Gunify pneumatic cannon (#13296)

Content.Shared/Weapons/Ranged/Systems/SharedGunSystem.Container.cs

@@ -0,0 +1,51 @@
+using System.Linq;
+using Content.Shared.Weapons.Ranged.Components;
+using Content.Shared.Weapons.Ranged.Events;
+using Robust.Shared.Containers;
+using Robust.Shared.Network;
+
+namespace Content.Shared.Weapons.Ranged.Systems;
+
+public partial class SharedGunSystem
+{
+    [Dependency] private readonly INetManager _netMan = default!;
+    [Dependency] private readonly SharedContainerSystem _container = default!;
+
+    public void InitializeContainer()
+    {
+        SubscribeLocalEvent<ContainerAmmoProviderComponent, TakeAmmoEvent>(OnContainerTakeAmmo);
+        SubscribeLocalEvent<ContainerAmmoProviderComponent, GetAmmoCountEvent>(OnContainerAmmoCount);
+    }
+
+    private void OnContainerTakeAmmo(EntityUid uid, ContainerAmmoProviderComponent component, TakeAmmoEvent args)
+    {
+        if (!_container.TryGetContainer(uid, component.Container, out var container))
+            return;
+
+        for (int i = 0; i < args.Shots; i++)
+        {
+            if (!container.ContainedEntities.Any())
+                break;
+
+            var ent = container.ContainedEntities[0];
+
+            if (_netMan.IsServer)
+                container.Remove(ent);
+
+            args.Ammo.Add(EnsureComp<AmmoComponent>(ent));
+        }
+    }
+
+    private void OnContainerAmmoCount(EntityUid uid, ContainerAmmoProviderComponent component, ref GetAmmoCountEvent args)
+    {
+        if (!_container.TryGetContainer(uid, component.Container, out var container))
+        {
+            args.Capacity = 0;
+            args.Count = 0;
+            return;
+        }
+
+        args.Capacity = int.MaxValue;
+        args.Count = container.ContainedEntities.Count;
+    }
+}