/* static */ VehicleID ScriptVehicle::GetVehicleID(UnitID unit_number, ScriptVehicle::VehicleType vehicle_type)
{
	EnforcePrecondition(INVALID_VEHICLE, vehicle_type == ScriptVehicle::VT_AIR || vehicle_type == ScriptVehicle::VT_ROAD || vehicle_type == ScriptVehicle::VT_RAIL || vehicle_type == ScriptVehicle::VT_WATER);
	EnforcePrecondition(INVALID_VEHICLE, unit_number >= 0 && unit_number <= UINT16_MAX);

	switch (vehicle_type) {
		case ScriptVehicle::VT_AIR: {
			Aircraft *v;
			FOR_ALL_AIRCRAFT(v) {
				if (!v->IsPrimaryVehicle()) continue;

				if (v->unitnumber == unit_number && v->owner == ScriptObject::GetCompany()) {
					return v->index;
				}
			}
			return INVALID_VEHICLE;
		}

		case ScriptVehicle::VT_ROAD: {
			RoadVehicle *v;
			FOR_ALL_ROADVEHICLES(v) {
				if (!v->IsPrimaryVehicle()) continue;

				if (v->unitnumber == unit_number && v->owner == ScriptObject::GetCompany()) {
					return v->index;
				}
			}
			return INVALID_VEHICLE;
		}

		case ScriptVehicle::VT_RAIL: {
			Train *v;
			FOR_ALL_TRAINS(v) {
				if (!v->IsPrimaryVehicle()) continue;

				if (v->unitnumber == unit_number && v->owner == ScriptObject::GetCompany()) {
					return v->index;
				}
			}
			return INVALID_VEHICLE;
		}

		case ScriptVehicle::VT_WATER: {
			Ship *v;
			FOR_ALL_SHIPS(v) {
				if (!v->IsPrimaryVehicle()) continue;

				if (v->unitnumber == unit_number && v->owner == ScriptObject::GetCompany()) {
					return v->index;
				}
			}
			return INVALID_VEHICLE;
		}

		default: return INVALID_VEHICLE;
	}
}