tbd-station-14/Content.Server/Labels/Label/LabelSystem.cs

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.Containers;
using Robust.Shared.GameObjects;
using Robust.Shared.IoC;
using Robust.Shared.Localization;
using Robust.Shared.Utility;
using Robust.Shared.Utility.Markup;

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 ItemSlotsSystem _itemSlotsSystem = default!;

        public override void Initialize()
        {
            base.Initialize();

            SubscribeLocalEvent<LabelComponent, ExaminedEvent>(OnExamine);
            SubscribeLocalEvent<PaperLabelComponent, ComponentInit>(OnComponentInit);
            SubscribeLocalEvent<PaperLabelComponent, ComponentRemove>(OnComponentRemove);
            SubscribeLocalEvent<PaperLabelComponent, EntInsertedIntoContainerMessage>(OnContainerModified);
            SubscribeLocalEvent<PaperLabelComponent, EntRemovedFromContainerMessage>(OnContainerModified);
            SubscribeLocalEvent<PaperLabelComponent, ExaminedEvent>(OnExamined);
        }

        private void OnComponentInit(EntityUid uid, PaperLabelComponent component, ComponentInit args)
        {
            _itemSlotsSystem.AddItemSlot(uid, component.Name, component.LabelSlot);

            if (!EntityManager.TryGetComponent(uid, out AppearanceComponent appearance))
                return;

            appearance.SetData(PaperLabelVisuals.HasLabel, false);
        }

        private void OnComponentRemove(EntityUid uid, PaperLabelComponent component, ComponentRemove args)
        {
            _itemSlotsSystem.RemoveItemSlot(uid, component.LabelSlot);
        }

        private void OnExamine(EntityUid uid, LabelComponent? label, ExaminedEvent args)
        {
            if (!Resolve(uid, ref label))
                return;

            if (label.CurrentLabel == null)
                return;

            args.Message.AddText(Loc.GetString("hand-labeler-has-label", ("label", label.CurrentLabel)));
        }

        private void OnExamined(EntityUid uid, PaperLabelComponent comp, ExaminedEvent args)
        {
            if (comp.LabelSlot.Item is not {Valid: true} item)
                return;

            if (!args.IsInDetailsRange)
            {
                args.PushMarkup(Loc.GetString("comp-paper-label-has-label-cant-read"));
                return;
            }

            if (!EntityManager.TryGetComponent(item, out PaperComponent paper))
                // Assuming yaml has the correct entity whitelist, this should not 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 OnContainerModified(EntityUid uid, PaperLabelComponent label, ContainerModifiedMessage args)
        {
            if (args.Container.ID != label.LabelSlot.ID)
                return;

            if (!EntityManager.TryGetComponent(uid, out AppearanceComponent appearance))
                return;

            appearance.SetData(PaperLabelVisuals.HasLabel, label.LabelSlot.HasItem);
        }
    }
}