// 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.Collections.Generic;
using System.Linq;
using JetBrains.Annotations;
using osu.Framework.Allocation;
using osu.Framework.Bindables;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Sprites;
using osu.Framework.Localisation;
using osu.Framework.Logging;
using osu.Framework.Platform;
using osu.Game.Configuration;
using osu.Game.Database;
using osu.Game.Graphics.UserInterface;
using osu.Game.Localisation;
using osu.Game.Skinning;
using osu.Game.Skinning.Editor;

namespace osu.Game.Overlays.Settings.Sections
{
    public class SkinSection : SettingsSection
    {
        private SkinSettingsDropdown skinDropdown;

        public override LocalisableString Header => SkinSettingsStrings.SkinSectionHeader;

        public override Drawable CreateIcon() => new SpriteIcon
        {
            Icon = FontAwesome.Solid.PaintBrush
        };

        private readonly Bindable<ILive<SkinInfo>> dropdownBindable = new Bindable<ILive<SkinInfo>> { Default = DefaultSkin.CreateInfo().ToLiveUnmanaged() };
        private readonly Bindable<string> configBindable = new Bindable<string>();

        private static readonly ILive<SkinInfo> random_skin_info = new SkinInfo
        {
            ID = SkinInfo.RANDOM_SKIN,
            Name = "<Random Skin>",
        }.ToLiveUnmanaged();

        private List<ILive<SkinInfo>> skinItems;

        [Resolved]
        private SkinManager skins { get; set; }

        [Resolved]
        private RealmAccess realm { get; set; }

        private IDisposable realmSubscription;

        private IQueryable<SkinInfo> queryRealmSkins() =>
            realm.Realm.All<SkinInfo>()
                 .Where(s => !s.DeletePending)
                 .OrderByDescending(s => s.Protected) // protected skins should be at the top.
                 .ThenBy(s => s.Name, StringComparer.OrdinalIgnoreCase);

        [BackgroundDependencyLoader(permitNulls: true)]
        private void load(OsuConfigManager config, [CanBeNull] SkinEditorOverlay skinEditor)
        {
            Children = new Drawable[]
            {
                skinDropdown = new SkinSettingsDropdown
                {
                    LabelText = SkinSettingsStrings.CurrentSkin
                },
                new SettingsButton
                {
                    Text = SkinSettingsStrings.SkinLayoutEditor,
                    Action = () => skinEditor?.Toggle(),
                },
                new ExportSkinButton(),
            };

            config.BindWith(OsuSetting.Skin, configBindable);
        }

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

            skinDropdown.Current = dropdownBindable;

            realmSubscription = realm.RegisterForNotifications(r => queryRealmSkins(), (sender, changes, error) =>
            {
                // The first fire of this is a bit redundant due to the call below,
                // but this is safest in case the subscription is restored after a context recycle.
                updateItems();
            });

            updateItems();

            configBindable.BindValueChanged(id => Scheduler.AddOnce(updateSelectedSkinFromConfig));
            updateSelectedSkinFromConfig();

            dropdownBindable.BindValueChanged(skin =>
            {
                if (skin.NewValue.Equals(random_skin_info))
                {
                    var skinBefore = skins.CurrentSkinInfo.Value;

                    skins.SelectRandomSkin();

                    if (skinBefore == skins.CurrentSkinInfo.Value)
                    {
                        // the random selection didn't change the skin, so we should manually update the dropdown to match.
                        dropdownBindable.Value = skins.CurrentSkinInfo.Value;
                    }

                    return;
                }

                configBindable.Value = skin.NewValue.ID.ToString();
            });
        }

        private void updateSelectedSkinFromConfig()
        {
            ILive<SkinInfo> skin = null;

            if (Guid.TryParse(configBindable.Value, out var configId))
                skin = skinDropdown.Items.FirstOrDefault(s => s.ID == configId);

            dropdownBindable.Value = skin ?? skinDropdown.Items.First();
        }

        private void updateItems()
        {
            int protectedCount = queryRealmSkins().Count(s => s.Protected);

            skinItems = queryRealmSkins().ToLive(realm);

            skinItems.Insert(protectedCount, random_skin_info);

            skinDropdown.Items = skinItems;
        }

        protected override void Dispose(bool isDisposing)
        {
            base.Dispose(isDisposing);

            realmSubscription?.Dispose();
        }

        private class SkinSettingsDropdown : SettingsDropdown<ILive<SkinInfo>>
        {
            protected override OsuDropdown<ILive<SkinInfo>> CreateDropdown() => new SkinDropdownControl();

            private class SkinDropdownControl : DropdownControl
            {
                protected override LocalisableString GenerateItemText(ILive<SkinInfo> item) => item.ToString();
            }
        }

        public class ExportSkinButton : SettingsButton
        {
            [Resolved]
            private SkinManager skins { get; set; }

            [Resolved]
            private Storage storage { get; set; }

            private Bindable<Skin> currentSkin;

            [BackgroundDependencyLoader]
            private void load()
            {
                Text = SkinSettingsStrings.ExportSkinButton;
                Action = export;
            }

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

                currentSkin = skins.CurrentSkin.GetBoundCopy();
                currentSkin.BindValueChanged(skin => Enabled.Value = skin.NewValue.SkinInfo.PerformRead(s => !s.Protected), true);
            }

            private void export()
            {
                try
                {
                    currentSkin.Value.SkinInfo.PerformRead(s => new LegacySkinExporter(storage).Export(s));
                }
                catch (Exception e)
                {
                    Logger.Log($"Could not export current skin: {e.Message}", level: LogLevel.Error);
                }
            }
        }
    }
}