order_cmd.cpp

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/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <https://www.gnu.org/licenses/old-licenses/gpl-2.0>.
 */

 
#include "stdafx.h"
#include "debug.h"
#include "command_func.h"
#include "company_func.h"
#include "news_func.h"
#include "strings_func.h"
#include "timetable.h"
#include "vehicle_func.h"
#include "depot_base.h"
#include "core/pool_func.hpp"
#include "aircraft.h"
#include "roadveh.h"
#include "station_base.h"
#include "waypoint_base.h"
#include "company_base.h"
#include "order_backup.h"
#include "cheat_type.h"
#include "order_cmd.h"
#include "train_cmd.h"
 
#include "table/strings.h"
 
#include "safeguards.h"
 
/* DestinationID must be at least as large as every these below, because it can
 * be any of them
 */
static_assert(sizeof(DestinationID) >= sizeof(DepotID));
static_assert(sizeof(DestinationID) >= sizeof(StationID));
 
OrderListPool _orderlist_pool("OrderList");
INSTANTIATE_POOL_METHODS(OrderList)
 

void Order::Free()
{
  this->type  = OT_NOTHING;
  this->flags = 0;
  this->dest  = 0;
}

void Order::MakeGoToStation(StationID destination)
{
  this->type = OT_GOTO_STATION;
  this->flags = 0;
  this->dest = destination;
}

void Order::MakeGoToDepot(DestinationID destination, OrderDepotTypeFlags order, OrderNonStopFlags non_stop_type, OrderDepotActionFlags action, CargoType cargo)
{
  this->type = OT_GOTO_DEPOT;
  this->SetDepotOrderType(order);
  this->SetDepotActionType(action);
  this->SetNonStopType(non_stop_type);
  this->dest = destination;
  this->SetRefit(cargo);
}

void Order::MakeGoToWaypoint(StationID destination)
{
  this->type = OT_GOTO_WAYPOINT;
  this->flags = 0;
  this->dest = destination;
}

void Order::MakeLoading(bool ordered)
{
  this->type = OT_LOADING;
  if (!ordered) this->flags = 0;
}

void Order::MakeLeaveStation()
{
  this->type = OT_LEAVESTATION;
  this->flags = 0;
}

void Order::MakeDummy()
{
  this->type = OT_DUMMY;
  this->flags = 0;
}

void Order::MakeConditional(VehicleOrderID order)
{
  this->type = OT_CONDITIONAL;
  this->flags = order;
  this->dest = 0;
}

void Order::MakeImplicit(StationID destination)
{
  this->type = OT_IMPLICIT;
  this->dest = destination;
}

void Order::SetRefit(CargoType cargo)
{
  this->refit_cargo = cargo;
}

bool Order::Equals(const Order &other) const
{
  /* In case of go to nearest depot orders we need "only" compare the flags
   * with the other and not the nearest depot order bit or the actual
   * destination because those get clear/filled in during the order
   * evaluation. If we do not do this the order will continuously be seen as
   * a different order and it will try to find a "nearest depot" every tick. */
  if ((this->IsType(OT_GOTO_DEPOT) && this->type == other.type) &&
      (this->GetDepotActionType().Test(OrderDepotActionFlag::NearestDepot) ||
       other.GetDepotActionType().Test(OrderDepotActionFlag::NearestDepot))) {
    return this->GetDepotOrderType() == other.GetDepotOrderType() &&
        this->GetDepotActionType().Reset(OrderDepotActionFlag::NearestDepot) == other.GetDepotActionType().Reset(OrderDepotActionFlag::NearestDepot);
  }
 
  return this->type == other.type && this->flags == other.flags && this->dest == other.dest;
}

uint16_t Order::MapOldOrder() const
{
  uint16_t order = this->GetType();
  switch (this->GetType()) {
    case OT_GOTO_STATION:
      if (this->GetUnloadType() == OrderUnloadType::Unload) SetBit(order, 5);
      if (this->IsFullLoadOrder()) SetBit(order, 6);
      if (this->GetNonStopType().Test(OrderNonStopFlag::NoIntermediate)) SetBit(order, 7);
      order |= GB(this->GetDestination().value, 0, 8) << 8;
      break;
    case OT_GOTO_DEPOT:
      if (!this->GetDepotOrderType().Test(OrderDepotTypeFlag::PartOfOrders)) SetBit(order, 6);
      SetBit(order, 7);
      order |= GB(this->GetDestination().value, 0, 8) << 8;
      break;
    case OT_LOADING:
      if (this->IsFullLoadOrder()) SetBit(order, 6);
      /* If both "no load" and "no unload" are set, return nothing order instead */
      if (this->GetLoadType() == OrderLoadType::NoLoad && this->GetUnloadType() == OrderUnloadType::NoUnload) {
        order = OT_NOTHING;
      }
      break;
    default:
      break;
  }
  return order;
}

void InvalidateVehicleOrder(const Vehicle *v, int data)
{
  InvalidateWindowData(WC_VEHICLE_VIEW, v->index);
 
  if (data != 0) {
    /* Calls SetDirty() too */
    InvalidateWindowData(WC_VEHICLE_ORDERS,    v->index, data);
    InvalidateWindowData(WC_VEHICLE_TIMETABLE, v->index, data);
    return;
  }
 
  SetWindowDirty(WC_VEHICLE_ORDERS,    v->index);
  SetWindowDirty(WC_VEHICLE_TIMETABLE, v->index);
}

void Order::AssignOrder(const Order &other)
{
  this->type  = other.type;
  this->flags = other.flags;
  this->dest  = other.dest;
 
  this->refit_cargo   = other.refit_cargo;
 
  this->wait_time   = other.wait_time;
  this->travel_time = other.travel_time;
  this->max_speed   = other.max_speed;
}

void OrderList::Initialize(Vehicle *v)
{
  this->first_shared = v;
 
  this->num_manual_orders = 0;
  this->num_vehicles = 1;
  this->timetable_duration = 0;
 
  for (const Order &o : this->orders) {
    if (!o.IsType(OT_IMPLICIT)) ++this->num_manual_orders;
    this->total_duration += o.GetWaitTime() + o.GetTravelTime();
  }
 
  this->RecalculateTimetableDuration();
 
  for (Vehicle *u = this->first_shared->PreviousShared(); u != nullptr; u = u->PreviousShared()) {
    ++this->num_vehicles;
    this->first_shared = u;
  }
 
  for (const Vehicle *u = v->NextShared(); u != nullptr; u = u->NextShared()) ++this->num_vehicles;
}

void OrderList::RecalculateTimetableDuration()
{
  this->timetable_duration = 0;
  for (const Order &o : this->orders) {
    this->timetable_duration += o.GetTimetabledWait() + o.GetTimetabledTravel();
  }
}

void OrderList::FreeChain(bool keep_orderlist)
{
  /* We can visit oil rigs and buoys that are not our own. They will be shown in
   * the list of stations. So, we need to invalidate that window if needed. */
  for (Order &order: this->orders) {
    if (order.IsType(OT_GOTO_STATION) || order.IsType(OT_GOTO_WAYPOINT)) {
      BaseStation *bs = BaseStation::GetIfValid(order.GetDestination().ToStationID());
      if (bs != nullptr && bs->owner == OWNER_NONE) {
        InvalidateWindowClassesData(WC_STATION_LIST, 0);
        break;
      }
    }
  }
 
  if (keep_orderlist) {
    this->orders.clear();
    this->num_manual_orders = 0;
    this->timetable_duration = 0;
  } else {
    delete this;
  }
}

VehicleOrderID OrderList::GetNextDecisionNode(VehicleOrderID next, uint hops) const
{
  if (hops > this->GetNumOrders() || next >= this->GetNumOrders()) return INVALID_VEH_ORDER_ID;
 
  const Order &order_next = this->orders[next];
  if (order_next.IsType(OT_CONDITIONAL)) {
    if (order_next.GetConditionVariable() != OrderConditionVariable::Unconditionally) return next;
 
    /* We can evaluate trivial conditions right away. They're conceptually
     * the same as regular order progression. */
    return this->GetNextDecisionNode(
        order_next.GetConditionSkipToOrder(),
        hops + 1);
  }
 
  if (order_next.IsType(OT_GOTO_DEPOT)) {
    if (order_next.GetDepotActionType().Test(OrderDepotActionFlag::Halt)) return INVALID_VEH_ORDER_ID;
    if (order_next.IsRefit()) return next;
  }
 
  if (!order_next.CanLoadOrUnload()) {
    return this->GetNextDecisionNode(this->GetNext(next), hops + 1);
  }
 
  return next;
}

void OrderList::GetNextStoppingStation(std::vector<StationID> &next_station, const Vehicle *v, VehicleOrderID first, uint hops) const
{
  VehicleOrderID next = first;
  if (first == INVALID_VEH_ORDER_ID) {
    next = v->cur_implicit_order_index;
    if (next >= this->GetNumOrders()) {
      next = this->GetFirstOrder();
      if (next == INVALID_VEH_ORDER_ID) return;
    } else {
      /* GetNext never returns INVALID_VEH_ORDER_ID if there is a valid station in the list.
       * As the given "next" is already valid and a station in the list, we
       * don't have to check for INVALID_VEH_ORDER_ID here. */
      next = this->GetNext(next);
      assert(next != INVALID_VEH_ORDER_ID);
    }
  }
 
  auto orders = v->Orders();
  do {
    next = this->GetNextDecisionNode(next, ++hops);
 
