// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE

using osu.Framework.Allocation;
using osu.Framework.Configuration;
using osu.Framework.Graphics.Containers;
using osu.Framework.Lists;
using osu.Game.Configuration;
using osu.Game.Rulesets.Timing;
using osu.Game.Rulesets.UI.Scrolling;
using osu.Game.Rulesets.UI.Scrolling.Algorithms;

namespace osu.Game.Tests.Visual
{
    /// <summary>
    /// A container which provides a <see cref="IScrollingInfo"/> to children.
    /// This should only be used when testing
    /// </summary>
    public class ScrollingTestContainer : Container
    {
        public SortedList<MultiplierControlPoint> ControlPoints => scrollingInfo.Algorithm.ControlPoints;

        public ScrollVisualisationMethod ScrollAlgorithm { set => scrollingInfo.Algorithm.Algorithm = value; }

        public double TimeRange { set => scrollingInfo.TimeRange.Value = value; }

        public IScrollingInfo ScrollingInfo => scrollingInfo;

        [Cached(Type = typeof(IScrollingInfo))]
        private readonly TestScrollingInfo scrollingInfo = new TestScrollingInfo();

        public ScrollingTestContainer(ScrollingDirection direction)
        {
            scrollingInfo.Direction.Value = direction;
        }

        public void Flip() => scrollingInfo.Direction.Value = scrollingInfo.Direction.Value == ScrollingDirection.Up ? ScrollingDirection.Down : ScrollingDirection.Up;

        private class TestScrollingInfo : IScrollingInfo
        {
            public readonly Bindable<ScrollingDirection> Direction = new Bindable<ScrollingDirection>();
            IBindable<ScrollingDirection> IScrollingInfo.Direction => Direction;

            public readonly Bindable<double> TimeRange = new Bindable<double>(1000) { Value = 1000 };
            IBindable<double> IScrollingInfo.TimeRange => TimeRange;

            public readonly TestScrollAlgorithm Algorithm = new TestScrollAlgorithm();
            IScrollAlgorithm IScrollingInfo.Algorithm => Algorithm;
        }

        private class TestScrollAlgorithm : IScrollAlgorithm
        {
            public readonly SortedList<MultiplierControlPoint> ControlPoints = new SortedList<MultiplierControlPoint>();

            private IScrollAlgorithm implementation;

            public TestScrollAlgorithm()
            {
                Algorithm = ScrollVisualisationMethod.Constant;
            }

            public ScrollVisualisationMethod Algorithm
            {
                set
                {
                    switch (value)
                    {
                        case ScrollVisualisationMethod.Constant:
                            implementation = new ConstantScrollAlgorithm();
                            break;
                        case ScrollVisualisationMethod.Overlapping:
                            implementation = new OverlappingScrollAlgorithm(ControlPoints);
                            break;
                        case ScrollVisualisationMethod.Sequential:
                            implementation = new SequentialScrollAlgorithm(ControlPoints);
                            break;
                    }
                }
            }

            public double GetDisplayStartTime(double time, double timeRange)
                => implementation.GetDisplayStartTime(time, timeRange);

            public float GetLength(double startTime, double endTime, double timeRange, float scrollLength)
                => implementation.GetLength(startTime, endTime, timeRange, scrollLength);

            public float PositionAt(double time, double currentTime, double timeRange, float scrollLength)
                => implementation.PositionAt(time, currentTime, timeRange, scrollLength);

            public double TimeAt(float position, double currentTime, double timeRange, float scrollLength)
                => implementation.TimeAt(position, currentTime, timeRange, scrollLength);

            public void Reset()
                => implementation.Reset();
        }
    }
}