#include <unistd.h>

#include "liblte_rrc.h"
#include "srsapps/radio/radio_uhd.h"
#include "srsapps/ue/phy/phy.h"
#include "srsapps/common/tti_sync_cv.h"
#include "srsapps/common/log_stdout.h"
#include "srsapps/ue/mac/mac.h"



/**********************************************************************
 *  Program arguments processing
 ***********************************************************************/
typedef struct {
  float uhd_rx_freq;
  float uhd_tx_freq; 
  float uhd_rx_gain;
  float uhd_tx_gain;
}prog_args_t;

void args_default(prog_args_t *args) {
  args->uhd_rx_freq = -1.0;
  args->uhd_tx_freq = -1.0;
  args->uhd_rx_gain = 60.0;
  args->uhd_tx_gain = 60.0; 
}

void usage(prog_args_t *args, char *prog) {
  printf("Usage: %s [gv] -f rx_frequency (in Hz) -F tx_frequency (in Hz)\n", prog);
  printf("\t-g UHD RX gain [Default %.2f dB]\n", args->uhd_rx_gain);
  printf("\t-g UHD RX gain [Default %.2f dB]\n", args->uhd_tx_gain);
  printf("\t-v [increase verbosity, default none]\n");
}

void parse_args(prog_args_t *args, int argc, char **argv) {
  int opt;
  args_default(args);
  while ((opt = getopt(argc, argv, "gGfFv")) != -1) {
    switch (opt) {
    case 'g':
      args->uhd_rx_gain = atof(argv[optind]);
      break;
    case 'G':
      args->uhd_tx_gain = atof(argv[optind]);
      break;
    case 'f':
      args->uhd_rx_freq = atof(argv[optind]);
      break;
    case 'F':
      args->uhd_tx_freq = atof(argv[optind]);
      break;
    case 'v':
      srslte_verbose++;
      break;
    default:
      usage(args, argv[0]);
      exit(-1);
    }
  }
  if (args->uhd_rx_freq < 0 || args->uhd_tx_freq < 0) {
    usage(args, argv[0]);
    exit(-1);
  }
}

// Determine SI messages scheduling as in 36.331 5.2.3 Acquisition of an SI message
uint32_t sib_start_tti(uint32_t tti, uint32_t period, uint32_t x) {
  return (period*10*(1+tti/(period*10))+x)%10240; // the 1 means next opportunity
}

void setup_mac_phy_sib2(LIBLTE_RRC_SYS_INFO_BLOCK_TYPE_2_STRUCT *sib2, srslte::ue::mac *mac, srslte::ue::phy *phy) {
  // RACH-CONFIGCOMMON
  if (sib2->rr_config_common_sib.rach_cnfg.preambles_group_a_cnfg.present) {
    mac->set_param(srslte::ue::mac_params::RA_NOFGROUPAPREAMBLES, 
                   liblte_rrc_message_size_group_a_num[sib2->rr_config_common_sib.rach_cnfg.preambles_group_a_cnfg.size_of_ra]);
    mac->set_param(srslte::ue::mac_params::RA_MESSAGESIZEA, 
                   liblte_rrc_message_size_group_a_num[sib2->rr_config_common_sib.rach_cnfg.preambles_group_a_cnfg.msg_size]);
    mac->set_param(srslte::ue::mac_params::RA_MESSAGEPOWEROFFSETB, 
                   liblte_rrc_message_power_offset_group_b_num[sib2->rr_config_common_sib.rach_cnfg.preambles_group_a_cnfg.msg_pwr_offset_group_b]);        
  }
  mac->set_param(srslte::ue::mac_params::RA_NOFPREAMBLES, 
                 liblte_rrc_number_of_ra_preambles_num[sib2->rr_config_common_sib.rach_cnfg.num_ra_preambles]);
  mac->set_param(srslte::ue::mac_params::RA_POWERRAMPINGSTEP, 
                 liblte_rrc_power_ramping_step_num[sib2->rr_config_common_sib.rach_cnfg.pwr_ramping_step]);
  mac->set_param(srslte::ue::mac_params::RA_INITRECEIVEDPOWER, 
                 liblte_rrc_preamble_initial_received_target_power_num[sib2->rr_config_common_sib.rach_cnfg.preamble_init_rx_target_pwr]);
  mac->set_param(srslte::ue::mac_params::RA_PREAMBLETRANSMAX, 
                 liblte_rrc_preamble_trans_max_num[sib2->rr_config_common_sib.rach_cnfg.preamble_trans_max]);
  mac->set_param(srslte::ue::mac_params::RA_RESPONSEWINDOW, 
                 liblte_rrc_ra_response_window_size_num[sib2->rr_config_common_sib.rach_cnfg.ra_resp_win_size]);
  mac->set_param(srslte::ue::mac_params::RA_CONTENTIONTIMER, 
                 liblte_rrc_mac_contention_resolution_timer_num[sib2->rr_config_common_sib.rach_cnfg.mac_con_res_timer]);
  mac->set_param(srslte::ue::mac_params::RA_MAXTXMSG3, 
                 sib2->rr_config_common_sib.rach_cnfg.max_harq_msg3_tx);
  
