/**
 *
 * \section COPYRIGHT
 *
 * Copyright 2013-2017 Software Radio Systems Limited
 *
 * \section LICENSE
 *
 * This file is part of srsLTE.
 *
 * srsUE 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.
 *
 * srsUE 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 SRSENB_MAC_H
#define SRSENB_MAC_H

#include <vector>
#include "srslte/common/log.h"
#include "srslte/common/timers.h"
#include "srslte/interfaces/enb_interfaces.h"
#include "srslte/interfaces/sched_interface.h"
#include "srslte/common/tti_sync_cv.h"
#include "srslte/common/threads.h"
#include "srslte/common/tti_sync_cv.h"
#include "srslte/common/mac_pcap.h"
#include "scheduler.h"
#include "scheduler_metric.h"
#include "srslte/interfaces/enb_metrics_interface.h"
#include "ue.h"

namespace srsenb {
  
class pdu_process_handler
{
public: 
  virtual bool process_pdus() = 0; 
};

typedef struct {
  sched_interface::sched_args_t sched; 
  int link_failure_nof_err; 
} mac_args_t; 

class mac
    :public mac_interface_phy, 
     public mac_interface_rlc, 
     public mac_interface_rrc,     
     public srslte::mac_interface_timers, 
     public pdu_process_handler
{
public:
  mac();
  bool init(mac_args_t *args, srslte_cell_t *cell, phy_interface_mac *phy, rlc_interface_mac *rlc, rrc_interface_mac *rrc, srslte::log *log_h);
  void stop();
  
  void start_pcap(srslte::mac_pcap* pcap_);
  
  /******** Interface from PHY (PHY -> MAC) ****************/ 
  int sr_detected(uint32_t tti, uint16_t rnti); 
  int rach_detected(uint32_t tti, uint32_t preamble_idx, uint32_t time_adv); 
  
  int set_dl_ant_info(uint16_t rnti, LIBLTE_RRC_ANTENNA_INFO_DEDICATED_STRUCT *dl_ant_info);

  int ri_info(uint32_t tti, uint16_t rnti, uint32_t ri_value);
  int pmi_info(uint32_t tti, uint16_t rnti, uint32_t pmi_value);
  int cqi_info(uint32_t tti, uint16_t rnti, uint32_t cqi_value); 
  int snr_info(uint32_t tti, uint16_t rnti, float snr); 
  int ack_info(uint32_t tti, uint16_t rnti, uint32_t tb_idx, bool ack);
  int crc_info(uint32_t tti, uint16_t rnti, uint32_t nof_bytes, bool crc_res); 
    
  int get_dl_sched(uint32_t tti, dl_sched_t *dl_sched_res);
  int get_ul_sched(uint32_t tti, ul_sched_t *ul_sched_res);
  int get_mch_sched(bool is_mcch, dl_sched_t *dl_sched_res);
  void build_mch_sched(uint32_t tbs);
  void rl_failure(uint16_t rnti);
  void rl_ok(uint16_t rnti); 
  void tti_clock(); 
  
  /******** Interface from RRC (RRC -> MAC) ****************/ 
  /* Provides cell configuration including SIB periodicity, etc. */
  int cell_cfg(sched_interface::cell_cfg_t *cell_cfg); 
  void reset();

  /* Manages UE scheduling context */
  int ue_cfg(uint16_t rnti, sched_interface::ue_cfg_t *cfg); 
  int ue_rem(uint16_t rnti);
  
  // Indicates that the PHY config dedicated has been enabled or not
  void phy_config_enabled(uint16_t rnti, bool enabled); 

  /* Manages UE bearers and associated configuration */
  int bearer_ue_cfg(uint16_t rnti, uint32_t lc_id, sched_interface::ue_bearer_cfg_t *cfg); 
  int bearer_ue_rem(uint16_t rnti, uint32_t lc_id); 
  int rlc_buffer_state(uint16_t rnti, uint32_t lc_id, uint32_t tx_queue, uint32_t retx_queue);
    
  bool process_pdus(); 

