using AcDream.Core.Net;
using AcDream.Core.Net.Messages;
using AcDream.Core.Physics;
using AcDream.Runtime.Physics;

namespace AcDream.Runtime.Entities;

/// <summary>
/// The single update-thread authority for live server GUIDs, incarnations,
/// accepted wire snapshots, teardown tombstones, and runtime-local identity.
/// It owns no graphical state and can run without loading App or a backend.
/// </summary>
public sealed class RuntimeEntityDirectory
{
    public const uint FirstLocalEntityId = 1_000_000u;
    public const uint LastLocalEntityId = 0x3FFF_FFFFu;

    private readonly InboundPhysicsStateController _inbound = new();
    private readonly Dictionary<uint, RuntimeEntityRecord> _activeByGuid = new();
    private readonly Dictionary<(uint Guid, ushort Incarnation), RuntimeEntityRecord>
        _teardownByIncarnation = new();
    private readonly Dictionary<uint, RuntimeEntityRecord> _byLocalId = new();
    private readonly Dictionary<uint, ulong> _lifetimeMutationByGuid = new();
    private uint _nextLocalEntityId;

    public RuntimeEntityDirectory(uint firstLocalEntityId = FirstLocalEntityId)
    {
        if (firstLocalEntityId is < FirstLocalEntityId or > LastLocalEntityId)
        {
            throw new ArgumentOutOfRangeException(
                nameof(firstLocalEntityId),
                $"Live entity ids must stay in 0x{FirstLocalEntityId:X8}..0x{LastLocalEntityId:X8}.");
        }

        _nextLocalEntityId = firstLocalEntityId;
    }

    public int Count => _activeByGuid.Count;
    public int PendingTeardownCount => _teardownByIncarnation.Count;
    public int ClaimedLocalIdCount => _byLocalId.Count;
    public ulong SessionLifetimeVersion { get; private set; }
    public IReadOnlyCollection<RuntimeEntityRecord> ActiveRecords => _activeByGuid.Values;
    public IReadOnlyCollection<RuntimeEntityRecord> TeardownRecords =>
        _teardownByIncarnation.Values;
    public IReadOnlyDictionary<uint, WorldSession.EntitySpawn> Snapshots => _inbound.Snapshots;
    public ParentAttachmentState ParentAttachments { get; } = new();

    public InboundCreateResult AcceptCreate(WorldSession.EntitySpawn incoming) =>
        _inbound.AcceptCreate(incoming);

    internal InboundCreateResult AcceptCreateDeferredSameGeneration(
        WorldSession.EntitySpawn incoming) =>
        _inbound.AcceptCreateDeferredSameGeneration(incoming);

    public CreateObjectTimestampDisposition PreviewCreateDisposition(
        WorldSession.EntitySpawn incoming) =>
        _inbound.PreviewCreateDisposition(incoming);

    public bool TryDelete(
        AcDream.Core.Net.Messages.DeleteObject.Parsed delete,
        bool isLocalPlayer) =>
        _inbound.TryDelete(delete, isLocalPlayer);

    public bool TryGetSnapshot(uint guid, out WorldSession.EntitySpawn spawn) =>
        _inbound.TryGetSnapshot(guid, out spawn);

    internal bool TryGetAcceptedTimestamps(
        uint guid,
        out AcceptedPhysicsTimestamps timestamps) =>
        _inbound.TryGetAcceptedTimestamps(guid, out timestamps);

    public bool TryGetActive(uint guid, out RuntimeEntityRecord record) =>
        _activeByGuid.TryGetValue(guid, out record!);

    public bool IsCurrent(RuntimeEntityRecord record) =>
        _activeByGuid.TryGetValue(record.ServerGuid, out RuntimeEntityRecord? current)
        && ReferenceEquals(current, record);

    public bool TryGetByLocalId(uint localEntityId, out RuntimeEntityRecord record) =>
        _byLocalId.TryGetValue(localEntityId, out record!);

