tbd-station-14/Content.Shared/Damage/Systems/StaminaSystem.cs

using Content.Shared.Administration.Logs;
using Content.Shared.Alert;
using Content.Shared.CombatMode;
using Content.Shared.Damage.Components;
using Content.Shared.Damage.Events;
using Content.Shared.Database;
using Content.Shared.IdentityManagement;
using Content.Shared.Interaction;
using Content.Shared.Popups;
using Content.Shared.Rounding;
using Content.Shared.Stunnable;
using Content.Shared.Weapons.Melee.Events;
using JetBrains.Annotations;
using Robust.Shared.GameStates;
using Robust.Shared.Physics.Events;
using Robust.Shared.Player;
using Robust.Shared.Random;
using Robust.Shared.Serialization;
using Robust.Shared.Timing;

namespace Content.Shared.Damage.Systems;

public sealed class StaminaSystem : EntitySystem
{
    [Dependency] private readonly IGameTiming _timing = default!;
    [Dependency] private readonly AlertsSystem _alerts = default!;
    [Dependency] private readonly MetaDataSystem _metadata = default!;
    [Dependency] private readonly SharedPopupSystem _popup = default!;
    [Dependency] private readonly SharedStunSystem _stunSystem = default!;
    [Dependency] private readonly IRobustRandom _random = default!;
    [Dependency] private readonly ISharedAdminLogManager _adminLogger = default!;

    private const string CollideFixture = "projectile";

    /// <summary>
    /// How much of a buffer is there between the stun duration and when stuns can be re-applied.
    /// </summary>
    private static readonly TimeSpan StamCritBufferTime = TimeSpan.FromSeconds(3f);

    public override void Initialize()
    {
        base.Initialize();
        SubscribeLocalEvent<StaminaComponent, ComponentStartup>(OnStartup);
        SubscribeLocalEvent<StaminaComponent, ComponentShutdown>(OnShutdown);
        SubscribeLocalEvent<StaminaComponent, ComponentGetState>(OnStamGetState);
        SubscribeLocalEvent<StaminaComponent, ComponentHandleState>(OnStamHandleState);
        SubscribeLocalEvent<StaminaComponent, DisarmedEvent>(OnDisarmed);
        SubscribeLocalEvent<StaminaDamageOnCollideComponent, StartCollideEvent>(OnCollide);
        SubscribeLocalEvent<StaminaDamageOnHitComponent, MeleeHitEvent>(OnHit);
    }

    private void OnStamGetState(EntityUid uid, StaminaComponent component, ref ComponentGetState args)
    {
        args.State = new StaminaComponentState()
        {
            Critical = component.Critical,
            Decay = component.Decay,
            CritThreshold = component.CritThreshold,
            DecayCooldown = component.DecayCooldown,
            LastUpdate = component.NextUpdate,
            StaminaDamage = component.StaminaDamage,
        };
    }

    private void OnStamHandleState(EntityUid uid, StaminaComponent component, ref ComponentHandleState args)
    {
        if (args.Current is not StaminaComponentState state)
            return;

        component.Critical = state.Critical;
        component.Decay = state.Decay;
        component.CritThreshold = state.CritThreshold;
        component.DecayCooldown = state.DecayCooldown;
        component.NextUpdate = state.LastUpdate;
        component.StaminaDamage = state.StaminaDamage;

        if (component.Critical)
            EnterStamCrit(uid, component);
        else
        {
            if (component.StaminaDamage > 0f)
                EnsureComp<ActiveStaminaComponent>(uid);

            ExitStamCrit(uid, component);
        }
    }

    private void OnShutdown(EntityUid uid, StaminaComponent component, ComponentShutdown args)
    {
        if (MetaData(uid).EntityLifeStage < EntityLifeStage.Terminating)
        {
            RemCompDeferred<ActiveStaminaComponent>(uid);
        }

        SetStaminaAlert(uid);
    }

    private void OnStartup(EntityUid uid, StaminaComponent component, ComponentStartup args)
    {
        SetStaminaAlert(uid, component);
    }

