/*
 * Copyright 2013-2020 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/.
 *
 */

#include "srslte/upper/pdcp.h"

namespace srslte {

pdcp::pdcp(srslte::task_handler_interface* task_executor_, const char* logname) :
  task_executor(task_executor_),
  pdcp_log(logname)
{
}

pdcp::~pdcp()
{
  {
    std::lock_guard<std::mutex> lock(cache_mutex);
    valid_lcids_cached.clear();
  }
  // destroy all remaining entities
  for (pdcp_map_t::iterator it = pdcp_array.begin(); it != pdcp_array.end(); ++it) {
    delete (it->second);
  }
  pdcp_array.clear();

  for (pdcp_map_t::iterator it = pdcp_array_mrb.begin(); it != pdcp_array_mrb.end(); ++it) {
    delete (it->second);
  }
  pdcp_array_mrb.clear();
}

void pdcp::init(srsue::rlc_interface_pdcp* rlc_, srsue::rrc_interface_pdcp* rrc_, srsue::gw_interface_pdcp* gw_)
{
  rlc = rlc_;
  rrc = rrc_;
  gw  = gw_;
}

void pdcp::stop() {}

void pdcp::reestablish()
{
  for (pdcp_map_t::iterator it = pdcp_array.begin(); it != pdcp_array.end(); ++it) {
    it->second->reestablish();
  }
}

void pdcp::reestablish(uint32_t lcid)
{
  if (valid_lcid(lcid)) {
    pdcp_array.at(lcid)->reestablish();
  }
}

void pdcp::reset()
{
  {
    std::lock_guard<std::mutex> lock(cache_mutex);
    valid_lcids_cached.clear();
  }
  // destroy all bearers
  for (pdcp_map_t::iterator it = pdcp_array.begin(); it != pdcp_array.end(); /* post increment in erase */) {
    it->second->reset();
    delete (it->second);
    pdcp_array.erase(it++);
  }
}

/*******************************************************************************
  RRC/GW interface
*******************************************************************************/

// NOTE: Called from separate thread
bool pdcp::is_lcid_enabled(uint32_t lcid)
{
  std::lock_guard<std::mutex> lock(cache_mutex);
  return valid_lcids_cached.count(lcid) > 0;
}

void pdcp::write_sdu(uint32_t lcid, unique_byte_buffer_t sdu, bool blocking)
{
  if (valid_lcid(lcid)) {
    pdcp_array.at(lcid)->write_sdu(std::move(sdu), blocking);
  } else {
    pdcp_log->warning("Writing sdu: lcid=%d. Deallocating sdu\n", lcid);
  }
}

void pdcp::write_sdu_mch(uint32_t lcid, unique_byte_buffer_t sdu)
{
  if (valid_mch_lcid(lcid)) {
    pdcp_array_mrb.at(lcid)->write_sdu(std::move(sdu), true);
  }
}

void pdcp::add_bearer(uint32_t lcid, pdcp_config_t cfg)
{
  if (not valid_lcid(lcid)) {
    if (not pdcp_array.insert(pdcp_map_pair_t(lcid, new pdcp_entity_lte(rlc, rrc, gw, task_executor, pdcp_log)))
                .second) {
      pdcp_log->error("Error inserting PDCP entity in to array\n.");
      return;
    }
    pdcp_array.at(lcid)->init(lcid, cfg);
    pdcp_log->info("Add %s (lcid=%d, bearer_id=%d, sn_len=%dbits)\n",
                   rrc->get_rb_name(lcid).c_str(),
                   lcid,
                   cfg.bearer_id,
                   cfg.sn_len);
    {
      std::lock_guard<std::mutex> lock(cache_mutex);
      valid_lcids_cached.insert(lcid);
    }
  } else {
    pdcp_log->warning("Bearer %s already configured. Reconfiguration not supported\n", rrc->get_rb_name(lcid).c_str());
  }
}

void pdcp::add_bearer_mrb(uint32_t lcid, pdcp_config_t cfg)
{
  if (not valid_mch_lcid(lcid)) {
    if (not pdcp_array_mrb.insert(pdcp_map_pair_t(lcid, new pdcp_entity_lte(rlc, rrc, gw, task_executor, pdcp_log)))
                .second) {
      pdcp_log->error("Error inserting PDCP entity in to array\n.");
      return;
    }
    pdcp_array_mrb.at(lcid)->init(lcid, cfg);
    pdcp_log->info("Add %s (lcid=%d, bearer_id=%d, sn_len=%dbits)\n",
                   rrc->get_rb_name(lcid).c_str(),
                   lcid,
                   cfg.bearer_id,
                   cfg.sn_len);
  } else {
    pdcp_log->warning("Bearer %s already configured. Reconfiguration not supported\n", rrc->get_rb_name(lcid).c_str());
  }
}

