// 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.Graphics;
using osu.Framework.Allocation;
using osu.Framework.Configuration;
using osu.Framework.Extensions.Color4Extensions;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Sprites;
using osu.Framework.Graphics.UserInterface;
using osu.Game.Graphics.Sprites;
using OpenTK;

namespace osu.Game.Graphics.UserInterface
{
    public class OsuDropdown<T> : Dropdown<T>
    {
        public readonly Bindable<Color4?> AccentColour = new Bindable<Color4?>();

        [BackgroundDependencyLoader]
        private void load(OsuColour colours)
        {
            if (AccentColour.Value == null)
                AccentColour.Value = colours.PinkDarker;
        }

        protected override DropdownHeader CreateHeader()
        {
            var newHeader = new OsuDropdownHeader();
            newHeader.AccentColour.BindTo(AccentColour);

            return newHeader;
        }

        protected override DropdownMenu CreateMenu()
        {
            var newMenu = new OsuDropdownMenu();
            newMenu.AccentColour.BindTo(AccentColour);

            return newMenu;
        }

        #region OsuDropdownMenu
        protected class OsuDropdownMenu : DropdownMenu
        {
            public readonly Bindable<Color4?> AccentColour = new Bindable<Color4?>();

            protected override MenuItemRepresentation CreateMenuItemRepresentation(DropdownMenuItem<T> model)
            {
                var newItem = new OsuDropdownMenuItemRepresentation(this, model);
                newItem.AccentColour.BindTo(AccentColour);

                return newItem;
            }

            #region OsuDropdownMenuItemRepresentation
            protected class OsuDropdownMenuItemRepresentation : DropdownMenuItemRepresentation
            {
                public readonly Bindable<Color4?> AccentColour = new Bindable<Color4?>();

                private SpriteIcon chevron;
                protected OsuSpriteText Label;

                private Color4 nonAccentHoverColour;
                private Color4 nonAccentSelectedColour;

                public OsuDropdownMenuItemRepresentation(Menu<DropdownMenuItem<T>> menu, DropdownMenuItem<T> model)
                    : base(menu, model)
                {
                    Foreground.Padding = new MarginPadding(2);

                    Masking = true;
                    CornerRadius = 6;

                    AccentColour.ValueChanged += updateAccent;
                }

                [BackgroundDependencyLoader]
                private void load(OsuColour colours)
                {
                    BackgroundColour = Color4.Transparent;
                    nonAccentHoverColour = colours.PinkDarker;
                    nonAccentSelectedColour = Color4.Black.Opacity(0.5f);
                }

                private void updateAccent(Color4? newValue)
                {
                    BackgroundColourHover = newValue ?? nonAccentHoverColour;
                    BackgroundColourSelected = newValue ?? nonAccentSelectedColour;
                    AnimateBackground(IsHovered);
                    AnimateForeground(IsHovered);
                }

                protected override void AnimateForeground(bool hover)
                {
                    base.AnimateForeground(hover);
                    chevron.Alpha = hover ? 1 : 0;
                }

                protected override Drawable CreateText(string title) => new FillFlowContainer
                {
                    Direction = FillDirection.Horizontal,
                    RelativeSizeAxes = Axes.X,
                    AutoSizeAxes = Axes.Y,
                    Children = new Drawable[]
                    {
                        chevron = new SpriteIcon
                        {
                            AlwaysPresent = true,
                            Icon = FontAwesome.fa_chevron_right,
                            Colour = Color4.Black,
                            Alpha = 0.5f,
                            Size = new Vector2(8),
                            Margin = new MarginPadding { Left = 3, Right = 3 },
                            Origin = Anchor.CentreLeft,
                            Anchor = Anchor.CentreLeft,
                        },
                        Label = new OsuSpriteText
                        {
                            Text = title,
                            Origin = Anchor.CentreLeft,
                            Anchor = Anchor.CentreLeft,
                        }
                    }
                };
            }
            #endregion
        }
        #endregion

        public class OsuDropdownHeader : DropdownHeader
        {
            protected readonly SpriteText Text;
            protected override string Label
            {
                get { return Text.Text; }
                set { Text.Text = value; }
            }

            protected readonly SpriteIcon Icon;

            public readonly Bindable<Color4?> AccentColour = new Bindable<Color4?>();

            public OsuDropdownHeader()
            {
                Foreground.Padding = new MarginPadding(4);

                AutoSizeAxes = Axes.None;
                Margin = new MarginPadding { Bottom = 4 };
                CornerRadius = 4;
                Height = 40;

                Foreground.Children = new Drawable[]
                {
                    Text = new OsuSpriteText
                    {
                        Anchor = Anchor.CentreLeft,
                        Origin = Anchor.CentreLeft,
                    },
                    Icon = new SpriteIcon
                    {
                        Icon = FontAwesome.fa_chevron_down,
                        Anchor = Anchor.CentreRight,
                        Origin = Anchor.CentreRight,
                        Margin = new MarginPadding { Right = 4 },
                        Size = new Vector2(20),
                    }
                };

                AccentColour.ValueChanged += accentColourChanged;
            }

            [BackgroundDependencyLoader]
            private void load(OsuColour colours)
            {
                BackgroundColour = Color4.Black.Opacity(0.5f);
                BackgroundColourHover = AccentColour?.Value ?? colours.PinkDarker;
            }

            private void accentColourChanged(Color4? newValue)
            {
                BackgroundColourHover = newValue ?? Color4.White;
            }
        }
    }
}