using System;
using Amphora;
using Annulus;
using Azimuth;
using UnitTestSharp;

namespace Glass.UnitTests
{
    public class WorldAnchoredPanelTests : TestFixture
    {
        private static readonly Vector Size = new Vector(30, 10);
        private static readonly Vector Offset = new Vector(-15, -20);

        private static WorldAnchoredPanel NewPanel(Func<Vector, Vector> toGlassSpace, Vector worldPosition)
        {
            return new WorldAnchoredPanel(toGlassSpace)
            {
                Bounds = Rect.FromPositionAndSize(Vector.Zero, Size),
                WorldPosition = worldPosition,
                OffsetFromAnchor = Offset,
            };
        }

        public class CtorTests : TestFixture
        {
            public void IsHoistedAndAlwaysOnTopAndUnclipped()
            {
                WorldAnchoredPanel panel = NewPanel(point => point, Vector.Zero);

                CheckTrue(panel.Hoisted);
                CheckTrue(panel.AlwaysOnTop);
                CheckFalse(panel.ClipToAncestors);
            }
        }

        public class UpdateTests : TestFixture
        {
            public void SitsAtTheConvertedPositionPlusTheOffset()
            {
                WorldAnchoredPanel panel = NewPanel(point => point * 2, new Vector(100, 50));

                panel.Update(Duration.FromMilliseconds(16), new UpdateState());

                CheckEqual(new Vector(185, 80), panel.Bounds.TopLeft);
            }

            public void KeepsItsSize()
            {
                WorldAnchoredPanel panel = NewPanel(point => point, new Vector(100, 50));

                panel.Update(Duration.FromMilliseconds(16), new UpdateState());

                CheckEqual(Size, panel.Bounds.Size);
            }

            public void WhenTheConversionChanges_FollowsIt()
            {
                var cameraShift = new Vector(0, 0);
                WorldAnchoredPanel panel = NewPanel(point => point - cameraShift, new Vector(100, 50));

                cameraShift = new Vector(10, 0);
                panel.Update(Duration.FromMilliseconds(16), new UpdateState());

                CheckEqual(new Vector(75, 30), panel.Bounds.TopLeft);
            }

            public void WhenTheWorldPositionMoves_FollowsIt()
            {
                WorldAnchoredPanel panel = NewPanel(point => point, new Vector(100, 50));

                panel.WorldPosition = new Vector(120, 40);
                panel.Update(Duration.FromMilliseconds(16), new UpdateState());

                CheckEqual(new Vector(105, 20), panel.Bounds.TopLeft);
            }
        }
    }
}