    /* Resolve possibly nested conditionals by estimation. */
    while (next != INVALID_VEH_ORDER_ID && orders[next].IsType(OT_CONDITIONAL)) {
      /* We return both options of conditional orders. */
      VehicleOrderID skip_to = this->GetNextDecisionNode(orders[next].GetConditionSkipToOrder(), hops);
      VehicleOrderID advance = this->GetNextDecisionNode(this->GetNext(next), hops);
      if (advance == INVALID_VEH_ORDER_ID || advance == first || skip_to == advance) {
        next = (skip_to == first) ? INVALID_VEH_ORDER_ID : skip_to;
      } else if (skip_to == INVALID_VEH_ORDER_ID || skip_to == first) {
        next = (advance == first) ? INVALID_VEH_ORDER_ID : advance;
      } else {
        this->GetNextStoppingStation(next_station, v, skip_to, hops);
        this->GetNextStoppingStation(next_station, v, advance, hops);
        return;
      }
      ++hops;
    }
 
    /* Don't return a next stop if the vehicle has to unload everything. */
    if (next == INVALID_VEH_ORDER_ID || ((orders[next].IsType(OT_GOTO_STATION) || orders[next].IsType(OT_IMPLICIT)) &&
        orders[next].GetDestination() == v->last_station_visited &&
        (orders[next].GetUnloadType() == OrderUnloadType::Transfer || orders[next].GetUnloadType() == OrderUnloadType::Unload))) {
      return;
    }
  } while (orders[next].IsType(OT_GOTO_DEPOT) || orders[next].GetDestination() == v->last_station_visited);
 
  next_station.push_back(orders[next].GetDestination().ToStationID());
}

void OrderList::InsertOrderAt(Order &&order, VehicleOrderID index)
{
  auto it = std::ranges::next(std::begin(this->orders), index, std::end(this->orders));
  auto new_order = this->orders.emplace(it, std::move(order));
 
  if (!new_order->IsType(OT_IMPLICIT)) ++this->num_manual_orders;
  this->timetable_duration += new_order->GetTimetabledWait() + new_order->GetTimetabledTravel();
  this->total_duration += new_order->GetWaitTime() + new_order->GetTravelTime();
 
  /* We can visit oil rigs and buoys that are not our own. They will be shown in
   * the list of stations. So, we need to invalidate that window if needed. */
  if (new_order->IsType(OT_GOTO_STATION) || new_order->IsType(OT_GOTO_WAYPOINT)) {
    BaseStation *bs = BaseStation::Get(new_order->GetDestination().ToStationID());
    if (bs->owner == OWNER_NONE) InvalidateWindowClassesData(WC_STATION_LIST, 0);
  }
}
 

void OrderList::DeleteOrderAt(VehicleOrderID index)
{
  auto to_remove = std::ranges::next(std::begin(this->orders), index, std::end(this->orders));
  if (to_remove == std::end(this->orders)) return;
 
  if (!to_remove->IsType(OT_IMPLICIT)) --this->num_manual_orders;
 
  this->timetable_duration -= (to_remove->GetTimetabledWait() + to_remove->GetTimetabledTravel());
  this->total_duration -= (to_remove->GetWaitTime() + to_remove->GetTravelTime());
 
  this->orders.erase(to_remove);
}

void OrderList::MoveOrder(VehicleOrderID from, VehicleOrderID to)
{
  if (from == to) return;
  if (from >= this->GetNumOrders()) return;
  if (to >= this->GetNumOrders()) return;
 
  auto it = std::begin(this->orders);
  if (from < to) {
    std::rotate(it + from, it + from + 1, it + to + 1);
  } else {
    std::rotate(it + to, it + from, it + from + 1);
  }
}

void OrderList::RemoveVehicle(Vehicle *v)
{
  --this->num_vehicles;
  if (v == this->first_shared) this->first_shared = v->NextShared();
}

bool OrderList::IsCompleteTimetable() const
{
  for (const Order &o : this->orders) {
    /* Implicit orders are, by definition, not timetabled. */
    if (o.IsType(OT_IMPLICIT)) continue;
    if (!o.IsCompletelyTimetabled()) return false;
  }
  return true;
}
 
#ifdef WITH_ASSERT
void OrderList::DebugCheckSanity() const
{
  VehicleOrderID check_num_orders = 0;
  VehicleOrderID check_num_manual_orders = 0;
  uint check_num_vehicles = 0;
  TimerGameTick::Ticks check_timetable_duration = 0;
  TimerGameTick::Ticks check_total_duration = 0;
 
  Debug(misc, 6, "Checking OrderList {} for sanity...", this->index);
 
  for (const Order &o : this->orders) {
    ++check_num_orders;
    if (!o.IsType(OT_IMPLICIT)) ++check_num_manual_orders;
    check_timetable_duration += o.GetTimetabledWait() + o.GetTimetabledTravel();
    check_total_duration += o.GetWaitTime() + o.GetTravelTime();
  }
  assert(this->GetNumOrders() == check_num_orders);
  assert(this->num_manual_orders == check_num_manual_orders);
  assert(this->timetable_duration == check_timetable_duration);
  assert(this->total_duration == check_total_duration);
 
  for (const Vehicle *v = this->first_shared; v != nullptr; v = v->NextShared()) {
    ++check_num_vehicles;
    assert(v->orders == this);
  }
  assert(this->num_vehicles == check_num_vehicles);
  Debug(misc, 6, "... detected {} orders ({} manual), {} vehicles, {} timetabled, {} total",
      (uint)this->GetNumOrders(), (uint)this->num_manual_orders,
      this->num_vehicles, this->timetable_duration, this->total_duration);
}
#endif

static inline bool OrderGoesToStation(const Vehicle *v, const Order &o)
{
  return o.IsType(OT_GOTO_STATION) ||
      (v->type == VEH_AIRCRAFT && o.IsType(OT_GOTO_DEPOT) && o.GetDestination() != StationID::Invalid());
}

static void DeleteOrderWarnings(const Vehicle *v)
{
  DeleteVehicleNews(v->index, AdviceType::Order);
}

TileIndex Order::GetLocation(const Vehicle *v, bool airport) const
{
  switch (this->GetType()) {
    case OT_GOTO_WAYPOINT:
    case OT_GOTO_STATION:
    case OT_IMPLICIT:
      if (airport && v->type == VEH_AIRCRAFT) return Station::Get(this->GetDestination().ToStationID())->airport.tile;
      return BaseStation::Get(this->GetDestination().ToStationID())->xy;
 
    case OT_GOTO_DEPOT:
      if (this->GetDestination() == DepotID::Invalid()) return INVALID_TILE;
      return (v->type == VEH_AIRCRAFT) ? Station::Get(this->GetDestination().ToStationID())->xy : Depot::Get(this->GetDestination().ToDepotID())->xy;
 
    default:
      return INVALID_TILE;
  }
}

uint GetOrderDistance(VehicleOrderID prev, VehicleOrderID cur, const Vehicle *v, int conditional_depth)
{
  assert(v->orders != nullptr);
  const OrderList &orderlist = *v->orders;
  auto orders = orderlist.GetOrders();
 
  if (orders[cur].IsType(OT_CONDITIONAL)) {
    if (conditional_depth > v->GetNumOrders()) return 0;
 
    conditional_depth++;
 
    int dist1 = GetOrderDistance(prev, orders[cur].GetConditionSkipToOrder(), v, conditional_depth);
    int dist2 = GetOrderDistance(prev, orderlist.GetNext(cur), v, conditional_depth);
    return std::max(dist1, dist2);
  }
 
  TileIndex prev_tile = orders[prev].GetLocation(v, true);
  TileIndex cur_tile = orders[cur].GetLocation(v, true);
  if (prev_tile == INVALID_TILE || cur_tile == INVALID_TILE) return 0;
  return v->type == VEH_AIRCRAFT ? DistanceSquare(prev_tile, cur_tile) : DistanceManhattan(prev_tile, cur_tile);
}

CommandCost CmdInsertOrder(DoCommandFlags flags, VehicleID veh, VehicleOrderID sel_ord, const Order &new_order)
{
  Vehicle *v = Vehicle::GetIfValid(veh);
  if (v == nullptr || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
  CommandCost ret = CheckOwnership(v->owner);
  if (ret.Failed()) return ret;
 
  /* Validate properties we don't want to have different from default as they are set by other commands. */
  if (new_order.GetRefitCargo() != CARGO_NO_REFIT || new_order.GetWaitTime() != 0 || new_order.GetTravelTime() != 0 || new_order.GetMaxSpeed() != UINT16_MAX) return CMD_ERROR;
 
  /* Check if the inserted order is to the correct destination (owner, type),
   * and has the correct flags if any */
  switch (new_order.GetType()) {
    case OT_GOTO_STATION: {
      const Station *st = Station::GetIfValid(new_order.GetDestination().ToStationID());
      if (st == nullptr) return CMD_ERROR;
 
      if (st->owner != OWNER_NONE) {
        ret = CheckOwnership(st->owner);
        if (ret.Failed()) return ret;
      }
 
      if (!CanVehicleUseStation(v, st)) return CommandCost(STR_ERROR_CAN_T_ADD_ORDER, GetVehicleCannotUseStationReason(v, st));
      for (Vehicle *u = v->FirstShared(); u != nullptr; u = u->NextShared()) {
        if (!CanVehicleUseStation(u, st)) return CommandCost(STR_ERROR_CAN_T_ADD_ORDER_SHARED, GetVehicleCannotUseStationReason(u, st));
      }
 
      /* Non stop only allowed for ground vehicles. */
      if (new_order.GetNonStopType().Any() && !v->IsGroundVehicle()) return CMD_ERROR;
 
