/*
 * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The OpenAirInterface Software Alliance licenses this file to You under
 * the OAI Public License, Version 1.1  (the "License"); you may not use this file
 * except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.openairinterface.org/?page_id=698
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *-------------------------------------------------------------------------------
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 */

/*! \file PHY/NR_UE_TRANSPORT/nr_ulsch.c
* \brief Top-level routines for transmission of the PUSCH TS 38.211 v 15.4.0
* \author Khalid Ahmed
* \date 2019
* \version 0.1
* \company Fraunhofer IIS
* \email: khalid.ahmed@iis.fraunhofer.de
* \note
* \warning
*/
#include <stdint.h>
#include "PHY/NR_REFSIG/dmrs_nr.h"
#include "PHY/NR_UE_TRANSPORT/nr_transport_ue.h"
#include "PHY/NR_UE_TRANSPORT/nr_transport_proto_ue.h"
#include "PHY/MODULATION/nr_modulation.h"
#include "PHY/MODULATION/modulation_common.h"
#include "common/utils/assertions.h"
#include "common/utils/LOG/vcd_signal_dumper.h"
#include "PHY/NR_TRANSPORT/nr_transport_common_proto.h"
#include "PHY/NR_TRANSPORT/nr_sch_dmrs.h"
#include "PHY/defs_nr_common.h"
#include "PHY/TOOLS/tools_defs.h"

//#define DEBUG_SCFDMA
//#define DEBUG_PUSCH_MAPPING

void nr_pusch_codeword_scrambling(uint8_t *in,
                         uint32_t size,
                         uint32_t Nid,
                         uint32_t n_RNTI,
                         uint32_t* out) {

  uint8_t reset, b_idx;
  uint32_t x1, x2, s=0, temp_out;

  reset = 1;
  x2 = (n_RNTI<<15) + Nid;

  for (int i=0; i<size; i++) {
    b_idx = i&0x1f;
    if (b_idx==0) {
      s = lte_gold_generic(&x1, &x2, reset);
      reset = 0;
      if (i)
        out++;
    }
    if (in[i]==NR_PUSCH_x)
      *out ^= 1<<b_idx;
    else if (in[i]==NR_PUSCH_y){
      if (b_idx!=0)
        *out ^= (*out & (1<<(b_idx-1)))<<1;
      else{

        temp_out = *(out-1);
        *out ^= temp_out>>31;

      }
    }
    else
      *out ^= (((in[i])&1) ^ ((s>>b_idx)&1))<<b_idx;
    //printf("i %d b_idx %d in %d s 0x%08x out 0x%08x\n", i, b_idx, in[i], s, *out);
  }

}

void nr_ue_ulsch_procedures(PHY_VARS_NR_UE *UE,
                               unsigned char harq_pid,
                               uint8_t slot,
                               uint8_t thread_id,
                               int gNB_id) {

  uint32_t available_bits;
  uint8_t mod_order, cwd_index, num_of_codewords;
  uint32_t scrambled_output[NR_MAX_NB_CODEWORDS][NR_MAX_PDSCH_ENCODED_LENGTH>>5];
  uint32_t ***pusch_dmrs;
  int16_t **tx_layers;
  int32_t **txdataF;
  uint16_t start_sc, start_rb;
  int8_t Wf[2], Wt[2], l0, l_prime[2], delta;
  uint16_t n_dmrs,code_rate;
  uint8_t dmrs_type, length_dmrs;
  uint8_t mapping_type;
  int ap, start_symbol, Nid_cell, i;
  int sample_offsetF, N_RE_prime, N_PRB_oh;
  uint16_t n_rnti;

