using System.Collections.Immutable;
using System.Linq;
using UnitTestSharp;

namespace Vellum.Generator.UnitTests
{
    public class TypePartTests : TestFixture
    {
        public static TypePart Part(string name = "Foo", string openName = null, PartKind kind = PartKind.Plain,
            int firstChild = 1, int childCount = 0, string[] familyNames = null)
        {
            return new TypePart(name, openName, kind, firstChild, childCount,
                new EquatableArray<string>((familyNames ?? new string[0]).ToImmutableArray()));
        }

        public class CtorTests : TestFixture
        {
            public void KeepsEveryArgument()
            {
                TypePart part = Part("Box<Foo>", "Box<ItemType>", PartKind.Generic, 3, 1, new[] { "Box<ItemType>" });

                CheckEqual(new[] { "Box<ItemType>" }, part.FamilyNames.Items.ToArray());
                CheckEqual("Box<Foo>", part.Name);
                CheckEqual("Box<ItemType>", part.OpenName);
                CheckEqual(PartKind.Generic, part.Kind);
                CheckEqual(3, part.FirstChild);
                CheckEqual(1, part.ChildCount);
            }
        }

        public class EqualsTests : TestFixture
        {
            public void SameValues_AreEqual()
            {
                CheckTrue(Part().Equals(Part()));
                CheckTrue(Part().Equals((object)Part()));
            }

            public void Null_IsNotEqual()
            {
                CheckFalse(Part().Equals((TypePart)null));
                CheckFalse(Part().Equals((object)null));
            }

            public void OtherType_IsNotEqual()
            {
                CheckFalse(Part().Equals("Foo"));
            }

            public void DifferentName_IsNotEqual()
            {
                CheckFalse(Part().Equals(Part(name: "Bar")));
            }

            public void DifferentOpenName_IsNotEqual()
            {
                CheckFalse(Part().Equals(Part(openName: "Box<ItemType>")));
            }

            public void DifferentKind_IsNotEqual()
            {
                CheckFalse(Part().Equals(Part(kind: PartKind.Whole)));
            }

            public void DifferentFirstChild_IsNotEqual()
            {
                CheckFalse(Part().Equals(Part(firstChild: 2)));
            }

            public void DifferentChildCount_IsNotEqual()
            {
                CheckFalse(Part().Equals(Part(childCount: 1)));
            }

            public void DifferentBaseArguments_AreNotEqual()
            {
                var other = new TypePart("Foo", null, PartKind.Plain, 1, 0, default,
                    new EquatableArray<BaseArguments>(ImmutableArray.Create(BaseArgumentsTests.Variant())));

                CheckFalse(Part().Equals(other));
            }

            public void DifferentFamilyNames_AreNotEqual()
            {
                CheckFalse(Part().Equals(Part(familyNames: new[] { "Foo" })));
            }
        }

        public class GetHashCodeTests : TestFixture
        {
            public void EqualParts_HaveEqualHashCodes()
            {
                CheckEqual(Part().GetHashCode(), Part().GetHashCode());
            }
        }
    }
}