ensure " +
            "CreationEventArgs<TCreated>.CreatedInstance " +
            "does not throw an exception when CreationEventArgs<TCreated>.Error is " +
            "set to null value.")]
        public void CreatedInstanceErrorNoExceptionTest()
        {
            CreationEventArgs<int> args = new CreationEventArgs<int>(null);
            Console.Write(args.CreatedInstance);
        }

        [Test, Description("Test to ensure " +
            "CreationEventArgs<TCreated>.CreatedInstance " +
            "throws an exception when CreationEventArgs<TCreated>.Canceled is set " +
            "to true.")]
        public void CreatedInstanceCanceledExceptionTest()
        {
            CreationEventArgs<int> args = new CreationEventArgs<int>(true);
            Assert.Throws<InvalidOperationException>(() => Console.Write(args.CreatedInstance));
        }

        [Test, Description("Test to ensure " +
            "CreationEventArgs<TCreated>.CreatedInstance " +
            "does not throw an exception when CreationEventArgs<TCreated>.Canceled " +
            "is set to false.")]
        public void CreatedInstanceCanceledNoExceptionTest()
        {
            CreationEventArgs<int> args = new CreationEventArgs<int>(false);
            Console.Write(args.CreatedInstance);
        }
    }
}