CatStation/Content.Shared/Forensics/Systems/ForensicsSystem.cs

using Content.Shared.Body.Systems;
using Content.Shared.Chemistry.Components;
using Content.Shared.Chemistry.EntitySystems;
using Content.Shared.Chemistry.Reagent;
using Content.Shared.DoAfter;
using Content.Shared.Fluids;
using Content.Shared.Forensics.Components;
using Content.Shared.Hands.Components;
using Content.Shared.Interaction;
using Content.Shared.Interaction.Events;
using Content.Shared.Inventory;
using Content.Shared.Gibbing;
using Content.Shared.IdentityManagement;
using Content.Shared.Nutrition.EntitySystems;
using Content.Shared.Popups;
using Content.Shared.Verbs;
using Content.Shared.Weapons.Melee.Events;
using Robust.Shared.Random;
using Robust.Shared.Utility;

namespace Content.Shared.Forensics.Systems;

/// <summary>
/// A system for storing forensics data on entities, and transferring them between entities when interacting.
/// </summary>
public sealed partial class ForensicsSystem : EntitySystem
{
    [Dependency] private IRobustRandom _random = default!;
    [Dependency] private InventorySystem _inventory = default!;
    [Dependency] private SharedDoAfterSystem _doAfterSystem = default!;
    [Dependency] private SharedPopupSystem _popupSystem = default!;
    [Dependency] private SharedSolutionContainerSystem _solutionContainerSystem = default!;

    [Dependency] private EntityQuery<DnaComponent> _dnaQuery = default!;
    [Dependency] private EntityQuery<FiberComponent> _fiberQuery = default!;
    [Dependency] private EntityQuery<FingerprintComponent> _fingerprintQuery = default!;
    [Dependency] private EntityQuery<ForensicsComponent> _forensicsQuery = default!;
    [Dependency] private EntityQuery<IgnoresFingerprintsComponent> _ignoresFingerprintsQuery = default!;
    [Dependency] private EntityQuery<InventoryComponent> _inventoryQuery = default!;
    [Dependency] private EntityQuery<ResidueComponent> _residueQuery = default!;

    [SubscribeLocalEvent]
    private void OnSolutionChanged(Entity<DnaSubstanceTraceComponent> ent, ref SolutionChangedEvent ev)
    {
        var soln = GetSolutionsDNA(ev.Solution);

        if (soln.Count <= 0)
            return;

        var comp = EnsureComp<ForensicsComponent>(ent.Owner);
        foreach (var dna in soln)
        {
            comp.DNAs.Add(dna);
        }
        Dirty(ent);
    }

    [SubscribeLocalEvent]
    private void OnInteract(Entity<HandsComponent> ent, ref ContactInteractionEvent args)
    {
        ApplyEvidence(ent.Owner, args.Other);
    }

    [SubscribeLocalEvent(after: [typeof(BloodstreamSystem)])]
    private void OnFingerprintInit(Entity<FingerprintComponent> ent, ref MapInitEvent args)
    {
        if (ent.Comp.Fingerprint == null)
            RandomizeFingerprint((ent.Owner, ent.Comp));
    }

    [SubscribeLocalEvent(after: [typeof(BloodstreamSystem)])]
    private void OnDNAInit(Entity<DnaComponent> ent, ref MapInitEvent args)
    {
        if (ent.Comp.DNA == null)
            RandomizeDNA(ent.AsNullable());
        else
        {
            // If set manually (for example by cloning) we also need to inform the bloodstream of the correct DNA string so it can be updated
            var ev = new GenerateDnaEvent { Owner = ent.Owner, DNA = ent.Comp.DNA };
            RaiseLocalEvent(ent.Owner, ref ev);
            Dirty(ent);
        }
    }

