From 2871001cc294da01f2db8e8c35d84a86ab1503ac Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 22 Oct 2020 18:21:28 +0200
Subject: [PATCH 01/32] Add BackgroundSource.Seasonal

---
 osu.Game/Configuration/BackgroundSource.cs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/osu.Game/Configuration/BackgroundSource.cs b/osu.Game/Configuration/BackgroundSource.cs
index 5726e96eb1..beef9ef1de 100644
--- a/osu.Game/Configuration/BackgroundSource.cs
+++ b/osu.Game/Configuration/BackgroundSource.cs
@@ -6,6 +6,7 @@ namespace osu.Game.Configuration
     public enum BackgroundSource
     {
         Skin,
-        Beatmap
+        Beatmap,
+        Seasonal
     }
 }

From cdb2d23578e6de7ca266a23a51b5fac2ed15b8f4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 22 Oct 2020 18:23:03 +0200
Subject: [PATCH 02/32] Set BackgroundSource.Seasonal as default setting

---
 osu.Game/Configuration/OsuConfigManager.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/osu.Game/Configuration/OsuConfigManager.cs b/osu.Game/Configuration/OsuConfigManager.cs
index 7d601c0cb9..5c5af701bb 100644
--- a/osu.Game/Configuration/OsuConfigManager.cs
+++ b/osu.Game/Configuration/OsuConfigManager.cs
@@ -130,7 +130,7 @@ namespace osu.Game.Configuration
 
             Set(OsuSetting.IntroSequence, IntroSequence.Triangles);
 
-            Set(OsuSetting.MenuBackgroundSource, BackgroundSource.Skin);
+            Set(OsuSetting.MenuBackgroundSource, BackgroundSource.Seasonal);
         }
 
         public OsuConfigManager(Storage storage)

From 09d49aa0f7b2d953370e02897ef382bd3ea04f92 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 22 Oct 2020 18:25:01 +0200
Subject: [PATCH 03/32] Add GetSeasonalBackgroundsRequest

---
 .../Requests/GetSeasonalBackgroundsRequest.cs | 12 +++++++++++
 .../Responses/APISeasonalBackgrounds.cs       | 20 +++++++++++++++++++
 2 files changed, 32 insertions(+)
 create mode 100644 osu.Game/Online/API/Requests/GetSeasonalBackgroundsRequest.cs
 create mode 100644 osu.Game/Online/API/Requests/Responses/APISeasonalBackgrounds.cs

diff --git a/osu.Game/Online/API/Requests/GetSeasonalBackgroundsRequest.cs b/osu.Game/Online/API/Requests/GetSeasonalBackgroundsRequest.cs
new file mode 100644
index 0000000000..941b47244a
--- /dev/null
+++ b/osu.Game/Online/API/Requests/GetSeasonalBackgroundsRequest.cs
@@ -0,0 +1,12 @@
+// 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 osu.Game.Online.API.Requests.Responses;
+
+namespace osu.Game.Online.API.Requests
+{
+    public class GetSeasonalBackgroundsRequest : APIRequest<APISeasonalBackgrounds>
+    {
+        protected override string Target => @"seasonal-backgrounds";
+    }
+}
diff --git a/osu.Game/Online/API/Requests/Responses/APISeasonalBackgrounds.cs b/osu.Game/Online/API/Requests/Responses/APISeasonalBackgrounds.cs
new file mode 100644
index 0000000000..6996ac4d9b
--- /dev/null
+++ b/osu.Game/Online/API/Requests/Responses/APISeasonalBackgrounds.cs
@@ -0,0 +1,20 @@
+// 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.Generic;
+using Newtonsoft.Json;
+
+namespace osu.Game.Online.API.Requests.Responses
+{
+    public class APISeasonalBackgrounds
+    {
+        [JsonProperty("backgrounds")]
+        public List<APISeasonalBackground> Backgrounds { get; set; }
+    }
+
+    public class APISeasonalBackground
+    {
+        [JsonProperty("url")]
+        public string Url { get; set; }
+    }
+}

From c1d03a5baceb23be78f0d55458a9085ad5b652ad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Fri, 23 Oct 2020 13:40:13 +0200
Subject: [PATCH 04/32] Add SeasonalBackgroundLoader and SeasonalBackground

---
 .../Backgrounds/SeasonalBackgroundLoader.cs   | 68 +++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs

diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
new file mode 100644
index 0000000000..af81b25cee
--- /dev/null
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -0,0 +1,68 @@
+// 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.Generic;
+using System.Linq;
+using JetBrains.Annotations;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Textures;
+using osu.Framework.Utils;
+using osu.Game.Online.API;
+using osu.Game.Online.API.Requests;
+using osu.Game.Online.API.Requests.Responses;
+
+namespace osu.Game.Graphics.Backgrounds
+{
+    [LongRunningLoad]
+    public class SeasonalBackgroundLoader : Component
+    {
+        private List<APISeasonalBackground> backgrounds = new List<APISeasonalBackground>();
+        private int current;
+
+        [BackgroundDependencyLoader]
+        private void load(IAPIProvider api)
+        {
+            var request = new GetSeasonalBackgroundsRequest();
+            request.Success += response =>
+            {
+                backgrounds = response.Backgrounds ?? backgrounds;
+                current = RNG.Next(0, backgrounds.Count);
+            };
+
+            api.PerformAsync(request);
+        }
+
+        public SeasonalBackground LoadBackground(string fallbackTextureName)
+        {
+            string url = null;
+
+            if (backgrounds.Any())
+            {
+                current = (current + 1) % backgrounds.Count;
+                url = backgrounds[current].Url;
+            }
+
+            return new SeasonalBackground(url, fallbackTextureName);
+        }
+    }
+
+    [LongRunningLoad]
+    public class SeasonalBackground : Background
+    {
+        private readonly string url;
+        private readonly string fallbackTextureName;
+
+        public SeasonalBackground([CanBeNull] string url, string fallbackTextureName = @"Backgrounds/bg1")
+        {
+            this.url = url;
+            this.fallbackTextureName = fallbackTextureName;
+        }
+
+        [BackgroundDependencyLoader]
+        private void load(LargeTextureStore textures)
+        {
+            Sprite.Texture = textures.Get(url) ?? textures.Get(fallbackTextureName);
+        }
+    }
+}

From 81ebcd879668eb13cb28aa11bf4edfb8afb0fb99 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Fri, 23 Oct 2020 13:41:00 +0200
Subject: [PATCH 05/32] Load SeasonalBackgroundLoader asynchronously

---
 .../Backgrounds/BackgroundScreenDefault.cs    | 20 +++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index ef41c5be3d..ec91dcc99f 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -25,6 +25,7 @@ namespace osu.Game.Screens.Backgrounds
         private Bindable<Skin> skin;
         private Bindable<BackgroundSource> mode;
         private Bindable<IntroSequence> introSequence;
+        private readonly SeasonalBackgroundLoader seasonalBackgroundLoader = new SeasonalBackgroundLoader();
 
         [Resolved]
         private IBindable<WorkingBeatmap> beatmap { get; set; }
@@ -50,7 +51,7 @@ namespace osu.Game.Screens.Backgrounds
 
             currentDisplay = RNG.Next(0, background_count);
 
-            display(createBackground());
+            LoadComponentAsync(seasonalBackgroundLoader, _ => LoadComponentAsync(createBackground(), display));
         }
 
         private void display(Background newBackground)
@@ -90,6 +91,10 @@ namespace osu.Game.Screens.Backgrounds
             {
                 switch (mode.Value)
                 {
+                    case BackgroundSource.Seasonal:
+                        newBackground = seasonalBackgroundLoader.LoadBackground(backgroundName);
+                        break;
+
                     case BackgroundSource.Beatmap:
                         newBackground = new BeatmapBackground(beatmap.Value, backgroundName);
                         break;
@@ -100,7 +105,18 @@ namespace osu.Game.Screens.Backgrounds
                 }
             }
             else
-                newBackground = new Background(backgroundName);
+            {
+                switch (mode.Value)
+                {
+                    case BackgroundSource.Seasonal:
+                        newBackground = seasonalBackgroundLoader.LoadBackground(backgroundName);
+                        break;
+
+                    default:
+                        newBackground = new Background(backgroundName);
+                        break;
+                }
+            }
 
             newBackground.Depth = currentDisplay;
 

From 0c540537c9f3dde85e4ac74718be9d71a07c19b1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 29 Oct 2020 14:30:50 +0100
Subject: [PATCH 06/32] Revert "Add BackgroundSource.Seasonal"

