Deseasonify: fallback on evergreen on incomplete branding

The previous implementation would simply ignore assets not present in
the current season's directory.

On the condition that at least one asset is missing, and the current
season is not the evergreen, we also poll the evergreen directory,
and use it as fallback.

This behaviour is shielded such that we only make the extra API call if
there is a missing asset, i.e. if there is something to be gained.

1 files changed, 23 insertions, 3 deletions

diff --git a/bot/branding.py b/bot/branding.py
index 2a554eac..35cc304c 100644
--- a/bot/branding.py
+++ b/bot/branding.py
@@ -191,19 +191,39 @@ class BrandingManager(commands.Cog):
         """
         Poll Github API to refresh currently available icons.
 
+        If the current season is not the evergreen, and lacks at least one asset,
+        we also pol the evergreen seasonal dir as fallback for missing assets.
+
+        Finally, if neither the seasonal nor fallback branding directories contain
+        an asset, it will simply be ignored.
+
         Return True if the branding has changed. This will be the case when we enter
         a new season, or when something changes in the current seasons's directory
         in the branding repository.
         """
         old_branding = (self.banner, self.avatar, self.available_icons)
-
         seasonal_dir = await self._get_files(self.current_season.branding_path)
-        self.banner = seasonal_dir.get("banner.png")
-        self.avatar = seasonal_dir.get("bot_icon.png")
+
+        branding_incomplete = any(
+            asset not in seasonal_dir
+            for asset in ("banner.png", "bot_icon.png", "server_icons")
+        )
+        if branding_incomplete and self.current_season is not SeasonBase:
+            fallback_dir = await self._get_files(SeasonBase.branding_path)
+        else:
+            fallback_dir = {}
+
+        self.banner = seasonal_dir.get("banner.png") or fallback_dir.get("banner.png")
+        self.avatar = seasonal_dir.get("bot_icon.png") or fallback_dir.get("bot_icon.png")
 
         if "server_icons" in seasonal_dir:
             icons_dir = await self._get_files(f"{self.current_season.branding_path}/server_icons")
             self.available_icons = list(icons_dir.values())
+
+        elif "server_icons" in fallback_dir:
+            icons_dir = await self._get_files(f"{SeasonBase.branding_path}/server_icons")
+            self.available_icons = list(icons_dir.values())
+
         else:
             self.available_icons = []