Layering for atmospheric pipes (#36124)

Co-authored-by: ArtisticRoomba <145879011+ArtisticRoomba@users.noreply.github.com>
Co-authored-by: Kevin Zheng <kevinz5000@gmail.com>

Content.Client/Atmos/EntitySystems/AtmosPipeLayersSystem.cs

@@ -0,0 +1,56 @@
+using Content.Shared.Atmos.Components;
+using Content.Shared.Atmos.EntitySystems;
+using Robust.Client.GameObjects;
+using Robust.Client.ResourceManagement;
+using Robust.Shared.Reflection;
+using Robust.Shared.Serialization.TypeSerializers.Implementations;
+using Robust.Shared.Utility;
+using System.Diagnostics.CodeAnalysis;
+
+namespace Content.Client.Atmos.EntitySystems;
+
+/// <summary>
+/// The system responsible for updating the appearance of layered gas pipe
+/// </summary>
+public sealed partial class AtmosPipeLayersSystem : SharedAtmosPipeLayersSystem
+{
+    [Dependency] private readonly SharedAppearanceSystem _appearance = default!;
+    [Dependency] private readonly IReflectionManager _reflection = default!;
+    [Dependency] private readonly IResourceCache _resourceCache = default!;
+    [Dependency] private readonly SpriteSystem _sprite = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+
+        SubscribeLocalEvent<AtmosPipeLayersComponent, AppearanceChangeEvent>(OnAppearanceChange);
+    }
+
+    private void OnAppearanceChange(Entity<AtmosPipeLayersComponent> ent, ref AppearanceChangeEvent ev)
+    {
+        if (!TryComp<SpriteComponent>(ent, out var sprite))
+            return;
+
+        if (_appearance.TryGetData<string>(ent, AtmosPipeLayerVisuals.Sprite, out var spriteRsi) &&
+            _resourceCache.TryGetResource(SpriteSpecifierSerializer.TextureRoot / spriteRsi, out RSIResource? resource))
+        {
+            _sprite.SetBaseRsi((ent, sprite), resource.RSI);
+        }
+
+        if (_appearance.TryGetData<Dictionary<string, string>>(ent, AtmosPipeLayerVisuals.SpriteLayers, out var pipeState))
+        {
+            foreach (var (layerKey, rsiPath) in pipeState)
+            {
+                if (TryParseKey(layerKey, out var @enum))
+                    _sprite.LayerSetRsi((ent, sprite), @enum, new ResPath(rsiPath));
+                else
+                    _sprite.LayerSetRsi((ent, sprite), layerKey, new ResPath(rsiPath));
+            }
+        }
+    }
+
+    private bool TryParseKey(string keyString, [NotNullWhen(true)] out Enum? @enum)
+    {
+        return _reflection.TryParseEnumReference(keyString, out @enum);
+    }
+}