This reverts commit 2871001cc294da01f2db8e8c35d84a86ab1503ac.
---
 osu.Game/Configuration/BackgroundSource.cs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/osu.Game/Configuration/BackgroundSource.cs b/osu.Game/Configuration/BackgroundSource.cs
index beef9ef1de..5726e96eb1 100644
--- a/osu.Game/Configuration/BackgroundSource.cs
+++ b/osu.Game/Configuration/BackgroundSource.cs
@@ -6,7 +6,6 @@ namespace osu.Game.Configuration
     public enum BackgroundSource
     {
         Skin,
-        Beatmap,
-        Seasonal
+        Beatmap
     }
 }

From 7d523fee2896c71b7bb919cf99f41e88bb3ed2d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 29 Oct 2020 14:31:07 +0100
Subject: [PATCH 07/32] Revert "Set BackgroundSource.Seasonal as default
 setting"

This reverts commit cdb2d23578e6de7ca266a23a51b5fac2ed15b8f4.
---
 osu.Game/Configuration/OsuConfigManager.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/osu.Game/Configuration/OsuConfigManager.cs b/osu.Game/Configuration/OsuConfigManager.cs
index 5c5af701bb..7d601c0cb9 100644
--- a/osu.Game/Configuration/OsuConfigManager.cs
+++ b/osu.Game/Configuration/OsuConfigManager.cs
@@ -130,7 +130,7 @@ namespace osu.Game.Configuration
 
             Set(OsuSetting.IntroSequence, IntroSequence.Triangles);
 
-            Set(OsuSetting.MenuBackgroundSource, BackgroundSource.Seasonal);
+            Set(OsuSetting.MenuBackgroundSource, BackgroundSource.Skin);
         }
 
         public OsuConfigManager(Storage storage)

From b189e0b7cfd8e761b313ab3b1c27371ff270a056 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 29 Oct 2020 16:01:22 +0100
Subject: [PATCH 08/32] Revert "Load SeasonalBackgroundLoader asynchronously"

This reverts commit 81ebcd879668eb13cb28aa11bf4edfb8afb0fb99.
---
 .../Backgrounds/BackgroundScreenDefault.cs    | 20 ++-----------------
 1 file changed, 2 insertions(+), 18 deletions(-)

diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index ec91dcc99f..ef41c5be3d 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -25,7 +25,6 @@ namespace osu.Game.Screens.Backgrounds
         private Bindable<Skin> skin;
         private Bindable<BackgroundSource> mode;
         private Bindable<IntroSequence> introSequence;
-        private readonly SeasonalBackgroundLoader seasonalBackgroundLoader = new SeasonalBackgroundLoader();
 
         [Resolved]
         private IBindable<WorkingBeatmap> beatmap { get; set; }
@@ -51,7 +50,7 @@ namespace osu.Game.Screens.Backgrounds
 
             currentDisplay = RNG.Next(0, background_count);
 
-            LoadComponentAsync(seasonalBackgroundLoader, _ => LoadComponentAsync(createBackground(), display));
+            display(createBackground());
         }
 
         private void display(Background newBackground)
@@ -91,10 +90,6 @@ namespace osu.Game.Screens.Backgrounds
             {
                 switch (mode.Value)
                 {
-                    case BackgroundSource.Seasonal:
-                        newBackground = seasonalBackgroundLoader.LoadBackground(backgroundName);
-                        break;
-
                     case BackgroundSource.Beatmap:
                         newBackground = new BeatmapBackground(beatmap.Value, backgroundName);
                         break;
@@ -105,18 +100,7 @@ namespace osu.Game.Screens.Backgrounds
                 }
             }
             else
-            {
-                switch (mode.Value)
-                {
-                    case BackgroundSource.Seasonal:
-                        newBackground = seasonalBackgroundLoader.LoadBackground(backgroundName);
-                        break;
-
-                    default:
-                        newBackground = new Background(backgroundName);
-                        break;
-                }
-            }
+                newBackground = new Background(backgroundName);
 
             newBackground.Depth = currentDisplay;
 

From 76c0a790b404ef1afd65e30078473126a8b677c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 29 Oct 2020 17:28:04 +0100
Subject: [PATCH 09/32] Add separate Seasonal Backgrounds setting (Always,
 Sometimes, Never)

---
 osu.Game/Configuration/OsuConfigManager.cs           |  2 ++
 osu.Game/Configuration/SeasonalBackgrounds.cs        | 12 ++++++++++++
 .../Settings/Sections/Audio/MainMenuSettings.cs      |  6 ++++++
 3 files changed, 20 insertions(+)
 create mode 100644 osu.Game/Configuration/SeasonalBackgrounds.cs

diff --git a/osu.Game/Configuration/OsuConfigManager.cs b/osu.Game/Configuration/OsuConfigManager.cs
index 7d601c0cb9..9f7280eef4 100644
--- a/osu.Game/Configuration/OsuConfigManager.cs
+++ b/osu.Game/Configuration/OsuConfigManager.cs
@@ -131,6 +131,7 @@ namespace osu.Game.Configuration
             Set(OsuSetting.IntroSequence, IntroSequence.Triangles);
 
             Set(OsuSetting.MenuBackgroundSource, BackgroundSource.Skin);
+            Set(OsuSetting.SeasonalBackgrounds, SeasonalBackgrounds.Sometimes);
         }
 
         public OsuConfigManager(Storage storage)
@@ -239,5 +240,6 @@ namespace osu.Game.Configuration
         HitLighting,
         MenuBackgroundSource,
         GameplayDisableWinKey,
+        SeasonalBackgrounds
     }
 }
diff --git a/osu.Game/Configuration/SeasonalBackgrounds.cs b/osu.Game/Configuration/SeasonalBackgrounds.cs
new file mode 100644
index 0000000000..7708ae584f
--- /dev/null
+++ b/osu.Game/Configuration/SeasonalBackgrounds.cs
@@ -0,0 +1,12 @@
+// 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.
+
+namespace osu.Game.Configuration
+{
+    public enum SeasonalBackgrounds
+    {
+        Always,
+        Sometimes,
+        Never
+    }
+}
diff --git a/osu.Game/Overlays/Settings/Sections/Audio/MainMenuSettings.cs b/osu.Game/Overlays/Settings/Sections/Audio/MainMenuSettings.cs
index d5de32ed05..ee57c0cfa6 100644
--- a/osu.Game/Overlays/Settings/Sections/Audio/MainMenuSettings.cs
+++ b/osu.Game/Overlays/Settings/Sections/Audio/MainMenuSettings.cs
@@ -39,6 +39,12 @@ namespace osu.Game.Overlays.Settings.Sections.Audio
                     LabelText = "Background source",
                     Current = config.GetBindable<BackgroundSource>(OsuSetting.MenuBackgroundSource),
                     Items = Enum.GetValues(typeof(BackgroundSource)).Cast<BackgroundSource>()
+                },
+                new SettingsDropdown<SeasonalBackgrounds>
+                {
+                    LabelText = "Seasonal backgrounds",
+                    Current = config.GetBindable<SeasonalBackgrounds>(OsuSetting.SeasonalBackgrounds),
+                    Items = Enum.GetValues(typeof(SeasonalBackgrounds)).Cast<SeasonalBackgrounds>()
                 }
             };
         }

From 907e1921c720fc99cf9d76d135744fdf3d52fbeb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 29 Oct 2020 17:31:42 +0100
Subject: [PATCH 10/32] Make SeasonalBackgroundLoader read from SessionStatics

---
 osu.Game/Configuration/SessionStatics.cs      |  7 ++++++-
 .../Backgrounds/SeasonalBackgroundLoader.cs   | 19 ++++++++++++-------
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/osu.Game/Configuration/SessionStatics.cs b/osu.Game/Configuration/SessionStatics.cs
index 40b2adb867..326abed8fe 100644
--- a/osu.Game/Configuration/SessionStatics.cs
+++ b/osu.Game/Configuration/SessionStatics.cs
@@ -1,6 +1,9 @@
 // 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.Generic;
+using osu.Game.Online.API.Requests.Responses;
+
 namespace osu.Game.Configuration
 {
     /// <summary>
@@ -12,12 +15,14 @@ namespace osu.Game.Configuration
         {
             Set(Static.LoginOverlayDisplayed, false);
             Set(Static.MutedAudioNotificationShownOnce, false);
+            Set(Static.SeasonalBackgrounds, new List<APISeasonalBackground>());
         }
     }
 
     public enum Static
     {
         LoginOverlayDisplayed,
-        MutedAudioNotificationShownOnce
+        MutedAudioNotificationShownOnce,
+        SeasonalBackgrounds
     }
 }
diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index af81b25cee..72785be3b4 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -5,9 +5,11 @@ 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.Textures;
 using osu.Framework.Utils;
+using osu.Game.Configuration;
 using osu.Game.Online.API;
 using osu.Game.Online.API.Requests;
 using osu.Game.Online.API.Requests.Responses;
@@ -17,17 +19,20 @@ namespace osu.Game.Graphics.Backgrounds
     [LongRunningLoad]
     public class SeasonalBackgroundLoader : Component
     {
-        private List<APISeasonalBackground> backgrounds = new List<APISeasonalBackground>();
+        private Bindable<List<APISeasonalBackground>> backgrounds;
         private int current;
 