      /* Filter invalid load/unload types. */
      switch (new_order.GetLoadType()) {
        case OrderLoadType::LoadIfPossible:
        case OrderLoadType::NoLoad:
          break;
 
        case OrderLoadType::FullLoad:
        case OrderLoadType::FullLoadAny:
          if (v->HasUnbunchingOrder()) return CommandCost(STR_ERROR_UNBUNCHING_NO_FULL_LOAD);
          break;
 
        default:
          return CMD_ERROR;
      }
      switch (new_order.GetUnloadType()) {
        case OrderUnloadType::UnloadIfPossible:
        case OrderUnloadType::Unload:
        case OrderUnloadType::Transfer:
        case OrderUnloadType::NoUnload:
          break;
 
        default:
          return CMD_ERROR;
      }
 
      /* Filter invalid stop locations */
      switch (new_order.GetStopLocation()) {
        case OrderStopLocation::NearEnd:
        case OrderStopLocation::Middle:
          if (v->type != VEH_TRAIN) return CMD_ERROR;
          [[fallthrough]];
 
        case OrderStopLocation::FarEnd:
          break;
 
        default:
          return CMD_ERROR;
      }
 
      break;
    }
 
    case OT_GOTO_DEPOT: {
      if (!new_order.GetDepotActionType().Test(OrderDepotActionFlag::NearestDepot)) {
        if (v->type == VEH_AIRCRAFT) {
          const Station *st = Station::GetIfValid(new_order.GetDestination().ToStationID());
 
          if (st == nullptr) return CMD_ERROR;
 
          ret = CheckOwnership(st->owner);
          if (ret.Failed()) return ret;
 
          if (!CanVehicleUseStation(v, st) || !st->airport.HasHangar()) {
            return CMD_ERROR;
          }
        } else {
          const Depot *dp = Depot::GetIfValid(new_order.GetDestination().ToDepotID());
 
          if (dp == nullptr) return CMD_ERROR;
 
          ret = CheckOwnership(GetTileOwner(dp->xy));
          if (ret.Failed()) return ret;
 
          switch (v->type) {
            case VEH_TRAIN:
              if (!IsRailDepotTile(dp->xy)) return CMD_ERROR;
              break;
 
            case VEH_ROAD:
              if (!IsRoadDepotTile(dp->xy)) return CMD_ERROR;
              break;
 
            case VEH_SHIP:
              if (!IsShipDepotTile(dp->xy)) return CMD_ERROR;
              break;
 
            default: return CMD_ERROR;
          }
        }
      }
 
      if (new_order.GetNonStopType().Any() && !v->IsGroundVehicle()) return CMD_ERROR;
 
      /* Check depot order type is valid. */
      OrderDepotTypeFlags depot_order_type = new_order.GetDepotOrderType();
      if (depot_order_type.Test(OrderDepotTypeFlag::PartOfOrders)) depot_order_type.Reset(OrderDepotTypeFlag::Service);
      depot_order_type.Reset(OrderDepotTypeFlag::PartOfOrders);
      if (depot_order_type.Any()) return CMD_ERROR;
 
      /* Check depot action type is valid. */
      if (new_order.GetDepotActionType().Reset({OrderDepotActionFlag::Halt, OrderDepotActionFlag::NearestDepot, OrderDepotActionFlag::Unbunch}).Any()) return CMD_ERROR;
 
      /* Vehicles cannot have a "service if needed" order that also has a depot action. */
      if (new_order.GetDepotOrderType().Test(OrderDepotTypeFlag::Service) && new_order.GetDepotActionType().Any({OrderDepotActionFlag::Halt, OrderDepotActionFlag::Unbunch})) return CMD_ERROR;
 
      /* Check if we're allowed to have a new unbunching order. */
      if (new_order.GetDepotActionType().Test(OrderDepotActionFlag::Unbunch)) {
        if (v->HasFullLoadOrder()) return CommandCost(STR_ERROR_UNBUNCHING_NO_UNBUNCHING_FULL_LOAD);
        if (v->HasUnbunchingOrder()) return CommandCost(STR_ERROR_UNBUNCHING_ONLY_ONE_ALLOWED);
        if (v->HasConditionalOrder()) return CommandCost(STR_ERROR_UNBUNCHING_NO_UNBUNCHING_CONDITIONAL);
      }
      break;
    }
 
    case OT_GOTO_WAYPOINT: {
      const Waypoint *wp = Waypoint::GetIfValid(new_order.GetDestination().ToStationID());
      if (wp == nullptr) return CMD_ERROR;
 
      switch (v->type) {
        default: return CMD_ERROR;
 
        case VEH_TRAIN: {
          if (!wp->facilities.Test(StationFacility::Train)) return CommandCost(STR_ERROR_CAN_T_ADD_ORDER, STR_ERROR_NO_RAIL_WAYPOINT);
 
          ret = CheckOwnership(wp->owner);
          if (ret.Failed()) return ret;
          break;
        }
 
        case VEH_ROAD: {
          if (!wp->facilities.Test(StationFacility::BusStop) && !wp->facilities.Test(StationFacility::TruckStop)) return CommandCost(STR_ERROR_CAN_T_ADD_ORDER, STR_ERROR_NO_ROAD_WAYPOINT);
 
          ret = CheckOwnership(wp->owner);
          if (ret.Failed()) return ret;
          break;
        }
 
        case VEH_SHIP:
          if (!wp->facilities.Test(StationFacility::Dock)) return CommandCost(STR_ERROR_CAN_T_ADD_ORDER, STR_ERROR_NO_BUOY);
          if (wp->owner != OWNER_NONE) {
            ret = CheckOwnership(wp->owner);
            if (ret.Failed()) return ret;
          }
          break;
      }
 
      /* Order flags can be any of the following for waypoints:
       * [non-stop]
       * non-stop orders (if any) are only valid for trains and road vehicles */
      if (new_order.GetNonStopType().Any() && !v->IsGroundVehicle()) return CMD_ERROR;
      break;
    }
 
    case OT_CONDITIONAL: {
      VehicleOrderID skip_to = new_order.GetConditionSkipToOrder();
      if (skip_to != 0 && skip_to >= v->GetNumOrders()) return CMD_ERROR; // Always allow jumping to the first (even when there is no order).
      if (new_order.GetConditionVariable() >= OrderConditionVariable::End) return CMD_ERROR;
      if (v->HasUnbunchingOrder()) return CommandCost(STR_ERROR_UNBUNCHING_NO_CONDITIONAL);
 
      OrderConditionComparator occ = new_order.GetConditionComparator();
      if (occ >= OrderConditionComparator::End) return CMD_ERROR;
      switch (new_order.GetConditionVariable()) {
        case OrderConditionVariable::RequiresService:
          if (occ != OrderConditionComparator::IsTrue && occ != OrderConditionComparator::IsFalse) return CMD_ERROR;
          break;
 
        case OrderConditionVariable::Unconditionally:
          if (occ != OrderConditionComparator::Equal) return CMD_ERROR;
          if (new_order.GetConditionValue() != 0) return CMD_ERROR;
          break;
 
        case OrderConditionVariable::LoadPercentage:
        case OrderConditionVariable::Reliability:
          if (new_order.GetConditionValue() > 100) return CMD_ERROR;
          [[fallthrough]];
 
        default:
          if (occ == OrderConditionComparator::IsTrue || occ == OrderConditionComparator::IsFalse) return CMD_ERROR;
          break;
      }
      break;
    }
 
    default: return CMD_ERROR;
  }
 
  if (sel_ord > v->GetNumOrders()) return CMD_ERROR;
 
  if (v->GetNumOrders() >= MAX_VEH_ORDER_ID) return CommandCost(STR_ERROR_TOO_MANY_ORDERS);
  if (v->orders == nullptr && !OrderList::CanAllocateItem()) return CommandCost(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
 
  if (flags.Test(DoCommandFlag::Execute)) {
    InsertOrder(v, Order(new_order), sel_ord);
  }
 
  return CommandCost();
}

void InsertOrder(Vehicle *v, Order &&new_o, VehicleOrderID sel_ord)
{
  /* Create new order and link in list */
  if (v->orders == nullptr) {
    v->orders = OrderList::Create(std::move(new_o), v);
  } else {
    v->orders->InsertOrderAt(std::move(new_o), sel_ord);
  }
 
  Vehicle *u = v->FirstShared();
  DeleteOrderWarnings(u);
  for (; u != nullptr; u = u->NextShared()) {
    assert(v->orders == u->orders);
 
    /* If there is added an order before the current one, we need
     * to update the selected order. We do not change implicit/real order indices though.
     * If the new order is between the current implicit order and real order, the implicit order will
     * later skip the inserted order. */
    if (sel_ord <= u->cur_real_order_index) {
      uint cur = u->cur_real_order_index + 1;
      /* Check if we don't go out of bound */
      if (cur < u->GetNumOrders()) {
        u->cur_real_order_index = cur;
      }
    }
    if (sel_ord == u->cur_implicit_order_index && u->IsGroundVehicle()) {
      /* We are inserting an order just before the current implicit order.
       * We do not know whether we will reach current implicit or the newly inserted order first.
       * So, disable creation of implicit orders until we are on track again. */
      uint16_t &gv_flags = u->GetGroundVehicleFlags();
      SetBit(gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
    }
    if (sel_ord <= u->cur_implicit_order_index) {
      uint cur = u->cur_implicit_order_index + 1;
      /* Check if we don't go out of bound */
      if (cur < u->GetNumOrders()) {
        u->cur_implicit_order_index = cur;
      }
    }
    /* Unbunching data is no longer valid. */
    u->ResetDepotUnbunching();
 
    /* Update any possible open window of the vehicle */
    InvalidateVehicleOrder(u, INVALID_VEH_ORDER_ID | (sel_ord << 8));
  }
 
  /* As we insert an order, the order to skip to will be 'wrong'. */
  VehicleOrderID cur_order_id = 0;
  for (Order &order : v->Orders()) {
    if (order.IsType(OT_CONDITIONAL)) {
      VehicleOrderID order_id = order.GetConditionSkipToOrder();
      if (order_id >= sel_ord) {
        order.SetConditionSkipToOrder(order_id + 1);
      }
      if (order_id == cur_order_id) {
        order.SetConditionSkipToOrder((order_id + 1) % v->GetNumOrders());
      }
    }
    cur_order_id++;
  }
 
