crystall-punk-14/Content.Server/Damage/Systems/StaminaSystem.cs

using Content.Server.Damage.Components;
using Content.Server.Damage.Events;
using Content.Server.Popups;
using Content.Server.Administration.Logs;
using Content.Server.CombatMode;
using Content.Server.Weapons.Melee.Events;
using Content.Shared.Alert;
using Content.Shared.Rounding;
using Content.Shared.Stunnable;
using Content.Shared.Database;
using Content.Shared.IdentityManagement;
using Content.Shared.Popups;
using Robust.Shared.Collections;
using Robust.Shared.Physics.Dynamics;
using Robust.Shared.Player;
using Robust.Shared.Timing;
using Robust.Shared.Audio;
using Robust.Shared.Random;
using Robust.Shared.Physics.Events;


namespace Content.Server.Damage.Systems;

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

    private const float UpdateCooldown = 2f;
    private float _accumulator;

    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 const float StamCritBufferTime = 3f;

    private readonly List<EntityUid> _dirtyEntities = new();

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

    private void OnShutdown(EntityUid uid, StaminaComponent component, ComponentShutdown args)
    {
        SetStaminaAlert(uid);
    }

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

    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);

        // 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), PopupType.LargeCaution);
        _popup.PopupCursor(Loc.GetString("stunned-component-disarm-success", ("target", targetEnt)), Filter.Entities(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 (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 ValueList<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);
            if (comp.StaminaDamage.Equals(oldDamage))
            {
                _popup.PopupEntity(Loc.GetString("stamina-resist"), comp.Owner, Filter.Entities(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);
    }

    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)
    {
        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)
        {
            component.StaminaDecayAccumulator = component.DecayCooldown;
        }

        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);

        // Can't do it here as resetting prediction gets cooked.
        _dirtyEntities.Add(uid);

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

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

        if (!_timing.IsFirstTimePredicted) return;

        _accumulator -= frameTime;

        if (_accumulator > 0f) return;

        var stamQuery = GetEntityQuery<StaminaComponent>();

        foreach (var uid in _dirtyEntities)
        {
            // Don't need to RemComp as they will get handled below.
            if (!stamQuery.TryGetComponent(uid, out var comp) || comp.StaminaDamage <= 0f) continue;
            EnsureComp<ActiveStaminaComponent>(uid);
        }

        _dirtyEntities.Clear();
        _accumulator += UpdateCooldown;

        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)
            {
                RemComp<ActiveStaminaComponent>(active.Owner);
                continue;
            }

            comp.StaminaDecayAccumulator -= UpdateCooldown;

            if (comp.StaminaDecayAccumulator > 0f) continue;

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

            comp.StaminaDecayAccumulator = 0f;
            TakeStaminaDamage(comp.Owner, -comp.Decay * UpdateCooldown, 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;
        component.StaminaDecayAccumulator = 0f;

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

        // Give them buffer before being able to be re-stunned
        component.StaminaDecayAccumulator = (float) stunTime.TotalSeconds + StamCritBufferTime;
    }

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

        component.Critical = false;
        component.StaminaDamage = 0f;
        SetStaminaAlert(uid, component);
    }
}