/**
 *
 * \section COPYRIGHT
 *
 * Copyright 2013-2015 The srsLTE Developers. See the
 * COPYRIGHT file at the top-level directory of this distribution.
 *
 * \section LICENSE
 *
 * This file is part of the srsLTE library.
 *
 * srsLTE 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.
 *
 * srsLTE 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/.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <sys/time.h>

#include "srslte/srslte.h"

srslte_cell_t cell = {
  6,            // nof_prb
  1,            // nof_ports
  0,            // cell_id
  SRSLTE_CP_NORM,       // cyclic prefix
  SRSLTE_PHICH_SRSLTE_PHICH_R_1_6,          // PHICH resources      
  SRSLTE_PHICH_NORM    // PHICH length
};

uint32_t cfi = 2;
uint32_t tbs = 0;
uint32_t subframe = 1;
srslte_mod_t modulation = SRSLTE_MOD_QPSK;
uint32_t rv_idx = 0;
uint32_t L_prb = 2; 
uint32_t n_prb = 0; 
int freq_hop = -1; 
int riv = -1; 

void usage(char *prog) {
  printf("Usage: %s [csrnfvmtLNF] -l TBS \n", prog);
  printf("\t-m modulation (1: BPSK, 2: QPSK, 3: QAM16, 4: QAM64) [Default BPSK]\n");
  printf("\t-c cell id [Default %d]\n", cell.id);
  printf("\t-s subframe [Default %d]\n", subframe);
  printf("\t-L L_prb [Default %d]\n", L_prb);
  printf("\t-N n_prb [Default %d]\n", n_prb);
  printf("\t-F frequency hopping [Default %d]\n", freq_hop);
  printf("\t-R RIV [Default %d]\n", riv);
  printf("\t-r rv_idx [Default %d]\n", rv_idx);
  printf("\t-f cfi [Default %d]\n", cfi);
  printf("\t-n cell.nof_prb [Default %d]\n", cell.nof_prb);
  printf("\t-v [set srslte_verbose to debug, default none]\n");
}

void parse_args(int argc, char **argv) {
  int opt;
  while ((opt = getopt(argc, argv, "lcnfvmtsrLNFR")) != -1) {
    switch(opt) {
    case 'm':
      switch(atoi(argv[optind])) {
      case 1:
        modulation = SRSLTE_MOD_BPSK;
        break;
      case 2:
        modulation = SRSLTE_MOD_QPSK;
        break;
      case 4:
        modulation = SRSLTE_MOD_16QAM;
        break;
      case 6:
        modulation = SRSLTE_MOD_64QAM;
        break;
      default:
        fprintf(stderr, "Invalid modulation %d. Possible values: "
            "(1: BPSK, 2: QPSK, 3: QAM16, 4: QAM64)\n", atoi(argv[optind]));
        break;
      }
      break;
    case 's':
      subframe = atoi(argv[optind]);
      break;
    case 'L':
      L_prb = atoi(argv[optind]);
      break;
    case 'N':
      n_prb = atoi(argv[optind]);
      break;
    case 'R':
      riv = atoi(argv[optind]);
      break;
    case 'F':
      freq_hop = atoi(argv[optind]);
      break;
    case 'r':
      rv_idx = atoi(argv[optind]);
      break;
    case 'l':
      tbs = atoi(argv[optind]);
      break;
    case 'n':
      cell.nof_prb = atoi(argv[optind]);
      break;
    case 'c':
      cell.id = atoi(argv[optind]);
      break;
    case 'v':
      srslte_verbose++;
      break;
    default:
      usage(argv[0]);
      exit(-1);
    }
  }
}

int main(int argc, char **argv) {
  srslte_pusch_t pusch;
  uint8_t *data = NULL;
  cf_t *sf_symbols = NULL;
  int ret = -1;
  struct timeval t[3];
  srslte_pusch_cfg_t cfg; 
  srslte_softbuffer_tx_t softbuffer; 
  
  parse_args(argc,argv);

  bzero(&cfg, sizeof(srslte_pusch_cfg_t));

  srslte_ra_ul_dci_t dci;
  dci.freq_hop_fl = freq_hop;
  if (riv < 0) {
    dci.type2_alloc.L_crb = L_prb; 
    dci.type2_alloc.RB_start = n_prb;    
  } else {
    srslte_ra_type2_from_riv((uint32_t) riv, &dci.type2_alloc.L_crb, &dci.type2_alloc.RB_start, cell.nof_prb, cell.nof_prb);
  }
  cfg.grant.mcs.tbs = tbs;
  cfg.grant.mcs.mod = modulation;

