ECS chemical ammo shooting (#5620)

Content.Server/Weapon/Ranged/ChemicalAmmoSystem.cs

@@ -0,0 +1,52 @@
+using System.Collections.Generic;
+using System.Linq;
+using Content.Server.Chemistry.EntitySystems;
+using Content.Server.Weapon.Ranged.Ammunition.Components;
+using Content.Server.Weapon.Ranged.Barrels.Components;
+using Content.Shared.Chemistry.Components;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+
+namespace Content.Server.Weapon.Ranged
+{
+    public sealed class ChemicalAmmoSystem : EntitySystem
+    {
+        [Dependency] private SolutionContainerSystem _solutionSystem = default!;
+
+        public override void Initialize()
+        {
+            SubscribeLocalEvent<ChemicalAmmoComponent, AmmoShotEvent>(OnFire);
+        }
+
+        private void OnFire(EntityUid uid, ChemicalAmmoComponent component, AmmoShotEvent args)
+        {
+            if (!_solutionSystem.TryGetSolution(uid, component.SolutionName, out var ammoSolution))
+                return;
+
+            var projectiles = args.FiredProjectiles;
+
+            var projectileSolutionContainers = new List<(EntityUid, Solution)>();
+            foreach (var projectile in projectiles)
+            {
+                if (_solutionSystem
+                    .TryGetSolution(projectile, component.SolutionName, out var projectileSolutionContainer))
+                {
+                    projectileSolutionContainers.Add((uid, projectileSolutionContainer));
+                }
+            }
+
+            if (!projectileSolutionContainers.Any())
+                return;
+
+            var solutionPerProjectile = ammoSolution.CurrentVolume * (1 / projectileSolutionContainers.Count);
+
+            foreach (var (projectileUid, projectileSolution) in projectileSolutionContainers)
+            {
+                var solutionToTransfer = _solutionSystem.SplitSolution(uid, ammoSolution, solutionPerProjectile);
+                _solutionSystem.TryAddSolution(projectileUid, projectileSolution, solutionToTransfer);
+            }
+
+            _solutionSystem.RemoveAllSolution(uid, ammoSolution);
+        }
+    }
+}