         [BackgroundDependencyLoader]
-        private void load(IAPIProvider api)
+        private void load(SessionStatics sessionStatics, IAPIProvider api)
         {
+            backgrounds = sessionStatics.GetBindable<List<APISeasonalBackground>>(Static.SeasonalBackgrounds);
+            if (backgrounds.Value.Any()) return;
+
             var request = new GetSeasonalBackgroundsRequest();
             request.Success += response =>
             {
-                backgrounds = response.Backgrounds ?? backgrounds;
-                current = RNG.Next(0, backgrounds.Count);
+                backgrounds.Value = response.Backgrounds ?? backgrounds.Value;
+                current = RNG.Next(0, backgrounds.Value.Count);
             };
 
             api.PerformAsync(request);
@@ -37,10 +42,10 @@ namespace osu.Game.Graphics.Backgrounds
         {
             string url = null;
 
-            if (backgrounds.Any())
+            if (backgrounds.Value.Any())
             {
-                current = (current + 1) % backgrounds.Count;
-                url = backgrounds[current].Url;
+                current = (current + 1) % backgrounds.Value.Count;
+                url = backgrounds.Value[current].Url;
             }
 
             return new SeasonalBackground(url, fallbackTextureName);

From bf4d99dfe7aa3ad5a4422430ae2079e4ef93d7f4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 29 Oct 2020 17:43:10 +0100
Subject: [PATCH 11/32] Load SeasonalBackgroundLoader asynchronously

---
 osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index ef41c5be3d..98552dda71 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -25,6 +25,7 @@ namespace osu.Game.Screens.Backgrounds
         private Bindable<Skin> skin;
         private Bindable<BackgroundSource> mode;
         private Bindable<IntroSequence> introSequence;
+        private readonly SeasonalBackgroundLoader seasonalBackgroundLoader = new SeasonalBackgroundLoader();
 
         [Resolved]
         private IBindable<WorkingBeatmap> beatmap { get; set; }
@@ -50,7 +51,7 @@ namespace osu.Game.Screens.Backgrounds
 
             currentDisplay = RNG.Next(0, background_count);
 
-            display(createBackground());
+            LoadComponentAsync(seasonalBackgroundLoader, _ => LoadComponentAsync(createBackground(), display));
         }
 
         private void display(Background newBackground)

From 34371b8888980ec2de400b16924657449263ea1d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 29 Oct 2020 17:44:23 +0100
Subject: [PATCH 12/32] Show next Background on
 showSeasonalBackgrounds.ValueChanged

---
 osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index 98552dda71..1be19c5854 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -25,6 +25,7 @@ namespace osu.Game.Screens.Backgrounds
         private Bindable<Skin> skin;
         private Bindable<BackgroundSource> mode;
         private Bindable<IntroSequence> introSequence;
+        private Bindable<SeasonalBackgrounds> showSeasonalBackgrounds;
         private readonly SeasonalBackgroundLoader seasonalBackgroundLoader = new SeasonalBackgroundLoader();
 
         [Resolved]
@@ -42,12 +43,14 @@ namespace osu.Game.Screens.Backgrounds
             skin = skinManager.CurrentSkin.GetBoundCopy();
             mode = config.GetBindable<BackgroundSource>(OsuSetting.MenuBackgroundSource);
             introSequence = config.GetBindable<IntroSequence>(OsuSetting.IntroSequence);
+            showSeasonalBackgrounds = config.GetBindable<SeasonalBackgrounds>(OsuSetting.SeasonalBackgrounds);
 
             user.ValueChanged += _ => Next();
             skin.ValueChanged += _ => Next();
             mode.ValueChanged += _ => Next();
             beatmap.ValueChanged += _ => Next();
             introSequence.ValueChanged += _ => Next();
+            showSeasonalBackgrounds.ValueChanged += _ => Next();
 
             currentDisplay = RNG.Next(0, background_count);
 

From d9846fad37d4d2b9453621c2b225b9a3cf12cc8c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 29 Oct 2020 18:03:36 +0100
Subject: [PATCH 13/32] Remove fallback texture parameter

 When there isn't a seasonal event, we don't want to fall back to the basic background here, but rather to the user selected background source.
---
 .../Backgrounds/SeasonalBackgroundLoader.cs   | 21 +++++++------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index 72785be3b4..abd9664106 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -3,7 +3,6 @@
 
 using System.Collections.Generic;
 using System.Linq;
-using JetBrains.Annotations;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -38,17 +37,14 @@ namespace osu.Game.Graphics.Backgrounds
             api.PerformAsync(request);
         }
 
-        public SeasonalBackground LoadBackground(string fallbackTextureName)
+        public SeasonalBackground LoadBackground()
         {
-            string url = null;
+            if (!backgrounds.Value.Any()) return null;
 
-            if (backgrounds.Value.Any())
-            {
-                current = (current + 1) % backgrounds.Value.Count;
-                url = backgrounds.Value[current].Url;
-            }
+            current = (current + 1) % backgrounds.Value.Count;
+            string url = backgrounds.Value[current].Url;
 
-            return new SeasonalBackground(url, fallbackTextureName);
+            return new SeasonalBackground(url);
         }
     }
 
@@ -56,18 +52,17 @@ namespace osu.Game.Graphics.Backgrounds
     public class SeasonalBackground : Background
     {
         private readonly string url;
-        private readonly string fallbackTextureName;
+        private const string fallback_texture_name = @"Backgrounds/bg1";
 
-        public SeasonalBackground([CanBeNull] string url, string fallbackTextureName = @"Backgrounds/bg1")
+        public SeasonalBackground(string url)
         {
             this.url = url;
-            this.fallbackTextureName = fallbackTextureName;
         }
 
         [BackgroundDependencyLoader]
         private void load(LargeTextureStore textures)
         {
-            Sprite.Texture = textures.Get(url) ?? textures.Get(fallbackTextureName);
+            Sprite.Texture = textures.Get(url) ?? textures.Get(fallback_texture_name);
         }
     }
 }

From fb1e09b3e793fae71caada4ad754d586ce7f5a12 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Thu, 29 Oct 2020 18:04:48 +0100
Subject: [PATCH 14/32] Load seasonal backgrounds according to setting

---
 .../Screens/Backgrounds/BackgroundScreenDefault.cs   | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index 1be19c5854..70eafd4aff 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -106,6 +106,18 @@ namespace osu.Game.Screens.Backgrounds
             else
                 newBackground = new Background(backgroundName);
 
+            switch (showSeasonalBackgrounds.Value)
+            {
+                case SeasonalBackgrounds.Sometimes:
+                    if (RNG.NextBool())
+                        goto case SeasonalBackgrounds.Always;
+                    break;
+
+                case SeasonalBackgrounds.Always:
+                    newBackground = seasonalBackgroundLoader.LoadBackground() ?? newBackground;
+                    break;
+            }
+
             newBackground.Depth = currentDisplay;
 
             return newBackground;

From f27ce7521d69295e7af78478118e436db6f400ba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Fri, 30 Oct 2020 10:27:43 +0100
Subject: [PATCH 15/32] Make "Sometimes" setting depend on season end date,
 rather than chance

---
 osu.Game/Configuration/SessionStatics.cs                  | 5 ++++-
 osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs | 8 ++++++++
 .../API/Requests/Responses/APISeasonalBackgrounds.cs      | 4 ++++
 osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs   | 2 +-
 4 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/osu.Game/Configuration/SessionStatics.cs b/osu.Game/Configuration/SessionStatics.cs
index 326abed8fe..8100e0fb12 100644
--- a/osu.Game/Configuration/SessionStatics.cs
+++ b/osu.Game/Configuration/SessionStatics.cs
@@ -1,6 +1,7 @@
 // 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 osu.Game.Online.API.Requests.Responses;
 
@@ -15,6 +16,7 @@ namespace osu.Game.Configuration
         {
             Set(Static.LoginOverlayDisplayed, false);
             Set(Static.MutedAudioNotificationShownOnce, false);
+            Set(Static.SeasonEndDate, DateTimeOffset.MinValue);
             Set(Static.SeasonalBackgrounds, new List<APISeasonalBackground>());
         }
     }
@@ -23,6 +25,7 @@ namespace osu.Game.Configuration
     {
         LoginOverlayDisplayed,
         MutedAudioNotificationShownOnce,
-        SeasonalBackgrounds
+        SeasonEndDate,
+        SeasonalBackgrounds,
     }
 }
diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index abd9664106..d806c62650 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -1,6 +1,7 @@
 // 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 osu.Framework.Allocation;
@@ -18,19 +19,24 @@ namespace osu.Game.Graphics.Backgrounds
     [LongRunningLoad]
     public class SeasonalBackgroundLoader : Component
     {
+        private Bindable<DateTimeOffset> endDate;
         private Bindable<List<APISeasonalBackground>> backgrounds;
         private int current;
 