    public bool TryGetTeardown(
        uint guid,
        ushort incarnation,
        out RuntimeEntityRecord record) =>
        _teardownByIncarnation.TryGetValue((guid, incarnation), out record!);

    public RuntimeEntityRecord AddActive(WorldSession.EntitySpawn snapshot)
    {
        if (_activeByGuid.ContainsKey(snapshot.Guid))
        {
            throw new InvalidOperationException(
                $"Live entity 0x{snapshot.Guid:X8} already has an active incarnation.");
        }

        var record = new RuntimeEntityRecord(snapshot);
        _activeByGuid.Add(snapshot.Guid, record);
        try
        {
            ClaimLocalId(record);
            return record;
        }
        catch
        {
            _activeByGuid.Remove(snapshot.Guid);
            throw;
        }
    }

    public bool RemoveActive(uint guid, out RuntimeEntityRecord? record) =>
        _activeByGuid.Remove(guid, out record);

    public bool RemoveActive(RuntimeEntityRecord expected)
    {
        if (!IsCurrent(expected))
            return false;
        return _activeByGuid.Remove(expected.ServerGuid);
    }

    public void RetainTeardown(RuntimeEntityRecord record)
    {
        var key = (record.ServerGuid, record.Incarnation);
        if (_teardownByIncarnation.TryGetValue(
                key,
                out RuntimeEntityRecord? retained)
            && !ReferenceEquals(retained, record))
        {
            throw new InvalidOperationException(
                $"Live entity teardown tombstone collision for 0x{record.ServerGuid:X8} generation {record.Incarnation}.");
        }

        _teardownByIncarnation[key] = record;
    }

    public void ReleaseTeardown(RuntimeEntityRecord record)
    {
        var key = (record.ServerGuid, record.Incarnation);
        if (_teardownByIncarnation.TryGetValue(
                key,
                out RuntimeEntityRecord? retained)
            && ReferenceEquals(retained, record))
        {
            _teardownByIncarnation.Remove(key);
        }
    }

    public bool HasPendingTeardown(uint serverGuid)
    {
        foreach ((uint Guid, ushort Incarnation) key in _teardownByIncarnation.Keys)
        {
            if (key.Guid == serverGuid)
                return true;
        }

        return false;
    }

    public uint ClaimLocalId(RuntimeEntityRecord record)
    {
        if (!IsKnown(record))
        {
            throw new InvalidOperationException(
                "A local id can only be claimed for an active or retained incarnation.");
        }

        if (record.LocalEntityId is { } existing)
            return existing;

        uint start = _nextLocalEntityId;
        do
        {
            uint candidate = _nextLocalEntityId;
            _nextLocalEntityId = candidate == LastLocalEntityId
                ? FirstLocalEntityId
                : candidate + 1u;
            if (_byLocalId.ContainsKey(candidate))
                continue;

            _byLocalId.Add(candidate, record);
            record.LocalEntityId = candidate;
            return candidate;
        }
        while (_nextLocalEntityId != start);

        throw new InvalidOperationException("The live entity id namespace is exhausted.");
    }

    public bool ReleaseLocalId(RuntimeEntityRecord record)
    {
        if (record.LocalEntityId is not { } localId)
            return false;
        if (_byLocalId.TryGetValue(localId, out RuntimeEntityRecord? retained)
            && ReferenceEquals(retained, record))
        {
            _byLocalId.Remove(localId);
        }

        record.LocalEntityId = null;
        return true;
    }

    public ulong AdvanceLifetimeMutation(uint serverGuid)
    {
        ulong next = _lifetimeMutationByGuid.GetValueOrDefault(serverGuid) + 1UL;
        _lifetimeMutationByGuid[serverGuid] = next;
        return next;
    }

    public ulong CurrentLifetimeMutation(uint serverGuid) =>
        _lifetimeMutationByGuid.GetValueOrDefault(serverGuid);

    public void BeginSessionClear()
    {
        SessionLifetimeVersion++;
        _lifetimeMutationByGuid.Clear();
        ParentAttachments.Clear();
        _inbound.Clear();
    }

    public bool CompleteSessionClearIfConverged()
    {
        if (_activeByGuid.Count != 0 || _teardownByIncarnation.Count != 0)
            return false;