  printf("Set RACH ConfigCommon: NofPreambles=%d, ResponseWindow=%d\n",  
         liblte_rrc_number_of_ra_preambles_num[sib2->rr_config_common_sib.rach_cnfg.num_ra_preambles], 
         liblte_rrc_ra_response_window_size_num[sib2->rr_config_common_sib.rach_cnfg.ra_resp_win_size]);
  
  // PDSCH ConfigCommon
  mac->set_param(srslte::ue::mac_params::PDSCH_RSPOWER, 
                 sib2->rr_config_common_sib.pdsch_cnfg.rs_power);
  mac->set_param(srslte::ue::mac_params::PDSCH_PB, 
                 sib2->rr_config_common_sib.pdsch_cnfg.p_b);

  // PUSCH ConfigCommon
  phy->set_param(srslte::ue::phy_params::PUSCH_EN_64QAM, 
                 sib2->rr_config_common_sib.pusch_cnfg.enable_64_qam);
  phy->set_param(srslte::ue::phy_params::PUSCH_HOPPING_OFFSET, 
                 sib2->rr_config_common_sib.pusch_cnfg.pusch_hopping_offset);
  phy->set_param(srslte::ue::phy_params::PUSCH_HOPPING_N_SB, 
                 sib2->rr_config_common_sib.pusch_cnfg.n_sb);
  phy->set_param(srslte::ue::phy_params::PUSCH_HOPPING_INTRA_SF, 
                 sib2->rr_config_common_sib.pusch_cnfg.hopping_mode == LIBLTE_RRC_HOPPING_MODE_INTRA_AND_INTER_SUBFRAME?1:0);
  phy->set_param(srslte::ue::phy_params::PUSCH_RS_GROUP_HOPPING_EN, 
                 sib2->rr_config_common_sib.pusch_cnfg.ul_rs.group_hopping_enabled?1:0);
  phy->set_param(srslte::ue::phy_params::PUSCH_RS_SEQUENCE_HOPPING_EN, 
                 sib2->rr_config_common_sib.pusch_cnfg.ul_rs.sequence_hopping_enabled?1:0);
  phy->set_param(srslte::ue::phy_params::PUSCH_RS_CYCLIC_SHIFT, 
                 sib2->rr_config_common_sib.pusch_cnfg.ul_rs.cyclic_shift);
  phy->set_param(srslte::ue::phy_params::PUSCH_RS_GROUP_ASSIGNMENT, 
                 sib2->rr_config_common_sib.pusch_cnfg.ul_rs.group_assignment_pusch);

  printf("Set PUSCH ConfigCommon: HopOffset=%d, RSGroup=%d, RSNcs=%d\n",
    sib2->rr_config_common_sib.pusch_cnfg.pusch_hopping_offset,
    sib2->rr_config_common_sib.pusch_cnfg.ul_rs.group_assignment_pusch,
    sib2->rr_config_common_sib.pusch_cnfg.ul_rs.cyclic_shift);
  