         [BackgroundDependencyLoader]
         private void load(SessionStatics sessionStatics, IAPIProvider api)
         {
+            endDate = sessionStatics.GetBindable<DateTimeOffset>(Static.SeasonEndDate);
             backgrounds = sessionStatics.GetBindable<List<APISeasonalBackground>>(Static.SeasonalBackgrounds);
+
             if (backgrounds.Value.Any()) return;
 
             var request = new GetSeasonalBackgroundsRequest();
             request.Success += response =>
             {
+                endDate.Value = response.EndDate;
                 backgrounds.Value = response.Backgrounds ?? backgrounds.Value;
+
                 current = RNG.Next(0, backgrounds.Value.Count);
             };
 
@@ -46,6 +52,8 @@ namespace osu.Game.Graphics.Backgrounds
 
             return new SeasonalBackground(url);
         }
+
+        public bool IsInSeason() => DateTimeOffset.Now < endDate.Value;
     }
 
     [LongRunningLoad]
diff --git a/osu.Game/Online/API/Requests/Responses/APISeasonalBackgrounds.cs b/osu.Game/Online/API/Requests/Responses/APISeasonalBackgrounds.cs
index 6996ac4d9b..8e395f7397 100644
--- a/osu.Game/Online/API/Requests/Responses/APISeasonalBackgrounds.cs
+++ b/osu.Game/Online/API/Requests/Responses/APISeasonalBackgrounds.cs
@@ -1,6 +1,7 @@
 // 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 Newtonsoft.Json;
 
@@ -8,6 +9,9 @@ namespace osu.Game.Online.API.Requests.Responses
 {
     public class APISeasonalBackgrounds
     {
+        [JsonProperty("ends_at")]
+        public DateTimeOffset EndDate;
+
         [JsonProperty("backgrounds")]
         public List<APISeasonalBackground> Backgrounds { get; set; }
     }
diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index 70eafd4aff..de73c82d5c 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -109,7 +109,7 @@ namespace osu.Game.Screens.Backgrounds
             switch (showSeasonalBackgrounds.Value)
             {
                 case SeasonalBackgrounds.Sometimes:
-                    if (RNG.NextBool())
+                    if (seasonalBackgroundLoader.IsInSeason())
                         goto case SeasonalBackgrounds.Always;
                     break;
 

From 4e3fb615d25c6a2edfbec009401ec73f925840f2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Fri, 30 Oct 2020 15:54:10 +0100
Subject: [PATCH 16/32] Rename "SeasonalBackgrounds" to
 "SeasonalBackgroundMode"

---
 osu.Game/Configuration/OsuConfigManager.cs         |  4 ++--
 ...nalBackgrounds.cs => SeasonalBackgroundMode.cs} |  2 +-
 .../Settings/Sections/Audio/MainMenuSettings.cs    |  6 +++---
 .../Screens/Backgrounds/BackgroundScreenDefault.cs | 14 +++++++-------
 4 files changed, 13 insertions(+), 13 deletions(-)
 rename osu.Game/Configuration/{SeasonalBackgrounds.cs => SeasonalBackgroundMode.cs} (86%)

diff --git a/osu.Game/Configuration/OsuConfigManager.cs b/osu.Game/Configuration/OsuConfigManager.cs
index e579898c05..e0971d238a 100644
--- a/osu.Game/Configuration/OsuConfigManager.cs
+++ b/osu.Game/Configuration/OsuConfigManager.cs
@@ -131,7 +131,7 @@ namespace osu.Game.Configuration
             Set(OsuSetting.IntroSequence, IntroSequence.Triangles);
 
             Set(OsuSetting.MenuBackgroundSource, BackgroundSource.Skin);
-            Set(OsuSetting.SeasonalBackgrounds, SeasonalBackgrounds.Sometimes);
+            Set(OsuSetting.SeasonalBackgroundMode, SeasonalBackgroundMode.Sometimes);
         }
 
         public OsuConfigManager(Storage storage)
@@ -241,6 +241,6 @@ namespace osu.Game.Configuration
         HitLighting,
         MenuBackgroundSource,
         GameplayDisableWinKey,
-        SeasonalBackgrounds
+        SeasonalBackgroundMode
     }
 }
diff --git a/osu.Game/Configuration/SeasonalBackgrounds.cs b/osu.Game/Configuration/SeasonalBackgroundMode.cs
similarity index 86%
rename from osu.Game/Configuration/SeasonalBackgrounds.cs
rename to osu.Game/Configuration/SeasonalBackgroundMode.cs
index 7708ae584f..406736b2a4 100644
--- a/osu.Game/Configuration/SeasonalBackgrounds.cs
+++ b/osu.Game/Configuration/SeasonalBackgroundMode.cs
@@ -3,7 +3,7 @@
 
 namespace osu.Game.Configuration
 {
-    public enum SeasonalBackgrounds
+    public enum SeasonalBackgroundMode
     {
         Always,
         Sometimes,
diff --git a/osu.Game/Overlays/Settings/Sections/Audio/MainMenuSettings.cs b/osu.Game/Overlays/Settings/Sections/Audio/MainMenuSettings.cs
index ee57c0cfa6..7682967d10 100644
--- a/osu.Game/Overlays/Settings/Sections/Audio/MainMenuSettings.cs
+++ b/osu.Game/Overlays/Settings/Sections/Audio/MainMenuSettings.cs
@@ -40,11 +40,11 @@ namespace osu.Game.Overlays.Settings.Sections.Audio
                     Current = config.GetBindable<BackgroundSource>(OsuSetting.MenuBackgroundSource),
                     Items = Enum.GetValues(typeof(BackgroundSource)).Cast<BackgroundSource>()
                 },
-                new SettingsDropdown<SeasonalBackgrounds>
+                new SettingsDropdown<SeasonalBackgroundMode>
                 {
                     LabelText = "Seasonal backgrounds",
-                    Current = config.GetBindable<SeasonalBackgrounds>(OsuSetting.SeasonalBackgrounds),
-                    Items = Enum.GetValues(typeof(SeasonalBackgrounds)).Cast<SeasonalBackgrounds>()
+                    Current = config.GetBindable<SeasonalBackgroundMode>(OsuSetting.SeasonalBackgroundMode),
+                    Items = Enum.GetValues(typeof(SeasonalBackgroundMode)).Cast<SeasonalBackgroundMode>()
                 }
             };
         }
diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index de73c82d5c..a5bdcee8d4 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -25,7 +25,7 @@ namespace osu.Game.Screens.Backgrounds
         private Bindable<Skin> skin;
         private Bindable<BackgroundSource> mode;
         private Bindable<IntroSequence> introSequence;
-        private Bindable<SeasonalBackgrounds> showSeasonalBackgrounds;
+        private Bindable<SeasonalBackgroundMode> seasonalBackgroundMode;
         private readonly SeasonalBackgroundLoader seasonalBackgroundLoader = new SeasonalBackgroundLoader();
 
         [Resolved]
@@ -43,14 +43,14 @@ namespace osu.Game.Screens.Backgrounds
             skin = skinManager.CurrentSkin.GetBoundCopy();
             mode = config.GetBindable<BackgroundSource>(OsuSetting.MenuBackgroundSource);
             introSequence = config.GetBindable<IntroSequence>(OsuSetting.IntroSequence);
-            showSeasonalBackgrounds = config.GetBindable<SeasonalBackgrounds>(OsuSetting.SeasonalBackgrounds);
+            seasonalBackgroundMode = config.GetBindable<SeasonalBackgroundMode>(OsuSetting.SeasonalBackgroundMode);
 
             user.ValueChanged += _ => Next();
             skin.ValueChanged += _ => Next();
             mode.ValueChanged += _ => Next();
             beatmap.ValueChanged += _ => Next();
             introSequence.ValueChanged += _ => Next();
-            showSeasonalBackgrounds.ValueChanged += _ => Next();
+            seasonalBackgroundMode.ValueChanged += _ => Next();
 
             currentDisplay = RNG.Next(0, background_count);
 
@@ -106,14 +106,14 @@ namespace osu.Game.Screens.Backgrounds
             else
                 newBackground = new Background(backgroundName);
 
-            switch (showSeasonalBackgrounds.Value)
+            switch (seasonalBackgroundMode.Value)
             {
-                case SeasonalBackgrounds.Sometimes:
+                case SeasonalBackgroundMode.Sometimes:
                     if (seasonalBackgroundLoader.IsInSeason())
-                        goto case SeasonalBackgrounds.Always;
+                        goto case SeasonalBackgroundMode.Always;
                     break;
 
-                case SeasonalBackgrounds.Always:
+                case SeasonalBackgroundMode.Always:
                     newBackground = seasonalBackgroundLoader.LoadBackground() ?? newBackground;
                     break;
             }