  NR_UE_ULSCH_t *ulsch_ue;
  NR_UL_UE_HARQ_t *harq_process_ul_ue;
  NR_DL_FRAME_PARMS *frame_parms = &UE->frame_parms;
  NR_UE_PUSCH *pusch_ue = UE->pusch_vars[thread_id][gNB_id];

  num_of_codewords = 1; // tmp assumption
  length_dmrs = 1;
  n_rnti = 0x1234;
  Nid_cell = 0;
  N_PRB_oh = 0; // higher layer (RRC) parameter xOverhead in PUSCH-ServingCellConfig

  for (cwd_index = 0;cwd_index < num_of_codewords; cwd_index++) {

    ulsch_ue = UE->ulsch[thread_id][gNB_id][cwd_index];
    harq_process_ul_ue = ulsch_ue->harq_processes[harq_pid];

    ulsch_ue->length_dmrs = length_dmrs;
    ulsch_ue->rnti        = n_rnti;
    ulsch_ue->Nid_cell    = Nid_cell;
    ulsch_ue->nb_re_dmrs  = UE->dmrs_UplinkConfig.pusch_maxLength*(UE->dmrs_UplinkConfig.pusch_dmrs_type == pusch_dmrs_type1)?6:4;

    N_RE_prime = NR_NB_SC_PER_RB*harq_process_ul_ue->number_of_symbols - ulsch_ue->nb_re_dmrs - N_PRB_oh;

    harq_process_ul_ue->num_of_mod_symbols = N_RE_prime*harq_process_ul_ue->nb_rb*num_of_codewords;

    mod_order      = nr_get_Qm_ul(harq_process_ul_ue->mcs, 0);
    code_rate      = nr_get_code_rate_ul(harq_process_ul_ue->mcs, 0);

    harq_process_ul_ue->TBS = nr_compute_tbs(mod_order, 
                                             code_rate,
                                             harq_process_ul_ue->nb_rb,
                                             harq_process_ul_ue->number_of_symbols,
                                             ulsch_ue->nb_re_dmrs*ulsch_ue->length_dmrs,
                                             0,
                                             harq_process_ul_ue->Nl);

    //-----------------------------------------------------//
    // to be removed later when MAC is ready

    if (harq_process_ul_ue != NULL){
      for (i = 0; i < harq_process_ul_ue->TBS / 8; i++) {
        harq_process_ul_ue->a[i] = (unsigned char) rand();
	//printf("input encoder a[%d]=0x%02x\n",i,harq_process_ul_ue->a[i]);
      }
    } else {
      LOG_E(PHY, "[phy_procedures_nrUE_TX] harq_process_ul_ue is NULL !!\n");
      return;
    }

    //-----------------------------------------------------//

    /////////////////////////ULSCH coding/////////////////////////
    ///////////

    nr_ulsch_encoding(ulsch_ue, frame_parms, harq_pid);

    ///////////
    ////////////////////////////////////////////////////////////////////

    /////////////////////////ULSCH scrambling/////////////////////////
    ///////////

    mod_order      = nr_get_Qm_ul(harq_process_ul_ue->mcs, 0);

    available_bits = nr_get_G(harq_process_ul_ue->nb_rb,
                              harq_process_ul_ue->number_of_symbols,
                              ulsch_ue->nb_re_dmrs,
                              ulsch_ue->length_dmrs,
                              mod_order,
                              1);

    memset(scrambled_output[cwd_index], 0, ((available_bits>>5)+1)*sizeof(uint32_t));

    nr_pusch_codeword_scrambling(ulsch_ue->g,
                                 available_bits,
                                 ulsch_ue->Nid_cell,
                                 ulsch_ue->rnti,
                                 scrambled_output[cwd_index]); // assume one codeword for the moment


    /////////////
    //////////////////////////////////////////////////////////////////////////

    /////////////////////////ULSCH modulation/////////////////////////
    ///////////

    nr_modulation(scrambled_output[cwd_index], // assume one codeword for the moment
                  available_bits,
                  mod_order,
                  (int16_t *)ulsch_ue->d_mod);


    // pusch_transform_precoding(ulsch_ue, frame_parms, harq_pid);