    [PublicAPI]
    public float GetStaminaDamage(EntityUid uid, StaminaComponent? component = null)
    {
        if (!Resolve(uid, ref component))
            return 0f;

        var curTime = _timing.CurTime;
        var pauseTime = _metadata.GetPauseTime(uid);
        return MathF.Max(0f, component.StaminaDamage - MathF.Max(0f, (float) (curTime - (component.NextUpdate + pauseTime)).TotalSeconds * component.Decay));
    }

    private void OnDisarmed(EntityUid uid, StaminaComponent component, DisarmedEvent args)
    {
        if (args.Handled || !_random.Prob(args.PushProbability))
            return;

        if (component.Critical)
            return;

        var damage = args.PushProbability * component.CritThreshold;
        TakeStaminaDamage(uid, damage, component, source:args.Source);

        // We need a better method of getting if the entity is going to resist stam damage, both this and the lines in the foreach at the end of OnHit() are awful
        if (!component.Critical)
            return;

        var targetEnt = Identity.Entity(args.Target, EntityManager);
        var sourceEnt = Identity.Entity(args.Source, EntityManager);

        _popup.PopupEntity(Loc.GetString("stunned-component-disarm-success-others", ("source", sourceEnt), ("target", targetEnt)), targetEnt, Filter.PvsExcept(args.Source), true, PopupType.LargeCaution);
        _popup.PopupCursor(Loc.GetString("stunned-component-disarm-success", ("target", targetEnt)), args.Source, PopupType.Large);

        _adminLogger.Add(LogType.DisarmedKnockdown, LogImpact.Medium, $"{ToPrettyString(args.Source):user} knocked down {ToPrettyString(args.Target):target}");

        args.Handled = true;
    }

    private void OnHit(EntityUid uid, StaminaDamageOnHitComponent component, MeleeHitEvent args)
    {
        if (!args.IsHit)
            return;

        if (component.Damage <= 0f) return;

        var ev = new StaminaDamageOnHitAttemptEvent();
        RaiseLocalEvent(uid, ref ev);

        if (ev.Cancelled) return;

        args.HitSoundOverride = ev.HitSoundOverride;
        var stamQuery = GetEntityQuery<StaminaComponent>();
        var toHit = new List<StaminaComponent>();

        // Split stamina damage between all eligible targets.
        foreach (var ent in args.HitEntities)
        {
            if (!stamQuery.TryGetComponent(ent, out var stam)) continue;
            toHit.Add(stam);
        }

        var hitEvent = new StaminaMeleeHitEvent(toHit);
        RaiseLocalEvent(uid, hitEvent, false);

        if (hitEvent.Handled)
            return;

        var damage = component.Damage;

        damage *= hitEvent.Multiplier;

        damage += hitEvent.FlatModifier;

        foreach (var comp in toHit)
        {
            var oldDamage = comp.StaminaDamage;
            TakeStaminaDamage(comp.Owner, damage / toHit.Count, comp, source:args.User, with:component.Owner);
            if (comp.StaminaDamage.Equals(oldDamage))
            {
                _popup.PopupEntity(Loc.GetString("stamina-resist"), comp.Owner, args.User);
            }
        }
    }

    private void OnCollide(EntityUid uid, StaminaDamageOnCollideComponent component, ref StartCollideEvent args)
    {
        if (!args.OurFixture.ID.Equals(CollideFixture)) return;

        TakeStaminaDamage(args.OtherFixture.Body.Owner, component.Damage, source:args.OurFixture.Body.Owner);
    }

    private void SetStaminaAlert(EntityUid uid, StaminaComponent? component = null)
    {
        if (!Resolve(uid, ref component, false) || component.Deleted)
        {
            _alerts.ClearAlert(uid, AlertType.Stamina);
            return;
        }

        var severity = ContentHelpers.RoundToLevels(MathF.Max(0f, component.CritThreshold - component.StaminaDamage), component.CritThreshold, 7);
        _alerts.ShowAlert(uid, AlertType.Stamina, (short) severity);
    }

    public void TakeStaminaDamage(EntityUid uid, float value, StaminaComponent? component = null, EntityUid? source = null, EntityUid? with = null)
    {
        if (!Resolve(uid, ref component, false) || component.Critical)
            return;

        var oldDamage = component.StaminaDamage;
        component.StaminaDamage = MathF.Max(0f, component.StaminaDamage + value);

