// 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.Specialized;
using System.Linq;
using osu.Framework.Allocation;
using osu.Framework.Bindables;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Screens;
using osu.Game.Online.API;
using osu.Game.Online.API.Requests;
using osu.Game.Online.Spectator;
using osu.Game.Screens.Play;
using osu.Game.Users;
using osuTK;

namespace osu.Game.Overlays.Dashboard
{
    internal class CurrentlyPlayingDisplay : CompositeDrawable
    {
        private IBindableList<int> playingUsers;

        private FillFlowContainer<UserPanel> userFlow;

        [Resolved]
        private SpectatorStreamingClient spectatorStreaming { get; set; }

        [BackgroundDependencyLoader]
        private void load()
        {
            RelativeSizeAxes = Axes.X;
            AutoSizeAxes = Axes.Y;

            InternalChild = userFlow = new FillFlowContainer<UserPanel>
            {
                RelativeSizeAxes = Axes.X,
                AutoSizeAxes = Axes.Y,
                Spacing = new Vector2(10),
            };
        }

        [Resolved]
        private IAPIProvider api { get; set; }

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

            playingUsers = spectatorStreaming.PlayingUsers.GetBoundCopy();
            playingUsers.BindCollectionChanged((sender, e) => Schedule(() =>
            {
                switch (e.Action)
                {
                    case NotifyCollectionChangedAction.Add:
                        foreach (var u in e.NewItems.OfType<int>())
                        {
                            var request = new GetUserRequest(u);
                            request.Success += user => Schedule(() =>
                            {
                                if (playingUsers.Contains((int)user.Id))
                                    userFlow.Add(createUserPanel(user));
                            });
                            api.Queue(request);
                        }

                        break;

                    case NotifyCollectionChangedAction.Remove:
                        foreach (var u in e.OldItems.OfType<int>())
                            userFlow.FirstOrDefault(card => card.User.Id == u)?.Expire();
                        break;

                    case NotifyCollectionChangedAction.Reset:
                        userFlow.Clear();
                        break;
                }
            }), true);
        }

        [Resolved(canBeNull: true)]
        private OsuGame game { get; set; }

        private UserPanel createUserPanel(User user)
        {
            return new UserGridPanel(user).With(panel =>
            {
                panel.Anchor = Anchor.TopCentre;
                panel.Origin = Anchor.TopCentre;
                panel.Width = 290;
                panel.ShowProfileOnClick = false;
                panel.Action = () => game?.PerformFromScreen(s => s.Push(new Spectator(user)));
            });
        }
    }
}