CatStation/Content.Shared/Research/TechnologyDisk/Systems/TechnologyDiskSystem.cs

using Content.Shared.Examine;
using Content.Shared.Interaction;
using Content.Shared.Lathe;
using Content.Shared.Popups;
using Content.Shared.Random.Helpers;
using Content.Shared.Research.Components;
using Content.Shared.Research.Prototypes;
using Content.Shared.Research.Systems;
using Content.Shared.Research.TechnologyDisk.Components;
using Robust.Shared.Network;
using Robust.Shared.Prototypes;
using Robust.Shared.Random;

namespace Content.Shared.Research.TechnologyDisk.Systems;

public sealed class TechnologyDiskSystem : EntitySystem
{
    [Dependency] private readonly IPrototypeManager _protoMan = default!;
    [Dependency] private readonly IRobustRandom _random = default!;
    [Dependency] private readonly SharedPopupSystem _popup = default!;
    [Dependency] private readonly SharedResearchSystem _research = default!;
    [Dependency] private readonly SharedLatheSystem _lathe = default!;

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

        SubscribeLocalEvent<TechnologyDiskComponent, MapInitEvent>(OnMapInit);
        SubscribeLocalEvent<TechnologyDiskComponent, AfterInteractEvent>(OnAfterInteract);
        SubscribeLocalEvent<TechnologyDiskComponent, ExaminedEvent>(OnExamine);
    }

    private void OnMapInit(Entity<TechnologyDiskComponent> ent, ref MapInitEvent args)
    {
        if (ent.Comp.Recipes != null)
            return;

        var weightedRandom = _protoMan.Index(ent.Comp.TierWeightPrototype);
        var tier = int.Parse(weightedRandom.Pick(_random));

        //get a list of every distinct recipe in all the technologies.
        var techs = new HashSet<ProtoId<LatheRecipePrototype>>();
        foreach (var tech in _protoMan.EnumeratePrototypes<TechnologyPrototype>())
        {
            if (tech.Tier != tier)
                continue;

            techs.UnionWith(tech.RecipeUnlocks);
        }

        if (techs.Count == 0)
            return;

        //pick one
        ent.Comp.Recipes = [];
        ent.Comp.Recipes.Add(_random.Pick(techs));
        Dirty(ent);
    }

    private void OnAfterInteract(Entity<TechnologyDiskComponent> ent, ref AfterInteractEvent args)
    {
        if (args.Handled || !args.CanReach || args.Target is not { } target)
            return;

        if (!HasComp<ResearchServerComponent>(target) || !TryComp<TechnologyDatabaseComponent>(target, out var database))
            return;

        if (ent.Comp.Recipes != null)
        {
            foreach (var recipe in ent.Comp.Recipes)
            {
                _research.AddLatheRecipe(target, recipe, database);
            }
        }
        _popup.PopupClient(Loc.GetString("tech-disk-inserted"), target, args.User);
        PredictedQueueDel(ent.Owner);
        args.Handled = true;
    }

    private void OnExamine(Entity<TechnologyDiskComponent> ent, ref ExaminedEvent args)
    {
        var message = Loc.GetString("tech-disk-examine-none");
        if (ent.Comp.Recipes != null && ent.Comp.Recipes.Count > 0)
        {
            var prototype = _protoMan.Index(ent.Comp.Recipes[0]);
            message = Loc.GetString("tech-disk-examine", ("result", _lathe.GetRecipeName(prototype)));

            if (ent.Comp.Recipes.Count > 1) //idk how to do this well. sue me.
                message += " " + Loc.GetString("tech-disk-examine-more");
        }
        args.PushMarkup(message);
    }
}