using NUnit.Framework;

namespace Chernobyl.Mathematics.Collision
{
    /// <summary>
    /// A base class test fixture that tests the
    /// <see cref="IExtendedCollidable{TCollidable}"/> type. This class also 
    /// tests the <see cref="ICollidable"/> type using the 
    /// <see cref="CollidableTests"/> class.
    /// </summary>
    /// <typeparam name="TCollidable">The type that can be collided with by the 
    /// <see cref="IExtendedCollidable{TCollidable}"/>.</typeparam>
    public abstract class ExtendedCollidableTests<TCollidable> : CollidableTests
    {
        [Test, Description("Checks the IsColliding method to ensure it properly " + 
            "collides with the collidable passed to it.")]
        public virtual void IsColliding()
        {
            IExtendedCollidable<TCollidable> collidable = CreateExtendedCollidable();

            Assert.That(collidable.IsColliding(CreateCollidingCollidable()),
                "The IsColliding method is reporting that the object passed to " +
                "it is not colliding with the test IExtendedCollidable<TCollidable> " + 
                "even though it should be colliding.");
        }

        [Test, Description("Checks the IsColliding method to ensure it properly " +
            "collides with the edge of the collidable passed to it.")]
        public virtual void IsCollidingWithEdge()
        {
            IExtendedCollidable<TCollidable> collidable = CreateExtendedCollidable();

            Assert.That(collidable.IsColliding(CreateEdgeCollidingCollidable()),
                "The IsColliding method is reporting that the object passed to " +
                "it is not colliding with the test IExtendedCollidable<TCollidable> " +
                "even though it should be colliding.");
        }

        [Test, Description("Checks the IsColliding method to ensure it does not " +
            "collides with the collidable passed to it.")]
        public virtual void IsNotColliding()
        {
            IExtendedCollidable<TCollidable> collidable = CreateExtendedCollidable();

            Assert.That(collidable.IsColliding(CreateNonCollidingCollidable()) == false,
                "The IsColliding method is reporting that the object passed to " +
                "is colliding with the test IExtendedCollidable<TCollidable> " +
                "even though it should NOT be colliding.");
        }

        /// <summary>
        /// Should create an <see cref="IExtendedCollidable{TCollidable}"/> that 
        /// can be collided against for testing purposes. This method should 
        /// always create a new <see cref="IExtendedCollidable{TCollidable}"/> 
        /// and never reuse the same instance.
        /// </summary>
        /// <returns>The new <see cref="IExtendedCollidable{TCollidable}"/> to 
        /// test with.</returns>
        protected abstract IExtendedCollidable<TCollidable> CreateExtendedCollidable();

        /// <summary>
        /// Should create an <typeparamref name="TCollidable"/> that is set up
        /// to collide against the <see cref="IExtendedCollidable{TCollidable}"/>
        /// created by the method <see cref="CreateExtendedCollidable"/>. This method 
        /// should always create a new
        /// <see cref="IExtendedCollidable{TCollidable}"/> and never reuse the
        /// same instance.
        /// </summary>
        /// <returns>The new <typeparamref name="TCollidable"/> to test with.</returns>
        protected abstract TCollidable CreateCollidingCollidable();

        /// <summary>
        /// Should create an <typeparamref name="TCollidable"/> that is set up
        /// to collide against the edge of the 
        /// <see cref="IExtendedCollidable{TCollidable}"/> created by the method 
        /// <see cref="CreateExtendedCollidable"/>. This method should always create a 
        /// new <see cref="IExtendedCollidable{TCollidable}"/> and never reuse 
        /// the same instance.
        /// </summary>
        /// <returns>The new <typeparamref name="TCollidable"/> to test with.</returns>
        protected abstract TCollidable CreateEdgeCollidingCollidable();

        /// <summary>
        /// Should create an <typeparamref name="TCollidable"/> that is set up
        /// to NOT collide against the 
        /// <see cref="IExtendedCollidable{TCollidable}"/> created by the method 
        /// <see cref="CreateExtendedCollidable"/>. This method should 
        /// always create a new <see cref="IExtendedCollidable{TCollidable}"/> 
        /// and never reuse the same instance.
        /// </summary>
        /// <returns>The new <typeparamref name="TCollidable"/> to test with.</returns>
        protected abstract TCollidable CreateNonCollidingCollidable();

        protected override ICollidable CreateCollidable()
        {
            return CreateExtendedCollidable();
        }
    }
}