// 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 osu.Framework.Allocation;
using osu.Framework.Bindables;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Shapes;
using osu.Framework.Logging;
using osu.Framework.Screens;
using osu.Game.Beatmaps;
using osu.Game.Graphics;
using osu.Game.Graphics.Backgrounds;
using osu.Game.Graphics.Containers;
using osu.Game.Graphics.UserInterface;
using osu.Game.Input;
using osu.Game.Online.API;
using osu.Game.Online.Multiplayer;
using osu.Game.Overlays.BeatmapSet.Buttons;
using osu.Game.Screens.Menu;
using osu.Game.Screens.Multi.Lounge;
using osu.Game.Screens.Multi.Lounge.Components;
using osu.Game.Screens.Multi.Match;
using osu.Game.Screens.Play;
using osuTK;

namespace osu.Game.Screens.Multi
{
    [Cached]
    public class Multiplayer : OsuScreen, IOnlineComponent
    {
        public override bool CursorVisible => (screenStack.CurrentScreen as IMultiplayerSubScreen)?.CursorVisible ?? true;

        // this is required due to PlayerLoader eventually being pushed to the main stack
        // while leases may be taken out by a subscreen.
        public override bool DisallowExternalBeatmapRulesetChanges => true;

        private readonly MultiplayerWaveContainer waves;

        private readonly OsuButton createButton;
        private readonly LoungeSubScreen loungeSubScreen;
        private readonly ScreenStack screenStack;

        private readonly IBindable<bool> isIdle = new BindableBool();

        [Cached]
        private readonly Bindable<Room> currentRoom = new Bindable<Room>();

        [Cached]
        private readonly Bindable<FilterCriteria> currentFilter = new Bindable<FilterCriteria>(new FilterCriteria());

        [Cached(Type = typeof(IRoomManager))]
        private RoomManager roomManager;

        [Resolved]
        private OsuGameBase game { get; set; }

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

        [Resolved(CanBeNull = true)]
        private OsuLogo logo { get; set; }

        public Multiplayer()
        {
            Anchor = Anchor.Centre;
            Origin = Anchor.Centre;
            RelativeSizeAxes = Axes.Both;
            Padding = new MarginPadding { Horizontal = -HORIZONTAL_OVERFLOW_PADDING };

            InternalChild = waves = new MultiplayerWaveContainer
            {
                RelativeSizeAxes = Axes.Both,
                Children = new Drawable[]
                {
                    new Container
                    {
                        RelativeSizeAxes = Axes.Both,
                        Masking = true,
                        Children = new Drawable[]
                        {
                            new Box
                            {
                                RelativeSizeAxes = Axes.Both,
                                Colour = OsuColour.FromHex(@"3e3a44"),
                            },
                            new Triangles
                            {
                                RelativeSizeAxes = Axes.Both,
                                ColourLight = OsuColour.FromHex(@"3c3842"),
                                ColourDark = OsuColour.FromHex(@"393540"),
                                TriangleScale = 5,
                            },
                        },
                    },
                    new Container
                    {
                        RelativeSizeAxes = Axes.Both,
                        Padding = new MarginPadding { Top = Header.HEIGHT },
                        Child = screenStack = new MultiplayerSubScreenStack { RelativeSizeAxes = Axes.Both }
                    },
                    new Header(screenStack),
                    createButton = new HeaderButton
                    {
                        Anchor = Anchor.TopRight,
                        Origin = Anchor.TopRight,
                        RelativeSizeAxes = Axes.None,
                        Size = new Vector2(150, Header.HEIGHT - 20),
                        Margin = new MarginPadding
                        {
                            Top = 10,
                            Right = 10 + HORIZONTAL_OVERFLOW_PADDING,
                        },
                        Text = "Create room",
                        Action = () => loungeSubScreen.Open(new Room
                        {
                            Name = { Value = $"{api.LocalUser}'s awesome room" }
                        }),
                    },
                    roomManager = new RoomManager()
                }
            };

            screenStack.Push(loungeSubScreen = new LoungeSubScreen());

            screenStack.ScreenPushed += screenPushed;
            screenStack.ScreenExited += screenExited;
        }

        [BackgroundDependencyLoader(true)]
        private void load(IdleTracker idleTracker)
        {
            api.Register(this);

            if (idleTracker != null)
                isIdle.BindTo(idleTracker.IsIdle);
        }

        protected override void LoadComplete()
        {
            base.LoadComplete();
            isIdle.BindValueChanged(idle => updatePollingRate(idle.NewValue), true);
        }

        protected override IReadOnlyDependencyContainer CreateChildDependencies(IReadOnlyDependencyContainer parent)
        {
            var dependencies = new CachedModelDependencyContainer<Room>(base.CreateChildDependencies(parent));
            dependencies.Model.BindTo(currentRoom);
            return dependencies;
        }

        private void updatePollingRate(bool idle)
        {
            roomManager.TimeBetweenPolls = !this.IsCurrentScreen() || !(screenStack.CurrentScreen is LoungeSubScreen) ? 0 : (idle ? 120000 : 15000);
            Logger.Log($"Polling adjusted to {roomManager.TimeBetweenPolls}");
        }

