using System.Collections.Generic;
using UnitTestSharp;

namespace Vellum.UnitTests
{
    public class FamilyChoiceTests : TestFixture
    {
        // Each name extends the names listed after it, and nothing else.
        private static readonly Dictionary<string, string[]> Extending = new Dictionary<string, string[]>
        {
            { "Animal", new string[0] },
            { "Predator", new[] { "Animal" } },
            { "Cat", new[] { "Predator", "Animal" } },
            { "Pet", new string[0] },
        };

        private static bool Extends(string derived, string baseName)
        {
            return System.Array.IndexOf(Extending[derived], baseName) >= 0;
        }

        public class MostDerivedTests : TestFixture
        {
            public void NoCandidates_ReturnsNone()
            {
                CheckEqual(0, FamilyChoice.MostDerived(new string[0], Extends).Count);
            }

            public void OneCandidate_IsTheChoice()
            {
                CheckEqual(new[] { "Animal" }, FamilyChoice.MostDerived(new[] { "Animal" }, Extends));
            }

            public void CandidateExtendingTheOthers_IsTheOnlyChoice()
            {
                CheckEqual(new[] { "Cat" }, FamilyChoice.MostDerived(new[] { "Animal", "Cat", "Predator" }, Extends));
            }

            public void UnrelatedCandidates_AreAllReturnedInTheirOrder()
            {
                CheckEqual(new[] { "Pet", "Predator" },
                    FamilyChoice.MostDerived(new[] { "Pet", "Animal", "Predator" }, Extends));
            }

            public void CandidateEqualToAnotherInValue_IsNotExtendedByIt()
            {
                CheckEqual(new[] { "Pet", "Pet" }, FamilyChoice.MostDerived(new[] { "Pet", "Pet" }, Extends));
            }
        }
    }
}