enum ERR_InfantryAmmoTransferState { FAILED = -1, PENDING, SUCCEEDED }

class ERR_InfantryAmmoCallback : ScriptedInventoryOperationCallback
{
 ERR_InfantryAmmoTransfer Transfer;
 protected override void OnComplete() { if (Transfer) Transfer.Acknowledge(true); }
 protected override void OnFailed() { if (Transfer) Transfer.Acknowledge(false); }
 protected override void OnAllComplete() { if (Transfer) Transfer.Acknowledge(true); }
 protected override void OnAllFailed() { if (Transfer) Transfer.Acknowledge(false); }
}

// One exact physical magazine movement. The caller owns HQ authorization and
// the spent-item reservation; this leaf never selects tasks or retries a move.
class ERR_InfantryAmmoTransfer
{
 protected ERR_GameMode m_Mode;
 protected Vehicle m_Donor;
 protected SCR_AIGroup m_DonorGroup;
 protected IEntity m_Recipient;
 protected SCR_AIGroup m_RecipientGroup;
 protected IEntity m_Magazine;
 protected IEntity m_Driver;
 protected ERR_ForceRecord m_DonorRecord;
 protected ERR_ForceRecord m_RecipientRecord;
 protected InventoryStorageManagerComponent m_Source;
 protected InventoryStorageManagerComponent m_Destination;
 protected BaseInventoryStorageComponent m_Storage;
 protected ref ERR_InfantryAmmoCallback m_Callback;
 protected bool m_Submitted;
 protected bool m_Accepted;
 protected int m_Acknowledgement;
 protected float m_Started = -1;
 protected ERR_InfantryAmmoTransferState m_State = ERR_InfantryAmmoTransferState.PENDING;
 protected string m_Reason;
 void ERR_InfantryAmmoTransfer(ERR_GameMode mode, Vehicle donorVehicle, SCR_AIGroup donorGroup, IEntity recipientActor, SCR_AIGroup recipientGroup, IEntity exactMagazine)
 {
  m_Mode = mode; m_Donor = donorVehicle; m_DonorGroup = donorGroup;
  m_Recipient = recipientActor; m_RecipientGroup = recipientGroup; m_Magazine = exactMagazine;
 }
 static bool Compatible(IEntity actor, IEntity exactMagazine)
 {
  if (!actor || !exactMagazine) return false;
  BaseMagazineComponent magazine = BaseMagazineComponent.Cast(exactMagazine.FindComponent(BaseMagazineComponent));
  BaseWeaponManagerComponent manager = BaseWeaponManagerComponent.Cast(actor.FindComponent(BaseWeaponManagerComponent));
  if (!magazine || !manager || !magazine.GetMagazineWell() || magazine.GetAmmoCount() <= 0 || magazine.GetMaxAmmoCount() <= 0 || magazine.GetAmmoCount() > magazine.GetMaxAmmoCount()) return false;
  array<IEntity> weapons = {}; manager.GetWeaponsList(weapons);
  if (weapons.IsEmpty() || weapons.Count() > 8) return false;
  foreach (IEntity rifle : weapons)
  {
   if (!rifle) continue;
   BaseWeaponComponent weapon = BaseWeaponComponent.Cast(rifle.FindComponent(BaseWeaponComponent));
   if (!weapon || weapon.GetOwner() != rifle) continue;
   EWeaponType kind = weapon.GetWeaponType();
   if (kind != EWeaponType.WT_RIFLE && kind != EWeaponType.WT_SNIPERRIFLE && kind != EWeaponType.WT_MACHINEGUN && kind != EWeaponType.WT_HANDGUN) continue;
   array<BaseMuzzleComponent> muzzles = {}; weapon.GetMuzzlesList(muzzles);
   if (muzzles.Count() > 4) continue;
   foreach (BaseMuzzleComponent muzzle : muzzles)
   {
    if (!muzzle || !muzzle.GetMagazineWell()) continue;
    EMuzzleType muzzleKind = muzzle.GetMuzzleType();
    if (muzzleKind != EMuzzleType.MT_BaseMuzzle) continue;
    // Same direction as the stock magazine inventory predicate: a magazine's
    // derived well must inherit the actual carried small-arms muzzle's well.
