// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.

using osu.Framework.Allocation;
using osu.Framework.Bindables;
using osu.Framework.Extensions.Color4Extensions;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Effects;
using osu.Framework.Graphics.Shapes;
using osu.Game.Beatmaps;
using osu.Game.Configuration;
using osu.Game.Skinning;
using osuTK;
using osuTK.Graphics;

namespace osu.Game.Rulesets.Osu.UI.Cursor
{
    public class OsuCursor : SkinReloadableDrawable
    {
        private bool cursorExpand;

        private Bindable<double> cursorScale;
        private Bindable<bool> autoCursorScale;
        private readonly IBindable<WorkingBeatmap> beatmap = new Bindable<WorkingBeatmap>();

        private Container expandTarget;
        private Drawable scaleTarget;

        public OsuCursor()
        {
            Origin = Anchor.Centre;
            Size = new Vector2(28);
        }

        protected override void SkinChanged(ISkinSource skin, bool allowFallback)
        {
            cursorExpand = skin.GetValue<SkinConfiguration, bool>(s => s.CursorExpand ?? true);
        }

        [BackgroundDependencyLoader]
        private void load(OsuConfigManager config, IBindable<WorkingBeatmap> beatmap)
        {
            InternalChild = expandTarget = new Container
            {
                RelativeSizeAxes = Axes.Both,
                Origin = Anchor.Centre,
                Anchor = Anchor.Centre,
                Child = scaleTarget = new SkinnableDrawable("cursor", _ => new CircularContainer
                {
                    RelativeSizeAxes = Axes.Both,
                    Masking = true,
                    BorderThickness = Size.X / 6,
                    BorderColour = Color4.White,
                    EdgeEffect = new EdgeEffectParameters
                    {
                        Type = EdgeEffectType.Shadow,
                        Colour = Color4.Pink.Opacity(0.5f),
                        Radius = 5,
                    },
                    Children = new Drawable[]
                    {
                        new Box
                        {
                            RelativeSizeAxes = Axes.Both,
                            Alpha = 0,
                            AlwaysPresent = true,
                        },
                        new CircularContainer
                        {
                            Origin = Anchor.Centre,
                            Anchor = Anchor.Centre,
                            RelativeSizeAxes = Axes.Both,
                            Masking = true,
                            BorderThickness = Size.X / 3,
                            BorderColour = Color4.White.Opacity(0.5f),
                            Children = new Drawable[]
                            {
                                new Box
                                {
                                    RelativeSizeAxes = Axes.Both,
                                    Alpha = 0,
                                    AlwaysPresent = true,
                                },
                            },
                        },
                        new CircularContainer
                        {
                            Origin = Anchor.Centre,
                            Anchor = Anchor.Centre,
                            RelativeSizeAxes = Axes.Both,
                            Scale = new Vector2(0.1f),
                            Masking = true,
                            Children = new Drawable[]
                            {
                                new Box
                                {
                                    RelativeSizeAxes = Axes.Both,
                                    Colour = Color4.White,
                                },
                            },
                        },
                    }
                }, restrictSize: false)
                {
                    Origin = Anchor.Centre,
                    Anchor = Anchor.Centre,
                    RelativeSizeAxes = Axes.Both,
                }
            };

            this.beatmap.BindTo(beatmap);
            this.beatmap.ValueChanged += _ => calculateScale();

            cursorScale = config.GetBindable<double>(OsuSetting.GameplayCursorSize);
            cursorScale.ValueChanged += _ => calculateScale();

            autoCursorScale = config.GetBindable<bool>(OsuSetting.AutoCursorSize);
            autoCursorScale.ValueChanged += _ => calculateScale();

            calculateScale();
        }

        private void calculateScale()
        {
            float scale = (float)cursorScale.Value;

            if (autoCursorScale.Value && beatmap.Value != null)
            {
                // if we have a beatmap available, let's get its circle size to figure out an automatic cursor scale modifier.
                scale *= (float)(1 - 0.7 * (1 + beatmap.Value.BeatmapInfo.BaseDifficulty.CircleSize - BeatmapDifficulty.DEFAULT_DIFFICULTY) / BeatmapDifficulty.DEFAULT_DIFFICULTY);
            }

            scaleTarget.Scale = new Vector2(scale);
        }

        private const float pressed_scale = 1.2f;
        private const float released_scale = 1f;

        public void Expand()
        {
            if (!cursorExpand) return;

            expandTarget.ScaleTo(released_scale).ScaleTo(pressed_scale, 100, Easing.OutQuad);
        }

        public void Contract() => expandTarget.ScaleTo(released_scale, 100, Easing.OutQuad);
    }
}