        _byLocalId.Clear();
        ParentAttachments.Clear();
        _inbound.Clear();
        return true;
    }

    public void RefreshSnapshot(
        RuntimeEntityRecord record,
        WorldSession.EntitySpawn accepted,
        bool refreshPosition = false)
    {
        EnsureKnown(record);
        uint previousCell = record.FullCellId;
        record.Snapshot = accepted;
        record.RefreshDerivedState(refreshPosition);
        if (record.FullCellId != previousCell)
        {
            PropagateFullCellToChildren(
                record,
                record.FullCellId,
                record.CanonicalLandblockId);
        }
    }

    public void AdvanceCreateAuthority(RuntimeEntityRecord record)
    {
        EnsureKnown(record);
        record.AdvanceCreateAuthority();
    }

    public void AdvancePositionAuthority(RuntimeEntityRecord record)
    {
        EnsureKnown(record);
        record.AdvancePositionAuthority();
    }

    public void AdvanceVectorAuthority(RuntimeEntityRecord record)
    {
        EnsureKnown(record);
        record.AdvanceVectorAuthority();
    }

    public void AdvanceMovementAuthority(RuntimeEntityRecord record)
    {
        EnsureKnown(record);
        record.AdvanceMovementAuthority();
    }

    public void AdvanceMovementCommit(RuntimeEntityRecord record)
    {
        EnsureKnown(record);
        record.AdvanceMovementCommit();
    }

    public void AdvancePlacementCommit(RuntimeEntityRecord record)
    {
        EnsureKnown(record);
        record.AdvancePlacementCommit();
    }

    public void AdvanceParentCommit(RuntimeEntityRecord record)
    {
        EnsureKnown(record);
        record.AdvanceParentCommit();
    }

    public void AdvanceObjDescAuthority(RuntimeEntityRecord record)
    {
        EnsureKnown(record);
        record.AdvanceObjDescAuthority();
    }

    public RetailPhysicsStateTransition ApplyRawPhysicsState(
        RuntimeEntityRecord record,
        uint rawState)
    {
        EnsureKnown(record);
        return record.ApplyRawPhysicsState(rawState);
    }

    public bool TryDequeueStateTransition(
        RuntimeEntityRecord record,
        out RetailPhysicsStateTransition transition)
    {
        EnsureKnown(record);
        return record.TryDequeueStateTransition(out transition);
    }

    public void SetChildNoDraw(RuntimeEntityRecord record, bool noDraw)
    {
        EnsureKnown(record);
        record.SetChildNoDraw(noDraw);
    }

    public void SuspendObjectClock(RuntimeEntityRecord record)
    {
        EnsureKnown(record);
        record.SuspendObjectClock();
    }

    /// <summary>
    /// Re-activates a clock suspended by <see cref="SuspendObjectClock"/>, for
    /// rolling back a withdrawal that is being cancelled rather than
    /// completed. NOT an exact inverse — the retained sub-quantum time is
    /// discarded, which is retail's <c>set_active(1)</c> rebase semantic; see
    /// <see cref="RuntimeEntityRecord.ResumeObjectClock"/>. Distinct from
    /// <see cref="ResetObjectClockForEnterWorld"/>, which is the
    /// entering-the-world edge and additionally rebases the static/dynamic
    /// quantum shape; a rollback re-activates a clock that never conceptually
    /// left.
    /// </summary>
    public void ResumeObjectClock(RuntimeEntityRecord record)
    {
        EnsureKnown(record);
        record.ResumeObjectClock();
    }

    public void ResetObjectClockForEnterWorld(RuntimeEntityRecord record, bool isStatic)
    {
        EnsureKnown(record);
        record.ResetObjectClockForEnterWorld(isStatic);
    }

    public void SetFullCell(
        RuntimeEntityRecord record,
        uint fullCellId,
        uint canonicalLandblockId)
    {
        EnsureKnown(record);
        record.SetFullCell(fullCellId, canonicalLandblockId);
        PropagateFullCellToChildren(record, fullCellId, canonicalLandblockId);
    }