  /* Make sure to rebuild the whole list */
  InvalidateWindowClassesData(GetWindowClassForVehicleType(v->type), 0);
}

static CommandCost DecloneOrder(Vehicle *dst, DoCommandFlags flags)
{
  if (flags.Test(DoCommandFlag::Execute)) {
    DeleteVehicleOrders(dst);
    InvalidateVehicleOrder(dst, VIWD_REMOVE_ALL_ORDERS);
    InvalidateWindowClassesData(GetWindowClassForVehicleType(dst->type), 0);
  }
  return CommandCost();
}

CommandCost CmdDeleteOrder(DoCommandFlags flags, VehicleID veh_id, VehicleOrderID sel_ord)
{
  Vehicle *v = Vehicle::GetIfValid(veh_id);
 
  if (v == nullptr || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
  CommandCost ret = CheckOwnership(v->owner);
  if (ret.Failed()) return ret;
 
  /* If we did not select an order, we maybe want to de-clone the orders */
  if (sel_ord >= v->GetNumOrders()) return DecloneOrder(v, flags);
 
  if (v->GetOrder(sel_ord) == nullptr) return CMD_ERROR;
 
  if (flags.Test(DoCommandFlag::Execute)) DeleteOrder(v, sel_ord);
  return CommandCost();
}

static void CancelLoadingDueToDeletedOrder(Vehicle *v)
{
  assert(v->current_order.IsType(OT_LOADING));
  /* NON-stop flag is misused to see if a train is in a station that is
   * on its order list or not */
  v->current_order.SetNonStopType({});
  /* When full loading, "cancel" that order so the vehicle doesn't
   * stay indefinitely at this station anymore. */
  if (v->current_order.IsFullLoadOrder()) v->current_order.SetLoadType(OrderLoadType::LoadIfPossible);
}

void DeleteOrder(Vehicle *v, VehicleOrderID sel_ord)
{
  v->orders->DeleteOrderAt(sel_ord);
 
  Vehicle *u = v->FirstShared();
  DeleteOrderWarnings(u);
  for (; u != nullptr; u = u->NextShared()) {
    assert(v->orders == u->orders);
 
    if (sel_ord == u->cur_real_order_index && u->current_order.IsType(OT_LOADING)) {
      CancelLoadingDueToDeletedOrder(u);
    }
 
    if (sel_ord < u->cur_real_order_index) {
      u->cur_real_order_index--;
    } else if (sel_ord == u->cur_real_order_index) {
      u->UpdateRealOrderIndex();
    }
 
    if (sel_ord < u->cur_implicit_order_index) {
      u->cur_implicit_order_index--;
    } else if (sel_ord == u->cur_implicit_order_index) {
      /* Make sure the index is valid */
      if (u->cur_implicit_order_index >= u->GetNumOrders()) u->cur_implicit_order_index = 0;
 
      /* Skip non-implicit orders for the implicit-order-index (e.g. if the current implicit order was deleted */
      while (u->cur_implicit_order_index != u->cur_real_order_index && !u->GetOrder(u->cur_implicit_order_index)->IsType(OT_IMPLICIT)) {
        u->cur_implicit_order_index++;
        if (u->cur_implicit_order_index >= u->GetNumOrders()) u->cur_implicit_order_index = 0;
      }
    }
    /* Unbunching data is no longer valid. */
    u->ResetDepotUnbunching();
 
    /* Update any possible open window of the vehicle */
    InvalidateVehicleOrder(u, sel_ord | (INVALID_VEH_ORDER_ID << 8));
  }
 
  /* As we delete an order, the order to skip to will be 'wrong'. */
  VehicleOrderID cur_order_id = 0;
  for (Order &order : v->Orders()) {
    if (order.IsType(OT_CONDITIONAL)) {
      VehicleOrderID order_id = order.GetConditionSkipToOrder();
      if (order_id >= sel_ord) {
        order_id = std::max(order_id - 1, 0);
      }
      if (order_id == cur_order_id) {
        order_id = (order_id + 1) % v->GetNumOrders();
      }
      order.SetConditionSkipToOrder(order_id);
    }
    cur_order_id++;
  }
 
  InvalidateWindowClassesData(GetWindowClassForVehicleType(v->type), 0);
}

CommandCost CmdSkipToOrder(DoCommandFlags flags, VehicleID veh_id, VehicleOrderID sel_ord)
{
  Vehicle *v = Vehicle::GetIfValid(veh_id);
 
  if (v == nullptr || !v->IsPrimaryVehicle() || sel_ord == v->cur_implicit_order_index || sel_ord >= v->GetNumOrders() || v->GetNumOrders() < 2) return CMD_ERROR;
 
  CommandCost ret = CheckOwnership(v->owner);
  if (ret.Failed()) return ret;
 
  if (flags.Test(DoCommandFlag::Execute)) {
    if (v->current_order.IsType(OT_LOADING)) v->LeaveStation();
 
    v->cur_implicit_order_index = v->cur_real_order_index = sel_ord;
    v->UpdateRealOrderIndex();
 
    /* Unbunching data is no longer valid. */
    v->ResetDepotUnbunching();
 
    InvalidateVehicleOrder(v, VIWD_MODIFY_ORDERS);
 
    /* We have an aircraft/ship, they have a mini-schedule, so update them all */
    if (v->type == VEH_AIRCRAFT) SetWindowClassesDirty(WC_AIRCRAFT_LIST);
    if (v->type == VEH_SHIP) SetWindowClassesDirty(WC_SHIPS_LIST);
  }
 
  return CommandCost();
}

CommandCost CmdMoveOrder(DoCommandFlags flags, VehicleID veh, VehicleOrderID moving_order, VehicleOrderID target_order)
{
  Vehicle *v = Vehicle::GetIfValid(veh);
  if (v == nullptr || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
  CommandCost ret = CheckOwnership(v->owner);
  if (ret.Failed()) return ret;
 
  /* Don't make senseless movements */
  if (moving_order >= v->GetNumOrders() || target_order >= v->GetNumOrders() ||
      moving_order == target_order || v->GetNumOrders() <= 1) return CMD_ERROR;
 
  Order *moving_one = v->GetOrder(moving_order);
  /* Don't move an empty order */
  if (moving_one == nullptr) return CMD_ERROR;
 
  if (flags.Test(DoCommandFlag::Execute)) {
    v->orders->MoveOrder(moving_order, target_order);
 
    /* Update shared list */
    Vehicle *u = v->FirstShared();
 
    DeleteOrderWarnings(u);
 
    for (; u != nullptr; u = u->NextShared()) {
      /* Update the current order.
       * There are multiple ways to move orders, which result in cur_implicit_order_index
       * and cur_real_order_index to not longer make any sense. E.g. moving another
       * real order between them.
       *
       * Basically one could choose to preserve either of them, but not both.
       * While both ways are suitable in this or that case from a human point of view, neither
       * of them makes really sense.
       * However, from an AI point of view, preserving cur_real_order_index is the most
       * predictable and transparent behaviour.
       *
       * With that decision it basically does not matter what we do to cur_implicit_order_index.
       * If we change orders between the implicit- and real-index, the implicit orders are mostly likely
       * completely out-dated anyway. So, keep it simple and just keep cur_implicit_order_index as well.
       * The worst which can happen is that a lot of implicit orders are removed when reaching current_order.
       */
      if (u->cur_real_order_index == moving_order) {
        u->cur_real_order_index = target_order;
      } else if (u->cur_real_order_index > moving_order && u->cur_real_order_index <= target_order) {
        u->cur_real_order_index--;
      } else if (u->cur_real_order_index < moving_order && u->cur_real_order_index >= target_order) {
        u->cur_real_order_index++;
      }
 
      if (u->cur_implicit_order_index == moving_order) {
        u->cur_implicit_order_index = target_order;
      } else if (u->cur_implicit_order_index > moving_order && u->cur_implicit_order_index <= target_order) {
        u->cur_implicit_order_index--;
      } else if (u->cur_implicit_order_index < moving_order && u->cur_implicit_order_index >= target_order) {
        u->cur_implicit_order_index++;
      }
      /* Unbunching data is no longer valid. */
      u->ResetDepotUnbunching();
 
 
      assert(v->orders == u->orders);
      /* Update any possible open window of the vehicle */
      InvalidateVehicleOrder(u, moving_order | (target_order << 8));
    }
 
    /* As we move an order, the order to skip to will be 'wrong'. */
    for (Order &order : v->Orders()) {
      if (order.IsType(OT_CONDITIONAL)) {
        VehicleOrderID order_id = order.GetConditionSkipToOrder();
        if (order_id == moving_order) {
          order_id = target_order;
        } else if (order_id > moving_order && order_id <= target_order) {
          order_id--;
        } else if (order_id < moving_order && order_id >= target_order) {
          order_id++;
        }
        order.SetConditionSkipToOrder(order_id);
      }
    }
 
    /* Make sure to rebuild the whole list */
    InvalidateWindowClassesData(GetWindowClassForVehicleType(v->type), 0);
  }
 
  return CommandCost();
}

CommandCost CmdModifyOrder(DoCommandFlags flags, VehicleID veh, VehicleOrderID sel_ord, ModifyOrderFlags mof, uint16_t data)
{
  if (mof >= MOF_END) return CMD_ERROR;
 
  Vehicle *v = Vehicle::GetIfValid(veh);
  if (v == nullptr || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
  CommandCost ret = CheckOwnership(v->owner);
  if (ret.Failed()) return ret;
 
  /* Is it a valid order? */
  if (sel_ord >= v->GetNumOrders()) return CMD_ERROR;
 