From d19dd4eef6ba621616f684b5b07d41d154d68f87 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Fri, 30 Oct 2020 15:56:19 +0100
Subject: [PATCH 17/32] IsInSeason() -> IsInSeason

---
 osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs | 2 +-
 osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index d806c62650..ff1a2c9f37 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -53,7 +53,7 @@ namespace osu.Game.Graphics.Backgrounds
             return new SeasonalBackground(url);
         }
 
-        public bool IsInSeason() => DateTimeOffset.Now < endDate.Value;
+        public bool IsInSeason => DateTimeOffset.Now < endDate.Value;
     }
 
     [LongRunningLoad]
diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index a5bdcee8d4..5fa4ddc041 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -109,7 +109,7 @@ namespace osu.Game.Screens.Backgrounds
             switch (seasonalBackgroundMode.Value)
             {
                 case SeasonalBackgroundMode.Sometimes:
-                    if (seasonalBackgroundLoader.IsInSeason())
+                    if (seasonalBackgroundLoader.IsInSeason)
                         goto case SeasonalBackgroundMode.Always;
                     break;
 

From 6f6a8e2a8fe09581630728d0e347b48e91c3f80e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Fri, 30 Oct 2020 16:06:48 +0100
Subject: [PATCH 18/32] Convert switch to if

---
 .../Screens/Backgrounds/BackgroundScreenDefault.cs   | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index 5fa4ddc041..39ecd70084 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -106,16 +106,10 @@ namespace osu.Game.Screens.Backgrounds
             else
                 newBackground = new Background(backgroundName);
 
-            switch (seasonalBackgroundMode.Value)
+            if (seasonalBackgroundMode.Value == SeasonalBackgroundMode.Always
+                || seasonalBackgroundMode.Value == SeasonalBackgroundMode.Sometimes && seasonalBackgroundLoader.IsInSeason)
             {
-                case SeasonalBackgroundMode.Sometimes:
-                    if (seasonalBackgroundLoader.IsInSeason)
-                        goto case SeasonalBackgroundMode.Always;
-                    break;
-
-                case SeasonalBackgroundMode.Always:
-                    newBackground = seasonalBackgroundLoader.LoadBackground() ?? newBackground;
-                    break;
+                newBackground = seasonalBackgroundLoader.LoadBackground() ?? newBackground;
             }
 
             newBackground.Depth = currentDisplay;

From f6eb5680ec53626707452cf08c0926713fbf2ac1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Fri, 30 Oct 2020 16:43:18 +0100
Subject: [PATCH 19/32] Save full api response in SessionStatics

---
 osu.Game/Configuration/SessionStatics.cs      |  8 ++-----
 .../Backgrounds/SeasonalBackgroundLoader.cs   | 24 ++++++++-----------
 2 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/osu.Game/Configuration/SessionStatics.cs b/osu.Game/Configuration/SessionStatics.cs
index 8100e0fb12..199889391b 100644
--- a/osu.Game/Configuration/SessionStatics.cs
+++ b/osu.Game/Configuration/SessionStatics.cs
@@ -1,8 +1,6 @@
 // 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 osu.Game.Online.API.Requests.Responses;
 
 namespace osu.Game.Configuration
@@ -16,8 +14,7 @@ namespace osu.Game.Configuration
         {
             Set(Static.LoginOverlayDisplayed, false);
             Set(Static.MutedAudioNotificationShownOnce, false);
-            Set(Static.SeasonEndDate, DateTimeOffset.MinValue);
-            Set(Static.SeasonalBackgrounds, new List<APISeasonalBackground>());
+            Set<APISeasonalBackgrounds>(Static.SeasonalBackgroundsResponse, null);
         }
     }
 
@@ -25,7 +22,6 @@ namespace osu.Game.Configuration
     {
         LoginOverlayDisplayed,
         MutedAudioNotificationShownOnce,
-        SeasonEndDate,
-        SeasonalBackgrounds,
+        SeasonalBackgroundsResponse,
     }
 }
diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index ff1a2c9f37..c884756c80 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -2,7 +2,6 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
-using System.Collections.Generic;
 using System.Linq;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
@@ -19,25 +18,21 @@ namespace osu.Game.Graphics.Backgrounds
     [LongRunningLoad]
     public class SeasonalBackgroundLoader : Component
     {
-        private Bindable<DateTimeOffset> endDate;
-        private Bindable<List<APISeasonalBackground>> backgrounds;
+        private Bindable<APISeasonalBackgrounds> cachedResponse;
         private int current;
 
         [BackgroundDependencyLoader]
         private void load(SessionStatics sessionStatics, IAPIProvider api)
         {
-            endDate = sessionStatics.GetBindable<DateTimeOffset>(Static.SeasonEndDate);
-            backgrounds = sessionStatics.GetBindable<List<APISeasonalBackground>>(Static.SeasonalBackgrounds);
+            cachedResponse = sessionStatics.GetBindable<APISeasonalBackgrounds>(Static.SeasonalBackgroundsResponse);
 
-            if (backgrounds.Value.Any()) return;
+            if (cachedResponse.Value != null) return;
 
             var request = new GetSeasonalBackgroundsRequest();
             request.Success += response =>
             {
-                endDate.Value = response.EndDate;
-                backgrounds.Value = response.Backgrounds ?? backgrounds.Value;
-
-                current = RNG.Next(0, backgrounds.Value.Count);
+                cachedResponse.Value = response;
+                current = RNG.Next(0, cachedResponse.Value.Backgrounds.Count);
             };
 
             api.PerformAsync(request);
@@ -45,15 +40,16 @@ namespace osu.Game.Graphics.Backgrounds
 
         public SeasonalBackground LoadBackground()
         {
-            if (!backgrounds.Value.Any()) return null;
+            var backgrounds = cachedResponse.Value.Backgrounds;
+            if (!backgrounds.Any()) return null;
 
-            current = (current + 1) % backgrounds.Value.Count;
-            string url = backgrounds.Value[current].Url;
+            current = (current + 1) % backgrounds.Count;
+            string url = backgrounds[current].Url;
 
             return new SeasonalBackground(url);
         }
 
-        public bool IsInSeason => DateTimeOffset.Now < endDate.Value;
+        public bool IsInSeason => DateTimeOffset.Now < cachedResponse.Value.EndDate;
     }
 
     [LongRunningLoad]

From 0b46c19b23995f42e35b82877b41404200f109ff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Fri, 30 Oct 2020 17:16:51 +0100
Subject: [PATCH 20/32] Move seasonalBackgroundMode check up and early return
 if available

---
 .../Backgrounds/BackgroundScreenDefault.cs     | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index 39ecd70084..b65b45060f 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -79,6 +79,18 @@ namespace osu.Game.Screens.Backgrounds
             Background newBackground;
             string backgroundName;
 
+            if (seasonalBackgroundMode.Value == SeasonalBackgroundMode.Always
+                || seasonalBackgroundMode.Value == SeasonalBackgroundMode.Sometimes && seasonalBackgroundLoader.IsInSeason)
+            {
+                var seasonalBackground = seasonalBackgroundLoader.LoadBackground();
+
+                if (seasonalBackground != null)
+                {
+                    seasonalBackground.Depth = currentDisplay;
+                    return seasonalBackground;
+                }
+            }
+
             switch (introSequence.Value)
             {
                 case IntroSequence.Welcome:
@@ -106,12 +118,6 @@ namespace osu.Game.Screens.Backgrounds
             else
                 newBackground = new Background(backgroundName);
 
-            if (seasonalBackgroundMode.Value == SeasonalBackgroundMode.Always
-                || seasonalBackgroundMode.Value == SeasonalBackgroundMode.Sometimes && seasonalBackgroundLoader.IsInSeason)
-            {
-                newBackground = seasonalBackgroundLoader.LoadBackground() ?? newBackground;
-            }
-
             newBackground.Depth = currentDisplay;
 
             return newBackground;

From 51a58269add518f7ea68f590fceeff11612cc5c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Fri, 30 Oct 2020 17:57:29 +0100
Subject: [PATCH 21/32] Fix nullref in case of successfull request but no
 backgrounds available

---
 osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index c884756c80..daceb05fd7 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -32,7 +32,7 @@ namespace osu.Game.Graphics.Backgrounds
             request.Success += response =>
             {
                 cachedResponse.Value = response;
-                current = RNG.Next(0, cachedResponse.Value.Backgrounds.Count);
+                current = RNG.Next(0, response.Backgrounds?.Count ?? 0);
             };
 
             api.PerformAsync(request);
@@ -41,7 +41,7 @@ namespace osu.Game.Graphics.Backgrounds
         public SeasonalBackground LoadBackground()
         {
             var backgrounds = cachedResponse.Value.Backgrounds;
-            if (!backgrounds.Any()) return null;
+            if (backgrounds == null || !backgrounds.Any()) return null;
 
             current = (current + 1) % backgrounds.Count;
             string url = backgrounds[current].Url;

