// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE

using System;
using System.Linq;
using osu.Framework.Allocation;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Sprites;
using osu.Framework.Graphics.Textures;
using osu.Framework.Input.Bindings;
using osu.Framework.MathUtils;
using osu.Game.Rulesets.Catch.Objects;
using osu.Game.Rulesets.Objects.Drawables;
using OpenTK;

namespace osu.Game.Rulesets.Catch.UI
{
    public class Catcher : Container, IKeyBindingHandler<CatchAction>
    {
        private Texture texture;

        private Container<DrawableHitObject> caughtFruit;

        public Container ExplodingFruitTarget;

        [BackgroundDependencyLoader]
        private void load(TextureStore textures)
        {
            texture = textures.Get(@"Play/Catch/fruit-catcher-idle");

            Children = new Drawable[]
            {
                createCatcherSprite(),
                caughtFruit = new Container<DrawableHitObject>
                {
                    Anchor = Anchor.TopCentre,
                    Origin = Anchor.BottomCentre,
                }
            };
        }

        private int currentDirection;

        private bool dashing;

        protected bool Dashing
        {
            get { return dashing; }
            set
            {
                if (value == dashing) return;

                dashing = value;

                if (dashing)
                    Schedule(addAdditiveSprite);
            }
        }

        private void addAdditiveSprite()
        {
            if (!dashing) return;

            var additive = createCatcherSprite();

            additive.RelativePositionAxes = Axes.Both;
            additive.Blending = BlendingMode.Additive;
            additive.Position = Position;
            additive.Scale = Scale;

            ((Container)Parent).Add(additive);

            additive.FadeTo(0.4f).FadeOut(800, Easing.OutQuint).Expire();

            Scheduler.AddDelayed(addAdditiveSprite, 50);
        }

        private Sprite createCatcherSprite() => new Sprite
        {
            RelativeSizeAxes = Axes.Both,
            FillMode = FillMode.Fit,
            Texture = texture,
            OriginPosition = new Vector2(DrawWidth / 2, 10) //temporary until the sprite is aligned correctly.
        };

        public bool OnPressed(CatchAction action)
        {
            switch (action)
            {
                case CatchAction.MoveLeft:
                    currentDirection--;
                    return true;
                case CatchAction.MoveRight:
                    currentDirection++;
                    return true;
                case CatchAction.Dash:
                    Dashing = true;
                    return true;
            }

            return false;
        }

        public bool OnReleased(CatchAction action)
        {
            switch (action)
            {
                case CatchAction.MoveLeft:
                    currentDirection++;
                    return true;
                case CatchAction.MoveRight:
                    currentDirection--;
                    return true;
                case CatchAction.Dash:
                    Dashing = false;
                    return true;
            }

            return false;
        }

        /// <summary>
        /// The relative space to cover in 1 millisecond. based on 1 game pixel per millisecond as in osu-stable.
        /// </summary>
        private const double base_speed = 1.0 / 512;

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

            if (currentDirection == 0) return;

            double dashModifier = Dashing ? 1 : 0.5;

            Scale = new Vector2(Math.Sign(currentDirection), 1);
            X = (float)MathHelper.Clamp(X + Math.Sign(currentDirection) * Clock.ElapsedFrameTime * base_speed * dashModifier, 0, 1);
        }

        public void Add(DrawableHitObject fruit, Vector2 absolutePosition)
        {
            fruit.RelativePositionAxes = Axes.None;
            fruit.Position = new Vector2(ToLocalSpace(absolutePosition).X - DrawSize.X / 2, 0);

            fruit.Anchor = Anchor.TopCentre;
            fruit.Origin = Anchor.BottomCentre;
            fruit.Scale *= 0.7f;
            fruit.LifetimeEnd = double.MaxValue;

            float distance = fruit.DrawSize.X / 2 * fruit.Scale.X;

            while (caughtFruit.Any(f => f.LifetimeEnd == double.MaxValue && Vector2Extensions.DistanceSquared(f.Position, fruit.Position) < distance * distance))
            {
                fruit.X += RNG.Next(-5, 5);
                fruit.Y -= RNG.Next(0, 5);
            }

            caughtFruit.Add(fruit);

            if (((CatchBaseHit)fruit.HitObject).LastInCombo)
                explode();
        }

        private void explode()
        {
            var fruit = caughtFruit.ToArray();

            foreach (var f in fruit)
            {
                var originalX = f.X * Scale.X;

                if (ExplodingFruitTarget != null)
                {
                    f.Anchor = Anchor.TopLeft;
                    f.Position = caughtFruit.ToSpaceOfOtherDrawable(f.DrawPosition, ExplodingFruitTarget);

                    caughtFruit.Remove(f);

                    ExplodingFruitTarget.Add(f);
                }

                f.MoveToY(f.Y - 50, 250, Easing.OutSine)
                .Then()
                .MoveToY(f.Y + 50, 500, Easing.InSine);

                f.MoveToX(f.X + originalX * 6, 1000);
                f.FadeOut(750);

                f.Expire();
            }
        }
    }
}