    /// <summary>
    /// Reused across every <see cref="PropagateFullCellToChildren"/> call.
    /// Always empty on entry and on exit (the loop drains it unconditionally
    /// before returning) — see that method's remarks for why sharing it is
    /// safe rather than a repeat of the round-3 A6/B4 scratch-buffer
    /// reentrancy lesson: this stack never escapes the method, and nothing
    /// on the write path can trigger a nested call while it holds state.
    /// </summary>
    private readonly Stack<RuntimeEntityRecord> _propagationWorklist = new();

    /// <summary>
    /// C4 route 7 D2 — the sole propagation hook. Retail's parent-cell-
    /// crossing propagation (<c>CPhysicsObj::SetPositionInternal</c>
    /// @0x00515330's changed-cell branch @0x00515372 -&gt; <c>change_cell</c>
    /// @0x00513390 -&gt; the self-recursive <c>enter_cell</c>/<c>leave_cell</c>
    /// @0x00510ed0/@0x00510f50) has exactly one acdream analogue: every
    /// canonical cell write already funnels through this method or
    /// <see cref="RefreshSnapshot"/>'s derived-state write (see
    /// docs/research/2026-08-04-retail-parent-cell-propagation.md and the
    /// route-7 contract's D2).
    ///
    /// <para>
    /// ITERATIVE, not recursive (round-3 remediation — both the retail and
    /// architecture reviews independently converged on the same finding,
    /// N4/B3: a depth-capped RECURSIVE version left a subtree beyond the cap
    /// at a STALE NONZERO cell permanently — on the withdraw path that is
    /// the #184 shape verbatim, the exact defect AP-142 clause (a) exists to
    /// reject, shipped fresh inside the slice whose headline is fixing it.
    /// A reused <see cref="_propagationWorklist"/> stack removes the depth
    /// concept entirely rather than mitigating it: there is no C# call-stack
    /// growth to bound, so the only limit is the number of committed
    /// relations actually in the system (which cannot exceed the live
    /// entity count) — matching retail's own genuinely unbounded recursion
    /// exactly, with no acdream-only cap and no register row for one. This
    /// also retires B5 in the sense that there is no longer a RECURSIVE call
    /// to reason about — but the bypass itself is NOT retired: the loop
    /// below still calls a child's own <c>SetFullCell</c> directly rather
    /// than the public <see cref="SetFullCell"/>, and that bypass is
    /// DELIBERATE and LOAD-BEARING, not incidental. The public
    /// <see cref="SetFullCell"/> calls this method, and this method opens
    /// with <c>_propagationWorklist.Clear()</c> — routing a child through
    /// the public method would re-enter this method mid-drain, clear the
    /// shared worklist out from under the OUTER loop, and silently drop
    /// every sibling still waiting on the stack, with no error and no
    /// exception. Any side effect added to the public
    /// <see cref="SetFullCell"/> in the future MUST be mirrored by hand at
    /// this call site, because this call site cannot route through it.
    /// </para>
    ///
    /// <para>
    /// Skipping a child whose <see cref="RuntimeEntityRecord.FullCellId"/>
    /// (and <see cref="RuntimeEntityRecord.CanonicalLandblockId"/>, A7)
    /// already equals the target is BOTH the cycle guard (an A→B→A wire-
    /// induced relation cycle writes A, pushes B, writes B, pops B, finds A
    /// already at the target value, and does not re-push it — no visited
    /// set needed) and the retail-behavioral subsumption of retail's
    /// separate same-cell depth-1 id refresh (@0x0051539c-@0x005153d8)
    /// under this project's single-field cell model (AP-142). Zero
    /// allocation after warmup:
    /// <see cref="ParentAttachmentState.ChildrenAttachedToParent"/> returns
    /// the stored list or <see cref="Array.Empty{T}"/>, and the worklist
    /// stack is a reused field, never a fresh collection per call. Field
    /// writes only — no clock, workset, shadow, or placement work — so this
    /// is safe to run re-entrantly inside whatever transaction is mid-commit
    /// on the parent's own cell; the worklist field itself is safe to share
    /// across calls because the loop below unconditionally drains it to
    /// empty before this method returns, and nothing on the write path
    /// (a field assignment and an optional diagnostic log line) can call
    /// back into a nested <see cref="SetFullCell"/>. NOT gated on retail's
