/*
 * 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.
 *-------------------------------------------------------------------------------
 * For more information about the OpenAirInterface (OAI) Software Alliance:
 *      contact@openairinterface.org
 */

/*!\file PHY/CODING/nr_polar_init.h
 * \brief
 * \author Turker Yilmaz, Raymond Knopp
 * \date 2018
 * \version 0.1
 * \company EURECOM
 * \email turker.yilmaz@eurecom.fr, raymond.knopp@eurecom.fr
 * \note
 * \warning
*/

#include "PHY/CODING/nrPolar_tools/nr_polar_defs.h"
#include "PHY/NR_TRANSPORT/nr_dci.h"

#define PolarKey ((messageType<<24)|(messageLength<<8)|aggregation_level)
static t_nrPolar_params * PolarList=NULL;
pthread_mutex_t PolarListMutex=PTHREAD_MUTEX_INITIALIZER;

static int intcmp(const void *p1,const void *p2) {
  return(*(int16_t *)p1 > *(int16_t *)p2);
}

static void nr_polar_delete_list(t_nrPolar_params * polarParams) {
  if (!polarParams)
    return;
  if (polarParams->nextPtr)
    nr_polar_delete_list(polarParams->nextPtr);
  
  delete_decoder_tree(polarParams);
  //From build_polar_tables()
  for (int k=0; k < polarParams->K + polarParams->n_pc; k++)
    if (polarParams->G_N_tab[k]) 
      free(polarParams->G_N_tab[k]);
  free(polarParams->G_N_tab);
  free(polarParams->rm_tab);
  if (polarParams->crc_generator_matrix)
    free(polarParams->crc_generator_matrix);
  //polar_encoder vectors:
  free(polarParams->nr_polar_crc);
  free(polarParams->nr_polar_aPrime);
  free(polarParams->nr_polar_APrime);
  free(polarParams->nr_polar_D);
  free(polarParams->nr_polar_E);
    //Polar Coding vectors
  free(polarParams->nr_polar_U);
  free(polarParams->nr_polar_CPrime);
  free(polarParams->nr_polar_B);
  free(polarParams->nr_polar_A);
  free(polarParams->interleaving_pattern);
  free(polarParams->deinterleaving_pattern);
  free(polarParams->rate_matching_pattern);
  free(polarParams->information_bit_pattern);
  free(polarParams->Q_I_N);
  free(polarParams->Q_F_N);
  free(polarParams->Q_PC_N);
  free(polarParams->channel_interleaver_pattern);
  free(polarParams);
}

static void nr_polar_delete(void) {
  pthread_mutex_lock(&PolarListMutex);
  nr_polar_delete_list(PolarList);
  PolarList=NULL;
  pthread_mutex_unlock(&PolarListMutex);  
}

t_nrPolar_params *nr_polar_params(int8_t messageType, uint16_t messageLength, uint8_t aggregation_level, int decoder_flag)
{
  // The lock is weak, because we never delete in the list, only at exit time
  // therefore, returning t_nrPolar_params * from the list is safe for future usage
  pthread_mutex_lock(&PolarListMutex);
  if(!PolarList)
    atexit(nr_polar_delete);
  
  t_nrPolar_params *currentPtr = PolarList;
  //Parse the list. If the node is already created, return without initialization.
  while (currentPtr != NULL) {
    //printf("currentPtr->idx %d, (%d,%d)\n",currentPtr->idx,currentPtr->payloadBits,currentPtr->encoderLength);
    //LOG_D(PHY,"Looking for index %d\n",(messageType * messageLength * aggregation_prime));
    if (currentPtr->busy == false && currentPtr->idx == PolarKey ) {
      currentPtr->busy=true;
      pthread_mutex_unlock(&PolarListMutex);
      if (decoder_flag && !currentPtr->tree.root)
        build_decoder_tree(currentPtr);
      return currentPtr ;
    }
    else
      currentPtr = currentPtr->nextPtr;
  }

  //  printf("currentPtr %p (polarParams %p)\n",currentPtr,polarParams);
  //Else, initialize and add node to the end of the linked list.
  t_nrPolar_params *newPolarInitNode = calloc(sizeof(t_nrPolar_params),1);
  newPolarInitNode->busy=true;
  pthread_mutex_unlock(&PolarListMutex);