  // Interface for upper-layer timers
  srslte::timers::timer*   timer_get(uint32_t timer_id);
  void                     timer_release_id(uint32_t timer_id);
  u_int32_t                timer_get_unique_id();

  uint32_t get_current_tti();
  void get_metrics(mac_metrics_t metrics[ENB_METRICS_MAX_USERS]);
  void write_mcch(LIBLTE_RRC_SYS_INFO_BLOCK_TYPE_2_STRUCT *sib2, LIBLTE_RRC_SYS_INFO_BLOCK_TYPE_13_STRUCT *sib13, LIBLTE_RRC_MCCH_MSG_STRUCT *mcch);
private:  

  static const int MAX_LOCATIONS = 20;
  static const uint32_t cfi = 3; 
  srslte_dci_location_t locations[MAX_LOCATIONS];
  
  static const int MAC_PDU_THREAD_PRIO  = 60;

  // We use a rwlock in MAC to allow multiple workers to access MAC simultaneously. No conflicts will happen since access for different TTIs
  pthread_rwlock_t rwlock;
  
  // Interaction with PHY 
  phy_interface_mac    *phy_h; 
  rlc_interface_mac    *rlc_h;
  rrc_interface_mac    *rrc_h;
  srslte::log          *log_h;
  
  srslte_cell_t cell; 
  mac_args_t    args; 
  
  uint32_t      tti; 
  bool          started; 

  /* Scheduler unit */
  sched            scheduler; 
  dl_metric_rr     sched_metric_dl_rr;
  ul_metric_rr     sched_metric_ul_rr;
  sched_interface::cell_cfg_t cell_config;
  
  
  sched_interface::dl_pdu_mch_t mch;
  
  
  /* Map of active UEs */
  std::map<uint16_t, ue*> ue_db;   
  uint16_t        last_rnti;   
  
  uint8_t* assemble_rar(sched_interface::dl_sched_rar_grant_t *grants, uint32_t nof_grants, int rar_idx, uint32_t pdu_len);
  uint8_t* assemble_si(uint32_t index);

  const static int rar_payload_len = 128; 
  std::vector<srslte::rar_pdu> rar_pdu_msg;  
  uint8_t rar_payload[sched_interface::MAX_RAR_LIST][rar_payload_len]; 
  
  typedef struct {
    uint32_t preamble_idx; 
    uint32_t ta_cmd; 
    uint16_t temp_crnti; 
  } pending_rar_t; 

  const static int MAX_PENDING_RARS = 64; 
  pending_rar_t pending_rars[MAX_PENDING_RARS]; 
  
  const static int NOF_BCCH_DLSCH_MSG=sched_interface::MAX_SIBS; 
  uint8_t bcch_dlsch_payload[sched_interface::MAX_SIB_PAYLOAD_LEN];
  
  const static int pcch_payload_buffer_len = 1024;
  uint8_t pcch_payload_buffer[pcch_payload_buffer_len]; 
  srslte_softbuffer_tx_t bcch_softbuffer_tx[NOF_BCCH_DLSCH_MSG];
  srslte_softbuffer_tx_t pcch_softbuffer_tx;
  srslte_softbuffer_tx_t rar_softbuffer_tx;
  
  const static int mcch_payload_len = 3000; //TODO FIND OUT MAX LENGTH
  int current_mcch_length;
  uint8_t mcch_payload_buffer[mcch_payload_len];
  LIBLTE_RRC_MCCH_MSG_STRUCT mcch;
  LIBLTE_RRC_SYS_INFO_BLOCK_TYPE_2_STRUCT sib2; 
  LIBLTE_RRC_SYS_INFO_BLOCK_TYPE_13_STRUCT sib13;
  
  const static int mtch_payload_len = 10000;
  uint8_t mtch_payload_buffer[mtch_payload_len];
  
  /* Functions for MAC Timers */
  srslte::timers  timers_db;
  void            setup_timers();
  
  // pointer to MAC PCAP object
  srslte::mac_pcap* pcap;
  

  /* Class to run upper-layer timers with normal priority */
  class timer_thread : public thread {
  public:
    timer_thread(srslte::timers *t) : ttisync(10240),timers(t),running(false) {start();}
    void tti_clock();
    void stop();
  private:
    void run_thread();
    srslte::tti_sync_cv ttisync;
    srslte::timers     *timers;
    bool running; 
  };
  timer_thread   timers_thread;

  /* Class to process MAC PDUs from DEMUX unit */
  class pdu_process : public thread {
  public: 
    pdu_process(pdu_process_handler *h);
    void notify();
    void stop();
  private:
    void run_thread();
    bool running; 
    bool have_data; 
    pthread_mutex_t mutex;
    pthread_cond_t  cvar;
    pdu_process_handler *handler; 
  };
  pdu_process pdu_process_thread;
  
};

} // namespace srsenb

#endif // SRSENB_MAC_H