  // PUCCH ConfigCommon
  phy->set_param(srslte::ue::phy_params::PUCCH_DELTA_SHIFT, 
                 liblte_rrc_delta_pucch_shift_num[sib2->rr_config_common_sib.pucch_cnfg.delta_pucch_shift]);
  phy->set_param(srslte::ue::phy_params::PUCCH_CYCLIC_SHIFT, 
                 sib2->rr_config_common_sib.pucch_cnfg.n_cs_an);
  phy->set_param(srslte::ue::phy_params::PUCCH_N_PUCCH_1, 
                 sib2->rr_config_common_sib.pucch_cnfg.n1_pucch_an);
  phy->set_param(srslte::ue::phy_params::PUCCH_N_RB_2, 
                 sib2->rr_config_common_sib.pucch_cnfg.n_rb_cqi);
  printf("Set PUCCH ConfigCommon: DeltaShift=%d, CyclicShift=%d, N1=%d, NRB=%d\n",
         liblte_rrc_delta_pucch_shift_num[sib2->rr_config_common_sib.pucch_cnfg.delta_pucch_shift],
         sib2->rr_config_common_sib.pucch_cnfg.n_cs_an,
         sib2->rr_config_common_sib.pucch_cnfg.n1_pucch_an,
         sib2->rr_config_common_sib.pucch_cnfg.n_rb_cqi);

  
  // PRACH Configcommon
  phy->set_param(srslte::ue::phy_params::PRACH_ROOT_SEQ_IDX, 
                 sib2->rr_config_common_sib.prach_cnfg.root_sequence_index);
  phy->set_param(srslte::ue::phy_params::PRACH_HIGH_SPEED_FLAG, 
                 sib2->rr_config_common_sib.prach_cnfg.prach_cnfg_info.high_speed_flag?1:0);
  phy->set_param(srslte::ue::phy_params::PRACH_FREQ_OFFSET, 
                 sib2->rr_config_common_sib.prach_cnfg.prach_cnfg_info.prach_freq_offset);
  phy->set_param(srslte::ue::phy_params::PRACH_ZC_CONFIG, 
                 sib2->rr_config_common_sib.prach_cnfg.prach_cnfg_info.zero_correlation_zone_config);
  phy->set_param(srslte::ue::phy_params::PRACH_CONFIG_INDEX, 
                 sib2->rr_config_common_sib.prach_cnfg.prach_cnfg_info.prach_config_index);
  
  printf("Set PRACH ConfigCommon: SeqIdx=%d, HS=%d, FreqOffset=%d, ZC=%d, ConfigIndex=%d\n", 
     sib2->rr_config_common_sib.prach_cnfg.root_sequence_index, 
     sib2->rr_config_common_sib.prach_cnfg.prach_cnfg_info.high_speed_flag?1:0,
     sib2->rr_config_common_sib.prach_cnfg.prach_cnfg_info.prach_freq_offset,
     sib2->rr_config_common_sib.prach_cnfg.prach_cnfg_info.zero_correlation_zone_config,
     sib2->rr_config_common_sib.prach_cnfg.prach_cnfg_info.prach_config_index);
}

int main(int argc, char *argv[])
{
  prog_args_t prog_args; 
  srslte::ue::tti_sync_cv ttisync(10240); 
  srslte::radio_uhd radio_uhd; 
  srslte::ue::phy phy; 
  srslte::ue::mac mac; 
  srslte::log_stdout log("MAC"); 
  
  parse_args(&prog_args, argc, argv);

  // Init Radio 
  radio_uhd.init();

  // Init PHY 
  phy.init(&radio_uhd, &ttisync);
  
  // Init MAC 
  mac.init(&phy, &ttisync, &log);
    
  // Set RX freq and gain
  radio_uhd.set_rx_freq(prog_args.uhd_rx_freq);
  radio_uhd.set_rx_gain(prog_args.uhd_rx_gain);
  radio_uhd.set_tx_freq(prog_args.uhd_tx_freq);
  radio_uhd.set_tx_gain(prog_args.uhd_tx_gain);

  LIBLTE_BIT_MSG_STRUCT                bit_msg; 
  LIBLTE_RRC_MIB_STRUCT                bch_msg; 
  LIBLTE_RRC_BCCH_DLSCH_MSG_STRUCT     dlsch_msg; 
  LIBLTE_RRC_UL_CCCH_MSG_STRUCT        ul_ccch_msg;  
  LIBLTE_RRC_DL_CCCH_MSG_STRUCT        dl_ccch_msg;  
  
  uint32_t si_window_len, sib2_period; 
  int tti; 
  enum {START, SIB1, SIB2, CONNECT} state = START;
  int n; 
  