  // Compute PRB allocation 
  if (!srslte_ul_dci_to_grant_prb_allocation(&dci, &cfg.grant, 0, cell.nof_prb)) {
    cfg.grant.lstart = 0;
    cfg.grant.nof_symb = 2*(SRSLTE_CP_NSYMB(cell.cp)-1); 
    cfg.grant.M_sc = cfg.grant.L_prb*SRSLTE_NRE;
    cfg.grant.M_sc_init = cfg.grant.M_sc; // FIXME: What should M_sc_init be? 
    cfg.grant.nof_re = cfg.grant.nof_symb*cfg.grant.M_sc;
    cfg.grant.Qm = srslte_mod_bits_x_symbol(cfg.grant.mcs.mod);
    cfg.grant.nof_bits = cfg.grant.nof_re * cfg.grant.Qm;
  }

  if (srslte_pusch_init(&pusch, cell)) {
    fprintf(stderr, "Error creating PDSCH object\n");
    goto quit;
  }
  srslte_pusch_set_rnti(&pusch, 1234);
  
  if (srslte_softbuffer_tx_init(&softbuffer, cell)) {
    fprintf(stderr, "Error initiating soft buffer\n");
    goto quit;
  }
  
  printf("Encoding rv_idx=%d\n",rv_idx);
  cfg.rv = 0; 
  cfg.sf_idx = subframe; 
  
  uint8_t tmp[20];
  for (uint32_t i=0;i<20;i++) {
    tmp[i] = 1;
  }
  srslte_uci_data_t uci_data; 
  bzero(&uci_data, sizeof(srslte_uci_data_t));
  uci_data.I_offset_cqi = 7; 
  uci_data.I_offset_ri = 2; 
  uci_data.I_offset_ack = 4; 
  
  uci_data.uci_cqi_len = 8; 
  uci_data.uci_ri_len = 0; 
  uci_data.uci_ack_len = 1; 

  uci_data.uci_cqi = tmp;
  uci_data.uci_ri = 0; 
  uci_data.uci_ack = 0; 
    
  if (srslte_cbsegm(&cfg.cb_segm, cfg.grant.mcs.tbs)) {
    fprintf(stderr, "Error configuring CB segmentation\n");
    goto quit;
  }
  srslte_pusch_hopping_cfg_t ul_hopping; 
  ul_hopping.n_sb = 1; 
  ul_hopping.hopping_offset = 0;
  ul_hopping.hop_mode = SRSLTE_PUSCH_HOP_MODE_INTER_SF;
  ul_hopping.current_tx_nb = 0;
  
  srslte_pusch_set_hopping_cfg(&pusch, &ul_hopping);
  
  uint32_t nof_re = SRSLTE_NRE*cell.nof_prb*2*SRSLTE_CP_NSYMB(cell.cp);
  sf_symbols = srslte_vec_malloc(sizeof(cf_t) * nof_re);
  if (!sf_symbols) {
    perror("malloc");
    goto quit;
  }

  data = malloc(sizeof(uint8_t) * cfg.grant.mcs.tbs);
  if (!data) {
    perror("malloc");
    goto quit;
  }
  
  for (uint32_t i=0;i<cfg.grant.mcs.tbs;i++) {
    data[i] = 1;
  }

  if (srslte_pusch_uci_encode(&pusch, &cfg, &softbuffer, data, uci_data, sf_symbols)) {
    fprintf(stderr, "Error encoding TB\n");
    exit(-1);
  }

  if (rv_idx > 0) {
    cfg.rv = rv_idx; 
    if (srslte_pusch_uci_encode(&pusch, &cfg, &softbuffer, data, uci_data, sf_symbols)) {
      fprintf(stderr, "Error encoding TB\n");
      exit(-1);
    }
  }
    
  cf_t *scfdma = srslte_vec_malloc(sizeof(cf_t) * SRSLTE_SF_LEN_PRB(cell.nof_prb));
  bzero(scfdma, sizeof(cf_t) * SRSLTE_SF_LEN_PRB(cell.nof_prb));
  srslte_ofdm_t fft; 
  srslte_ofdm_tx_init(&fft, SRSLTE_CP_NORM, cell.nof_prb);
  srslte_ofdm_set_freq_shift(&fft, 0.5);
  srslte_ofdm_tx_sf(&fft, sf_symbols, scfdma);
  
  gettimeofday(&t[1], NULL);
  //int r = srslte_pusch_decode(&pusch, slot_symbols[0], ce, 0, data, subframe, &harq_process, rv);
  int r = 0; 
  gettimeofday(&t[2], NULL);
  get_time_interval(t);
  if (r) {
    printf("Error decoding\n");
    ret = -1;
    goto quit;
  } else {
    printf("DECODED OK in %d:%d (%.2f Mbps)\n", (int) t[0].tv_sec, (int) t[0].tv_usec, (float) cfg.grant.mcs.tbs/t[0].tv_usec);
  }
  
  ret = 0;
quit:
  srslte_pusch_free(&pusch);
  srslte_softbuffer_tx_free(&softbuffer);
  
  if (sf_symbols) {
    free(sf_symbols);
  }
  if (data) {
    free(data);
  }
  if (ret) {
    printf("Error\n");
  } else {
    printf("Ok\n");
  }
  exit(ret);
}