using System;

namespace Prism.UnitTests
{
    public class SrgbColorTests : UnitTestSharp.TestFixture
    {
        public class CtorTests : UnitTestSharp.TestFixture
        {
            public void AssignsAllFourChannels()
            {
                var color = new SrgbColor(0.1, 0.2, 0.3, 0.4);

                CheckEqual(0.1, color.Red);
                CheckEqual(0.2, color.Green);
                CheckEqual(0.3, color.Blue);
                CheckEqual(0.4, color.Alpha);
            }

            public void WithoutAlpha_IsOpaque()
            {
                CheckEqual(1.0, new SrgbColor(0.1, 0.2, 0.3).Alpha);
            }

            public void ChannelsBelowZero_LimitToZero()
            {
                var color = new SrgbColor(-1, -0.5, -2, -3);

                CheckEqual(new SrgbColor(0, 0, 0, 0), color);
            }

            public void ChannelsAboveOne_LimitToOne()
            {
                var color = new SrgbColor(1.5, 2, 3, 4);

                CheckEqual(new SrgbColor(1, 1, 1, 1), color);
            }

            public void NaNChannel_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                new SrgbColor(0, double.NaN, 0);
            }

            public void InfiniteChannel_Throws()
            {
                CheckThrow(typeof(ArgumentOutOfRangeException));
                new SrgbColor(0, 0, 0, double.PositiveInfinity);
            }
        }

        public class FromColorTests : UnitTestSharp.TestFixture
        {
            public void DividesEveryChannelBy255()
            {
                SrgbColor color = SrgbColor.FromColor(Color.FromArgb(51, 255, 102, 0));

                CheckEqual(new SrgbColor(1, 0.4, 0, 0.2), color);
            }
        }

        public class ToColorTests : UnitTestSharp.TestFixture
        {
            public void RoundsEveryChannelToTheNearestByte()
            {
                var color = new SrgbColor(100.4 / 255, 100.6 / 255, 0, 200.6 / 255);

                CheckEqual(Color.FromArgb(201, 100, 101, 0), color.ToColor());
            }

            public void UndoesFromColor()
            {
                Color original = Color.FromArgb(77, 12, 34, 56);

                CheckEqual(original, SrgbColor.FromColor(original).ToColor());
            }
        }

        public class EqualityTests : UnitTestSharp.TestFixture
        {
            public void SameChannels_AreEqual()
            {
                CheckTrue(new SrgbColor(0.1, 0.2, 0.3, 0.4).Equals(new SrgbColor(0.1, 0.2, 0.3, 0.4)));
                CheckTrue(new SrgbColor(0.1, 0.2, 0.3, 0.4) == new SrgbColor(0.1, 0.2, 0.3, 0.4));
                CheckFalse(new SrgbColor(0.1, 0.2, 0.3, 0.4) != new SrgbColor(0.1, 0.2, 0.3, 0.4));
            }

            public void AnyDifferentChannel_IsNotEqual()
            {
                var baseColor = new SrgbColor(0.1, 0.2, 0.3, 0.4);

                CheckFalse(baseColor.Equals(new SrgbColor(0.9, 0.2, 0.3, 0.4)));
                CheckFalse(baseColor.Equals(new SrgbColor(0.1, 0.9, 0.3, 0.4)));
                CheckFalse(baseColor.Equals(new SrgbColor(0.1, 0.2, 0.9, 0.4)));
                CheckFalse(baseColor.Equals(new SrgbColor(0.1, 0.2, 0.3, 0.9)));
                CheckTrue(baseColor != new SrgbColor(0.1, 0.2, 0.3, 0.9));
            }

            public void BoxedColor_IsEqualToTheSameColor()
            {
                CheckTrue(new SrgbColor(0.1, 0.2, 0.3).Equals((object)new SrgbColor(0.1, 0.2, 0.3)));
            }

            public void ANonSrgbColor_IsNotEqual()
            {
                CheckFalse(new SrgbColor(0.1, 0.2, 0.3).Equals("color"));
            }

            public void EqualColors_HaveTheSameHashCode()
            {
                CheckEqual(new SrgbColor(0.1, 0.2, 0.3, 0.4).GetHashCode(),
                    new SrgbColor(0.1, 0.2, 0.3, 0.4).GetHashCode());
            }
        }
    }
}