    [SubscribeLocalEvent]
    private void OnBeingGibbed(Entity<ForensicsComponent> ent, ref GibbedBeforeDeletionEvent args)
    {
        var dna = Loc.GetString("forensics-dna-unknown");

        if (_dnaQuery.TryComp(ent, out var dnaComp) && dnaComp.DNA != null)
            dna = dnaComp.DNA;

        foreach (var part in args.Giblets)
        {
            var partComp = EnsureComp<ForensicsComponent>(part);
            partComp.DNAs.Add(dna);
            partComp.CanDnaBeCleaned = false;
            Dirty(part, partComp);
        }
    }

    [SubscribeLocalEvent]
    private void OnMeleeHit(Entity<ForensicsComponent> weapon, ref MeleeHitEvent args)
    {
        if ((!args.BaseDamage.DamageDict.TryGetValue("Blunt", out var bluntDamage) || bluntDamage.Value <= 0) &&
            (!args.BaseDamage.DamageDict.TryGetValue("Slash", out var slashDamage) || slashDamage.Value <= 0) &&
            (!args.BaseDamage.DamageDict.TryGetValue("Piercing", out var pierceDamage) || pierceDamage.Value <= 0))
            return;

        foreach (var hitEntity in args.HitEntities)
        {
            if (_dnaQuery.TryComp(hitEntity, out var hitEntityComp) && hitEntityComp.DNA != null)
                weapon.Comp.DNAs.Add(hitEntityComp.DNA);
        }
        Dirty(weapon);
    }

    [SubscribeLocalEvent]
    private void OnRehydrated(Entity<ForensicsComponent> ent, ref GotRehydratedEvent args)
    {
        CopyForensicsFrom(ent.Owner, args.Target);
    }

    /// <summary>
    /// Copy forensic information from a source entity to a destination.
    /// Existing forensic information on the target is still kept.
    /// </summary>
    public void CopyForensicsFrom(Entity<ForensicsComponent?> src, EntityUid target)
    {
        if (!Resolve(src, ref src.Comp, false))
            return;

        var targetComp = EnsureComp<ForensicsComponent>(target);
        foreach (var dna in src.Comp.DNAs)
        {
            targetComp.DNAs.Add(dna);
        }

        foreach (var fiber in src.Comp.Fibers)
        {
            targetComp.Fibers.Add(fiber);
        }

        foreach (var print in src.Comp.Fingerprints)
        {
            targetComp.Fingerprints.Add(print);
        }

        foreach (var residue in src.Comp.Residues)
        {
            targetComp.Residues.Add(residue);
        }

        Dirty(target, targetComp);
    }

    public List<string> GetSolutionsDNA(EntityUid uid)
    {
        List<string> list = new();
        foreach (var (_, soln) in _solutionContainerSystem.EnumerateSolutions(uid))
        {
            list.AddRange(GetSolutionsDNA(soln.Comp.Solution));
        }
        return list;
    }

    public List<string> GetSolutionsDNA(Solution soln)
    {
        List<string> list = [];
        foreach (var reagent in soln.Contents)
        {
            foreach (var data in reagent.Reagent.EnsureReagentData())
            {
                if (data is DnaData dnaData)
                    list.Add(dnaData.DNA);
            }
        }
        return list;
    }

    // IngestionSystem is for stopping the player from feeding soap when trying to clean someone.
    [SubscribeLocalEvent(before: [typeof(IngestionSystem)], after: [typeof(SharedAbsorbentSystem)])]
    private void OnAfterInteract(Entity<CleansForensicsComponent> cleanForensicsEntity, ref AfterInteractEvent args)
    {
        if (args.Handled || !args.CanReach || args.Target == null)
            return;

        args.Handled = TryStartCleaning(cleanForensicsEntity, args.User, args.Target.Value);
    }

    [SubscribeLocalEvent]
    private void OnUtilityVerb(Entity<CleansForensicsComponent> entity, ref GetVerbsEvent<UtilityVerb> args)
    {
        if (!args.CanInteract || !args.CanAccess)
            return;

