Automatic holiday sprites (#22929)

Content.Server/Holiday/HolidaySystem.cs

@@ -2,6 +2,7 @@ using System.Linq;
 using Content.Server.Chat.Managers;
 using Content.Server.GameTicking;
 using Content.Shared.CCVar;
+using Content.Shared.Holiday;
 using Robust.Shared.Configuration;
 using Robust.Shared.Prototypes;
 
@@ -12,6 +13,7 @@ namespace Content.Server.Holiday
         [Dependency] private readonly IConfigurationManager _configManager = default!;
         [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
         [Dependency] private readonly IChatManager _chatManager = default!;
+        [Dependency] private readonly SharedAppearanceSystem _appearance = default!;
 
         [ViewVariables]
         private readonly List<HolidayPrototype> _currentHolidays = new();
@@ -24,6 +26,7 @@ namespace Content.Server.Holiday
             _configManager.OnValueChanged(CCVars.HolidaysEnabled, OnHolidaysEnableChange, true);
 
             SubscribeLocalEvent<GameRunLevelChangedEvent>(OnRunLevelChanged);
+            SubscribeLocalEvent<HolidayVisualsComponent, ComponentInit>(OnVisualsInit);
         }
 
         public void RefreshCurrentHolidays()
@@ -102,6 +105,17 @@ namespace Content.Server.Holiday
                     break;
             }
         }
+
+        private void OnVisualsInit(Entity<HolidayVisualsComponent> ent, ref ComponentInit args)
+        {
+            foreach (var (key, holidays) in ent.Comp.Holidays)
+            {
+                if (!holidays.Any(h => IsCurrentlyHoliday(h)))
+                    continue;
+                _appearance.SetData(ent, HolidayVisuals.Holiday, key);
+                break;
+            }
+        }
     }
 
     /// <summary>

Content.Server/Holiday/HolidayVisualsComponent.cs

@@ -0,0 +1,17 @@
+using Robust.Shared.Prototypes;
+
+namespace Content.Server.Holiday;
+
+/// <summary>
+/// This is used for an entity that enables unique visuals on specified holidays.
+/// </summary>
+[RegisterComponent]
+public sealed partial class HolidayVisualsComponent : Component
+{
+    /// <summary>
+    /// A dictionary relating a generic key to a list of holidays.
+    /// If any of the holidays are being celebrated, that key will be set for holiday visuals.
+    /// </summary>
+    [DataField]
+    public Dictionary<string, List<ProtoId<HolidayPrototype>>> Holidays = new();
+}