Cargo: pizza & bureaucracy (#5123)

* add paper label component

* git mv

* rename namespace

* add cargo printouts

* more crates

* directly attach paper

* comment typo

Content.Server/Labels/Label/LabelSystem.cs

@@ -0,0 +1,97 @@
+using Content.Server.Labels.Components;
+using Content.Server.Paper;
+using Content.Shared.Containers.ItemSlots;
+using Content.Shared.Examine;
+using Content.Shared.Labels;
+using JetBrains.Annotations;
+using Robust.Shared.GameObjects;
+using Robust.Shared.IoC;
+using Robust.Shared.Localization;
+using Robust.Shared.Utility;
+using System;
+
+namespace Content.Server.Labels
+{
+    /// <summary>
+    /// A system that lets players see the contents of a label on an object.
+    /// </summary>
+    [UsedImplicitly]
+    public class LabelSystem : EntitySystem
+    {
+        [Dependency] private readonly SharedItemSlotsSystem _itemSlotsSystem = default!;
+
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            SubscribeLocalEvent<LabelComponent, ExaminedEvent>(OnExamine);
+            SubscribeLocalEvent<PaperLabelComponent, ComponentInit>(InitializePaperLabel);
+            SubscribeLocalEvent<PaperLabelComponent, ItemSlotChangedEvent>(OnItemSlotChanged);
+            SubscribeLocalEvent<PaperLabelComponent, ExaminedEvent>(OnExamined);
+        }
+
+        private void InitializePaperLabel(EntityUid uid, PaperLabelComponent component, ComponentInit args)
+        {
+            if (!EntityManager.TryGetComponent(uid, out SharedAppearanceComponent appearance))
+                return;
+
+            appearance.SetData(PaperLabelVisuals.HasLabel, false);
+        }
+
+        private void OnExamine(EntityUid uid, LabelComponent? label, ExaminedEvent args)
+        {
+            if (!Resolve(uid, ref label))
+                return;
+
+            if (label.CurrentLabel == null)
+                return;
+
+            var message = new FormattedMessage();
+            message.AddText(Loc.GetString("hand-labeler-has-label", ("label", label.CurrentLabel)));
+            args.PushMessage(message);
+        }
+
+        private void OnExamined(EntityUid uid, PaperLabelComponent comp, ExaminedEvent args)
+        {
+            if (!EntityManager.TryGetComponent(uid, out SharedItemSlotsComponent slots))
+                return;
+
+            var label = _itemSlotsSystem.PeekItemInSlot(slots, comp.LabelSlot);
+
+            if (label == null)
+                return;
+
+            if (!args.IsInDetailsRange)
+            {
+                args.PushMarkup(Loc.GetString("comp-paper-label-has-label-cant-read"));
+                return;
+            }
+
+            if (!EntityManager.TryGetComponent(label.Uid, out PaperComponent paper))
+                // should never happen
+                return;
+
+            if (string.IsNullOrWhiteSpace(paper.Content))
+            {
+                args.PushMarkup(Loc.GetString("comp-paper-label-has-label-blank"));
+                return;
+            }
+
+            args.PushMarkup(Loc.GetString("comp-paper-label-has-label"));
+            var text = paper.Content;
+            args.PushMarkup(text.TrimEnd());
+        }
+
+
+        private void OnItemSlotChanged(EntityUid uid, PaperLabelComponent component, ItemSlotChangedEvent args)
+        {
+            if (args.SlotName != component.LabelSlot)
+                return;
+
+            if (!EntityManager.TryGetComponent(uid, out SharedAppearanceComponent appearance))
+                return;
+
+            appearance.SetData(PaperLabelVisuals.HasLabel, args.ContainedItem != null);
+        }
+    }
+}