// 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;
using System.Linq;
using osu.Framework.Allocation;
using osu.Framework.Utils;
using osu.Game.Graphics;
using osu.Game.Rulesets.Objects.Drawables;
using osuTK.Graphics;
using osu.Game.Rulesets.Taiko.Objects.Drawables.Pieces;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Game.Rulesets.Judgements;
using osu.Game.Rulesets.Objects;
using osu.Game.Rulesets.Scoring;

namespace osu.Game.Rulesets.Taiko.Objects.Drawables
{
    public class DrawableDrumRoll : DrawableTaikoHitObject<DrumRoll>
    {
        /// <summary>
        /// Number of rolling hits required to reach the dark/final colour.
        /// </summary>
        private const int rolling_hits_for_engaged_colour = 5;

        /// <summary>
        /// Rolling number of tick hits. This increases for hits and decreases for misses.
        /// </summary>
        private int rollingHits;

        private readonly Container<DrawableDrumRollTick> tickContainer;

        private Color4 colourIdle;
        private Color4 colourEngaged;

        private bool judgingStarted;

        /// <summary>
        /// A handler action for when the drumroll has been hit,
        /// regardless of any judgement.
        /// </summary>
        public Action<TaikoAction> OnHit;

        public DrawableDrumRoll(DrumRoll drumRoll)
            : base(drumRoll)
        {
            RelativeSizeAxes = Axes.Y;
            MainPiece.Add(tickContainer = new Container<DrawableDrumRollTick> { RelativeSizeAxes = Axes.Both });
        }

        [BackgroundDependencyLoader]
        private void load(OsuColour colours)
        {
            MainPiece.AccentColour = colourIdle = colours.YellowDark;
            colourEngaged = colours.YellowDarker;
        }

        protected override void LoadComplete()
        {
            base.LoadComplete();

            OnNewResult += onNewResult;
        }

        protected override void AddNestedHitObject(DrawableHitObject hitObject)
        {
            base.AddNestedHitObject(hitObject);

            switch (hitObject)
            {
                case DrawableDrumRollTick tick:
                    tickContainer.Add(tick);
                    break;
            }
        }

        protected override void ClearNestedHitObjects()
        {
            base.ClearNestedHitObjects();
            tickContainer.Clear();
        }

        protected override DrawableHitObject CreateNestedHitObject(HitObject hitObject)
        {
            switch (hitObject)
            {
                case DrumRollTick tick:
                    return new DrawableDrumRollTick(tick);
            }

            return base.CreateNestedHitObject(hitObject);
        }

        protected override TaikoPiece CreateMainPiece() => new ElongatedCirclePiece();

        public override bool OnPressed(TaikoAction action)
        {
            if (judgingStarted)
                OnHit.Invoke(action);

            return false;
        }

        private void onNewResult(DrawableHitObject obj, JudgementResult result)
        {
            if (!(obj is DrawableDrumRollTick))
                return;

            DrawableDrumRollTick drumRollTick = (DrawableDrumRollTick)obj;

            if (result.Type > HitResult.Miss)
            {
                OnHit.Invoke(drumRollTick.JudgedAction);
                judgingStarted = true;
                rollingHits++;
            }
            else
                rollingHits--;

            rollingHits = Math.Clamp(rollingHits, 0, rolling_hits_for_engaged_colour);

            Color4 newColour = Interpolation.ValueAt((float)rollingHits / rolling_hits_for_engaged_colour, colourIdle, colourEngaged, 0, 1);
            MainPiece.FadeAccent(newColour, 100);
        }

        protected override void CheckForResult(bool userTriggered, double timeOffset)
        {
            if (userTriggered)
                return;

            if (timeOffset < 0)
                return;

            int countHit = NestedHitObjects.Count(o => o.IsHit);

            if (countHit >= HitObject.RequiredGoodHits)
            {
                ApplyResult(r => r.Type = countHit >= HitObject.RequiredGreatHits ? HitResult.Great : HitResult.Good);
            }
            else
                ApplyResult(r => r.Type = HitResult.Miss);
        }

        protected override void UpdateStateTransforms(ArmedState state)
        {
            switch (state)
            {
                case ArmedState.Hit:
                case ArmedState.Miss:
                    this.Delay(HitObject.Duration).FadeOut(100);
                    break;
            }
        }

        protected override DrawableStrongNestedHit CreateStrongHit(StrongHitObject hitObject) => new StrongNestedHit(hitObject, this);

        private class StrongNestedHit : DrawableStrongNestedHit
        {
            public StrongNestedHit(StrongHitObject strong, DrawableDrumRoll drumRoll)
                : base(strong, drumRoll)
            {
            }

            protected override void CheckForResult(bool userTriggered, double timeOffset)
            {
                if (!MainObject.Judged)
                    return;

                ApplyResult(r => r.Type = MainObject.IsHit ? HitResult.Great : HitResult.Miss);
            }

            public override bool OnPressed(TaikoAction action) => false;
        }
    }
}