  Order *order = v->GetOrder(sel_ord);
  assert(order != nullptr);
  switch (order->GetType()) {
    case OT_GOTO_STATION:
      if (mof != MOF_NON_STOP && mof != MOF_STOP_LOCATION && mof != MOF_UNLOAD && mof != MOF_LOAD) return CMD_ERROR;
      break;
 
    case OT_GOTO_DEPOT:
      if (mof != MOF_NON_STOP && mof != MOF_DEPOT_ACTION) return CMD_ERROR;
      break;
 
    case OT_GOTO_WAYPOINT:
      if (mof != MOF_NON_STOP) return CMD_ERROR;
      break;
 
    case OT_CONDITIONAL:
      if (mof != MOF_COND_VARIABLE && mof != MOF_COND_COMPARATOR && mof != MOF_COND_VALUE && mof != MOF_COND_DESTINATION) return CMD_ERROR;
      break;
 
    default:
      return CMD_ERROR;
  }
 
  switch (mof) {
    default: NOT_REACHED();
 
    case MOF_NON_STOP: {
      if (!v->IsGroundVehicle()) return CMD_ERROR;
 
      OrderNonStopFlags nonstop_flags = static_cast<OrderNonStopFlags>(data);
      if (nonstop_flags == order->GetNonStopType()) return CMD_ERROR;
 
      /* Test for invalid flags. */
      nonstop_flags.Reset({OrderNonStopFlag::NoIntermediate, OrderNonStopFlag::NoDestination});
      if (nonstop_flags.Any()) return CMD_ERROR;
      break;
    }
 
    case MOF_STOP_LOCATION:
      if (v->type != VEH_TRAIN) return CMD_ERROR;
      if (data >= to_underlying(OrderStopLocation::End)) return CMD_ERROR;
      break;
 
    case MOF_UNLOAD: {
      if (order->GetNonStopType().Test(OrderNonStopFlag::NoDestination)) return CMD_ERROR;
 
      OrderUnloadType unload_type = static_cast<OrderUnloadType>(data);
      if (unload_type == order->GetUnloadType()) return CMD_ERROR;
 
      /* Test for invalid types. */
      switch (unload_type) {
        case OrderUnloadType::UnloadIfPossible:
        case OrderUnloadType::Unload:
        case OrderUnloadType::Transfer:
        case OrderUnloadType::NoUnload:
          break;
 
        default: return CMD_ERROR;
      }
      break;
    }
 
    case MOF_LOAD: {
      if (order->GetNonStopType().Test(OrderNonStopFlag::NoDestination)) return CMD_ERROR;
 
      OrderLoadType load_type = static_cast<OrderLoadType>(data);
      if (load_type == order->GetLoadType()) return CMD_ERROR;
 
      /* Test for invalid types. */
      switch (load_type) {
        case OrderLoadType::LoadIfPossible:
        case OrderLoadType::NoLoad:
          break;
 
        case OrderLoadType::FullLoad:
        case OrderLoadType::FullLoadAny:
          if (v->HasUnbunchingOrder()) return CommandCost(STR_ERROR_UNBUNCHING_NO_FULL_LOAD);
          break;
 
        default: return CMD_ERROR;
      }
      break;
    }
 
    case MOF_DEPOT_ACTION: {
      OrderDepotAction depot_action = static_cast<OrderDepotAction>(data);
      if (depot_action >= OrderDepotAction::End) return CMD_ERROR;
      /* Check if we are allowed to add unbunching. We are always allowed to remove it. */
      if (depot_action == OrderDepotAction::Unbunch) {
        /* Only one unbunching order is allowed in a vehicle's orders. If this order already has an unbunching action, no error is needed. */
        if (v->HasUnbunchingOrder() && !order->GetDepotActionType().Test(OrderDepotActionFlag::Unbunch)) return CommandCost(STR_ERROR_UNBUNCHING_ONLY_ONE_ALLOWED);
        /* We don't allow unbunching if the vehicle has a conditional order. */
        if (v->HasConditionalOrder()) return CommandCost(STR_ERROR_UNBUNCHING_NO_UNBUNCHING_CONDITIONAL);
        /* We don't allow unbunching if the vehicle has a full load order. */
        if (v->HasFullLoadOrder()) return CommandCost(STR_ERROR_UNBUNCHING_NO_UNBUNCHING_FULL_LOAD);
      }
      break;
    }
 
    case MOF_COND_VARIABLE: {
      OrderConditionVariable cond_variable = static_cast<OrderConditionVariable>(data);
      if (cond_variable >= OrderConditionVariable::End) return CMD_ERROR;
      break;
    }
 
    case MOF_COND_COMPARATOR: {
      OrderConditionComparator cond_comparator = static_cast<OrderConditionComparator>(data);
      if (cond_comparator >= OrderConditionComparator::End) return CMD_ERROR;
      switch (order->GetConditionVariable()) {
        case OrderConditionVariable::Unconditionally: return CMD_ERROR;
 
        case OrderConditionVariable::RequiresService:
          if (cond_comparator != OrderConditionComparator::IsTrue && cond_comparator != OrderConditionComparator::IsFalse) return CMD_ERROR;
          break;
 
        default:
          if (cond_comparator == OrderConditionComparator::IsTrue || cond_comparator == OrderConditionComparator::IsFalse) return CMD_ERROR;
          break;
      }
      break;
    }
 
    case MOF_COND_VALUE:
      switch (order->GetConditionVariable()) {
        case OrderConditionVariable::Unconditionally:
        case OrderConditionVariable::RequiresService:
          return CMD_ERROR;
 
        case OrderConditionVariable::LoadPercentage:
        case OrderConditionVariable::Reliability:
          if (data > 100) return CMD_ERROR;
          break;
 
        default:
          if (data > 2047) return CMD_ERROR;
          break;
      }
      break;
 
    case MOF_COND_DESTINATION:
      if (data >= v->GetNumOrders()) return CMD_ERROR;
      break;
  }
 
  if (flags.Test(DoCommandFlag::Execute)) {
    switch (mof) {
      case MOF_NON_STOP:
        order->SetNonStopType(static_cast<OrderNonStopFlags>(data));
        if (order->GetNonStopType().Test(OrderNonStopFlag::NoDestination)) {
          order->SetRefit(CARGO_NO_REFIT);
          order->SetLoadType(OrderLoadType::LoadIfPossible);
          order->SetUnloadType(OrderUnloadType::UnloadIfPossible);
        }
        break;
 
      case MOF_STOP_LOCATION:
        order->SetStopLocation(static_cast<OrderStopLocation>(data));
        break;
 
      case MOF_UNLOAD:
        order->SetUnloadType(static_cast<OrderUnloadType>(data));
        break;
 
      case MOF_LOAD:
        order->SetLoadType(static_cast<OrderLoadType>(data));
        if (order->GetLoadType() == OrderLoadType::NoLoad) order->SetRefit(CARGO_NO_REFIT);
        break;
 
      case MOF_DEPOT_ACTION: {
        switch (static_cast<OrderDepotAction>(data)) {
          case OrderDepotAction::AlwaysGo:
            order->SetDepotOrderType(order->GetDepotOrderType().Reset(OrderDepotTypeFlag::Service));
            order->SetDepotActionType(order->GetDepotActionType().Reset({OrderDepotActionFlag::Halt, OrderDepotActionFlag::Unbunch}));
            break;
 
          case OrderDepotAction::Service:
            order->SetDepotOrderType(order->GetDepotOrderType().Set(OrderDepotTypeFlag::Service));
            order->SetDepotActionType(order->GetDepotActionType().Reset({OrderDepotActionFlag::Halt, OrderDepotActionFlag::Unbunch}));
            order->SetRefit(CARGO_NO_REFIT);
            break;
 
          case OrderDepotAction::Stop:
            order->SetDepotOrderType(order->GetDepotOrderType().Reset(OrderDepotTypeFlag::Service));
            order->SetDepotActionType(order->GetDepotActionType().Set(OrderDepotActionFlag::Halt).Reset(OrderDepotActionFlag::Unbunch));
            order->SetRefit(CARGO_NO_REFIT);
            break;
 
          case OrderDepotAction::Unbunch:
            order->SetDepotOrderType(order->GetDepotOrderType().Reset(OrderDepotTypeFlag::Service));
            order->SetDepotActionType(order->GetDepotActionType().Reset(OrderDepotActionFlag::Halt).Set(OrderDepotActionFlag::Unbunch));
            break;
 
          default:
            NOT_REACHED();
        }
        break;
      }
 
      case MOF_COND_VARIABLE: {
        order->SetConditionVariable((OrderConditionVariable)data);
 
        OrderConditionComparator occ = order->GetConditionComparator();
        switch (order->GetConditionVariable()) {
          case OrderConditionVariable::Unconditionally:
            order->SetConditionComparator(OrderConditionComparator::Equal);
            order->SetConditionValue(0);
            break;
 
          case OrderConditionVariable::RequiresService:
            if (occ != OrderConditionComparator::IsTrue && occ != OrderConditionComparator::IsFalse) order->SetConditionComparator(OrderConditionComparator::IsTrue);
            order->SetConditionValue(0);
            break;
 
          case OrderConditionVariable::LoadPercentage:
          case OrderConditionVariable::Reliability:
            if (order->GetConditionValue() > 100) order->SetConditionValue(100);
            [[fallthrough]];
 
          default:
            if (occ == OrderConditionComparator::IsTrue || occ == OrderConditionComparator::IsFalse) order->SetConditionComparator(OrderConditionComparator::Equal);
            break;
        }
        break;
      }
 
      case MOF_COND_COMPARATOR:
        order->SetConditionComparator((OrderConditionComparator)data);
        break;
 
      case MOF_COND_VALUE:
        order->SetConditionValue(data);
        break;
 
      case MOF_COND_DESTINATION:
        order->SetConditionSkipToOrder(data);
        break;
 
      default: NOT_REACHED();
    }
 
    /* Update the windows and full load flags, also for vehicles that share the same order list */
    Vehicle *u = v->FirstShared();
    DeleteOrderWarnings(u);
    for (; u != nullptr; u = u->NextShared()) {
      /* Toggle u->current_order "Full load" flag if it changed.
       * However, as the same flag is used for depot orders, check
       * whether we are not going to a depot as there are three
       * cases where the full load flag can be active and only
       * one case where the flag is used for depot orders. In the
       * other cases for the OrderType the flags are not used,
       * so do not care and those orders should not be active
       * when this function is called.
       */
      if (sel_ord == u->cur_real_order_index &&
          (u->current_order.IsType(OT_GOTO_STATION) || u->current_order.IsType(OT_LOADING)) &&
          u->current_order.GetLoadType() != order->GetLoadType()) {
        u->current_order.SetLoadType(order->GetLoadType());
      }
 
