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

using OpenTK;
using OpenTK.Graphics;
using OpenTK.Input;
using osu.Framework.Extensions.Color4Extensions;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Shapes;
using osu.Framework.Graphics.Colour;
using osu.Framework.Input;
using osu.Game.Graphics;
using osu.Game.Rulesets.Objects.Drawables;
using System;
using osu.Framework.Configuration;
using osu.Game.Rulesets.UI;
using osu.Game.Rulesets.Mania.Objects;
using osu.Game.Rulesets.Mania.Judgements;

namespace osu.Game.Rulesets.Mania.UI
{
    public class Column : ScrollingPlayfield<ManiaHitObject, ManiaJudgement>, IHasAccentColour
    {
        private const float key_icon_size = 10;
        private const float key_icon_corner_radius = 3;
        private const float key_icon_border_radius = 2;

        private const float hit_target_height = 10;
        private const float hit_target_bar_height = 2;

        private const float column_width = 45;
        private const float special_column_width = 70;

        /// <summary>
        /// The key that will trigger input actions for this column and hit objects contained inside it.
        /// </summary>
        public Bindable<Key> Key = new Bindable<Key>();

        private readonly Box background;
        private readonly Container hitTargetBar;
        private readonly Container keyIcon;

        protected override Container<Drawable> Content => content;
        private readonly Container<Drawable> content;

        public Column()
            : base(Axes.Y)
        {
            Width = column_width;

            InternalChildren = new Drawable[]
            {
                background = new Box
                {
                    Name = "Foreground",
                    RelativeSizeAxes = Axes.Both,
                    Alpha = 0.2f
                },
                new Container
                {
                    Name = "Hit target + hit objects",
                    RelativeSizeAxes = Axes.Both,
                    Padding = new MarginPadding { Top = ManiaPlayfield.HIT_TARGET_POSITION },
                    Children = new Drawable[]
                    {
                        new Container
                        {
                            Name = "Hit target",
                            RelativeSizeAxes = Axes.X,
                            Height = hit_target_height,
                            Children = new Drawable[]
                            {
                                new Box
                                {
                                    Name = "Background",
                                    RelativeSizeAxes = Axes.Both,
                                    Colour = Color4.Black
                                },
                                hitTargetBar = new Container
                                {
                                    Name = "Bar",
                                    RelativeSizeAxes = Axes.X,
                                    Height = hit_target_bar_height,
                                    Masking = true,
                                    Children = new[]
                                    {
                                        new Box
                                        {
                                            RelativeSizeAxes = Axes.Both
                                        }
                                    }
                                }
                            }
                        },
                        content = new Container
                        {
                            Name = "Hit objects",
                            RelativeSizeAxes = Axes.Both,
                        },
                        // For column lighting, we need to capture input events before the notes
                        new InputTarget
                        {
                            KeyDown = onKeyDown,
                            KeyUp = onKeyUp
                        }
                    }
                },
                new Container
                {
                    Name = "Key",
                    RelativeSizeAxes = Axes.X,
                    Height = ManiaPlayfield.HIT_TARGET_POSITION,
                    Children = new Drawable[]
                    {
                        new Box
                        {
                            Name = "Key gradient",
                            RelativeSizeAxes = Axes.Both,
                            Colour = ColourInfo.GradientVertical(Color4.Black, Color4.Black.Opacity(0)),
                            Alpha = 0.5f
                        },
                        keyIcon = new Container
                        {
                            Name = "Key icon",
                            Anchor = Anchor.Centre,
                            Origin = Anchor.Centre,
                            Size = new Vector2(key_icon_size),
                            Masking = true,
                            CornerRadius = key_icon_corner_radius,
                            BorderThickness = 2,
                            BorderColour = Color4.White, // Not true
                            Children = new[]
                            {
                                new Box
                                {
                                    RelativeSizeAxes = Axes.Both,
                                    Alpha = 0,
                                    AlwaysPresent = true
                                }
                            }
                        }
                    }
                }
            };
        }

        public override Axes RelativeSizeAxes => Axes.Y;

        private bool isSpecial;
        public bool IsSpecial
        {
            get { return isSpecial; }
            set
            {
                if (isSpecial == value)
                    return;
                isSpecial = value;

                Width = isSpecial ? special_column_width : column_width;
            }
        }

        private Color4 accentColour;
        public Color4 AccentColour
        {
            get { return accentColour; }
            set
            {
                if (accentColour == value)
                    return;
                accentColour = value;

                background.Colour = accentColour;

                hitTargetBar.EdgeEffect = new EdgeEffectParameters
                {
                    Type = EdgeEffectType.Glow,
                    Radius = 5,
                    Colour = accentColour.Opacity(0.5f),
                };

                keyIcon.EdgeEffect = new EdgeEffectParameters
                {
                    Type = EdgeEffectType.Glow,
                    Radius = 5,
                    Colour = accentColour.Opacity(0.5f),
                };
            }
        }

        /// <summary>
        /// Adds a DrawableHitObject to this Playfield.
        /// </summary>
        /// <param name="hitObject">The DrawableHitObject to add.</param>
        public override void Add(DrawableHitObject<ManiaHitObject, ManiaJudgement> hitObject)
        {
            hitObject.AccentColour = AccentColour;
            HitObjects.Add(hitObject);
        }

        private bool onKeyDown(InputState state, KeyDownEventArgs args)
        {
            if (args.Repeat)
                return false;

            if (args.Key == Key)
            {
                background.FadeTo(background.Alpha + 0.2f, 50, Easing.OutQuint);
                keyIcon.ScaleTo(1.4f, 50, Easing.OutQuint);
            }

            return false;
        }

        private bool onKeyUp(InputState state, KeyUpEventArgs args)
        {
            if (args.Key == Key)
            {
                background.FadeTo(0.2f, 800, Easing.OutQuart);
                keyIcon.ScaleTo(1f, 400, Easing.OutQuart);
            }

            return false;
        }

        /// <summary>
        /// This is a simple container which delegates various input events that have to be captured before the notes.
        /// </summary>
        private class InputTarget : Container
        {
            public Func<InputState, KeyDownEventArgs, bool> KeyDown;
            public Func<InputState, KeyUpEventArgs, bool> KeyUp;

            public InputTarget()
            {
                RelativeSizeAxes = Axes.Both;
                AlwaysPresent = true;
                Alpha = 0;
            }

            protected override bool OnKeyDown(InputState state, KeyDownEventArgs args) => KeyDown?.Invoke(state, args) ?? false;
            protected override bool OnKeyUp(InputState state, KeyUpEventArgs args) => KeyUp?.Invoke(state, args) ?? false;
        }
    }
}