From d5dfd1dffeee753cb47d70afc87a1b3055e1962e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Max=20H=C3=BCbner?= <maxshuebner@gmail.com>
Date: Fri, 30 Oct 2020 18:07:07 +0100
Subject: [PATCH 22/32] Insert optional parentheses

---
 osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index b65b45060f..45374e1223 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -80,7 +80,7 @@ namespace osu.Game.Screens.Backgrounds
             string backgroundName;
 
             if (seasonalBackgroundMode.Value == SeasonalBackgroundMode.Always
-                || seasonalBackgroundMode.Value == SeasonalBackgroundMode.Sometimes && seasonalBackgroundLoader.IsInSeason)
+                || (seasonalBackgroundMode.Value == SeasonalBackgroundMode.Sometimes && seasonalBackgroundLoader.IsInSeason))
             {
                 var seasonalBackground = seasonalBackgroundLoader.LoadBackground();
 

From 82ef85569bffe30e64a00414ddb8465348d645d5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Fri, 30 Oct 2020 19:35:08 +0100
Subject: [PATCH 23/32] Fix nullref when querying IsInSeason before request
 completion

---
 osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index daceb05fd7..2963d57a97 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -49,7 +49,7 @@ namespace osu.Game.Graphics.Backgrounds
             return new SeasonalBackground(url);
         }
 
-        public bool IsInSeason => DateTimeOffset.Now < cachedResponse.Value.EndDate;
+        public bool IsInSeason => cachedResponse.Value != null && DateTimeOffset.Now < cachedResponse.Value.EndDate;
     }
 
     [LongRunningLoad]

From 20c27c69431eb680781338c4e0deba1f2a1658ff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Fri, 30 Oct 2020 19:55:17 +0100
Subject: [PATCH 24/32] Rename lookup & field

---
 osu.Game/Configuration/SessionStatics.cs             |  4 ++--
 .../Graphics/Backgrounds/SeasonalBackgroundLoader.cs | 12 ++++++------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/osu.Game/Configuration/SessionStatics.cs b/osu.Game/Configuration/SessionStatics.cs
index 199889391b..c470058ae8 100644
--- a/osu.Game/Configuration/SessionStatics.cs
+++ b/osu.Game/Configuration/SessionStatics.cs
@@ -14,7 +14,7 @@ namespace osu.Game.Configuration
         {
             Set(Static.LoginOverlayDisplayed, false);
             Set(Static.MutedAudioNotificationShownOnce, false);
-            Set<APISeasonalBackgrounds>(Static.SeasonalBackgroundsResponse, null);
+            Set<APISeasonalBackgrounds>(Static.SeasonalBackgrounds, null);
         }
     }
 
@@ -22,6 +22,6 @@ namespace osu.Game.Configuration
     {
         LoginOverlayDisplayed,
         MutedAudioNotificationShownOnce,
-        SeasonalBackgroundsResponse,
+        SeasonalBackgrounds,
     }
 }
diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index 2963d57a97..1c38e67451 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -18,20 +18,20 @@ namespace osu.Game.Graphics.Backgrounds
     [LongRunningLoad]
     public class SeasonalBackgroundLoader : Component
     {
-        private Bindable<APISeasonalBackgrounds> cachedResponse;
+        private Bindable<APISeasonalBackgrounds> seasonalBackgrounds;
         private int current;
 
         [BackgroundDependencyLoader]
         private void load(SessionStatics sessionStatics, IAPIProvider api)
         {
-            cachedResponse = sessionStatics.GetBindable<APISeasonalBackgrounds>(Static.SeasonalBackgroundsResponse);
+            seasonalBackgrounds = sessionStatics.GetBindable<APISeasonalBackgrounds>(Static.SeasonalBackgrounds);
 
-            if (cachedResponse.Value != null) return;
+            if (seasonalBackgrounds.Value != null) return;
 
             var request = new GetSeasonalBackgroundsRequest();
             request.Success += response =>
             {
-                cachedResponse.Value = response;
+                seasonalBackgrounds.Value = response;
                 current = RNG.Next(0, response.Backgrounds?.Count ?? 0);
             };
 
@@ -40,7 +40,7 @@ namespace osu.Game.Graphics.Backgrounds
 
         public SeasonalBackground LoadBackground()
         {
-            var backgrounds = cachedResponse.Value.Backgrounds;
+            var backgrounds = seasonalBackgrounds.Value.Backgrounds;
             if (backgrounds == null || !backgrounds.Any()) return null;
 
             current = (current + 1) % backgrounds.Count;
@@ -49,7 +49,7 @@ namespace osu.Game.Graphics.Backgrounds
             return new SeasonalBackground(url);
         }
 
-        public bool IsInSeason => cachedResponse.Value != null && DateTimeOffset.Now < cachedResponse.Value.EndDate;
+        public bool IsInSeason => seasonalBackgrounds.Value != null && DateTimeOffset.Now < seasonalBackgrounds.Value.EndDate;
     }
 
     [LongRunningLoad]

From aeab2be5d1968c7a1a6a712afc2897033891bb6e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Fri, 30 Oct 2020 19:56:52 +0100
Subject: [PATCH 25/32] Add xmldoc to SeasonalBackgroundMode

---
 osu.Game/Configuration/SeasonalBackgroundMode.cs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/osu.Game/Configuration/SeasonalBackgroundMode.cs b/osu.Game/Configuration/SeasonalBackgroundMode.cs
index 406736b2a4..6ef835ce5f 100644
--- a/osu.Game/Configuration/SeasonalBackgroundMode.cs
+++ b/osu.Game/Configuration/SeasonalBackgroundMode.cs
@@ -5,8 +5,19 @@ namespace osu.Game.Configuration
 {
     public enum SeasonalBackgroundMode
     {
+        /// <summary>
+        /// Seasonal backgrounds are shown regardless of season, if at all available.
+        /// </summary>
         Always,
+
+        /// <summary>
+        /// Seasonal backgrounds are shown only during their corresponding season.
+        /// </summary>
         Sometimes,
+
+        /// <summary>
+        /// Seasonal backgrounds are never shown.
+        /// </summary>
         Never
     }
 }

From cf0e8e0a620faaa77ba490ab3e71b9901eabd658 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Fri, 30 Oct 2020 19:59:52 +0100
Subject: [PATCH 26/32] Document nullability of seasonal backgrounds

---
 osu.Game/Configuration/SessionStatics.cs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/osu.Game/Configuration/SessionStatics.cs b/osu.Game/Configuration/SessionStatics.cs
index c470058ae8..03bc434aac 100644
--- a/osu.Game/Configuration/SessionStatics.cs
+++ b/osu.Game/Configuration/SessionStatics.cs
@@ -22,6 +22,11 @@ namespace osu.Game.Configuration
     {
         LoginOverlayDisplayed,
         MutedAudioNotificationShownOnce,
+
+        /// <summary>
+        /// Info about seasonal backgrounds available fetched from API - see <see cref="APISeasonalBackgrounds"/>.
+        /// Value under this lookup can be <c>null</c> if there are no backgrounds available (or API is not reachable).
+        /// </summary>
         SeasonalBackgrounds,
     }
 }

From 67a325f47dd608f625711a4e38b8968ee514716e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Fri, 30 Oct 2020 20:32:14 +0100
Subject: [PATCH 27/32] Move config setting logic to background loader

---
 .../Backgrounds/SeasonalBackgroundLoader.cs     | 17 +++++++++++++----
 .../Backgrounds/BackgroundScreenDefault.cs      | 14 +++++---------
 2 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index 1c38e67451..a9b9929c79 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -18,12 +18,14 @@ namespace osu.Game.Graphics.Backgrounds
     [LongRunningLoad]
     public class SeasonalBackgroundLoader : Component
     {
+        private Bindable<SeasonalBackgroundMode> seasonalBackgroundMode;
         private Bindable<APISeasonalBackgrounds> seasonalBackgrounds;
         private int current;
 
         [BackgroundDependencyLoader]
-        private void load(SessionStatics sessionStatics, IAPIProvider api)
+        private void load(OsuConfigManager config, SessionStatics sessionStatics, IAPIProvider api)
         {
+            seasonalBackgroundMode = config.GetBindable<SeasonalBackgroundMode>(OsuSetting.SeasonalBackgroundMode);
             seasonalBackgrounds = sessionStatics.GetBindable<APISeasonalBackgrounds>(Static.SeasonalBackgrounds);
 
             if (seasonalBackgrounds.Value != null) return;
@@ -38,10 +40,17 @@ namespace osu.Game.Graphics.Backgrounds
             api.PerformAsync(request);
         }
 