      /* Unbunching data is no longer valid. */
      u->ResetDepotUnbunching();
 
      InvalidateVehicleOrder(u, VIWD_MODIFY_ORDERS);
    }
  }
 
  return CommandCost();
}

static bool CheckAircraftOrderDistance(const Aircraft *v_new, const Vehicle *v_order)
{
  if (v_new->acache.cached_max_range == 0) return true;
  if (v_order->GetNumOrders() == 0) return true;
 
  const OrderList &orderlist = *v_order->orders;
  auto orders = orderlist.GetOrders();
 
  /* Iterate over all orders to check the distance between all
   * 'goto' orders and their respective next order (of any type). */
  for (VehicleOrderID cur = 0; cur < orderlist.GetNumOrders(); ++cur) {
    switch (orders[cur].GetType()) {
      case OT_GOTO_STATION:
      case OT_GOTO_DEPOT:
      case OT_GOTO_WAYPOINT:
        /* If we don't have a next order, we've reached the end and must check the first order instead. */
        if (GetOrderDistance(cur, orderlist.GetNext(cur), v_order) > v_new->acache.cached_max_range_sqr) return false;
        break;
 
      default: break;
    }
  }
 
  return true;
}

CommandCost CmdCloneOrder(DoCommandFlags flags, CloneOptions action, VehicleID veh_dst, VehicleID veh_src)
{
  Vehicle *dst = Vehicle::GetIfValid(veh_dst);
  if (dst == nullptr || !dst->IsPrimaryVehicle()) return CMD_ERROR;
 
  CommandCost ret = CheckOwnership(dst->owner);
  if (ret.Failed()) return ret;
 
  switch (action) {
    case CO_SHARE: {
      Vehicle *src = Vehicle::GetIfValid(veh_src);
 
      /* Sanity checks */
      if (src == nullptr || !src->IsPrimaryVehicle() || dst->type != src->type || dst == src) return CMD_ERROR;
 
      ret = CheckOwnership(src->owner);
      if (ret.Failed()) return ret;
 
      /* Trucks can't share orders with busses (and visa versa) */
      if (src->type == VEH_ROAD && RoadVehicle::From(src)->IsBus() != RoadVehicle::From(dst)->IsBus()) {
        return CMD_ERROR;
      }
 
      /* Is the vehicle already in the shared list? */
      if (src->FirstShared() == dst->FirstShared()) return CMD_ERROR;
 
      for (const Order &order : src->Orders()) {
        if (!OrderGoesToStation(dst, order)) continue;
 
        /* Allow copying unreachable destinations if they were already unreachable for the source.
         * This is basically to allow cloning / autorenewing / autoreplacing vehicles, while the stations
         * are temporarily invalid due to reconstruction. */
        const Station *st = Station::Get(order.GetDestination().ToStationID());
        if (CanVehicleUseStation(src, st) && !CanVehicleUseStation(dst, st)) {
          return CommandCost(STR_ERROR_CAN_T_COPY_SHARE_ORDER, GetVehicleCannotUseStationReason(dst, st));
        }
      }
 
      /* Check for aircraft range limits. */
      if (dst->type == VEH_AIRCRAFT && !CheckAircraftOrderDistance(Aircraft::From(dst), src)) {
        return CommandCost(STR_ERROR_AIRCRAFT_NOT_ENOUGH_RANGE);
      }
 
      if (src->orders == nullptr && !OrderList::CanAllocateItem()) {
        return CommandCost(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
      }
 
      if (flags.Test(DoCommandFlag::Execute)) {
        /* If the destination vehicle had a OrderList, destroy it.
         * We only reset the order indices, if the new orders are obviously different.
         * (We mainly do this to keep the order indices valid and in range.) */
        DeleteVehicleOrders(dst, false, dst->GetNumOrders() != src->GetNumOrders());
 
        dst->orders = src->orders;
 
        /* Link this vehicle in the shared-list */
        dst->AddToShared(src);
 
        InvalidateVehicleOrder(dst, VIWD_REMOVE_ALL_ORDERS);
        InvalidateVehicleOrder(src, VIWD_MODIFY_ORDERS);
 
        InvalidateWindowClassesData(GetWindowClassForVehicleType(dst->type), 0);
      }
      break;
    }
 
    case CO_COPY: {
      Vehicle *src = Vehicle::GetIfValid(veh_src);
 
      /* Sanity checks */
      if (src == nullptr || !src->IsPrimaryVehicle() || dst->type != src->type || dst == src) return CMD_ERROR;
 
      ret = CheckOwnership(src->owner);
      if (ret.Failed()) return ret;
 
      /* Trucks can't copy all the orders from busses (and visa versa),
       * and neither can helicopters and aircraft. */
      for (const Order &order : src->Orders()) {
        if (!OrderGoesToStation(dst, order)) continue;
        Station *st = Station::Get(order.GetDestination().ToStationID());
        if (!CanVehicleUseStation(dst, st)) {
          return CommandCost(STR_ERROR_CAN_T_COPY_SHARE_ORDER, GetVehicleCannotUseStationReason(dst, st));
        }
      }
 
      /* Check for aircraft range limits. */
      if (dst->type == VEH_AIRCRAFT && !CheckAircraftOrderDistance(Aircraft::From(dst), src)) {
        return CommandCost(STR_ERROR_AIRCRAFT_NOT_ENOUGH_RANGE);
      }
 
      /* make sure there are orders available */
      if (!OrderList::CanAllocateItem()) {
        return CommandCost(STR_ERROR_NO_MORE_SPACE_FOR_ORDERS);
      }
 
      if (flags.Test(DoCommandFlag::Execute)) {
        /* If the destination vehicle had an order list, destroy the chain but keep the OrderList.
         * We only reset the order indices, if the new orders are obviously different.
         * (We mainly do this to keep the order indices valid and in range.) */
        DeleteVehicleOrders(dst, true, dst->GetNumOrders() != src->GetNumOrders());
 
        std::vector<Order> dst_orders;
        for (const Order &order : src->Orders()) {
          dst_orders.emplace_back(order);
        }
 
        if (dst->orders != nullptr) {
          assert(dst->orders->GetNumOrders() == 0);
          assert(!dst->orders->IsShared());
          delete dst->orders;
        }
 
        assert(OrderList::CanAllocateItem());
        dst->orders = OrderList::Create(std::move(dst_orders), dst);
 
        InvalidateVehicleOrder(dst, VIWD_REMOVE_ALL_ORDERS);
 
        InvalidateWindowClassesData(GetWindowClassForVehicleType(dst->type), 0);
      }
      break;
    }
 
    case CO_UNSHARE: return DecloneOrder(dst, flags);
    default: return CMD_ERROR;
  }
 
  return CommandCost();
}

CommandCost CmdOrderRefit(DoCommandFlags flags, VehicleID veh, VehicleOrderID order_number, CargoType cargo)
{
  if (cargo >= NUM_CARGO && cargo != CARGO_NO_REFIT && cargo != CARGO_AUTO_REFIT) return CMD_ERROR;
 
  const Vehicle *v = Vehicle::GetIfValid(veh);
  if (v == nullptr || !v->IsPrimaryVehicle()) return CMD_ERROR;
 
  CommandCost ret = CheckOwnership(v->owner);
  if (ret.Failed()) return ret;
 
  Order *order = v->GetOrder(order_number);
  if (order == nullptr) return CMD_ERROR;
 
  /* Automatic refit cargo is only supported for goto station orders. */
  if (cargo == CARGO_AUTO_REFIT && !order->IsType(OT_GOTO_STATION)) return CMD_ERROR;
 
  if (order->GetLoadType() == OrderLoadType::NoLoad) return CMD_ERROR;
 
  if (flags.Test(DoCommandFlag::Execute)) {
    order->SetRefit(cargo);
 
    /* Make the depot order an 'always go' order. */
    if (cargo != CARGO_NO_REFIT && order->IsType(OT_GOTO_DEPOT)) {
      order->SetDepotOrderType(order->GetDepotOrderType().Reset(OrderDepotTypeFlag::Service));
      order->SetDepotActionType(order->GetDepotActionType().Reset(OrderDepotActionFlag::Halt));
    }
 
    for (Vehicle *u = v->FirstShared(); u != nullptr; u = u->NextShared()) {
      /* Update any possible open window of the vehicle */
      InvalidateVehicleOrder(u, VIWD_MODIFY_ORDERS);
 
      /* If the vehicle already got the current depot set as current order, then update current order as well */
      if (u->cur_real_order_index == order_number && u->current_order.GetDepotOrderType().Test(OrderDepotTypeFlag::PartOfOrders)) {
        u->current_order.SetRefit(cargo);
      }
    }
  }
 
  return CommandCost();
}
 

void CheckOrders(const Vehicle *v)
{
  /* Does the user wants us to check things? */
  if (_settings_client.gui.order_review_system == 0) return;
 