  AssertFatal(newPolarInitNode != NULL, "[nr_polar_init] New t_nrPolar_params * could not be created");
  
  //   LOG_D(PHY,"Setting new polarParams index %d, messageType %d, messageLength %d, aggregation_prime %d\n",(messageType * messageLength * aggregation_prime),messageType,messageLength,aggregation_prime);
  newPolarInitNode->idx = PolarKey;
  newPolarInitNode->nextPtr = NULL;
  //printf("newPolarInitNode->idx %d, (%d,%d,%d:%d)\n",newPolarInitNode->idx,messageType,messageLength,aggregation_prime,aggregation_level);

  if (messageType == NR_POLAR_PBCH_MESSAGE_TYPE) {
    newPolarInitNode->n_max = NR_POLAR_PBCH_N_MAX;
    newPolarInitNode->i_il = NR_POLAR_PBCH_I_IL;
    newPolarInitNode->i_seg = NR_POLAR_PBCH_I_SEG;
    newPolarInitNode->n_pc = NR_POLAR_PBCH_N_PC;
    newPolarInitNode->n_pc_wm = NR_POLAR_PBCH_N_PC_WM;
    newPolarInitNode->i_bil = NR_POLAR_PBCH_I_BIL;
    newPolarInitNode->crcParityBits = NR_POLAR_PBCH_CRC_PARITY_BITS;
    newPolarInitNode->payloadBits = NR_POLAR_PBCH_PAYLOAD_BITS;
    newPolarInitNode->encoderLength = NR_POLAR_PBCH_E;
    newPolarInitNode->crcCorrectionBits = NR_POLAR_PBCH_CRC_ERROR_CORRECTION_BITS;
    newPolarInitNode->crc_generator_matrix = crc24c_generator_matrix(newPolarInitNode->payloadBits); // G_P
    //printf("Initializing polar parameters for PBCH (K %d, E %d)\n",newPolarInitNode->payloadBits,newPolarInitNode->encoderLength);

  } else if (messageType == NR_POLAR_DCI_MESSAGE_TYPE) {
    newPolarInitNode->n_max = NR_POLAR_DCI_N_MAX;
    newPolarInitNode->i_il = NR_POLAR_DCI_I_IL;
    newPolarInitNode->i_seg = NR_POLAR_DCI_I_SEG;
    newPolarInitNode->n_pc = NR_POLAR_DCI_N_PC;
    newPolarInitNode->n_pc_wm = NR_POLAR_DCI_N_PC_WM;
    newPolarInitNode->i_bil = NR_POLAR_DCI_I_BIL;
    newPolarInitNode->crcParityBits = NR_POLAR_DCI_CRC_PARITY_BITS;
    newPolarInitNode->payloadBits = messageLength;
    newPolarInitNode->encoderLength = aggregation_level * 108;
    newPolarInitNode->crcCorrectionBits = NR_POLAR_DCI_CRC_ERROR_CORRECTION_BITS;
    newPolarInitNode->crc_generator_matrix = crc24c_generator_matrix(newPolarInitNode->payloadBits + newPolarInitNode->crcParityBits); // G_P
    //printf("Initializing polar parameters for DCI (K %d, E %d, L %d)\n",newPolarInitNode->payloadBits,newPolarInitNode->encoderLength,aggregation_level);

  } else if (messageType == NR_POLAR_UCI_PUCCH_MESSAGE_TYPE) {
    AssertFatal(aggregation_level > 2, "Aggregation level (%d) for PUCCH 2 encoding is NPRB and should be > 2\n", aggregation_level);
    AssertFatal(messageLength > 11, "Message length %d is too short for polar encoding of UCI\n", messageLength);