        // These need to be set outside for the anonymous method!
        var user = args.User;
        var target = args.Target;

        var verb = new UtilityVerb
        {
            Act = () => TryStartCleaning(entity, user, target),
            Icon = new SpriteSpecifier.Texture(new ResPath("/Textures/Interface/VerbIcons/bubbles.svg.192dpi.png")),
            Text = Loc.GetString("forensics-verb-text"),
            Message = Loc.GetString("forensics-verb-message"),
            // This is important because if its true using the cleaning device will count as touching the object.
            DoContactInteraction = false,
        };

        args.Verbs.Add(verb);
    }

    /// <summary>
    ///     Attempts to clean the given item with the given CleansForensics entity.
    /// </summary>
    /// <param name="cleanForensicsEntity">The entity that is being used to clean the target.</param>
    /// <param name="user">The user that is using the cleanForensicsEntity.</param>
    /// <param name="target">The target of the forensics clean.</param>
    /// <returns>True if the target can be cleaned and has some sort of DNA or fingerprints / fibers and false otherwise.</returns>
    public bool TryStartCleaning(Entity<CleansForensicsComponent> cleanForensicsEntity, EntityUid user, EntityUid target)
    {
        if (!_forensicsQuery.TryComp(target, out var forensicsComp))
        {
            _popupSystem.PopupEntity(Loc.GetString("forensics-cleaning-cannot-clean", ("target", Identity.Entity(target, EntityManager))), user, user, PopupType.MediumCaution);
            return false;
        }

        var totalPrintsAndFibers = forensicsComp.Fingerprints.Count + forensicsComp.Fibers.Count;
        var hasRemovableDNA = forensicsComp.DNAs.Count > 0 && forensicsComp.CanDnaBeCleaned;

        if (hasRemovableDNA || totalPrintsAndFibers > 0)
        {
            var cleanDelay = cleanForensicsEntity.Comp.CleanDelay;
            var doAfterArgs = new DoAfterArgs(EntityManager, user, cleanDelay, new CleanForensicsDoAfterEvent(), cleanForensicsEntity, target: target, used: cleanForensicsEntity)
            {
                NeedHand = true,
                BreakOnDamage = true,
                BreakOnMove = true,
                MovementThreshold = 0.01f,
                DistanceThreshold = forensicsComp.CleanDistance,
            };

            _doAfterSystem.TryStartDoAfter(doAfterArgs);

            var userPopupText = Loc.GetString("forensics-cleaning-user", ("target", Identity.Entity(target, EntityManager)));
            var othersPopupText = Loc.GetString("forensics-cleaning-others", ("user", Identity.Entity(user, EntityManager)), ("target", Identity.Entity(target, EntityManager)));
            _popupSystem.PopupEntity(userPopupText, othersPopupText, user, user);

            return true;
        }

        _popupSystem.PopupEntity(Loc.GetString("forensics-cleaning-cannot-clean", ("target", Identity.Entity(target, EntityManager))), user, user, PopupType.MediumCaution);
        return false;
    }

    [SubscribeLocalEvent]
    private void OnCleanForensicsDoAfter(Entity<ForensicsComponent> component, ref CleanForensicsDoAfterEvent args)
    {
        if (args.Handled || args.Cancelled || args.Args.Target == null)
            return;

        if (!_forensicsQuery.TryComp(args.Target, out var targetComp))
            return;

        targetComp.Fibers = [];
        targetComp.Fingerprints = [];

        if (targetComp.CanDnaBeCleaned)
            targetComp.DNAs = [];

        // leave behind evidence it was cleaned
        if (_fiberQuery.TryComp(args.Used, out var fiber))
            targetComp.Fibers.Add(string.IsNullOrEmpty(fiber.FiberColor) ? Loc.GetString("forensic-fibers", ("material", fiber.FiberMaterial)) : Loc.GetString("forensic-fibers-colored", ("color", fiber.FiberColor), ("material", fiber.FiberMaterial)));

        if (_residueQuery.TryComp(args.Used, out var residue))
            targetComp.Residues.Add(string.IsNullOrEmpty(residue.ResidueColor) ? Loc.GetString("forensic-residue", ("adjective", residue.ResidueAdjective)) : Loc.GetString("forensic-residue-colored", ("color", residue.ResidueColor), ("adjective", residue.ResidueAdjective)));

