using Azimuth;
using System;

namespace Glass.Blacklight
{
    public static class TintSpaceAdapter
    {
        /// <summary>
        /// Returns <paramref name="transform"/> as Blacklight needs it to measure a tint in <paramref name="space"/>.
        /// Blacklight's screen is in pixels and Glass's is <paramref name="uiScale"/> pixels to the unit, so a screen
        /// tint is scaled up to match.
        /// </summary>
        public static AffineMatrix TintTransformFor(
            AffineMatrix transform, global::Blacklight.Core.Drawables.FillSpace space, Scalar uiScale)
        {
            if (space != global::Blacklight.Core.Drawables.FillSpace.Screen || uiScale == 1)
            {
                return transform;
            }

            return AffineMatrix.BuildFromScale(uiScale) * transform;
        }

        public static global::Blacklight.Core.Drawables.FillSpace ToBlacklight(this global::Glass.TintSpace space)
        {
            switch (space)
            {
                case TintSpace.Screen:
                    return global::Blacklight.Core.Drawables.FillSpace.Screen;
                case TintSpace.Model:
                    return global::Blacklight.Core.Drawables.FillSpace.Model;
                default:
                    throw new InvalidOperationException($"Unknown tint space {space}");
            }
        }
    }
}