    if (magazine.GetMagazineWell().IsInherited(muzzle.GetMagazineWell().Type())) return true;
   }
  }
  return false;
 }
 static bool StoredUnder(IEntity entity, IEntity root)
 {
  for (int depth = 0; entity && depth < 16; depth++)
  {
   if (entity == root) return true;
   InventoryItemComponent item = InventoryItemComponent.Cast(entity.FindComponent(InventoryItemComponent));
   if (item && item.GetParentSlot())
   {
    BaseInventoryStorageComponent storage = item.GetParentSlot().GetStorage();
    if (!storage) return false;
    entity = storage.GetOwner();
   }
   else entity = entity.GetParent();
  }
  return false;
 }
 protected bool ManagedStorage(InventoryStorageManagerComponent inventory, BaseInventoryStorageComponent storage, IEntity owner)
 {
  if (!inventory || !storage || inventory.GetOwner() != owner || !StoredUnder(storage.GetOwner(), owner)) return false;
  array<BaseInventoryStorageComponent> storages = {};
  inventory.GetStorages(storages, EStoragePurpose.PURPOSE_DEPOSIT);
  return storages.Count() <= 64 && storages.Contains(storage);
 }
 protected int Ownership(InventoryStorageManagerComponent inventory)
 {
  if (!inventory || !m_Magazine) return -1;
  array<IEntity> items = {}; inventory.GetItems(items, EStoragePurpose.PURPOSE_DEPOSIT);
  if (items.Count() > 512) return -1;
  if (items.Contains(m_Magazine)) return 1;
  return 0;
 }
 protected bool PhysicalProof()
 {
  if (!m_Magazine || m_Acknowledgement != 1 || Ownership(m_Source) != 0 || Ownership(m_Destination) != 1 || !ManagedStorage(m_Destination, m_Storage, m_Recipient)) return false;
  InventoryItemComponent item = InventoryItemComponent.Cast(m_Magazine.FindComponent(InventoryItemComponent));
  return item && item.GetParentSlot() && item.GetParentSlot().GetStorage() == m_Storage;
 }
 void Acknowledge(bool success)
 {
  if (m_Acknowledgement != 0) return;
  if (success) m_Acknowledgement = 1;
  else m_Acknowledgement = -1;
 }
 // This read-only observation works even after Stop; the caller must retain
 // ambiguous accepted operations and cannot interpret failure as cancellation.
 bool Unresolved()
 {
  if (!m_Accepted || !m_Magazine || m_Acknowledgement < 0) return false;
  return !PhysicalProof();
 }
 bool Submitted() { return m_Submitted; }
 string Reason() { return m_Reason; }
 protected ERR_InfantryAmmoTransferState Fail(string reason)
 {
  if (m_State == ERR_InfantryAmmoTransferState.PENDING) { m_State = ERR_InfantryAmmoTransferState.FAILED; m_Reason = reason; }
  return m_State;
 }
 void Stop() { Fail("HQ authorization stopped; an accepted native move cannot be cancelled"); }
 protected bool Context()
 {
  if (!Replication.IsServer() || SCR_Global.IsEditMode() || !m_Mode || m_Mode != ERR_GameMode.Get() || !m_Mode.Active() || !m_Mode.Forces()) return false;
  if (!m_Donor || !ERR_Actors.Alive(m_Donor) || !m_DonorGroup || !m_RecipientGroup || m_DonorGroup == m_RecipientGroup) return false;
  if (!ERR_EnemyEquipmentRules.Eligible(m_Mode, m_RecipientGroup, m_Recipient) || CompartmentAccessComponent.GetVehicleIn(m_Recipient)) return false;
  if (m_DonorGroup.IsSlave() || m_RecipientGroup.IsSlave() || m_DonorGroup.GetPlayerCount(true) > 0 || m_DonorGroup.GetFaction() != m_Mode.EnemyFaction()) return false;
  if (SCR_FactionManager.SGetFaction(m_Donor) != m_Mode.EnemyFaction() || SCR_FactionManager.SGetFaction(m_Recipient) != m_Mode.EnemyFaction()) return false;
  ERR_ForceRecord donorRecord = m_Mode.Forces().FindGroup(m_DonorGroup);
  ERR_ForceRecord recipientRecord = m_Mode.Forces().FindGroup(m_RecipientGroup);
  if (!donorRecord || !recipientRecord || donorRecord.Group != m_DonorGroup || recipientRecord.Group != m_RecipientGroup || !donorRecord.Physical || !recipientRecord.Physical || donorRecord.Eliminated || recipientRecord.Eliminated) return false;
