Re-organize all projects (#4166)

Content.Shared/Chemistry/ChemistrySystem.cs

@@ -0,0 +1,73 @@
+#nullable enable
+using System;
+using System.Linq;
+using Content.Shared.Chemistry.Reaction;
+using Content.Shared.Chemistry.Reagent;
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Prototypes;
+
+namespace Content.Shared.Chemistry
+{
+    /// <summary>
+    /// This interface gives components behavior on whether entities solution (implying SolutionComponent is in place) is changed
+    /// </summary>
+    public interface ISolutionChange
+    {
+        /// <summary>
+        /// Called when solution is mixed with some other solution, or when some part of the solution is removed
+        /// </summary>
+        void SolutionChanged(SolutionChangeEventArgs eventArgs);
+    }
+
+    public class SolutionChangeEventArgs : EventArgs
+    {
+        public IEntity Owner { get; set; } = default!;
+    }
+
+    [UsedImplicitly]
+    public class ChemistrySystem : EntitySystem
+    {
+        [Dependency] private readonly IPrototypeManager _prototypeManager = default!;
+
+        public void HandleSolutionChange(IEntity owner)
+        {
+            var eventArgs = new SolutionChangeEventArgs
+            {
+                Owner = owner,
+            };
+            var solutionChangeArgs = owner.GetAllComponents<ISolutionChange>().ToList();
+
+            foreach (var solutionChangeArg in solutionChangeArgs)
+            {
+                solutionChangeArg.SolutionChanged(eventArgs);
+
+                if (owner.Deleted)
+                    return;
+            }
+        }
+
+        public void ReactionEntity(IEntity? entity, ReactionMethod method, string reagentId, ReagentUnit reactVolume, Solution.Solution? source)
+        {
+            // We throw if the reagent specified doesn't exist.
+            ReactionEntity(entity, method, _prototypeManager.Index<ReagentPrototype>(reagentId), reactVolume, source);
+        }
+
+        public void ReactionEntity(IEntity? entity, ReactionMethod method, ReagentPrototype reagent, ReagentUnit reactVolume, Solution.Solution? source)
+        {
+            if (entity == null || entity.Deleted || !entity.TryGetComponent(out ReactiveComponent? reactive))
+                return;
+
+            foreach (var reaction in reactive.Reactions)
+            {
+                // If we have a source solution, use the reagent quantity we have left. Otherwise, use the reaction volume specified.
+                reaction.React(method, entity, reagent, source?.GetReagentQuantity(reagent.ID) ?? reactVolume, source);
+
+                // Make sure we still have enough reagent to go...
+                if (source != null && !source.ContainsReagent(reagent.ID))
+                    break;
+            }
+        }
+    }
+}