Ice anomaly (#15925)

Co-authored-by: Nemanja <98561806+EmoGarbage404@users.noreply.github.com>

Content.Server/Anomaly/Effects/GasProducerAnomalySystem.cs

@@ -0,0 +1,75 @@
+using Content.Server.Atmos.EntitySystems;
+using Content.Server.Anomaly.Components;
+using Content.Shared.Anomaly.Components;
+using Content.Shared.Atmos;
+using Robust.Server.GameObjects;
+
+namespace Content.Server.Anomaly.Effects;
+
+/// <summary>
+/// This handles <see cref="GasProducerAnomalyComponent"/> and the events from <seealso cref="AnomalySystem"/>
+/// </summary>
+public sealed class GasProducerAnomalySystem : EntitySystem
+{
+    [Dependency] private readonly AtmosphereSystem _atmosphere = default!;
+    [Dependency] private readonly TransformSystem _xform = default!;
+
+    public override void Initialize()
+    {
+        base.Initialize();
+        SubscribeLocalEvent<GasProducerAnomalyComponent, AnomalySupercriticalEvent>(OnSupercritical);
+    }
+
+    private void OnSupercritical(EntityUid uid, GasProducerAnomalyComponent component, ref AnomalySupercriticalEvent args)
+    {
+        if (!component.ReleaseOnMaxSeverity)
+            return;
+
+        ReleaseGas(uid, component.ReleasedGas, component.SuperCriticalMoleAmount);
+    }
+
+    public override void Update(float frameTime)
+    {
+        base.Update(frameTime);
+
+        var query = EntityQueryEnumerator<GasProducerAnomalyComponent>();
+        while (query.MoveNext(out var ent, out var comp))
+        {
+            if (!comp.ReleasePassively)
+                continue;
+
+            // Yes this is unused code since there are no anomalies that
+            // release gas passively *yet*, but since I'm here I figured
+            // I'd save someone some time and just add it for the future
+            ReleaseGas(ent, comp.ReleasedGas, comp.PassiveMoleAmount * frameTime);
+        }
+    }
+
+    private void ReleaseGas(EntityUid uid, Gas gas, float amount)
+    {
+        var xform = Transform(uid);
+        var grid = xform.GridUid;
+        var map = xform.MapUid;
+
+        var indices = _xform.GetGridOrMapTilePosition(uid, xform);
+        var mixture = _atmosphere.GetTileMixture(grid, map, indices, true);
+
+        if (mixture == null)
+            return;
+
+        mixture.AdjustMoles(gas, amount);
+
+        if (grid is { })
+        {
+            foreach (var ind in _atmosphere.GetAdjacentTiles(grid.Value, indices))
+            {
+                var mix = _atmosphere.GetTileMixture(grid, map, ind, true);
+
+                if (mix is not { })
+                    continue;
+
+                mix.AdjustMoles(gas, amount);
+            }
+        }
+    }
+}