/*
 * 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 SRSUE_MUX_H
#define SRSUE_MUX_H

#include <pthread.h>

#include <vector>

#include "proc_bsr.h"
#include "proc_phr.h"
#include "srslte/common/common.h"
#include "srslte/common/log.h"
#include "srslte/common/pdu.h"
#include "srslte/interfaces/ue_interfaces.h"

/* Logical Channel Multiplexing and Prioritization + Msg3 Buffer */   


typedef struct {
  uint8_t  lcid;
  uint8_t  lcg;
  int      Bj;
  int      PBR; // -1 sets to infinity
  uint32_t BSD;
  uint32_t priority;
  int      sched_len;
  int      buffer_len;
} logical_channel_config_t;

namespace srsue {
  
class mux
{
public:
  mux();
  void     reset();
  void     init(rlc_interface_mac *rlc, srslte::log *log_h, bsr_interface_mux *bsr_procedure, phr_proc *phr_procedure_);

  bool     is_pending_any_sdu();
  bool     is_pending_sdu(uint32_t lcid);

  uint8_t* pdu_get(srslte::byte_buffer_t* payload, uint32_t pdu_sz);
  uint8_t* msg3_get(srslte::byte_buffer_t* payload, uint32_t pdu_sz);

  void     msg3_flush();
  bool     msg3_is_transmitted();

  void     msg3_prepare();
  bool     msg3_is_pending();

  void append_crnti_ce_next_tx(uint16_t crnti);

  void setup_lcid(const logical_channel_config_t& config);

  void print_logical_channel_state(const std::string& info);

private:
  bool     has_logical_channel(const uint32_t& lcid);
  bool     pdu_move_to_msg3(uint32_t pdu_sz);
  bool     allocate_sdu(uint32_t lcid, srslte::sch_pdu *pdu, int max_sdu_sz);
  bool     sched_sdu(logical_channel_config_t* ch, int* sdu_space, int max_sdu_sz);

  const static int MIN_RLC_SDU_LEN    = 2;
  const static int MAX_NOF_SUBHEADERS = 20;

  std::vector<logical_channel_config_t> logical_channels;

  // Mutex for exclusive access
  pthread_mutex_t mutex; 

  srslte::log       *log_h;
  rlc_interface_mac *rlc; 
  bsr_interface_mux *bsr_procedure;
  phr_proc          *phr_procedure;
  uint16_t           pending_crnti_ce;

  /* Msg3 Buffer */
  srslte::byte_buffer_t msg_buff;

  /* PDU Buffer */
  srslte::sch_pdu    pdu_msg; 
  bool msg3_has_been_transmitted;
  bool msg3_pending;
};

} // namespace srsue

#endif // SRSUE_MUX_H