  /* Do nothing for crashed vehicles */
  if (v->vehstatus.Test(VehState::Crashed)) return;
 
  /* Do nothing for stopped vehicles if setting is '1' */
  if (_settings_client.gui.order_review_system == 1 && v->vehstatus.Test(VehState::Stopped)) return;
 
  /* do nothing we we're not the first vehicle in a share-chain */
  if (v->FirstShared() != v) return;
 
  /* Only check every 20 days, so that we don't flood the message log */
  if (v->owner == _local_company && v->day_counter % 20 == 0) {
    StringID message = INVALID_STRING_ID;
 
    /* Check the order list */
    int n_st = 0;
 
    for (const Order &order : v->Orders()) {
      /* Dummy order? */
      if (order.IsType(OT_DUMMY)) {
        message = STR_NEWS_VEHICLE_HAS_VOID_ORDER;
        break;
      }
      /* Does station have a load-bay for this vehicle? */
      if (order.IsType(OT_GOTO_STATION)) {
        const Station *st = Station::Get(order.GetDestination().ToStationID());
 
        n_st++;
        if (!CanVehicleUseStation(v, st)) {
          message = STR_NEWS_VEHICLE_HAS_INVALID_ENTRY;
        } else if (v->type == VEH_AIRCRAFT &&
              (AircraftVehInfo(v->engine_type)->subtype & AIR_FAST) &&
              st->airport.GetFTA()->flags.Test(AirportFTAClass::Flag::ShortStrip) &&
              !_cheats.no_jetcrash.value &&
              message == INVALID_STRING_ID) {
          message = STR_NEWS_PLANE_USES_TOO_SHORT_RUNWAY;
        }
      }
    }
 
    /* Check if the last and the first order are the same */
    if (v->GetNumOrders() > 1) {
      auto orders = v->Orders();
 
      if (orders.front().Equals(orders.back())) {
        message = STR_NEWS_VEHICLE_HAS_DUPLICATE_ENTRY;
      }
    }
 
    /* Do we only have 1 station in our order list? */
    if (n_st < 2 && message == INVALID_STRING_ID) message = STR_NEWS_VEHICLE_HAS_TOO_FEW_ORDERS;
 
#ifdef WITH_ASSERT
    if (v->orders != nullptr) v->orders->DebugCheckSanity();
#endif
 
    /* We don't have a problem */
    if (message == INVALID_STRING_ID) return;
 
    AddVehicleAdviceNewsItem(AdviceType::Order, GetEncodedString(message, v->index), v->index);
  }
}

void RemoveOrderFromAllVehicles(OrderType type, DestinationID destination, bool hangar)
{
  /* Aircraft have StationIDs for depot orders and never use DepotIDs
   * This fact is handled specially below
   */
 
  /* Go through all vehicles */
  for (Vehicle *v : Vehicle::Iterate()) {
    if ((v->type == VEH_AIRCRAFT && v->current_order.IsType(OT_GOTO_DEPOT) && !hangar ? OT_GOTO_STATION : v->current_order.GetType()) == type &&
        (!hangar || v->type == VEH_AIRCRAFT) && v->current_order.GetDestination() == destination) {
      v->current_order.MakeDummy();
      InvalidateWindowData(WC_VEHICLE_VIEW, v->index);
    }
 
    if (v->orders == nullptr) continue;
 
    /* Clear the order from the order-list */
    for (VehicleOrderID id = 0, next_id = 0; id < v->GetNumOrders(); id = next_id) {
      next_id = id + 1;
      Order *order = v->orders->GetOrderAt(id);
      OrderType ot = order->GetType();
      if (ot == OT_GOTO_DEPOT && order->GetDepotActionType().Test(OrderDepotActionFlag::NearestDepot)) continue;
      if (ot == OT_GOTO_DEPOT && hangar && v->type != VEH_AIRCRAFT) continue; // Not an aircraft? Can't have a hangar order.
      if (ot == OT_IMPLICIT || (v->type == VEH_AIRCRAFT && ot == OT_GOTO_DEPOT && !hangar)) ot = OT_GOTO_STATION;
      if (ot == type && order->GetDestination() == destination) {
        /* We want to clear implicit orders, but we don't want to make them
         * dummy orders. They should just vanish. Also check the actual order
         * type as ot is currently OT_GOTO_STATION. */
        if (order->IsType(OT_IMPLICIT)) {
          DeleteOrder(v, id);
          next_id = id;
          continue;
        }
 
        /* Clear wait time */
        v->orders->UpdateTotalDuration(-order->GetWaitTime());
        if (order->IsWaitTimetabled()) {
          v->orders->UpdateTimetableDuration(-order->GetTimetabledWait());
          order->SetWaitTimetabled(false);
        }
        order->SetWaitTime(0);
 
        /* Clear order, preserving travel time */
        bool travel_timetabled = order->IsTravelTimetabled();
        order->MakeDummy();
        order->SetTravelTimetabled(travel_timetabled);
 
        for (const Vehicle *w = v->FirstShared(); w != nullptr; w = w->NextShared()) {
          /* In GUI, simulate by removing the order and adding it back */
          InvalidateVehicleOrder(w, id | (INVALID_VEH_ORDER_ID << 8));
          InvalidateVehicleOrder(w, (INVALID_VEH_ORDER_ID << 8) | id);
        }
      }
    }
  }
 
  OrderBackup::RemoveOrder(type, destination, hangar);
}

bool Vehicle::HasDepotOrder() const
{
  return std::ranges::any_of(this->Orders(), [](const Order &order) { return order.IsType(OT_GOTO_DEPOT); });
}

void DeleteVehicleOrders(Vehicle *v, bool keep_orderlist, bool reset_order_indices)
{
  DeleteOrderWarnings(v);
 
  if (v->IsOrderListShared()) {
    /* Remove ourself from the shared order list. */
    v->RemoveFromShared();
    v->orders = nullptr;
  } else if (v->orders != nullptr) {
    /* Remove the orders */
    v->orders->FreeChain(keep_orderlist);
    if (!keep_orderlist) v->orders = nullptr;
  }
 
  /* Unbunching data is no longer valid. */
  v->ResetDepotUnbunching();
 
  if (reset_order_indices) {
    v->cur_implicit_order_index = v->cur_real_order_index = 0;
    if (v->current_order.IsType(OT_LOADING)) {
      CancelLoadingDueToDeletedOrder(v);
    }
  }
}

uint16_t GetServiceIntervalClamped(int interval, bool ispercent)
{
  /* Service intervals are in percents. */
  if (ispercent) return Clamp(interval, MIN_SERVINT_PERCENT, MAX_SERVINT_PERCENT);
 
  /* Service intervals are in minutes. */
  if (TimerGameEconomy::UsingWallclockUnits(_game_mode == GM_MENU)) return Clamp(interval, MIN_SERVINT_MINUTES, MAX_SERVINT_MINUTES);
 
  /* Service intervals are in days. */
  return Clamp(interval, MIN_SERVINT_DAYS, MAX_SERVINT_DAYS);
}

static bool CheckForValidOrders(const Vehicle *v)
{
  /* Check if vehicle has any valid orders.
   * Function is only called for aircraft, no type check needed. */
  return std::ranges::any_of(v->Orders(), [](const Order &order) {
    return order.IsGotoOrder() && (!order.IsType(OT_GOTO_DEPOT) || !order.GetDepotActionType().Test(OrderDepotActionFlag::NearestDepot));
  });
}

static bool OrderConditionCompare(OrderConditionComparator occ, int variable, int value)
{
  switch (occ) {
    case OrderConditionComparator::Equal: return variable == value;
    case OrderConditionComparator::NotEqual: return variable != value;
    case OrderConditionComparator::LessThan: return variable < value;
    case OrderConditionComparator::LessThanOrEqual: return variable <= value;
    case OrderConditionComparator::MoreThan: return variable > value;
    case OrderConditionComparator::MoreThanOrEqual: return variable >= value;
    case OrderConditionComparator::IsTrue: return variable != 0;
    case OrderConditionComparator::IsFalse: return variable == 0;
    default: NOT_REACHED();
  }
}
 
static bool OrderConditionCompare(OrderConditionComparator occ, ConvertibleThroughBase auto variable, int value)
{
  return OrderConditionCompare(occ, variable.base(), value);
}

