using Blacklight.Core.Drawables;
using System;
using System.Drawing;
using UnitTestSharp;

namespace Blacklight.Core.UnitTests.Drawables
{
    public class SpriteBatchEntrySetTests : TestFixture
    {
        public static readonly SpriteBatch.Varying[] EachProperty =
        {
            SpriteBatch.Varying.Tiling,
            SpriteBatch.Varying.TintColor,
            SpriteBatch.Varying.ClipWindow,
            SpriteBatch.Varying.CoverageGamma,
            SpriteBatch.Varying.Additiveness,
        };

        public class CtorTests : TestFixture
        {
            public void Parameterless_HasNoEntriesOrColumns()
            {
                var set = new SpriteBatch.EntrySet();

                CheckEqual(0, set.Capacity);
                CheckEqual(SpriteBatch.Varying.None, set.Columns);
            }

            public void SizesTheEntriesAndAddsTheNamedColumns()
            {
                SpriteBatch.Varying columns = SpriteBatch.Varying.Tiling | SpriteBatch.Varying.ClipWindow;

                var set = new SpriteBatch.EntrySet(capacity: 3, columns);

                CheckEqual(3, set.Entries.Length);
                CheckEqual(columns, set.Columns);
                CheckEqual(3, set.TilingX.Length);
                CheckEqual(3, set.ClipWindows.Length);
            }
        }

        public class CapacityTests : TestFixture
        {
            public void IsHowManyEntriesFit()
            {
                CheckEqual(5, new SpriteBatch.EntrySet(capacity: 5, SpriteBatch.Varying.None).Capacity);
            }
        }

        public class ColumnsTests : TestFixture
        {
            public void EachColumn_IsReportedOnItsOwn()
            {
                foreach (SpriteBatch.Varying property in EachProperty)
                {
                    CheckEqual(property, new SpriteBatch.EntrySet(capacity: 1, property).Columns);
                }
            }
        }

        public class EnsureCapacityTests : TestFixture
        {
            public void AlreadyBigEnough_LeavesTheArraysAlone()
            {
                var set = new SpriteBatch.EntrySet(capacity: 4, SpriteBatch.Varying.Tiling);
                SpriteBatch.Entry[] entries = set.Entries;
                TilingBehavior[] tilingX = set.TilingX;

                set.EnsureCapacity(4);

                CheckTrue(ReferenceEquals(entries, set.Entries));
                CheckTrue(ReferenceEquals(tilingX, set.TilingX));
            }

            public void Growing_KeepsTheEntriesAndEveryColumn()
            {
                var set = new SpriteBatch.EntrySet(capacity: 1,
                    SpriteBatch.Varying.Tiling | SpriteBatch.Varying.TintColor | SpriteBatch.Varying.ClipWindow |
                    SpriteBatch.Varying.CoverageGamma | SpriteBatch.Varying.Additiveness);
                set.Entries[0].SourceOrigin = new Point(9, 0);
                set.TilingX[0] = TilingBehavior.Tile;
                set.TilingY[0] = TilingBehavior.StretchAndTile;
                set.TintColors[0] = new TintColor(0.5, 0.5, 0.5, 0.5);
                set.ClipWindows[0] = Annulus.Rect.FromPositionAndSize(Azimuth.Vector.Zero, new Azimuth.Vector(2, 3));
                set.CoverageGammas[0] = 1.5;
                set.Additivenesses[0] = 0.25;

                set.EnsureCapacity(10);

                CheckEqual(9, set.Entries[0].SourceOrigin.X);
                CheckEqual(TilingBehavior.Tile, set.TilingX[0]);
                CheckEqual(TilingBehavior.StretchAndTile, set.TilingY[0]);
                CheckEqual(new TintColor(0.5, 0.5, 0.5, 0.5), set.TintColors[0]);
                CheckEqual(new Azimuth.Vector(2, 3), set.ClipWindows[0].Value.Size);
                CheckEqual((Azimuth.Scalar)1.5, set.CoverageGammas[0]);
                CheckEqual((Azimuth.Scalar)0.25, set.Additivenesses[0]);
                CheckEqual(set.Entries.Length, set.TilingX.Length);
                CheckEqual(set.Entries.Length, set.Additivenesses.Length);
            }

            public void Growing_AtLeastDoubles()
            {
                var set = new SpriteBatch.EntrySet(capacity: 4, SpriteBatch.Varying.None);

                set.EnsureCapacity(5);

                CheckEqual(8, set.Capacity);
            }

            public void GrowingPastDouble_FitsTheRequestExactly()
            {
                var set = new SpriteBatch.EntrySet(capacity: 2, SpriteBatch.Varying.None);

                set.EnsureCapacity(9);

                CheckEqual(9, set.Capacity);
            }

            public void Growing_LeavesMissingColumnsMissing()
            {
                var set = new SpriteBatch.EntrySet(capacity: 1, SpriteBatch.Varying.Tiling);

                set.EnsureCapacity(10);

                CheckEqual(SpriteBatch.Varying.Tiling, set.Columns);
            }
        }

        public class AddColumnsTests : TestFixture
        {
            public void ExistingColumns_AreKept()
            {
                var set = new SpriteBatch.EntrySet(capacity: 2, SpriteBatch.Varying.Tiling);
                TilingBehavior[] tilingX = set.TilingX;

                set.AddColumns(SpriteBatch.Varying.Tiling | SpriteBatch.Varying.TintColor);

                CheckTrue(ReferenceEquals(tilingX, set.TilingX));
                CheckEqual(SpriteBatch.Varying.Tiling | SpriteBatch.Varying.TintColor, set.Columns);
            }

            public void NewColumns_MatchTheEntries()
            {
                var set = new SpriteBatch.EntrySet(capacity: 6, SpriteBatch.Varying.None);

                set.AddColumns(SpriteBatch.Varying.CoverageGamma);

                CheckEqual(6, set.CoverageGammas.Length);
            }

            public void Tiling_AddsBothAxes()
            {
                var set = new SpriteBatch.EntrySet();

                set.AddColumns(SpriteBatch.Varying.Tiling);

                CheckNotNull(set.TilingX);
                CheckNotNull(set.TilingY);
            }
        }
    }
}