    /// <c>part_array != 0</c> guard (@0x00510ed8) — see AP-142 clause (d)
    /// for why that guard has no reproducible analogue at acdream's
    /// canonical layer.
    ///
    /// <para>
    /// P8 (contract proof obligation, corrected at the architecture review
    /// round — A3): this step deliberately publishes NO per-child
    /// <c>RuntimeEntityChange.Rebucketed</c> delta, matching
    /// <c>RuntimePhysicsState.CommitCanonicalCell</c>'s precedent. The
    /// correct basis for that decision is BOTH observer interfaces, not
    /// just <c>IRuntimeEntityObjectObserver</c>'s direct implementations:
    /// <c>GameRuntimeEventHub</c> itself implements
    /// <c>IRuntimeEntityObjectObserver</c> and fans every entity delta out
    /// to <c>IRuntimeEventObserver</c>, and <c>RuntimeTraceRecorder.OnEntity</c>
    /// (<c>GameRuntimeEvents.cs</c>) is a non-stub shipped consumer that
    /// records <c>(delta.Change, delta.Entity.CellId)</c> for every entity
    /// delta — it is diagnostic tracing, not gameplay logic, and the
    /// entries it would lose are graphical-only equipped-child
    /// <c>Rebucketed</c> deltas that TickChild's demoted rebucket used to
    /// produce, so silence here is acceptable, but "no consumer at all" is
    /// false and must not be restated that way.
    /// </para>
    ///
    /// <para>
    /// P4 (contract proof obligation — the child broadphase story, stated):
    /// this step writes canonical cell FIELDS only. At attach, the
    /// preceding cell-less edge already force-ends collision reporting
    /// (<c>Physics.CollisionReports.LeaveWorld</c>) and no child broadphase
    /// registration exists to rebuild — retail's own
    /// <c>recalc_cross_cells</c> @0x00515A30 runs at attach only, never
    /// per-crossing (the §0 trap this hook deliberately does not port). At
    /// every crossing thereafter, a committed child never becomes a spatial
    /// root (<c>LiveEntityRuntime.HasSpatialRuntimeProjection</c> keys off
    /// <c>ProjectionKind is World</c>, and an attached child is always
    /// <c>ProjectionKind.Attached</c> — <c>AcknowledgeSpatialProjection</c>
    /// is never called on this path, headless or graphical), so it never
    /// joins any physics workset or shadow/cross-cell list this step would
    /// need to maintain. Confirmed, not assumed: zero shadow work is
    /// performed anywhere in this method.
    /// </para>
    /// </summary>
    private void PropagateFullCellToChildren(
        RuntimeEntityRecord root,
        uint fullCellId,
        uint canonicalLandblockId)
    {
        _propagationWorklist.Clear();
        _propagationWorklist.Push(root);
        while (_propagationWorklist.Count > 0)
        {
            RuntimeEntityRecord current = _propagationWorklist.Pop();
            IReadOnlyList<uint> children = ParentAttachments.ChildrenAttachedToParent(
                current.ServerGuid,
                current.Incarnation);
            for (int i = 0; i < children.Count; i++)
            {
                // A7 (architecture review, LOW): key the idempotence/cycle
                // skip on the PAIR, not FullCellId alone. Every production
                // writer derives canonicalLandblockId from fullCellId, so
                // the two are coupled today, but the coupling is not
                // enforced anywhere (LiveEntityRuntime.CanonicalLandblockId's
                // setter can write a same-cell, different-landblock pair) —
                // testing the pair is the version that is correct
                // independent of that coupling.
                if (!TryGetActive(children[i], out RuntimeEntityRecord child)
                    || (child.FullCellId == fullCellId
                        && child.CanonicalLandblockId == canonicalLandblockId))
                {
                    continue;
                }
                if (PhysicsDiagnostics.ProbeChildCellEnabled)
                {
                    Console.WriteLine(FormattableString.Invariant(
                        $"[child-cell] parent=0x{current.ServerGuid:X8} child=0x{child.ServerGuid:X8} old=0x{child.FullCellId:X8} new=0x{fullCellId:X8} cause={(fullCellId == 0u ? "withdraw" : "propagate")}"));
                }
                child.SetFullCell(fullCellId, canonicalLandblockId);
                _propagationWorklist.Push(child);
            }
        }
    }