    // TS 38.212 - Section 6.3.1.2.1 UCI encoded by Polar code
    int L = 0;
    if (messageLength >= 12 && messageLength <= 19) {
      L = 6;
    } else if (messageLength >= 20) {
      L = 11;
    } else {
      AssertFatal(1 == 0, "L = %i is an invalid value\n", L);
    }
    newPolarInitNode->encoderLength = aggregation_level * 16;
    newPolarInitNode->i_seg = 0;
    if ((messageLength >= 360 && newPolarInitNode->encoderLength >= 1088) || (messageLength >= 1013)) {
      newPolarInitNode->i_seg = 1;
      AssertFatal(1 == 0, "Segmentation is not supported yet (i_seg = %i)\n", newPolarInitNode->i_seg);
    }

    // TS 38.212 - Section 6.3.1.3.1 UCI encoded by Polar code
    newPolarInitNode->n_max = NR_POLAR_PUCCH_N_MAX;
    newPolarInitNode->i_il = NR_POLAR_PUCCH_I_IL;
    newPolarInitNode->crcParityBits = L;
    int Kr = messageLength + L;
    if (Kr >= 18 && Kr <= 25) {
      newPolarInitNode->n_pc = 3;
      if ((newPolarInitNode->encoderLength - Kr + 3) > 192) {
        newPolarInitNode->n_pc_wm = 1;
      } else {
        newPolarInitNode->n_pc_wm = 0;
      }
    } else if (Kr > 30) {
      newPolarInitNode->n_pc = 0;
      newPolarInitNode->n_pc_wm = 0;
    } else {
      AssertFatal(1 == 0, "Kr = %i is an invalid value\n", Kr);
    }

    newPolarInitNode->i_bil = NR_POLAR_PUCCH_I_BIL;
    newPolarInitNode->payloadBits = messageLength;
    newPolarInitNode->crcCorrectionBits = NR_POLAR_PUCCH_CRC_ERROR_CORRECTION_BITS;
    //LOG_D(PHY,"New polar node, encoderLength %d, aggregation_level %d\n",newPolarInitNode->encoderLength,aggregation_level);

  } else {
    AssertFatal(1 == 0, "[nr_polar_init] Incorrect Message Type(%d)", messageType);
  }

  newPolarInitNode->K = newPolarInitNode->payloadBits + newPolarInitNode->crcParityBits; // Number of bits to encode.
  newPolarInitNode->N = nr_polar_output_length(newPolarInitNode->K,
                                               newPolarInitNode->encoderLength,
                                               newPolarInitNode->n_max);
  newPolarInitNode->n = log2(newPolarInitNode->N);
  newPolarInitNode->G_N = nr_polar_kronecker_power_matrices(newPolarInitNode->n);
  //polar_encoder vectors:
  newPolarInitNode->nr_polar_crc = malloc(sizeof(uint8_t) * newPolarInitNode->crcParityBits);
  newPolarInitNode->nr_polar_aPrime = malloc(sizeof(uint8_t) * ((ceil((newPolarInitNode->payloadBits)/32.0)*4)+3));
  newPolarInitNode->nr_polar_APrime = malloc(sizeof(uint8_t) * newPolarInitNode->K);
  newPolarInitNode->nr_polar_D = malloc(sizeof(uint8_t) * newPolarInitNode->N);
  newPolarInitNode->nr_polar_E = malloc(sizeof(uint8_t) * newPolarInitNode->encoderLength);
  //Polar Coding vectors
  newPolarInitNode->nr_polar_U = malloc(sizeof(uint8_t) * newPolarInitNode->N); //Decoder: nr_polar_uHat
  newPolarInitNode->nr_polar_CPrime = malloc(sizeof(uint8_t) * newPolarInitNode->K); //Decoder: nr_polar_cHat
  newPolarInitNode->nr_polar_B = malloc(sizeof(uint8_t) * newPolarInitNode->K); //Decoder: nr_polar_bHat
  newPolarInitNode->nr_polar_A = malloc(sizeof(uint8_t) * newPolarInitNode->payloadBits); //Decoder: nr_polar_aHat
  newPolarInitNode->Q_0_Nminus1 = nr_polar_sequence_pattern(newPolarInitNode->n);
  newPolarInitNode->interleaving_pattern = malloc(sizeof(uint16_t) * newPolarInitNode->K);
  nr_polar_interleaving_pattern(newPolarInitNode->K,
                                newPolarInitNode->i_il,
                                newPolarInitNode->interleaving_pattern);
  newPolarInitNode->deinterleaving_pattern = malloc(sizeof(uint16_t) * newPolarInitNode->K);