        Dirty(args.Target.Value, targetComp);
    }

    public string GenerateFingerprint()
    {
        var fingerprint = new byte[16];
        _random.NextBytes(fingerprint);
        return Convert.ToHexString(fingerprint);
    }

    public string GenerateDNA()
    {
        var letters = new[] { "A", "C", "G", "T" };
        var dna = string.Empty;

        for (var i = 0; i < 16; i++)
        {
            dna += letters[_random.Next(letters.Length)];
        }

        return dna;
    }

    private void ApplyEvidence(EntityUid user, EntityUid target)
    {
        if (_ignoresFingerprintsQuery.HasComp(target))
            return;

        var component = EnsureComp<ForensicsComponent>(target);
        if (_inventory.TryGetSlotEntity(user, "gloves", out var gloves))
        {
            if (_fiberQuery.TryComp(gloves, out var fiber) && !string.IsNullOrEmpty(fiber.FiberMaterial))
                component.Fibers.Add(string.IsNullOrEmpty(fiber.FiberColor) ? Loc.GetString("forensic-fibers", ("material", fiber.FiberMaterial)) : Loc.GetString("forensic-fibers-colored", ("color", fiber.FiberColor), ("material", fiber.FiberMaterial)));
        }

        if (_fingerprintQuery.TryComp(user, out var fingerprint) && CanAccessFingerprint(user, out _))
            component.Fingerprints.Add(fingerprint.Fingerprint ?? "");

        Dirty(target, component);
    }

    #region PublicAPI

    public void RandomizeDNA(Entity<DnaComponent?> ent)
    {
        if (!Resolve(ent, ref ent.Comp, false))
            return;

        ent.Comp.DNA = GenerateDNA();

        var ev = new GenerateDnaEvent { Owner = ent.Owner, DNA = ent.Comp.DNA };
        RaiseLocalEvent(ent.Owner, ref ev);
        Dirty(ent);
    }

    public void RandomizeFingerprint(Entity<FingerprintComponent?> ent)
    {
        if (!Resolve(ent, ref ent.Comp, false))
            return;

        ent.Comp.Fingerprint = GenerateFingerprint();
        Dirty(ent);
    }

    /// <summary>
    /// Transfer DNA from one entity onto the forensics of another
    /// </summary>
    /// <param name="recipient">The entity receiving the DNA</param>
    /// <param name="donor">The entity applying its DNA</param>
    /// <param name="canDnaBeCleaned">If this DNA be cleaned off of the recipient. e.g. cleaning a knife vs cleaning a puddle of blood</param>
    public void TransferDna(EntityUid recipient, EntityUid donor, bool canDnaBeCleaned = true)
    {
        if (!_dnaQuery.TryComp(donor, out var donorComp) || donorComp.DNA == null)
            return;

        EnsureComp<ForensicsComponent>(recipient, out var recipientComp);
        recipientComp.DNAs.Add(donorComp.DNA);
        recipientComp.CanDnaBeCleaned = canDnaBeCleaned;

        Dirty(recipient, recipientComp);
    }

    /// <summary>
    /// Checks if there's a way to access the fingerprint of the target entity.
    /// </summary>
    /// <param name="target">The entity with the fingerprint</param>
    /// <param name="blocker">The entity that blocked accessing the fingerprint</param>
    public bool CanAccessFingerprint(EntityUid target, out EntityUid? blocker)
    {
        var ev = new TryAccessFingerprintEvent();

        RaiseLocalEvent(target, ev);
        if (!ev.Cancelled && _inventoryQuery.TryComp(target, out var inv))
            _inventory.RelayEvent((target, inv), ev);

        blocker = ev.Blocker;
        return !ev.Cancelled;
    }
    #endregion
}