Solution spiking (#8984)

Content.Server/Chemistry/EntitySystems/SolutionSpikableSystem.cs

@@ -0,0 +1,94 @@
+using Content.Server.Chemistry.Components;
+using Content.Server.Chemistry.Components.SolutionManager;
+using Content.Server.Explosion.EntitySystems;
+using Content.Server.Popups;
+using Content.Shared.Chemistry.Components;
+using Content.Shared.FixedPoint;
+using Content.Shared.Interaction;
+using Robust.Shared.Player;
+
+namespace Content.Server.Chemistry.EntitySystems;
+
+/// <summary>
+///     Entity system used to handle when solution containers are 'spiked'
+///     with another entity. Triggers the source entity afterwards.
+///     Uses refillable solution as the target solution, as that indicates
+///     'easy' refills.
+///
+///     Examples of spikable entity interactions include pills being dropped into glasses,
+///     eggs being cracked into bowls, and so on.
+/// </summary>
+public sealed class SolutionSpikableSystem : EntitySystem
+{
+    [Dependency] private readonly SolutionContainerSystem _solutionSystem = default!;
+    [Dependency] private readonly TriggerSystem _triggerSystem = default!;
+    [Dependency] private readonly PopupSystem _popupSystem = default!;
+
+    public override void Initialize()
+    {
+        SubscribeLocalEvent<RefillableSolutionComponent, InteractUsingEvent>(OnInteractUsing);
+    }
+
+    private void OnInteractUsing(EntityUid uid, RefillableSolutionComponent target, InteractUsingEvent args)
+    {
+        TrySpike(args.Used, args.Target, args.User, target);
+    }
+
+    /// <summary>
+    ///     Immediately transfer all reagents from this entity, to the other entity.
+    ///     The source entity will then be acted on by TriggerSystem.
+    /// </summary>
+    /// <param name="source">Source of the solution.</param>
+    /// <param name="target">Target to spike with the solution from source.</param>
+    /// <param name="user">User spiking the target solution.</param>
+    private void TrySpike(EntityUid source, EntityUid target, EntityUid user, RefillableSolutionComponent? spikableTarget = null,
+        SolutionSpikerComponent? spikableSource = null,
+        SolutionContainerManagerComponent? managerSource = null,
+        SolutionContainerManagerComponent? managerTarget = null)
+    {
+        if (!Resolve(source, ref spikableSource, ref managerSource, false)
+            || !Resolve(target, ref spikableTarget, ref managerTarget, false)
+            || !_solutionSystem.TryGetRefillableSolution(target, out var targetSolution, managerTarget, spikableTarget)
+            || !managerSource.Solutions.TryGetValue(spikableSource.SourceSolution, out var sourceSolution))
+        {
+            return;
+        }
+
+        if (targetSolution.CurrentVolume == 0 && !spikableSource.IgnoreEmpty)
+        {
+            _popupSystem.PopupEntity(Loc.GetString(spikableSource.PopupEmpty, ("spiked-entity", target), ("spike-entity", source)), user, Filter.Entities(user));
+            return;
+        }
+
+        if (_solutionSystem.TryMixAndOverflow(target,
+                targetSolution,
+                sourceSolution,
+                targetSolution.MaxVolume,
+                out var overflow))
+        {
+            if (overflow.TotalVolume > 0)
+            {
+                RaiseLocalEvent(target, new SolutionSpikeOverflowEvent(overflow));
+            }
+
+            _popupSystem.PopupEntity(Loc.GetString(spikableSource.Popup, ("spiked-entity", target), ("spike-entity", source)), user, Filter.Entities(user));
+
+            sourceSolution.RemoveAllSolution();
+
+            _triggerSystem.Trigger(source);
+        }
+    }
+}
+
+public sealed class SolutionSpikeOverflowEvent : HandledEntityEventArgs
+{
+    /// <summary>
+    ///     The solution that's been overflowed from the spike.
+    /// </summary>
+    public Solution Overflow { get; }
+
+    public SolutionSpikeOverflowEvent(Solution overflow)
+    {
+        Overflow = overflow;
+    }
+}