  for (int i=0; i<newPolarInitNode->K; i++)
    newPolarInitNode->deinterleaving_pattern[newPolarInitNode->interleaving_pattern[i]] = i;

  newPolarInitNode->rate_matching_pattern = malloc(sizeof(uint16_t) * newPolarInitNode->encoderLength);
  uint16_t J[newPolarInitNode->N];
  nr_polar_rate_matching_pattern(newPolarInitNode->rate_matching_pattern,
                                 J,
                                 nr_polar_subblock_interleaver_pattern,
                                 newPolarInitNode->K,
                                 newPolarInitNode->N,
                                 newPolarInitNode->encoderLength);
  newPolarInitNode->information_bit_pattern = malloc(sizeof(uint8_t) * newPolarInitNode->N);
  newPolarInitNode->Q_I_N = malloc(sizeof(int16_t) * (newPolarInitNode->K + newPolarInitNode->n_pc));
  newPolarInitNode->Q_F_N = malloc( sizeof(int16_t) * (newPolarInitNode->N + 1)); // Last element shows the final array index assigned a value.
  newPolarInitNode->Q_PC_N = malloc( sizeof(int16_t) * (newPolarInitNode->n_pc));

  for (int i = 0; i <= newPolarInitNode->N; i++)
    newPolarInitNode->Q_F_N[i] = -1; // Empty array.

  nr_polar_info_bit_pattern(newPolarInitNode->information_bit_pattern,
                            newPolarInitNode->Q_I_N,
                            newPolarInitNode->Q_F_N,
                            J,
                            newPolarInitNode->Q_0_Nminus1,
                            newPolarInitNode->K,
                            newPolarInitNode->N,
                            newPolarInitNode->encoderLength,
                            newPolarInitNode->n_pc);
  // sort the Q_I_N array in ascending order (first K positions)
  qsort((void *)newPolarInitNode->Q_I_N,newPolarInitNode->K,sizeof(int16_t),intcmp);
  newPolarInitNode->channel_interleaver_pattern = malloc(sizeof(uint16_t) * newPolarInitNode->encoderLength);
  nr_polar_channel_interleaver_pattern(newPolarInitNode->channel_interleaver_pattern,
                                       newPolarInitNode->i_bil,
                                       newPolarInitNode->encoderLength);
  if (decoder_flag == 1) 
    build_decoder_tree(newPolarInitNode);
  build_polar_tables(newPolarInitNode);
  init_polar_deinterleaver_table(newPolarInitNode);
  //printf("decoder tree nodes %d\n",newPolarInitNode->tree.num_nodes);

  newPolarInitNode->nextPtr=PolarList;
  PolarList=newPolarInitNode;
  return newPolarInitNode;
}

void nr_polar_print_polarParams() {
  uint8_t i = 0;

  if (PolarList == NULL) {
    printf("polarParams is empty.\n");
  } else {
    t_nrPolar_params * polarParams=PolarList;
    while (polarParams != NULL) {
      printf("polarParams[%d] = %d, %d, %d\n", i,
             polarParams->idx>>24, (polarParams->idx>>8)&0xFFFF, polarParams->idx&0xFF);
      polarParams = polarParams->nextPtr;
      i++;
    }
  }

  return;
}

uint16_t nr_polar_aggregation_prime (uint8_t aggregation_level) {
  if (aggregation_level == 0) return 0;
  else if (aggregation_level == 1) return NR_POLAR_AGGREGATION_LEVEL_1_PRIME;
  else if (aggregation_level == 2) return NR_POLAR_AGGREGATION_LEVEL_2_PRIME;
  else if (aggregation_level == 4) return NR_POLAR_AGGREGATION_LEVEL_4_PRIME;
  else if (aggregation_level == 8) return NR_POLAR_AGGREGATION_LEVEL_8_PRIME;
  else return NR_POLAR_AGGREGATION_LEVEL_16_PRIME; //aggregation_level == 16
}