VehicleOrderID ProcessConditionalOrder(const Order *order, const Vehicle *v)
{
  if (order->GetType() != OT_CONDITIONAL) return INVALID_VEH_ORDER_ID;
 
  bool skip_order = false;
  OrderConditionComparator occ = order->GetConditionComparator();
  uint16_t value = order->GetConditionValue();
 
  switch (order->GetConditionVariable()) {
    case OrderConditionVariable::LoadPercentage: skip_order = OrderConditionCompare(occ, CalcPercentVehicleFilled(v, nullptr), value); break;
    case OrderConditionVariable::Reliability: skip_order = OrderConditionCompare(occ, ToPercent16(v->reliability), value); break;
    case OrderConditionVariable::MaxReliability: skip_order = OrderConditionCompare(occ, ToPercent16(v->GetEngine()->reliability), value); break;
    case OrderConditionVariable::MaxSpeed: skip_order = OrderConditionCompare(occ, v->GetDisplayMaxSpeed() * 10 / 16, value); break;
    case OrderConditionVariable::Age: skip_order = OrderConditionCompare(occ, TimerGameCalendar::DateToYear(v->age), value); break;
    case OrderConditionVariable::RequiresService: skip_order = OrderConditionCompare(occ, v->NeedsServicing(), value); break;
    case OrderConditionVariable::Unconditionally: skip_order = true; break;
    case OrderConditionVariable::RemainingLifetime: skip_order = OrderConditionCompare(occ, std::max(TimerGameCalendar::DateToYear(v->max_age - v->age + CalendarTime::DAYS_IN_LEAP_YEAR - 1), TimerGameCalendar::Year(0)), value); break;
    default: NOT_REACHED();
  }
 
  return skip_order ? order->GetConditionSkipToOrder() : (VehicleOrderID)INVALID_VEH_ORDER_ID;
}

bool UpdateOrderDest(Vehicle *v, const Order *order, int conditional_depth, bool pbs_look_ahead)
{
  if (conditional_depth > v->GetNumOrders()) {
    v->current_order.Free();
    v->SetDestTile(INVALID_TILE);
    return false;
  }
 
  switch (order->GetType()) {
    case OT_GOTO_STATION:
      v->SetDestTile(v->GetOrderStationLocation(order->GetDestination().ToStationID()));
      return true;
 
    case OT_GOTO_DEPOT:
      if (order->GetDepotOrderType().Test(OrderDepotTypeFlag::Service) && !v->NeedsServicing()) {
        assert(!pbs_look_ahead);
        UpdateVehicleTimetable(v, true);
        v->IncrementRealOrderIndex();
        break;
      }
 
      if (v->current_order.GetDepotActionType().Test(OrderDepotActionFlag::NearestDepot)) {
        /* If the vehicle can't find its destination, delay its next search.
         * In case many vehicles are in this state, use the vehicle index to spread out pathfinder calls. */
        if (v->dest_tile == INVALID_TILE && TimerGameEconomy::date_fract != (v->index % Ticks::DAY_TICKS)) break;
 
        /* We need to search for the nearest depot (hangar). */
        ClosestDepot closest_depot = v->FindClosestDepot();
 
        if (closest_depot.found) {
          /* PBS reservations cannot reverse */
          if (pbs_look_ahead && closest_depot.reverse) return false;
 
          v->SetDestTile(closest_depot.location);
          v->current_order.SetDestination(closest_depot.destination);
 
          /* If there is no depot in front, reverse automatically (trains only) */
          if (v->type == VEH_TRAIN && closest_depot.reverse) Command<Commands::ReverseTrainDirection>::Do(DoCommandFlag::Execute, v->index, false);
 
          if (v->type == VEH_AIRCRAFT) {
            Aircraft *a = Aircraft::From(v);
            if (a->state == FLYING && a->targetairport != closest_depot.destination) {
              /* The aircraft is now heading for a different hangar than the next in the orders */
              AircraftNextAirportPos_and_Order(a);
            }
          }
          return true;
        }
 
        /* If there is no depot, we cannot help PBS either. */
        if (pbs_look_ahead) return false;
 
        UpdateVehicleTimetable(v, true);
        v->IncrementRealOrderIndex();
      } else {
        if (v->type != VEH_AIRCRAFT) {
          v->SetDestTile(Depot::Get(order->GetDestination().ToStationID())->xy);
        } else {
          Aircraft *a = Aircraft::From(v);
          DestinationID destination = a->current_order.GetDestination();
          if (a->targetairport != destination) {
            /* The aircraft is now heading for a different hangar than the next in the orders */
            a->SetDestTile(a->GetOrderStationLocation(destination.ToStationID()));
          }
        }
        return true;
      }
      break;
 
    case OT_GOTO_WAYPOINT:
      v->SetDestTile(Waypoint::Get(order->GetDestination().ToStationID())->xy);
      return true;
 
    case OT_CONDITIONAL: {
      assert(!pbs_look_ahead);
      VehicleOrderID next_order = ProcessConditionalOrder(order, v);
      if (next_order != INVALID_VEH_ORDER_ID) {
        /* Jump to next_order. cur_implicit_order_index becomes exactly that order,
         * cur_real_order_index might come after next_order. */
        UpdateVehicleTimetable(v, false);
        v->cur_implicit_order_index = v->cur_real_order_index = next_order;
        v->UpdateRealOrderIndex();
        v->current_order_time += v->GetOrder(v->cur_real_order_index)->GetTimetabledTravel();
 
        /* Disable creation of implicit orders.
         * When inserting them we do not know that we would have to make the conditional orders point to them. */
        if (v->IsGroundVehicle()) {
          uint16_t &gv_flags = v->GetGroundVehicleFlags();
          SetBit(gv_flags, GVF_SUPPRESS_IMPLICIT_ORDERS);
        }
      } else {
        UpdateVehicleTimetable(v, true);
        v->IncrementRealOrderIndex();
      }
      break;
    }
 
    default:
      v->SetDestTile(INVALID_TILE);
      return false;
  }
 
  assert(v->cur_implicit_order_index < v->GetNumOrders());
  assert(v->cur_real_order_index < v->GetNumOrders());
 
  /* Get the current order */
  order = v->GetOrder(v->cur_real_order_index);
  if (order != nullptr && order->IsType(OT_IMPLICIT)) {
    assert(v->GetNumManualOrders() == 0);
    order = nullptr;
  }
 
  if (order == nullptr) {
    v->current_order.Free();
    v->SetDestTile(INVALID_TILE);
    return false;
  }
 
  v->current_order = *order;
  return UpdateOrderDest(v, order, conditional_depth + 1, pbs_look_ahead);
}

bool ProcessOrders(Vehicle *v)
{
  switch (v->current_order.GetType()) {
    case OT_GOTO_DEPOT:
      /* Let a depot order in the orderlist interrupt. */
      if (!v->current_order.GetDepotOrderType().Test(OrderDepotTypeFlag::PartOfOrders)) return false;
      break;
 
    case OT_LOADING:
      return false;
 
    case OT_LEAVESTATION:
      if (v->type != VEH_AIRCRAFT) return false;
      break;
 
    default: break;
  }

  bool may_reverse = v->current_order.IsType(OT_NOTHING);
 
  /* Check if we've reached a 'via' destination. */
  if (((v->current_order.IsType(OT_GOTO_STATION) && v->current_order.GetNonStopType().Test(OrderNonStopFlag::NoDestination)) || v->current_order.IsType(OT_GOTO_WAYPOINT)) &&
      IsTileType(v->tile, TileType::Station) &&
      v->current_order.GetDestination() == GetStationIndex(v->tile)) {
    v->DeleteUnreachedImplicitOrders();
    /* We set the last visited station here because we do not want
     * the train to stop at this 'via' station if the next order
     * is a no-non-stop order; in that case not setting the last
     * visited station will cause the vehicle to still stop. */
    v->last_station_visited = v->current_order.GetDestination().ToStationID();
    UpdateVehicleTimetable(v, true);
    v->IncrementImplicitOrderIndex();
  }
 
  /* Get the current order */
  assert(v->cur_implicit_order_index == 0 || v->cur_implicit_order_index < v->GetNumOrders());
  v->UpdateRealOrderIndex();
 
  const Order *order = v->GetOrder(v->cur_real_order_index);
  if (order != nullptr && order->IsType(OT_IMPLICIT)) {
    assert(v->GetNumManualOrders() == 0);
    order = nullptr;
  }
 
  /* If no order, do nothing. */
  if (order == nullptr || (v->type == VEH_AIRCRAFT && !CheckForValidOrders(v))) {
    if (v->type == VEH_AIRCRAFT) {
      /* Aircraft do something vastly different here, so handle separately */
      HandleMissingAircraftOrders(Aircraft::From(v));
      return false;
    }
 
    v->current_order.Free();
    v->SetDestTile(INVALID_TILE);
    return false;
  }
 
  /* If it is unchanged, keep it. */
  if (order->Equals(v->current_order) && (v->type == VEH_AIRCRAFT || v->dest_tile != INVALID_TILE) &&
      (v->type != VEH_SHIP || !order->IsType(OT_GOTO_STATION) || Station::Get(order->GetDestination().ToStationID())->ship_station.tile != INVALID_TILE)) {
    return false;
  }
 
  /* Otherwise set it, and determine the destination tile. */
  v->current_order = *order;
 
  InvalidateVehicleOrder(v, VIWD_MODIFY_ORDERS);
  switch (v->type) {
    default:
      NOT_REACHED();
 
    case VEH_ROAD:
    case VEH_TRAIN:
      break;
 
    case VEH_AIRCRAFT:
    case VEH_SHIP:
      SetWindowClassesDirty(GetWindowClassForVehicleType(v->type));
      break;
  }
 
  return UpdateOrderDest(v, order) && may_reverse;
}

bool Order::ShouldStopAtStation(const Vehicle *v, StationID station) const
{
  bool is_dest_station = this->IsType(OT_GOTO_STATION) && this->dest == station;
 
  return (!this->IsType(OT_GOTO_DEPOT) || this->GetDepotOrderType().Test(OrderDepotTypeFlag::PartOfOrders)) &&
      v->last_station_visited != station && // Do stop only when we've not just been there
      /* Finally do stop when there is no non-stop flag set for this type of station. */
      !this->GetNonStopType().Test(is_dest_station ? OrderNonStopFlag::NoDestination : OrderNonStopFlag::NoIntermediate);
}
 
bool Order::CanLoadOrUnload() const
{
  return (this->IsType(OT_GOTO_STATION) || this->IsType(OT_IMPLICIT)) &&
      !this->GetNonStopType().Test(OrderNonStopFlag::NoDestination) &&
      (this->GetLoadType() != OrderLoadType::NoLoad ||
      this->GetUnloadType() != OrderUnloadType::NoUnload);
}

bool Order::CanLeaveWithCargo(bool has_cargo) const
{
  return this->GetLoadType() != OrderLoadType::NoLoad || (has_cargo &&
      this->GetUnloadType() != OrderUnloadType::Unload &&
      this->GetUnloadType() != OrderUnloadType::Transfer);
}