/*
 * Copyright 2013-2019 Software Radio Systems Limited
 *
 * This file is part of srsLTE.
 *
 * srsLTE is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 *
 * srsLTE 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 Affero General Public License for more details.
 *
 * A copy of the GNU Affero General Public License can be found in
 * the LICENSE file in the top-level directory of this distribution
 * and at http://www.gnu.org/licenses/.
 *
 */

#ifndef SRSLTE_PDCP_ENTITY_LTE_H
#define SRSLTE_PDCP_ENTITY_LTE_H

#include "srslte/common/buffer_pool.h"
#include "srslte/common/log.h"
#include "srslte/common/common.h"
#include "srslte/interfaces/ue_interfaces.h"
#include "srslte/common/security.h"
#include "srslte/common/threads.h"
#include "srslte/upper/pdcp_entity_base.h"


namespace srslte {

/****************************************************************************
 * Structs and Defines
 * Ref: 3GPP TS 36.323 v10.1.0
 ***************************************************************************/

#define PDCP_CONTROL_MAC_I 0x00000000

/****************************************************************************
 * LTE PDCP Entity 
 * Class for LTE PDCP entities
 ***************************************************************************/
class pdcp_entity_lte final: public pdcp_entity_base
{
public:
  pdcp_entity_lte();
  ~pdcp_entity_lte();
  void init(srsue::rlc_interface_pdcp* rlc_,
            srsue::rrc_interface_pdcp* rrc_,
            srsue::gw_interface_pdcp*  gw_,
            srslte::log*               log_,
            uint32_t                   lcid_,
            srslte_pdcp_config_t       cfg_);
  void reset();
  void reestablish();

  // GW/RRC interface
  void write_sdu(unique_byte_buffer_t sdu, bool blocking);

  uint32_t get_dl_count();
  uint32_t get_ul_count();

  // RLC interface
  void write_pdu(unique_byte_buffer_t pdu);

private:
  srsue::rlc_interface_pdcp* rlc = nullptr;
  srsue::rrc_interface_pdcp* rrc = nullptr;
  srsue::gw_interface_pdcp*  gw  = nullptr;

  srslte_pdcp_config_t cfg = {0, SECURITY_DIRECTION_UPLINK, false, false, 0};

  uint32_t rx_count = 0;
  uint32_t tx_count = 0;

  uint32_t rx_hfn                    = 0;
  uint32_t next_pdcp_rx_sn           = 0;
  uint32_t reordering_window         = 0;
  uint32_t last_submitted_pdcp_rx_sn = 0;
  uint32_t maximum_pdcp_sn           = 0;

  void handle_um_drb_pdu(const srslte::unique_byte_buffer_t& pdu);
  void handle_am_drb_pdu(const srslte::unique_byte_buffer_t& pdu);
};

/****************************************************************************
 * Pack/Unpack helper functions
 * Ref: 3GPP TS 36.323 v10.1.0
 ***************************************************************************/

void pdcp_pack_control_pdu(uint32_t sn, byte_buffer_t *sdu);
void pdcp_unpack_control_pdu(byte_buffer_t *sdu, uint32_t *sn);

void pdcp_pack_data_pdu_short_sn(uint32_t sn, byte_buffer_t *sdu);
void pdcp_unpack_data_pdu_short_sn(byte_buffer_t *sdu, uint32_t *sn);
void pdcp_pack_data_pdu_long_sn(uint32_t sn, byte_buffer_t *sdu);
void pdcp_unpack_data_pdu_long_sn(byte_buffer_t *sdu, uint32_t *sn);

} // namespace srslte
#endif // SRSLTE_PDCP_ENTITY_LTE_H