    ///////////
    ////////////////////////////////////////////////////////////////////////


  }

  start_symbol = 14 - harq_process_ul_ue->number_of_symbols;

  /////////////////////////DMRS Modulation/////////////////////////
  ///////////
  pusch_dmrs = UE->nr_gold_pusch_dmrs[slot];
  n_dmrs = (harq_process_ul_ue->nb_rb*ulsch_ue->nb_re_dmrs);
  int16_t mod_dmrs[n_dmrs<<1];
  dmrs_type = UE->dmrs_UplinkConfig.pusch_dmrs_type;
  mapping_type = UE->pusch_config.pusch_TimeDomainResourceAllocation[0]->mappingType;

  l0 = get_l0_ul(mapping_type, 2);
  nr_modulation(pusch_dmrs[l0][0], n_dmrs*2, DMRS_MOD_ORDER, mod_dmrs); // currently only codeword 0 is modulated. Qm = 2 as DMRS is QPSK modulated

  ///////////
  ////////////////////////////////////////////////////////////////////////

  /////////////////////////ULSCH layer mapping/////////////////////////
  ///////////

  tx_layers = (int16_t **)pusch_ue->txdataF_layers;

  nr_ue_layer_mapping(UE->ulsch[thread_id][gNB_id],
                   harq_process_ul_ue->Nl,
                   available_bits/mod_order,
                   tx_layers);

  ///////////
  ////////////////////////////////////////////////////////////////////////


  //////////////////////// ULSCH transform precoding ////////////////////////
  ///////////

  l_prime[0] = 0; // single symbol ap 0
  uint8_t dmrs_symbol = l0+l_prime[0], l; // Assuming dmrs-AdditionalPosition = 0

#ifdef NR_SC_FDMA
  uint32_t nb_re_pusch, nb_re_dmrs_per_rb;
  uint32_t y_offset = 0;

  for (l = start_symbol; l < start_symbol + harq_process_ul_ue->number_of_symbols; l++) {

    if(l == dmrs_symbol)
      nb_re_dmrs_per_rb = ulsch_ue->nb_re_dmrs; // [hna] ulsch_ue->nb_re_dmrs = 6 in this configuration
    else
      nb_re_dmrs_per_rb = 0;
    
    nb_re_pusch = harq_process_ul_ue->nb_rb * (NR_NB_SC_PER_RB - nb_re_dmrs_per_rb);

    nr_dft(&ulsch_ue->y[y_offset], &((int32_t*)tx_layers[0])[y_offset], nb_re_pusch);

    y_offset = y_offset + nb_re_pusch;
  }
#else
  memcpy(ulsch_ue->y, tx_layers[0], (available_bits/mod_order)*sizeof(int32_t));
#endif

  ///////////
  ////////////////////////////////////////////////////////////////////////



  /////////////////////////ULSCH RE mapping/////////////////////////
  ///////////

  txdataF = UE->common_vars.txdataF;

  start_rb = harq_process_ul_ue->first_rb;
  start_sc = frame_parms->first_carrier_offset + start_rb*NR_NB_SC_PER_RB;

  if (start_sc >= frame_parms->ofdm_symbol_size)
    start_sc -= frame_parms->ofdm_symbol_size;

  for (ap=0; ap<harq_process_ul_ue->Nl; ap++) {

    // DMRS params for this ap
    get_Wt(Wt, ap, dmrs_type);
    get_Wf(Wf, ap, dmrs_type);
    delta = get_delta(ap, dmrs_type);
    

    uint8_t k_prime=0;
    uint16_t m=0, n=0, dmrs_idx=0, k=0;

    for (l=start_symbol; l<start_symbol+harq_process_ul_ue->number_of_symbols; l++) {

      k = start_sc;

      for (i=0; i<harq_process_ul_ue->nb_rb*NR_NB_SC_PER_RB; i++) {

        sample_offsetF = l*frame_parms->ofdm_symbol_size + k;

        if ((l == dmrs_symbol) && (k == ((start_sc+get_dmrs_freq_idx_ul(n, k_prime, delta, dmrs_type))%(frame_parms->ofdm_symbol_size)))) {

