// 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.Diagnostics;
using osu.Framework.Allocation;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Shapes;
using osu.Framework.Input.Bindings;
using osu.Framework.Input.Events;
using osu.Game.Graphics;
using osuTK;
using osuTK.Graphics;

namespace osu.Game.Rulesets.Taiko.UI
{
    /// <summary>
    /// An overlay that captures and displays osu!taiko mouse and touch input.
    /// </summary>
    public class DrumTouchInputArea : Container
    {
        private KeyBindingContainer<TaikoAction> keyBindingContainer = null!;

        private readonly Dictionary<object, TaikoAction> trackedActions = new Dictionary<object, TaikoAction>();

        private Container mainContent = null!;

        private Circle centreCircle = null!;
        private Circle outerCircle = null!;

        [BackgroundDependencyLoader]
        private void load(TaikoInputManager taikoInputManager, OsuColour colours)
        {
            Debug.Assert(taikoInputManager.KeyBindingContainer != null);
            keyBindingContainer = taikoInputManager.KeyBindingContainer;

            // Container should handle input everywhere.
            RelativeSizeAxes = Axes.Both;

            Children = new Drawable[]
            {
                new Container
                {
                    Anchor = Anchor.BottomCentre,
                    Origin = Anchor.BottomCentre,
                    RelativeSizeAxes = Axes.X,
                    Height = 300,
                    Y = 20,
                    Masking = true,
                    FillMode = FillMode.Fit,
                    Children = new Drawable[]
                    {
                        mainContent = new Container
                        {
                            RelativeSizeAxes = Axes.Both,
                            Height = 2,
                            Children = new Drawable[]
                            {
                                outerCircle = new Circle
                                {
                                    FillMode = FillMode.Fit,
                                    Colour = colours.BlueDarker,
                                    RelativeSizeAxes = Axes.Both,
                                    Anchor = Anchor.Centre,
                                    Origin = Anchor.Centre,
                                },
                                centreCircle = new Circle
                                {
                                    FillMode = FillMode.Fit,
                                    Colour = colours.YellowDark,
                                    RelativeSizeAxes = Axes.Both,
                                    Anchor = Anchor.Centre,
                                    Origin = Anchor.Centre,
                                    Scale = new Vector2(0.8f),
                                },
                                new Box
                                {
                                    Colour = colours.BlueDarker,
                                    RelativeSizeAxes = Axes.Y,
                                    Height = 0.9f,
                                    Anchor = Anchor.BottomCentre,
                                    Origin = Anchor.BottomCentre,
                                    Width = 7,
                                },
                            }
                        },
                    }
                },
            };
        }

        protected override bool OnKeyDown(KeyDownEvent e)
        {
            // Hide whenever the keyboard is used.
            mainContent.Hide();
            return false;
        }

        protected override bool OnMouseDown(MouseDownEvent e)
        {
            handleDown(e.Button, e.ScreenSpaceMousePosition);
            return true;
        }

        protected override void OnMouseUp(MouseUpEvent e)
        {
            handleUp(e.Button);
            base.OnMouseUp(e);
        }

        protected override bool OnTouchDown(TouchDownEvent e)
        {
            handleDown(e.Touch.Source, e.ScreenSpaceTouchDownPosition);
            return true;
        }

        protected override void OnTouchUp(TouchUpEvent e)
        {
            handleUp(e.Touch.Source);
            base.OnTouchUp(e);
        }

        private void handleDown(object source, Vector2 position)
        {
            mainContent.Show();

            TaikoAction taikoAction = getTaikoActionFromInput(position);

            switch (taikoAction)
            {
                case TaikoAction.LeftCentre:
                case TaikoAction.RightCentre:
                    centreCircle.FlashColour(Color4.White, 2000, Easing.OutQuint);
                    break;

                case TaikoAction.LeftRim:
                case TaikoAction.RightRim:
                    outerCircle.FlashColour(Color4.White, 2000, Easing.OutQuint);
                    break;
            }

            trackedActions.Add(source, taikoAction);
            keyBindingContainer.TriggerPressed(taikoAction);
        }

        private void handleUp(object source)
        {
            keyBindingContainer.TriggerReleased(trackedActions[source]);
            trackedActions.Remove(source);
        }

        private TaikoAction getTaikoActionFromInput(Vector2 inputPosition)
        {
            bool centreHit = centreCircle.Contains(inputPosition);
            bool leftSide = ToLocalSpace(inputPosition).X < DrawWidth / 2;

            if (leftSide)
                return centreHit ? TaikoAction.LeftCentre : TaikoAction.LeftRim;

            return centreHit ? TaikoAction.RightCentre : TaikoAction.RightRim;
        }
    }
}