        // Reset the decay cooldown upon taking damage.
        if (oldDamage < component.StaminaDamage)
        {
            var nextUpdate = _timing.CurTime + TimeSpan.FromSeconds(component.DecayCooldown);

            if (component.NextUpdate < nextUpdate)
                component.NextUpdate = nextUpdate;
        }

        var slowdownThreshold = component.CritThreshold / 2f;

        // If we go above n% then apply slowdown
        if (oldDamage < slowdownThreshold &&
            component.StaminaDamage > slowdownThreshold)
        {
            _stunSystem.TrySlowdown(uid, TimeSpan.FromSeconds(3), true, 0.8f, 0.8f);
        }

        SetStaminaAlert(uid, component);

        if (!component.Critical)
        {
            if (component.StaminaDamage >= component.CritThreshold)
            {
                EnterStamCrit(uid, component);
            }
        }
        else
        {
            if (component.StaminaDamage < component.CritThreshold)
            {
                ExitStamCrit(uid, component);
            }
        }

        EnsureComp<ActiveStaminaComponent>(uid);
        Dirty(component);

        if (value <= 0)
            return;
        if (source != null)
        {
            _adminLogger.Add(LogType.Stamina, $"{ToPrettyString(source.Value):user} caused {value} stamina damage to {ToPrettyString(uid):target}{(with != null ? $" using {ToPrettyString(with.Value):using}" : "")}");
        }
        else
        {
            _adminLogger.Add(LogType.Stamina, $"{ToPrettyString(uid):target} took {value} stamina damage");
        }
    }

    public override void Update(float frameTime)
    {
        base.Update(frameTime);

        if (!_timing.IsFirstTimePredicted) return;

        var metaQuery = GetEntityQuery<MetaDataComponent>();
        var stamQuery = GetEntityQuery<StaminaComponent>();
        var curTime = _timing.CurTime;

        foreach (var active in EntityQuery<ActiveStaminaComponent>())
        {
            // Just in case we have active but not stamina we'll check and account for it.
            if (!stamQuery.TryGetComponent(active.Owner, out var comp) ||
                comp.StaminaDamage <= 0f && !comp.Critical)
            {
                RemComp<ActiveStaminaComponent>(active.Owner);
                continue;
            }

            // Shouldn't need to consider paused time as we're only iterating non-paused stamina components.
            var nextUpdate = comp.NextUpdate;

            if (nextUpdate > curTime)
                continue;

            // We were in crit so come out of it and continue.
            if (comp.Critical)
            {
                ExitStamCrit(active.Owner, comp);
                continue;
            }

            comp.NextUpdate += TimeSpan.FromSeconds(1f);
            TakeStaminaDamage(comp.Owner, -comp.Decay, comp);
            Dirty(comp);
        }
    }

    private void EnterStamCrit(EntityUid uid, StaminaComponent? component = null)
    {
        if (!Resolve(uid, ref component) ||
            component.Critical) return;

        // To make the difference between a stun and a stamcrit clear
        // TODO: Mask?

        component.Critical = true;
        component.StaminaDamage = component.CritThreshold;

        var stunTime = TimeSpan.FromSeconds(6);
        _stunSystem.TryParalyze(uid, stunTime, true);

        // Give them buffer before being able to be re-stunned
        component.NextUpdate = _timing.CurTime + stunTime + StamCritBufferTime;
        EnsureComp<ActiveStaminaComponent>(uid);
        Dirty(component);
        _adminLogger.Add(LogType.Stamina, LogImpact.Medium, $"{ToPrettyString(uid):user} entered stamina crit");
    }

    private void ExitStamCrit(EntityUid uid, StaminaComponent? component = null)
    {
        if (!Resolve(uid, ref component) ||
            !component.Critical) return;

        component.Critical = false;
        component.StaminaDamage = 0f;
        component.NextUpdate = _timing.CurTime;
        SetStaminaAlert(uid, component);
        RemComp<ActiveStaminaComponent>(uid);
        Dirty(component);
        _adminLogger.Add(LogType.Stamina, LogImpact.Low, $"{ToPrettyString(uid):user} recovered from stamina crit");
    }

    [Serializable, NetSerializable]
    private sealed class StaminaComponentState : ComponentState
    {
        public bool Critical;
        public float Decay;
        public float DecayCooldown;
        public float StaminaDamage;
        public float CritThreshold;
        public TimeSpan LastUpdate;
    }
}