/**
 *
 * \section COPYRIGHT
 *
 * Copyright 2013-2015 Software Radio Systems Limited
 *
 * \section LICENSE
 *
 * This file is part of the srsUE library.
 *
 * 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 PROCRA_H
#define PROCRA_H

#include <stdint.h>

#include "srslte/common/log.h"
#include "srslte/common/timers.h"
#include "mac/mux.h"
#include "mac/demux.h"
#include "srslte/common/pdu.h"
#include "srslte/common/mac_pcap.h"

/* Random access procedure as specified in Section 5.1 of 36.321 */


namespace srsue {

class ra_proc : public srslte::timer_callback
{
  public:
    ra_proc() : rar_pdu_msg(20) {
      bzero(&softbuffer_rar, sizeof(srslte_softbuffer_rx_t));
      pcap = NULL;
      backoff_interval_start    = 0; 
      backoff_inteval           = 0; 
      received_target_power_dbm = 0; 
      ra_rnti                   = 0; 
      current_ta                = 0; 
      state                     = IDLE; 
      last_msg3_group           = RA_GROUP_A; 
      msg3_transmitted          = false; 
      first_rar_received        = false; 
      phy_h                     = NULL; 
      log_h                     = NULL; 
      mac_cfg                   = NULL; 
      mux_unit                  = NULL;
      demux_unit                = NULL; 
      rrc                       = NULL; 
      transmitted_contention_id = 0; 
      transmitted_crnti         = 0; 
      pdcch_to_crnti_received   = PDCCH_CRNTI_NOT_RECEIVED; 
      started_by_pdcch          = false; 
      rar_grant_nbytes          = 0; 
      rar_grant_tti             = 0; 
      msg3_flushed              = false;

      time_alignment_timer        = NULL;
      contention_resolution_timer = NULL;
    };

    ~ra_proc();

    void init(phy_interface_mac *phy_h, 
              rrc_interface_mac *rrc_, 
              srslte::log *log_h, 
              mac_interface_rrc::ue_rnti_t *rntis, 
              mac_interface_rrc::mac_cfg_t *mac_cfg,
              srslte::timers::timer* time_alignment_timer_,
              srslte::timers::timer* contention_resolution_timer_,
              mux *mux_unit, 
              demux *demux_unit);
    void reset();
    void start_pdcch_order();
    void start_mac_order(uint32_t msg_len_bits = 56);
    void step(uint32_t tti);
    bool is_successful(); 
    bool is_response_error(); 
    bool is_contention_resolution(); 
    void harq_retx();
    bool is_error(); 
    bool in_progress();
    void pdcch_to_crnti(bool contains_uplink_grant);
    void timer_expired(uint32_t timer_id);
    
    void new_grant_dl(mac_interface_phy::mac_grant_t grant, mac_interface_phy::tb_action_dl_t* action);
    void tb_decoded_ok();
    
    void start_pcap(srslte::mac_pcap* pcap);
private: 
    static bool uecrid_callback(void *arg, uint64_t uecri);

    bool contention_resolution_id_received(uint64_t uecri);
    void process_timeadv_cmd(uint32_t ta_cmd);
    void step_initialization();
    void step_resource_selection();
    void step_preamble_transmission();
    void step_pdcch_setup();
    void step_response_reception();
    void step_response_error();
    void step_backoff_wait();
    void step_contention_resolution();
    void step_completition();

    //  Buffer to receive RAR PDU
    static const uint32_t MAX_RAR_PDU_LEN = 2048;
    uint8_t     rar_pdu_buffer[MAX_RAR_PDU_LEN];
    srslte::rar_pdu rar_pdu_msg;

    // Random Access parameters provided by higher layers defined in 5.1.1
    uint32_t configIndex;
    uint32_t nof_preambles;
    uint32_t nof_groupA_preambles;
    uint32_t nof_groupB_preambles;
    uint32_t messagePowerOffsetGroupB;
    uint32_t messageSizeGroupA;
    uint32_t responseWindowSize;
    uint32_t powerRampingStep;
    uint32_t preambleTransMax;
    uint32_t iniReceivedTargetPower;
    int      delta_preamble_db;
    uint32_t contentionResolutionTimer;
    uint32_t maskIndex;
    int      preambleIndex;
    uint32_t new_ra_msg_len;

    // Internal variables
    uint32_t preambleTransmissionCounter;
    uint32_t backoff_param_ms;
    uint32_t sel_maskIndex;
    uint32_t sel_preamble;
    uint32_t backoff_interval_start;
    uint32_t backoff_inteval;
    int      received_target_power_dbm;
    uint32_t ra_rnti;
    uint32_t current_ta;

    srslte_softbuffer_rx_t softbuffer_rar;

    enum {
      IDLE = 0,
      INITIALIZATION,           // Section 5.1.1
      RESOURCE_SELECTION,       // Section 5.1.2
      PREAMBLE_TRANSMISSION,    // Section 5.1.3
      PDCCH_SETUP,
      RESPONSE_RECEPTION,       // Section 5.1.4
      RESPONSE_ERROR,
      BACKOFF_WAIT,
      CONTENTION_RESOLUTION,    // Section 5.1.5
      COMPLETION,               // Section 5.1.6
      COMPLETION_DONE,
      RA_PROBLEM                // Section 5.1.5 last part
    } state;

    typedef enum {RA_GROUP_A, RA_GROUP_B} ra_group_t;

    ra_group_t  last_msg3_group;
    bool        msg3_transmitted;
    bool        first_rar_received;
    void        read_params();

    phy_interface_mac *phy_h;
    srslte::log       *log_h;
    mux               *mux_unit;
    demux             *demux_unit;
    srslte::mac_pcap  *pcap;
    rrc_interface_mac *rrc;

    srslte::timers::timer  *time_alignment_timer;
    srslte::timers::timer  *contention_resolution_timer;

    mac_interface_rrc::ue_rnti_t *rntis;
    mac_interface_rrc::mac_cfg_t *mac_cfg;

    uint64_t    transmitted_contention_id;
    uint16_t    transmitted_crnti;

    enum {
       PDCCH_CRNTI_NOT_RECEIVED = 0,
       PDCCH_CRNTI_UL_GRANT,
       PDCCH_CRNTI_DL_GRANT
    } pdcch_to_crnti_received;

    bool started_by_pdcch;
    uint32_t rar_grant_nbytes;
    uint32_t rar_grant_tti;
    bool msg3_flushed;
    bool rar_received;
};

} // namespace srsue

#endif // PROCRA_H