// 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 System.Collections.Generic;
using System.Linq;
using osu.Framework.Allocation;
using osu.Framework.Bindables;
using osu.Framework.Graphics;
using osu.Game.Beatmaps;
using osu.Game.Configuration;
using osu.Game.Rulesets.Mods;
using osu.Game.Rulesets.Objects.Drawables;
using osu.Game.Rulesets.Osu.Objects.Drawables;
using osu.Game.Rulesets.Osu.Skinning.Default;
using osu.Game.Rulesets.Osu.UI;
using osu.Game.Rulesets.UI;
using osuTK;

namespace osu.Game.Rulesets.Osu.Edit
{
    public class DrawableOsuEditorRuleset : DrawableOsuRuleset
    {
        /// <summary>
        /// Hit objects are intentionally made to fade out at a constant slower rate than in gameplay.
        /// This allows a mapper to gain better historical context and use recent hitobjects as reference / snap points.
        /// </summary>
        public const double EDITOR_HIT_OBJECT_FADE_OUT_EXTENSION = 700;

        public DrawableOsuEditorRuleset(Ruleset ruleset, IBeatmap beatmap, IReadOnlyList<Mod> mods)
            : base(ruleset, beatmap, mods)
        {
        }

        protected override Playfield CreatePlayfield() => new OsuEditorPlayfield();

        public override PlayfieldAdjustmentContainer CreatePlayfieldAdjustmentContainer() => new OsuPlayfieldAdjustmentContainer { Size = Vector2.One };

        private class OsuEditorPlayfield : OsuPlayfield
        {
            private Bindable<bool> hitAnimations;

            protected override GameplayCursorContainer CreateCursor() => null;

            public OsuEditorPlayfield()
            {
                HitPolicy = new AnyOrderHitPolicy();
            }

            [BackgroundDependencyLoader]
            private void load(OsuConfigManager config)
            {
                hitAnimations = config.GetBindable<bool>(OsuSetting.EditorHitAnimations);
            }

            protected override void OnNewDrawableHitObject(DrawableHitObject d)
            {
                d.ApplyCustomUpdateState += updateState;
            }

            private void updateState(DrawableHitObject hitObject, ArmedState state)
            {
                if (state == ArmedState.Idle || hitAnimations.Value)
                    return;

                if (hitObject is DrawableHitCircle circle)
                {
                    circle.ApproachCircle
                          .FadeOutFromOne(EDITOR_HIT_OBJECT_FADE_OUT_EXTENSION * 4)
                          .Expire();

                    circle.ApproachCircle.ScaleTo(1.1f, 300, Easing.OutQuint);
                }

                if (hitObject is IHasMainCirclePiece mainPieceContainer)
                {
                    // clear any explode animation logic.
                    // this is scheduled after children to ensure that the clear happens after invocations of ApplyCustomUpdateState on the circle piece's nested skinnables.
                    ScheduleAfterChildren(() =>
                    {
                        if (hitObject.HitObject == null) return;

                        mainPieceContainer.CirclePiece.ApplyTransformsAt(hitObject.StateUpdateTime, true);
                        mainPieceContainer.CirclePiece.ClearTransformsAfter(hitObject.StateUpdateTime, true);
                    });
                }

                if (hitObject is DrawableSliderRepeat repeat)
                {
                    repeat.Arrow.ApplyTransformsAt(hitObject.StateUpdateTime, true);
                    repeat.Arrow.ClearTransformsAfter(hitObject.StateUpdateTime, true);
                }

                // adjust the visuals of top-level object types to make them stay on screen for longer than usual.
                switch (hitObject)
                {
                    case DrawableSlider _:
                    case DrawableHitCircle _:
                        // Get the existing fade out transform
                        var existing = hitObject.Transforms.LastOrDefault(t => t.TargetMember == nameof(Alpha));

                        if (existing == null)
                            return;

                        hitObject.RemoveTransform(existing);

                        using (hitObject.BeginAbsoluteSequence(hitObject.HitStateUpdateTime))
                            hitObject.FadeOut(EDITOR_HIT_OBJECT_FADE_OUT_EXTENSION).Expire();
                        break;
                }
            }
        }
    }
}