        /// <summary>
        /// Push a <see cref="Player"/> to the main screen stack to begin gameplay.
        /// Generally called from a <see cref="MatchSubScreen"/> via DI resolution.
        /// </summary>
        public void Start(Func<Player> player)
        {
            if (!this.IsCurrentScreen())
                return;

            this.Push(new PlayerLoader(player));
        }

        public void APIStateChanged(IAPIProvider api, APIState state)
        {
            if (state != APIState.Online)
                Schedule(forcefullyExit);
        }

        private void forcefullyExit()
        {
            // This is temporary since we don't currently have a way to force screens to be exited
            if (this.IsCurrentScreen())
            {
                while (this.IsCurrentScreen())
                    this.Exit();
            }
            else
            {
                this.MakeCurrent();
                Schedule(forcefullyExit);
            }
        }

        public override void OnEntering(IScreen last)
        {
            this.FadeIn();
            waves.Show();

            beginHandlingTrack();
        }

        public override void OnResuming(IScreen last)
        {
            this.FadeIn(250);
            this.ScaleTo(1, 250, Easing.OutSine);

            base.OnResuming(last);

            beginHandlingTrack();
        }

        public override void OnSuspending(IScreen next)
        {
            this.ScaleTo(1.1f, 250, Easing.InSine);
            this.FadeOut(250);

            endHandlingTrack();

            roomManager.TimeBetweenPolls = 0;
        }

        public override bool OnExiting(IScreen next)
        {
            roomManager.PartRoom();

            if (screenStack.CurrentScreen != null && !(screenStack.CurrentScreen is LoungeSubScreen))
            {
                screenStack.Exit();
                return true;
            }

            waves.Hide();

            this.Delay(WaveContainer.DISAPPEAR_DURATION).FadeOut();

            if (screenStack.CurrentScreen != null)
                loungeSubScreen.MakeCurrent();

            endHandlingTrack();

            base.OnExiting(next);
            return false;
        }

        protected override void LogoExiting(OsuLogo logo)
        {
            base.LogoExiting(logo);

            // the wave overlay transition takes longer than expected to run.
            logo.Delay(WaveContainer.DISAPPEAR_DURATION / 2).FadeOut();
        }

        private void beginHandlingTrack()
        {
            Beatmap.BindValueChanged(updateTrack, true);
        }

        private void endHandlingTrack()
        {
            cancelLooping();
            Beatmap.ValueChanged -= updateTrack;
        }

        private void screenPushed(IScreen lastScreen, IScreen newScreen) => subScreenChanged(newScreen);

        private void screenExited(IScreen lastScreen, IScreen newScreen)
        {
            subScreenChanged(newScreen);

            if (screenStack.CurrentScreen == null && this.IsCurrentScreen())
                this.Exit();
        }

        private void subScreenChanged(IScreen newScreen)
        {
            updatePollingRate(isIdle.Value);
            createButton.FadeTo(newScreen is LoungeSubScreen ? 1 : 0, 200);

            updateTrack();
        }

        private void updateTrack(ValueChangedEvent<WorkingBeatmap> _ = null)
        {
            if (screenStack.CurrentScreen is MatchSubScreen)
            {
                var track = Beatmap.Value?.Track;

                if (track != null)
                {
                    track.RestartPoint = Beatmap.Value.Metadata.PreviewTime;
                    track.Looping = true;

                    if (!track.IsRunning)
                        track.Restart();
                }
            }
            else
            {
                cancelLooping();
            }
        }

        private void cancelLooping()
        {
            var track = Beatmap?.Value?.Track;

            if (track != null)
            {
                track.Looping = false;
                track.RestartPoint = 0;
            }
        }

        protected override void Dispose(bool isDisposing)
        {
            base.Dispose(isDisposing);
            api?.Unregister(this);
        }

        private class MultiplayerWaveContainer : WaveContainer
        {
            protected override bool StartHidden => true;

            public MultiplayerWaveContainer()
            {
                FirstWaveColour = OsuColour.FromHex(@"654d8c");
                SecondWaveColour = OsuColour.FromHex(@"554075");
                ThirdWaveColour = OsuColour.FromHex(@"44325e");
                FourthWaveColour = OsuColour.FromHex(@"392850");
            }
        }
    }
}