-        public SeasonalBackground LoadBackground()
+        public SeasonalBackground LoadNextBackground()
         {
+            if (seasonalBackgroundMode.Value == SeasonalBackgroundMode.Never
+                || (seasonalBackgroundMode.Value == SeasonalBackgroundMode.Sometimes && !isInSeason))
+            {
+                return null;
+            }
+
             var backgrounds = seasonalBackgrounds.Value.Backgrounds;
-            if (backgrounds == null || !backgrounds.Any()) return null;
+            if (backgrounds == null || !backgrounds.Any())
+                return null;
 
             current = (current + 1) % backgrounds.Count;
             string url = backgrounds[current].Url;
@@ -49,7 +58,7 @@ namespace osu.Game.Graphics.Backgrounds
             return new SeasonalBackground(url);
         }
 
-        public bool IsInSeason => seasonalBackgrounds.Value != null && DateTimeOffset.Now < seasonalBackgrounds.Value.EndDate;
+        private bool isInSeason => seasonalBackgrounds.Value != null && DateTimeOffset.Now < seasonalBackgrounds.Value.EndDate;
     }
 
     [LongRunningLoad]
diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index 45374e1223..cbe0841537 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -79,16 +79,12 @@ namespace osu.Game.Screens.Backgrounds
             Background newBackground;
             string backgroundName;
 
-            if (seasonalBackgroundMode.Value == SeasonalBackgroundMode.Always
-                || (seasonalBackgroundMode.Value == SeasonalBackgroundMode.Sometimes && seasonalBackgroundLoader.IsInSeason))
-            {
-                var seasonalBackground = seasonalBackgroundLoader.LoadBackground();
+            var seasonalBackground = seasonalBackgroundLoader.LoadNextBackground();
 
-                if (seasonalBackground != null)
-                {
-                    seasonalBackground.Depth = currentDisplay;
-                    return seasonalBackground;
-                }
+            if (seasonalBackground != null)
+            {
+                seasonalBackground.Depth = currentDisplay;
+                return seasonalBackground;
             }
 
             switch (introSequence.Value)

From 8632f0d77f18b6fb65aee838bced622aba6bdc84 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Fri, 30 Oct 2020 21:24:20 +0100
Subject: [PATCH 28/32] Add test coverage

---
 .../TestSceneSeasonalBackgroundLoader.cs      | 200 ++++++++++++++++++
 1 file changed, 200 insertions(+)
 create mode 100644 osu.Game.Tests/Visual/Background/TestSceneSeasonalBackgroundLoader.cs

diff --git a/osu.Game.Tests/Visual/Background/TestSceneSeasonalBackgroundLoader.cs b/osu.Game.Tests/Visual/Background/TestSceneSeasonalBackgroundLoader.cs
new file mode 100644
index 0000000000..8f5990aeb1
--- /dev/null
+++ b/osu.Game.Tests/Visual/Background/TestSceneSeasonalBackgroundLoader.cs
@@ -0,0 +1,200 @@
+// 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 NUnit.Framework;
+using osu.Framework.Allocation;
+using osu.Framework.Graphics;
+using osu.Framework.Graphics.Containers;
+using osu.Framework.Graphics.OpenGL.Textures;
+using osu.Framework.Graphics.Textures;
+using osu.Game.Configuration;
+using osu.Game.Graphics.Backgrounds;
+using osu.Game.Online.API;
+using osu.Game.Online.API.Requests;
+using osu.Game.Online.API.Requests.Responses;
+
+namespace osu.Game.Tests.Visual.Background
+{
+    public class TestSceneSeasonalBackgroundLoader : ScreenTestScene
+    {
+        [Resolved]
+        private OsuConfigManager config { get; set; }
+
+        [Resolved]
+        private SessionStatics statics { get; set; }
+
+        [Cached(typeof(LargeTextureStore))]
+        private LookupLoggingTextureStore textureStore = new LookupLoggingTextureStore();
+
+        private DummyAPIAccess dummyAPI => (DummyAPIAccess)API;
+
+        private SeasonalBackgroundLoader backgroundLoader;
+        private Container backgroundContainer;
+
+        // in real usages these would be online URLs, but correct execution of this test
+        // shouldn't be coupled to existence of online assets.
+        private static readonly List<string> seasonal_background_urls = new List<string>
+        {
+            "Backgrounds/bg2",
+            "Backgrounds/bg4",
+            "Backgrounds/bg3"
+        };
+
+        [BackgroundDependencyLoader]
+        private void load(LargeTextureStore wrappedStore)
+        {
+            textureStore.AddStore(wrappedStore);
+
+            Add(backgroundContainer = new Container
+            {
+                RelativeSizeAxes = Axes.Both
+            });
+        }
+
+        [SetUp]
+        public void SetUp() => Schedule(() =>
+        {
+            // reset API response in statics to avoid test crosstalk.
+            statics.Set<APISeasonalBackgrounds>(Static.SeasonalBackgrounds, null);
+            textureStore.PerformedLookups.Clear();
+            dummyAPI.SetState(APIState.Online);
+
+            backgroundContainer.Clear();
+        });
+
+        [TestCase(-5)]
+        [TestCase(5)]
+        public void TestAlwaysSeasonal(int daysOffset)
+        {
+            registerBackgroundsResponse(DateTimeOffset.Now.AddDays(daysOffset));
+            setSeasonalBackgroundMode(SeasonalBackgroundMode.Always);
+
+            createLoader();
+
+            for (int i = 0; i < 4; ++i)
+                loadNextBackground();
+
+            AddAssert("all backgrounds cycled", () => new HashSet<string>(textureStore.PerformedLookups).SetEquals(seasonal_background_urls));
+        }
+
+        [TestCase(-5)]
+        [TestCase(5)]
+        public void TestNeverSeasonal(int daysOffset)
+        {
+            registerBackgroundsResponse(DateTimeOffset.Now.AddDays(daysOffset));
+            setSeasonalBackgroundMode(SeasonalBackgroundMode.Never);
+
+            createLoader();
+
+            assertNoBackgrounds();
+        }
+
+        [Test]
+        public void TestSometimesInSeason()
+        {
+            registerBackgroundsResponse(DateTimeOffset.Now.AddDays(5));
+            setSeasonalBackgroundMode(SeasonalBackgroundMode.Sometimes);
+
+            createLoader();
+
+            assertAnyBackground();
+        }
+
+        [Test]
+        public void TestSometimesOutOfSeason()
+        {
+            registerBackgroundsResponse(DateTimeOffset.Now.AddDays(-10));
+            setSeasonalBackgroundMode(SeasonalBackgroundMode.Sometimes);
+
+            createLoader();
+
+            assertNoBackgrounds();
+        }
+
+        [Test]
+        public void TestDelayedConnectivity()
+        {
+            registerBackgroundsResponse(DateTimeOffset.Now.AddDays(30));
+            setSeasonalBackgroundMode(SeasonalBackgroundMode.Always);
+            AddStep("go offline", () => dummyAPI.SetState(APIState.Offline));
+
+            createLoader();
+            assertNoBackgrounds();
+
+            AddStep("go online", () => dummyAPI.SetState(APIState.Online));
+
+            assertAnyBackground();
+        }
+
+        private void registerBackgroundsResponse(DateTimeOffset endDate)
+            => AddStep("setup request handler", () =>
+            {
+                dummyAPI.HandleRequest = request =>
+                {
+                    if (dummyAPI.State.Value != APIState.Online || !(request is GetSeasonalBackgroundsRequest backgroundsRequest))
+                        return;
+
+                    backgroundsRequest.TriggerSuccess(new APISeasonalBackgrounds
+                    {
+                        Backgrounds = seasonal_background_urls.Select(url => new APISeasonalBackground { Url = url }).ToList(),
+                        EndDate = endDate
+                    });
+                };
+            });
+
+        private void setSeasonalBackgroundMode(SeasonalBackgroundMode mode)
+            => AddStep($"set seasonal mode to {mode}", () => config.Set(OsuSetting.SeasonalBackgroundMode, mode));
+
+        private void createLoader()
+        {
+            AddStep("create loader", () =>
+            {
+                if (backgroundLoader != null)
+                    Remove(backgroundLoader);
+
+                LoadComponentAsync(backgroundLoader = new SeasonalBackgroundLoader(), Add);
+            });
+
+            AddUntilStep("wait for loaded", () => backgroundLoader.IsLoaded);
+        }
+
+        private void loadNextBackground()
+        {
+            SeasonalBackground background = null;
+
+            AddStep("create next background", () =>
+            {
+                background = backgroundLoader.LoadNextBackground();
+                LoadComponentAsync(background, bg => backgroundContainer.Child = bg);
+            });
+
+            AddUntilStep("background loaded", () => background.IsLoaded);
+        }
+
+        private void assertAnyBackground()
+        {
+            loadNextBackground();
+            AddAssert("background looked up", () => textureStore.PerformedLookups.Any());
+        }
+
+        private void assertNoBackgrounds()
+        {
+            AddAssert("no background available", () => backgroundLoader.LoadNextBackground() == null);
+            AddAssert("no lookups performed", () => !textureStore.PerformedLookups.Any());
+        }
+
+        private class LookupLoggingTextureStore : LargeTextureStore
+        {
+            public List<string> PerformedLookups { get; } = new List<string>();
+
+            public override Texture Get(string name, WrapMode wrapModeS, WrapMode wrapModeT)
+            {
+                PerformedLookups.Add(name);
+                return base.Get(name, wrapModeS, wrapModeT);
+            }
+        }
+    }
+}