    public void SetFinalPhysicsState(
        RuntimeEntityRecord record,
        PhysicsStateFlags state)
    {
        EnsureKnown(record);
        record.SetFinalPhysicsState(state);
    }

    internal bool StopMissileAfterCollision(
        RuntimeEntityRecord record,
        bool requireCurrentMissile)
    {
        EnsureKnown(record);
        return record.StopMissileAfterCollision(requireCurrentMissile);
    }

    public void SetHasPartArray(RuntimeEntityRecord record, bool value)
    {
        EnsureKnown(record);
        record.HasPartArray = value;
    }

    public void SetPhysicsBody(
        RuntimeEntityRecord record,
        AcDream.Core.Physics.PhysicsBody? body)
    {
        EnsureKnown(record);
        record.SetPhysicsBody(body);
    }

    public void SetPhysicsBodyAcquisitionInProgress(
        RuntimeEntityRecord record,
        bool value)
    {
        EnsureKnown(record);
        record.PhysicsBodyAcquisitionInProgress = value;
    }

    public void SetRemoteMotion(
        RuntimeEntityRecord record,
        IRuntimeRemoteMotion? remote)
    {
        EnsureKnown(record);
        record.RemoteMotion = remote;
    }

    public void SetRemoteMotionBindingInProgress(
        RuntimeEntityRecord record,
        bool value)
    {
        EnsureKnown(record);
        record.RemoteMotionBindingInProgress = value;
    }

    public void SetProjectile(
        RuntimeEntityRecord record,
        IRuntimeProjectile? projectile)
    {
        EnsureKnown(record);
        record.Projectile = projectile;
    }

    public void SetProjectileBindingInProgress(
        RuntimeEntityRecord record,
        bool value)
    {
        EnsureKnown(record);
        record.ProjectileBindingInProgress = value;
    }

    public void SetRequiresRemotePlacementRuntime(
        RuntimeEntityRecord record,
        bool value)
    {
        EnsureKnown(record);
        record.RequiresRemotePlacementRuntime = value;
    }

    public void SetPhysicsHost(
        RuntimeEntityRecord record,
        AcDream.Core.Physics.Motion.IPhysicsObjHost? host)
    {
        EnsureKnown(record);
        record.PhysicsHost = host;
    }

    public void SetDeleteAcceptedForTeardown(
        RuntimeEntityRecord record,
        bool value)
    {
        EnsureKnown(record);
        record.DeleteAcceptedForTeardown = value;
    }

    public bool TryApplyObjDesc(
        AcDream.Core.Net.Messages.ObjDescEvent.Parsed update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.TryApplyObjDesc(update, out accepted);

    public bool TryApplyPickup(
        AcDream.Core.Net.Messages.PickupEvent.Parsed update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.TryApplyPickup(update, out accepted);

    public bool TryApplyCreateParent(
        CreateParentUpdate update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.TryApplyCreateParent(update, out accepted);

    public bool TryApplyParent(
        AcDream.Core.Net.Messages.ParentEvent.Parsed update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.TryApplyParent(update, out accepted);