void pdcp::del_bearer(uint32_t lcid)
{
  {
    std::lock_guard<std::mutex> lock(cache_mutex);
    valid_lcids_cached.erase(lcid);
  }
  if (valid_lcid(lcid)) {
    pdcp_map_t::iterator it = pdcp_array.find(lcid);
    delete (it->second);
    pdcp_array.erase(it);
    pdcp_log->warning("Deleted PDCP bearer %s\n", rrc->get_rb_name(lcid).c_str());
  } else {
    pdcp_log->warning("Can't delete bearer %s. Bearer doesn't exist.\n", rrc->get_rb_name(lcid).c_str());
  }
}

void pdcp::change_lcid(uint32_t old_lcid, uint32_t new_lcid)
{
  // make sure old LCID exists and new LCID is still free
  if (valid_lcid(old_lcid) && not valid_lcid(new_lcid)) {
    // insert old PDCP entity into new LCID
    pdcp_map_t::iterator it          = pdcp_array.find(old_lcid);
    pdcp_entity_lte*     pdcp_entity = it->second;
    if (not pdcp_array.insert(pdcp_map_pair_t(new_lcid, pdcp_entity)).second) {
      pdcp_log->error("Error inserting PDCP entity into array\n.");
      return;
    }
    {
      std::lock_guard<std::mutex> lock(cache_mutex);
      valid_lcids_cached.erase(old_lcid);
      valid_lcids_cached.insert(new_lcid);
    }
    // erase from old position
    pdcp_array.erase(it);
    pdcp_log->warning("Changed LCID of PDCP bearer from %d to %d\n", old_lcid, new_lcid);
  } else {
    pdcp_log->error(
        "Can't change PDCP of bearer %s from %d to %d. Bearer doesn't exist or new LCID already occupied.\n",
        rrc->get_rb_name(old_lcid).c_str(),
        old_lcid,
        new_lcid);
  }
}

void pdcp::config_security(uint32_t lcid, as_security_config_t sec_cfg)
{
  if (valid_lcid(lcid)) {
    pdcp_array.at(lcid)->config_security(sec_cfg);
  }
}

void pdcp::config_security_all(as_security_config_t sec_cfg)
{
  for (pdcp_map_t::iterator it = pdcp_array.begin(); it != pdcp_array.end(); ++it) {
    it->second->config_security(sec_cfg);
  }
}

void pdcp::enable_integrity(uint32_t lcid, srslte_direction_t direction)
{
  if (valid_lcid(lcid)) {
    pdcp_array.at(lcid)->enable_integrity(direction);
  }
}

void pdcp::enable_encryption(uint32_t lcid, srslte_direction_t direction)
{
  if (valid_lcid(lcid)) {
    pdcp_array.at(lcid)->enable_encryption(direction);
  }
}

bool pdcp::get_bearer_status(uint32_t lcid, uint16_t* dlsn, uint16_t* dlhfn, uint16_t* ulsn, uint16_t* ulhfn)
{
  if (not valid_lcid(lcid)) {
    return false;
  }
  pdcp_array[lcid]->get_bearer_status(dlsn, dlhfn, ulsn, ulhfn);
  return true;
}

/*******************************************************************************
  RLC interface
*******************************************************************************/
void pdcp::write_pdu(uint32_t lcid, unique_byte_buffer_t pdu)
{
  if (valid_lcid(lcid)) {
    pdcp_array.at(lcid)->write_pdu(std::move(pdu));
  } else {
    pdcp_log->warning("Writing pdu: lcid=%d. Deallocating pdu\n", lcid);
  }
}

void pdcp::write_pdu_bcch_bch(unique_byte_buffer_t sdu)
{
  rrc->write_pdu_bcch_bch(std::move(sdu));
}

void pdcp::write_pdu_bcch_dlsch(unique_byte_buffer_t sdu)
{
  rrc->write_pdu_bcch_dlsch(std::move(sdu));
}

void pdcp::write_pdu_pcch(unique_byte_buffer_t sdu)
{
  rrc->write_pdu_pcch(std::move(sdu));
}

void pdcp::write_pdu_mch(uint32_t lcid, unique_byte_buffer_t sdu)
{
  if (0 == lcid) {
    rrc->write_pdu_mch(lcid, std::move(sdu));
  } else {
    gw->write_pdu_mch(lcid, std::move(sdu));
  }
}

bool pdcp::valid_lcid(uint32_t lcid)
{
  if (lcid >= SRSLTE_N_RADIO_BEARERS) {
    pdcp_log->error("Radio bearer id must be in [0:%d] - %d", SRSLTE_N_RADIO_BEARERS, lcid);
    return false;
  }

  if (pdcp_array.find(lcid) == pdcp_array.end()) {
    return false;
  }

  return true;
}

bool pdcp::valid_mch_lcid(uint32_t lcid)
{
  if (lcid >= SRSLTE_N_MCH_LCIDS) {
    pdcp_log->error("Radio bearer id must be in [0:%d] - %d", SRSLTE_N_RADIO_BEARERS, lcid);
    return false;
  }

  if (pdcp_array_mrb.find(lcid) == pdcp_array_mrb.end()) {
    return false;
  }

  return true;
}

} // namespace srslte