From 29ad09990259245b8b828a49add4411a90d5f88a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Fri, 30 Oct 2020 21:49:14 +0100
Subject: [PATCH 29/32] Allow to fetch if going online after launch

---
 .../Backgrounds/SeasonalBackgroundLoader.cs    | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index a9b9929c79..ff290dd99e 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -18,17 +18,29 @@ namespace osu.Game.Graphics.Backgrounds
     [LongRunningLoad]
     public class SeasonalBackgroundLoader : Component
     {
+        [Resolved]
+        private IAPIProvider api { get; set; }
+
+        private readonly IBindable<APIState> apiState = new Bindable<APIState>();
         private Bindable<SeasonalBackgroundMode> seasonalBackgroundMode;
         private Bindable<APISeasonalBackgrounds> seasonalBackgrounds;
+
         private int current;
 
         [BackgroundDependencyLoader]
-        private void load(OsuConfigManager config, SessionStatics sessionStatics, IAPIProvider api)
+        private void load(OsuConfigManager config, SessionStatics sessionStatics)
         {
             seasonalBackgroundMode = config.GetBindable<SeasonalBackgroundMode>(OsuSetting.SeasonalBackgroundMode);
             seasonalBackgrounds = sessionStatics.GetBindable<APISeasonalBackgrounds>(Static.SeasonalBackgrounds);
 
-            if (seasonalBackgrounds.Value != null) return;
+            apiState.BindTo(api.State);
+            apiState.BindValueChanged(fetchSeasonalBackgrounds, true);
+        }
+
+        private void fetchSeasonalBackgrounds(ValueChangedEvent<APIState> stateChanged)
+        {
+            if (seasonalBackgrounds.Value != null || stateChanged.NewValue != APIState.Online)
+                return;
 
             var request = new GetSeasonalBackgroundsRequest();
             request.Success += response =>
@@ -48,7 +60,7 @@ namespace osu.Game.Graphics.Backgrounds
                 return null;
             }
 
-            var backgrounds = seasonalBackgrounds.Value.Backgrounds;
+            var backgrounds = seasonalBackgrounds.Value?.Backgrounds;
             if (backgrounds == null || !backgrounds.Any())
                 return null;
 

From 38cf90a69b8734343b68fce3646b618f4d3ad6a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Fri, 30 Oct 2020 22:03:26 +0100
Subject: [PATCH 30/32] Change background to seasonal right after login

---
 .../Graphics/Backgrounds/SeasonalBackgroundLoader.cs     | 9 +++++++++
 osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs  | 4 +---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index ff290dd99e..b439d98083 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -18,6 +18,12 @@ namespace osu.Game.Graphics.Backgrounds
     [LongRunningLoad]
     public class SeasonalBackgroundLoader : Component
     {
+        /// <summary>
+        /// Fired when background change should be changed due to receiving backgrounds from API
+        /// or when the user setting is changed (as it might require unloading the seasonal background).
+        /// </summary>
+        public event Action SeasonalBackgroundChanged;
+
         [Resolved]
         private IAPIProvider api { get; set; }
 
@@ -31,7 +37,10 @@ namespace osu.Game.Graphics.Backgrounds
         private void load(OsuConfigManager config, SessionStatics sessionStatics)
         {
             seasonalBackgroundMode = config.GetBindable<SeasonalBackgroundMode>(OsuSetting.SeasonalBackgroundMode);
+            seasonalBackgroundMode.BindValueChanged(_ => SeasonalBackgroundChanged?.Invoke());
+
             seasonalBackgrounds = sessionStatics.GetBindable<APISeasonalBackgrounds>(Static.SeasonalBackgrounds);
+            seasonalBackgrounds.BindValueChanged(_ => SeasonalBackgroundChanged?.Invoke());
 
             apiState.BindTo(api.State);
             apiState.BindValueChanged(fetchSeasonalBackgrounds, true);
diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index cbe0841537..f392386bf9 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -25,7 +25,6 @@ namespace osu.Game.Screens.Backgrounds
         private Bindable<Skin> skin;
         private Bindable<BackgroundSource> mode;
         private Bindable<IntroSequence> introSequence;
-        private Bindable<SeasonalBackgroundMode> seasonalBackgroundMode;
         private readonly SeasonalBackgroundLoader seasonalBackgroundLoader = new SeasonalBackgroundLoader();
 
         [Resolved]
@@ -43,14 +42,13 @@ namespace osu.Game.Screens.Backgrounds
             skin = skinManager.CurrentSkin.GetBoundCopy();
             mode = config.GetBindable<BackgroundSource>(OsuSetting.MenuBackgroundSource);
             introSequence = config.GetBindable<IntroSequence>(OsuSetting.IntroSequence);
-            seasonalBackgroundMode = config.GetBindable<SeasonalBackgroundMode>(OsuSetting.SeasonalBackgroundMode);
 
             user.ValueChanged += _ => Next();
             skin.ValueChanged += _ => Next();
             mode.ValueChanged += _ => Next();
             beatmap.ValueChanged += _ => Next();
             introSequence.ValueChanged += _ => Next();
-            seasonalBackgroundMode.ValueChanged += _ => Next();
+            seasonalBackgroundLoader.SeasonalBackgroundChanged += Next;
 
             currentDisplay = RNG.Next(0, background_count);
 

From 391dd73843b52fcf559b6b23eb56171c89e7c37a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Fri, 30 Oct 2020 22:39:34 +0100
Subject: [PATCH 31/32] Fix typo in comment

---
 osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index b439d98083..03b7300011 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -19,7 +19,7 @@ namespace osu.Game.Graphics.Backgrounds
     public class SeasonalBackgroundLoader : Component
     {
         /// <summary>
-        /// Fired when background change should be changed due to receiving backgrounds from API
+        /// Fired when background should be changed due to receiving backgrounds from API
         /// or when the user setting is changed (as it might require unloading the seasonal background).
         /// </summary>
         public event Action SeasonalBackgroundChanged;

From 78842ab95ae90862c704ee3c350cd08b8c6126e7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Dach?= <dach.bartlomiej@gmail.com>
Date: Fri, 30 Oct 2020 22:40:24 +0100
Subject: [PATCH 32/32] Improve look & behaviour of background transitions

---
 .../Graphics/Backgrounds/SeasonalBackgroundLoader.cs     | 2 ++
 osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs  | 9 +++++++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
index 03b7300011..99f3a8a6e8 100644
--- a/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
+++ b/osu.Game/Graphics/Backgrounds/SeasonalBackgroundLoader.cs
@@ -97,6 +97,8 @@ namespace osu.Game.Graphics.Backgrounds
         private void load(LargeTextureStore textures)
         {
             Sprite.Texture = textures.Get(url) ?? textures.Get(fallback_texture_name);
+            // ensure we're not loading in without a transition.
+            this.FadeInFromZero(200, Easing.InOutSine);
         }
     }
 }
diff --git a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
index f392386bf9..3f6210310f 100644
--- a/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
+++ b/osu.Game/Screens/Backgrounds/BackgroundScreenDefault.cs
@@ -1,6 +1,7 @@
 // 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.Threading;
 using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Graphics;
@@ -52,7 +53,8 @@ namespace osu.Game.Screens.Backgrounds
 
             currentDisplay = RNG.Next(0, background_count);
 
-            LoadComponentAsync(seasonalBackgroundLoader, _ => LoadComponentAsync(createBackground(), display));
+            LoadComponentAsync(seasonalBackgroundLoader);
+            Next();
         }
 
         private void display(Background newBackground)
@@ -65,11 +67,14 @@ namespace osu.Game.Screens.Backgrounds
         }
 
         private ScheduledDelegate nextTask;
+        private CancellationTokenSource cancellationTokenSource;
 
         public void Next()
         {
             nextTask?.Cancel();
-            nextTask = Scheduler.AddDelayed(() => { LoadComponentAsync(createBackground(), display); }, 100);
+            cancellationTokenSource?.Cancel();
+            cancellationTokenSource = new CancellationTokenSource();
+            nextTask = Scheduler.AddDelayed(() => LoadComponentAsync(createBackground(), display, cancellationTokenSource.Token), 100);
         }
 
         private Background createBackground()