MoverController.cs

using Content.Shared.Alert;
using Content.Shared.CCVar;
using Content.Shared.Movement.Components;
using Content.Shared.Movement.Pulling.Components;
using Content.Shared.Movement.Systems;
using Robust.Client.GameObjects;
using Robust.Client.Physics;
using Robust.Client.Player;
using Robust.Shared.Configuration;
using Robust.Shared.Physics.Components;
using Robust.Shared.Player;
using Robust.Shared.Timing;

namespace Content.Client.Physics.Controllers;

public sealed class MoverController : SharedMoverController
{
    [Dependency] private readonly IGameTiming _timing = default!;
    [Dependency] private readonly IPlayerManager _playerManager = default!;
    [Dependency] private readonly AlertsSystem _alerts = default!;
    [Dependency] private readonly IConfigurationManager _cfg = default!;

    public override void Initialize()
    {
        base.Initialize();
        SubscribeLocalEvent<RelayInputMoverComponent, LocalPlayerAttachedEvent>(OnRelayPlayerAttached);
        SubscribeLocalEvent<RelayInputMoverComponent, LocalPlayerDetachedEvent>(OnRelayPlayerDetached);
        SubscribeLocalEvent<InputMoverComponent, LocalPlayerAttachedEvent>(OnPlayerAttached);
        SubscribeLocalEvent<InputMoverComponent, LocalPlayerDetachedEvent>(OnPlayerDetached);

        SubscribeLocalEvent<InputMoverComponent, UpdateIsPredictedEvent>(OnUpdatePredicted);
        SubscribeLocalEvent<MovementRelayTargetComponent, UpdateIsPredictedEvent>(OnUpdateRelayTargetPredicted);
        SubscribeLocalEvent<PullableComponent, UpdateIsPredictedEvent>(OnUpdatePullablePredicted);
    }

    private void OnUpdatePredicted(Entity<InputMoverComponent> entity, ref UpdateIsPredictedEvent args)
    {
        // Enable prediction if an entity is controlled by the player
        if (entity.Owner == _playerManager.LocalEntity)
            args.IsPredicted = true;
    }

    private void OnUpdateRelayTargetPredicted(Entity<MovementRelayTargetComponent> entity, ref UpdateIsPredictedEvent args)
    {
        if (entity.Comp.Source == _playerManager.LocalEntity)
            args.IsPredicted = true;
    }

    private void OnUpdatePullablePredicted(Entity<PullableComponent> entity, ref UpdateIsPredictedEvent args)
    {
        // Enable prediction if an entity is being pulled by the player.
        // Disable prediction if an entity is being pulled by some non-player entity.

        if (entity.Comp.Puller == _playerManager.LocalEntity)
            args.IsPredicted = true;
        else if (entity.Comp.Puller != null)
            args.BlockPrediction = true;

        // TODO recursive pulling checks?
        // What if the entity is being pulled by a vehicle controlled by the player?
    }

    private void OnRelayPlayerAttached(Entity<RelayInputMoverComponent> entity, ref LocalPlayerAttachedEvent args)
    {
        Physics.UpdateIsPredicted(entity.Owner);
        Physics.UpdateIsPredicted(entity.Comp.RelayEntity);
        if (MoverQuery.TryGetComponent(entity.Comp.RelayEntity, out var inputMover))
            SetMoveInput((entity.Comp.RelayEntity, inputMover), MoveButtons.None);
    }

    private void OnRelayPlayerDetached(Entity<RelayInputMoverComponent> entity, ref LocalPlayerDetachedEvent args)
    {
        Physics.UpdateIsPredicted(entity.Owner);
        Physics.UpdateIsPredicted(entity.Comp.RelayEntity);
        if (MoverQuery.TryGetComponent(entity.Comp.RelayEntity, out var inputMover))
            SetMoveInput((entity.Comp.RelayEntity, inputMover), MoveButtons.None);
    }

    private void OnPlayerAttached(Entity<InputMoverComponent> entity, ref LocalPlayerAttachedEvent args)
    {
        SetMoveInput(entity, MoveButtons.None);
    }

    private void OnPlayerDetached(Entity<InputMoverComponent> entity, ref LocalPlayerDetachedEvent args)
    {
        SetMoveInput(entity, MoveButtons.None);
    }

    public override void UpdateBeforeSolve(bool prediction, float frameTime)
    {
        base.UpdateBeforeSolve(prediction, frameTime);

        if (_playerManager.LocalEntity is not {Valid: true} player)
            return;

        if (RelayQuery.TryGetComponent(player, out var relayMover))
            HandleClientsideMovement(relayMover.RelayEntity, frameTime);

        HandleClientsideMovement(player, frameTime);
    }

    private void HandleClientsideMovement(EntityUid player, float frameTime)
    {
        if (!MoverQuery.TryGetComponent(player, out var mover) ||
            !XformQuery.TryGetComponent(player, out var xform))
        {
            return;
        }

        var physicsUid = player;
        PhysicsComponent? body;
        var xformMover = xform;

        if (mover.ToParent && RelayQuery.HasComponent(xform.ParentUid))
        {
            if (!PhysicsQuery.TryGetComponent(xform.ParentUid, out body) ||
                !XformQuery.TryGetComponent(xform.ParentUid, out xformMover))
            {
                return;
            }

            physicsUid = xform.ParentUid;
        }
        else if (!PhysicsQuery.TryGetComponent(player, out body))
        {
            return;
        }

        // Server-side should just be handled on its own so we'll just do this shizznit
        HandleMobMovement(
            player,
            mover,
            physicsUid,
            body,
            xformMover,
            frameTime);
    }

    protected override bool CanSound()
    {
        return _timing is { IsFirstTimePredicted: true, InSimulation: true };
    }

    public override void SetSprinting(Entity<InputMoverComponent> entity, ushort subTick, bool walking)
    {
        // Logger.Info($"[{_gameTiming.CurTick}/{subTick}] Sprint: {enabled}");
        base.SetSprinting(entity, subTick, walking);

        if (walking && _cfg.GetCVar(CCVars.ToggleWalk))
            _alerts.ShowAlert(entity, WalkingAlert, showCooldown: false, autoRemove: false);
        else
            _alerts.ClearAlert(entity, WalkingAlert);
    }
}