    public bool TryCommitParent(
        uint childGuid,
        uint parentGuid,
        uint parentLocation,
        uint placementId,
        ushort positionSequence,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.TryCommitParent(
            childGuid,
            parentGuid,
            parentLocation,
            placementId,
            positionSequence,
            out accepted);

    public bool TryApplyMotion(
        WorldSession.EntityMotionUpdate update,
        bool retainPayload,
        out WorldSession.EntitySpawn accepted,
        out AcceptedPhysicsTimestamps timestamps) =>
        _inbound.TryApplyMotion(update, retainPayload, out accepted, out timestamps);

    public bool TryApplyVector(
        AcDream.Core.Net.Messages.VectorUpdate.Parsed update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.TryApplyVector(update, out accepted);

    public bool TryApplyState(
        AcDream.Core.Net.Messages.SetState.Parsed update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.TryApplyState(update, out accepted);

    public bool TryApplyPosition(
        WorldSession.EntityPositionUpdate update,
        bool isLocalPlayer,
        System.Numerics.Quaternion? forcePositionRotation,
        System.Numerics.Vector3? currentLocalVelocity,
        out PositionTimestampDisposition disposition,
        out WorldSession.EntitySpawn accepted,
        out AcceptedPhysicsTimestamps timestamps) =>
        _inbound.TryApplyPosition(
            update,
            isLocalPlayer,
            forcePositionRotation,
            currentLocalVelocity,
            out disposition,
            out accepted,
            out timestamps);

    internal bool TryAcceptDeferredPosition(
        WorldSession.EntityPositionUpdate update,
        bool isLocalPlayer,
        out PositionTimestampDisposition disposition,
        out AcceptedPhysicsTimestamps timestamps,
        out bool hasTimestampMutation) =>
        _inbound.TryAcceptDeferredPosition(
            update,
            isLocalPlayer,
            out disposition,
            out timestamps,
            out hasTimestampMutation);

    internal bool TryAcceptDeferredObjDesc(
        ObjDescEvent.Parsed update,
        out AcceptedPhysicsTimestamps timestamps) =>
        _inbound.TryAcceptDeferredObjDesc(update, out timestamps);

    internal bool TryAcceptDeferredPickup(
        PickupEvent.Parsed update,
        out AcceptedPhysicsTimestamps timestamps) =>
        _inbound.TryAcceptDeferredPickup(update, out timestamps);

    internal bool TryAcceptDeferredCreateParent(
        CreateParentUpdate update,
        out AcceptedPhysicsTimestamps timestamps) =>
        _inbound.TryAcceptDeferredCreateParent(update, out timestamps);

    internal bool TryAcceptDeferredParent(
        ParentEvent.Parsed update,
        out AcceptedPhysicsTimestamps timestamps) =>
        _inbound.TryAcceptDeferredParent(update, out timestamps);

    internal bool TryAcceptDeferredMotion(
        WorldSession.EntityMotionUpdate update,
        out AcceptedPhysicsTimestamps timestamps,
        out bool hasTimestampMutation) =>
        _inbound.TryAcceptDeferredMotion(
            update,
            out timestamps,
            out hasTimestampMutation);

    internal bool TryAcceptDeferredState(
        SetState.Parsed update,
        out AcceptedPhysicsTimestamps timestamps) =>
        _inbound.TryAcceptDeferredState(update, out timestamps);

    internal bool TryAcceptDeferredVector(
        VectorUpdate.Parsed update,
        out AcceptedPhysicsTimestamps timestamps) =>
        _inbound.TryAcceptDeferredVector(update, out timestamps);

    public bool IsFreshTeleportStart(uint guid, ushort teleportSequence) =>
        _inbound.IsFreshTeleportStart(guid, teleportSequence);

