using System;
using UnitTestSharp;

namespace Clave.UnitTests
{
    public class KeyboardSnapshotTests : TestFixture
    {
        public static readonly KeySpaceSnapshot PressedA =
            new KeySpaceSnapshot(new KeyState(KeyCode.A), new KeyState(KeyCode.A), default);

        public static readonly KeySpaceSnapshot HeldB = new KeySpaceSnapshot(new KeyState(KeyCode.B), default, default);

        public class SpaceCountTests : TestFixture
        {
            public void CountsEveryKeySpace()
            {
                CheckEqual(Enum.GetValues(typeof(KeySpace)).Length, KeyboardSnapshot.SpaceCount);
            }
        }

        public class SpaceAtTests : TestFixture
        {
            public void Zero_IsPhysical()
            {
                CheckEqual(KeySpace.Physical, KeyboardSnapshot.SpaceAt(0));
            }

            public void One_IsLayout()
            {
                CheckEqual(KeySpace.Layout, KeyboardSnapshot.SpaceAt(1));
            }

            public void ANegativeIndex_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                KeyboardSnapshot.SpaceAt(-1);
            }

            public void TheSpaceCount_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                KeyboardSnapshot.SpaceAt(KeyboardSnapshot.SpaceCount);
            }
        }

        public class IndexerTests : TestFixture
        {
            public void Physical_ReadsThePhysicalKeys()
            {
                CheckEqual(PressedA, new KeyboardSnapshot(PressedA, HeldB)[KeySpace.Physical]);
            }

            public void Layout_ReadsTheLayoutKeys()
            {
                CheckEqual(HeldB, new KeyboardSnapshot(PressedA, HeldB)[KeySpace.Layout]);
            }

            public void ADefaultSnapshot_HoldsNothingInEitherSpace()
            {
                CheckEqual(default(KeySpaceSnapshot), default(KeyboardSnapshot)[KeySpace.Physical]);
                CheckEqual(default(KeySpaceSnapshot), default(KeyboardSnapshot)[KeySpace.Layout]);
            }

            public void UndefinedSpace_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                KeySpaceSnapshot unused = default(KeyboardSnapshot)[(KeySpace)2];
            }
        }

        public class WithTests : TestFixture
        {
            public void Physical_ReplacesOnlyThePhysicalKeys()
            {
                var keyboard = new KeyboardSnapshot(PressedA, HeldB);

                CheckEqual(new KeyboardSnapshot(HeldB, HeldB), keyboard.With(KeySpace.Physical, HeldB));
            }

            public void Layout_ReplacesOnlyTheLayoutKeys()
            {
                var keyboard = new KeyboardSnapshot(PressedA, HeldB);

                CheckEqual(new KeyboardSnapshot(PressedA, PressedA), keyboard.With(KeySpace.Layout, PressedA));
            }

            public void UndefinedSpace_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                default(KeyboardSnapshot).With((KeySpace)2, PressedA);
            }
        }

        public class IsConsistentTests : TestFixture
        {
            public void Nothing_IsConsistent()
            {
                Check(default(KeyboardSnapshot).IsConsistent());
            }

            public void ConsistentSpaces_AreConsistent()
            {
                Check(new KeyboardSnapshot(PressedA, HeldB).IsConsistent());
            }

            public void AnInconsistentPhysicalSpace_IsNotConsistent()
            {
                var pressedButNotHeld = new KeySpaceSnapshot(default, new KeyState(KeyCode.A), default);

                CheckFalse(new KeyboardSnapshot(pressedButNotHeld, HeldB).IsConsistent());
            }

            public void AnInconsistentLayoutSpace_IsNotConsistent()
            {
                var pressedButNotHeld = new KeySpaceSnapshot(default, new KeyState(KeyCode.A), default);

                CheckFalse(new KeyboardSnapshot(PressedA, pressedButNotHeld).IsConsistent());
            }
        }
    }
}