  if (m_DonorRecord && (m_DonorRecord != donorRecord || m_RecipientRecord != recipientRecord)) return false;
  SCR_AIGroupUtilityComponent utility = m_DonorGroup.GetGroupUtilityComponent();
  if (!utility || !utility.IsMilitary() || !utility.m_VehicleMgr || !utility.m_VehicleMgr.FindVehicle(m_Donor)) return false;
  if (ERR_ConvoyRules.Captured(m_Donor, m_DonorGroup)) return false;
  SCR_AIVehicleUsageComponent usage = SCR_AIVehicleUsageComponent.Cast(m_Donor.FindComponent(SCR_AIVehicleUsageComponent));
  if (!usage || !usage.GetPilotCompartmentSlot()) return false;
  IEntity driver = usage.GetPilotCompartmentSlot().GetOccupant();
  if (!ERR_EnemyEquipmentRules.Eligible(m_Mode, m_DonorGroup, driver) || !ERR_ConvoyRules.PartOf(CompartmentAccessComponent.GetVehicleIn(driver), m_Donor)) return false;
  if (SCR_FactionManager.SGetFaction(driver) != m_Mode.EnemyFaction() || (m_Driver && driver != m_Driver)) return false;
  Physics physics = m_Donor.GetPhysics();
  if (!physics) return false;
  float speed = physics.GetVelocity().Length();
  float angular = physics.GetAngularVelocity().Length();
  float distance = vector.Distance(m_Donor.GetOrigin(), m_Recipient.GetOrigin());
  if (!(speed >= 0 && speed <= 0.25 && angular >= 0 && angular <= 0.1 && distance >= 0 && distance <= 4)) return false;
  if (!Compatible(m_Recipient, m_Magazine)) return false;
  m_Driver = driver; m_DonorRecord = donorRecord; m_RecipientRecord = recipientRecord;
  return true;
 }
 ERR_InfantryAmmoTransferState Tick(float now)
 {
  if (m_State != ERR_InfantryAmmoTransferState.PENDING) return m_State;
  if (!ERR_ForceRules.Finite(now) || now < 0) return Fail("invalid transaction clock");
  if (m_Started < 0) m_Started = now;
  if (now < m_Started || now - m_Started >= 8000) return Fail("native magazine move deadline expired");
  if (!Context()) return Fail("original owned groups, vehicle, driver, recipient, proximity or compatible weapon unavailable");
  if (!m_Submitted)
  {
   m_Source = InventoryStorageManagerComponent.Cast(m_Donor.FindComponent(InventoryStorageManagerComponent));
   m_Destination = InventoryStorageManagerComponent.Cast(m_Recipient.FindComponent(InventoryStorageManagerComponent));
   if (!m_Source || !m_Destination || m_Source == m_Destination || Ownership(m_Source) != 1 || Ownership(m_Destination) != 0) return Fail("exact magazine is not exclusive donor stock");
   InventoryItemComponent item = InventoryItemComponent.Cast(m_Magazine.FindComponent(InventoryItemComponent));
   if (!item || !item.GetParentSlot() || !ManagedStorage(m_Source, item.GetParentSlot().GetStorage(), m_Donor)) return Fail("exact source magazine storage does not belong to original donor");
   m_Storage = m_Destination.FindStorageForItem(m_Magazine, EStoragePurpose.PURPOSE_DEPOSIT);
   if (!ManagedStorage(m_Destination, m_Storage, m_Recipient) || !m_Source.CanMoveItemToStorage(m_Magazine, m_Storage, -1)) return Fail("recipient has no native compatible available storage");
   if (!ERR_InfantryAmmoAccess.Clear(m_Donor, m_Recipient)) return Fail("no unobstructed physical reach to an authored donor storage access point");
   m_Callback = new ERR_InfantryAmmoCallback(); m_Callback.Transfer = this;
   m_Submitted = true;
   m_Accepted = m_Source.TryMoveItemToStorage(m_Magazine, m_Storage, -1, m_Callback);
   if (m_Acknowledgement == 1) m_Accepted = true;
   if (!m_Accepted) return Fail("native magazine move rejected; exact item will not be retried");
  }
  if (PhysicalProof())
  {
   m_State = ERR_InfantryAmmoTransferState.SUCCEEDED;
   m_Reason = "native callback and exact destination storage confirm one physical magazine transferred";
   return m_State;
  }
  if (m_Acknowledgement < 0) return Fail("native magazine move failed");
  return ERR_InfantryAmmoTransferState.PENDING;
 }
}