    // Round 3 A1: gate-less instance seams for the initial-Create
    // continuation executor. Each merges against _inbound's OWN
    // _snapshots[guid] (never a caller-supplied base) and writes the result
    // back, keeping this store and RuntimeEntityRecord.Snapshot in lockstep.
    internal bool ApplyAcceptedObjDescSnapshot(
        uint guid,
        ObjDescEvent.Parsed update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.ApplyAcceptedObjDescSnapshot(guid, update, out accepted);

    internal bool ApplyAcceptedPickupSnapshot(
        uint guid,
        PickupEvent.Parsed update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.ApplyAcceptedPickupSnapshot(guid, update, out accepted);

    internal bool ApplyAcceptedCreateParentSnapshot(
        uint guid,
        CreateParentUpdate update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.ApplyAcceptedCreateParentSnapshot(guid, update, out accepted);

    internal bool ApplyAcceptedParentSnapshot(
        uint guid,
        ParentEvent.Parsed update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.ApplyAcceptedParentSnapshot(guid, update, out accepted);

    internal bool ApplyAcceptedMotionSnapshot(
        uint guid,
        ushort movementSequence,
        ushort acceptedServerControlledMove,
        WorldSession.EntityMotionUpdate update,
        bool retainPayload,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.ApplyAcceptedMotionSnapshot(
            guid,
            movementSequence,
            acceptedServerControlledMove,
            update,
            retainPayload,
            out accepted);

    internal bool ApplyAcceptedStateSnapshot(
        uint guid,
        SetState.Parsed update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.ApplyAcceptedStateSnapshot(guid, update, out accepted);

    internal bool ApplyAcceptedVectorSnapshot(
        uint guid,
        VectorUpdate.Parsed update,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.ApplyAcceptedVectorSnapshot(guid, update, out accepted);

    internal bool ApplyAcceptedPositionSnapshot(
        uint guid,
        WorldSession.EntityPositionUpdate update,
        PositionTimestampDisposition disposition,
        AcceptedPhysicsTimestamps timestamps,
        bool isLocalPlayer,
        System.Numerics.Quaternion? forcePositionRotation,
        System.Numerics.Vector3? currentLocalVelocity,
        bool installPlacementFrame,
        bool clearParent,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.ApplyAcceptedPositionSnapshot(
            guid,
            update,
            disposition,
            timestamps,
            isLocalPlayer,
            forcePositionRotation,
            currentLocalVelocity,
            installPlacementFrame,
            clearParent,
            out accepted);

    internal bool ApplyAcceptedPositionExecutionRejectedSnapshot(
        uint guid,
        ushort acceptedPositionSequence,
        AcceptedPhysicsTimestamps timestamps,
        out WorldSession.EntitySpawn accepted) =>
        _inbound.ApplyAcceptedPositionExecutionRejectedSnapshot(
            guid,
            acceptedPositionSequence,
            timestamps,
            out accepted);

    internal bool ApplyAcceptedWeenieDescriptionSnapshot(
        uint guid,
        WorldSession.EntitySpawn incoming,
        out WorldSession.EntitySpawn merged) =>
        _inbound.ApplyAcceptedWeenieDescriptionSnapshot(guid, incoming, out merged);

    /// <summary>
    /// #297 review round 2: see
    /// <see cref="InboundPhysicsStateController.TryRefreshObjectDescriptionFlags"/>.
    /// </summary>
    internal bool TryRefreshObjectDescriptionFlags(
        uint guid,
        uint bitfield,
        out WorldSession.EntitySpawn merged) =>
        _inbound.TryRefreshObjectDescriptionFlags(guid, bitfield, out merged);

    private bool IsKnown(RuntimeEntityRecord record)
    {
        if (IsCurrent(record))
            return true;
        return _teardownByIncarnation.TryGetValue(
                (record.ServerGuid, record.Incarnation),
                out RuntimeEntityRecord? retained)
            && ReferenceEquals(retained, record);
    }

    private void EnsureKnown(RuntimeEntityRecord record)
    {
        ArgumentNullException.ThrowIfNull(record);
        if (!IsKnown(record))
        {
            throw new InvalidOperationException(
                $"Runtime entity 0x{record.ServerGuid:X8}/{record.Incarnation} is no longer owned by the directory.");
        }
    }
}