  while(1) {
    switch(state) {
      case START: 
        n = mac.recv_bcch_sdu(bit_msg.msg, LIBLTE_MAX_MSG_SIZE); 
        if (n > 0) {
          bit_msg.N_bits = n; 
          liblte_rrc_unpack_bcch_bch_msg(&bit_msg, &bch_msg); 
          printf("MIB received %d bytes, BW=%s\n", n, liblte_rrc_dl_bandwidth_text[bch_msg.dl_bw]);
          state = SIB1;          
        }
        break;
      case SIB1:
        n = mac.recv_bcch_sdu(bit_msg.msg, LIBLTE_MAX_MSG_SIZE); 
        if (n > 0) {
          bit_msg.N_bits = n; 
          liblte_rrc_unpack_bcch_dlsch_msg(&bit_msg, &dlsch_msg);          
          si_window_len = liblte_rrc_si_window_length_num[dlsch_msg.sibs[0].sib.sib1.si_window_length];
          sib2_period = liblte_rrc_si_periodicity_num[dlsch_msg.sibs[0].sib.sib1.sched_info[0].si_periodicity];
          printf("SIB1 received %d bytes, CellID=%d, si_window=%d, sib2_period=%d\n", 
                 n/8, dlsch_msg.sibs[0].sib.sib1.cell_id&0xfff, si_window_len, sib2_period);          
          printf("Payload: ");
          srslte_vec_fprint_hex(stdout, bit_msg.msg, n);
          state = SIB2; 
        } else {
          tti = mac.get_tti();           
          mac.set_param(srslte::ue::mac_params::BCCH_SI_WINDOW_ST, sib_start_tti(tti, 2, 5));
          mac.set_param(srslte::ue::mac_params::BCCH_SI_WINDOW_LEN, 1);          
        }
        break;
      case SIB2: 
        n = mac.recv_bcch_sdu(bit_msg.msg, LIBLTE_MAX_MSG_SIZE);
        if (n > 0) {
          // Process SIB2
          bit_msg.N_bits = n; 
          liblte_rrc_unpack_bcch_dlsch_msg(&bit_msg, &dlsch_msg);                    
          printf("SIB2 received %d bytes\n", n/8);
          printf("Payload: ");
          srslte_vec_fprint_hex(stdout, bit_msg.msg, n);
          setup_mac_phy_sib2(&dlsch_msg.sibs[0].sib.sib2, &mac, &phy);
          
          // Prepare ConnectionRequest packet
          ul_ccch_msg.msg_type = LIBLTE_RRC_UL_CCCH_MSG_TYPE_RRC_CON_REQ;
          ul_ccch_msg.msg.rrc_con_req.ue_id_type = LIBLTE_RRC_CON_REQ_UE_ID_TYPE_RANDOM_VALUE; 
          ul_ccch_msg.msg.rrc_con_req.ue_id.random = 1000;
          ul_ccch_msg.msg.rrc_con_req.cause = LIBLTE_RRC_CON_REQ_EST_CAUSE_MO_DATA; 
          liblte_rrc_pack_ul_ccch_msg(&ul_ccch_msg, &bit_msg);
          
          mac.set_param(srslte::ue::mac_params::CONTENTION_ID, ul_ccch_msg.msg.rrc_con_req.ue_id.random);
          
          // Send ConnectionRequest Packet
          mac.send_ccch_sdu(bit_msg.msg, bit_msg.N_bits);
          state = CONNECT; 
        } else {
          tti = mac.get_tti(); 
          mac.set_param(srslte::ue::mac_params::BCCH_SI_WINDOW_ST, sib_start_tti(tti, sib2_period, 0));
          mac.set_param(srslte::ue::mac_params::BCCH_SI_WINDOW_LEN, si_window_len);      
        }
        break;
      case CONNECT: 
        // Waint for Connection Setup
        n = mac.recv_ccch_sdu(bit_msg.msg, LIBLTE_MAX_MSG_SIZE); 
        if (n > 0) {
          printf("ConnSetup received %d bytes\n", n/8);
          bit_msg.N_bits = n; 
          liblte_rrc_unpack_dl_ccch_msg(&bit_msg, &dl_ccch_msg);
          printf("Response: %s\n", liblte_rrc_dl_ccch_msg_type_text[dl_ccch_msg.msg_type]);
          if (dl_ccch_msg.msg_type == LIBLTE_RRC_DL_CCCH_MSG_TYPE_RRC_CON_SETUP) {
            // Process ConnectionRequest
          }
          exit(0);
        }
        break;
    }
      
    usleep(50000);
  }
}