          ((int16_t*)txdataF[ap])[(sample_offsetF)<<1] = (Wt[l_prime[0]]*Wf[k_prime]*AMP*mod_dmrs[dmrs_idx<<1]) >> 15;
          ((int16_t*)txdataF[ap])[((sample_offsetF)<<1) + 1] = (Wt[l_prime[0]]*Wf[k_prime]*AMP*mod_dmrs[(dmrs_idx<<1) + 1]) >> 15;

          #ifdef DEBUG_PUSCH_MAPPING
            printf("dmrs_idx %d\t l %d \t k %d \t k_prime %d \t n %d \t dmrs: %d %d\n",
            dmrs_idx, l, k, k_prime, n, ((int16_t*)txdataF[ap])[(sample_offsetF)<<1],
            ((int16_t*)txdataF[ap])[((sample_offsetF)<<1) + 1]);
          #endif


          dmrs_idx++;
          k_prime++;
          k_prime&=1;
          n+=(k_prime)?0:1;
        }

        else {

          ((int16_t*)txdataF[ap])[(sample_offsetF)<<1]       = ((int16_t *) ulsch_ue->y)[m<<1];
          ((int16_t*)txdataF[ap])[((sample_offsetF)<<1) + 1] = ((int16_t *) ulsch_ue->y)[(m<<1) + 1];

          #ifdef DEBUG_PUSCH_MAPPING
            printf("m %d\t l %d \t k %d \t txdataF: %d %d\n",
            m, l, k, ((int16_t*)txdataF[ap])[(sample_offsetF)<<1],
            ((int16_t*)txdataF[ap])[((sample_offsetF)<<1) + 1]);
          #endif

          m++;
        }

        if (++k >= frame_parms->ofdm_symbol_size)
          k -= frame_parms->ofdm_symbol_size;
      }
    }
  }

  ///////////
  ////////////////////////////////////////////////////////////////////////

  return;
}


uint8_t nr_ue_pusch_common_procedures(PHY_VARS_NR_UE *UE,
                                      uint8_t harq_pid,
                                      uint8_t slot,
                                      uint8_t thread_id,
                                      uint8_t gNB_id,
                                      NR_DL_FRAME_PARMS *frame_parms) {

  int tx_offset, ap;
  int32_t **txdata;
  int32_t **txdataF;
  int timing_advance;
  uint8_t Nl = UE->ulsch[thread_id][gNB_id][0]->harq_processes[harq_pid]->Nl; // cw 0

  /////////////////////////IFFT///////////////////////
  ///////////

#if defined(EXMIMO) || defined(OAI_USRP) || defined(OAI_BLADERF) || defined(OAI_LMSSDR)  || defined(OAI_ADRV9371_ZC706)
  timing_advance = UE->timing_advance;
#else
  timing_advance = 0;
#endif

  tx_offset = slot*frame_parms->samples_per_slot - timing_advance;

  if (tx_offset < 0)
    tx_offset += frame_parms->samples_per_frame;

  txdata = UE->common_vars.txdata;
  txdataF = UE->common_vars.txdataF;

  for (ap = 0; ap < Nl; ap++) {
      if (frame_parms->Ncp == 1) { // extended cyclic prefix
  PHY_ofdm_mod(txdataF[ap],
         &txdata[ap][tx_offset],
         frame_parms->ofdm_symbol_size,
         12,
         frame_parms->nb_prefix_samples,
         CYCLIC_PREFIX);
      } else { // normal cyclic prefix
  nr_normal_prefix_mod(txdataF[ap],
           &txdata[ap][tx_offset],
           14,
           frame_parms);
      }
    }
  ///////////
  ////////////////////////////////////////////////////
  return 0;
}
