/*
 * SPDX-License-Identifier: LicenseRef-CSSL-1.0
 */

/*!
 * \brief common APIs for different RF frontend device
 */
#include <pthread.h>
#include <stdio.h>
#include <strings.h>
#include <dlfcn.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>

#include "common_lib.h"
#include "assertions.h"
#include "common/utils/load_module_shlib.h"
#include "common/utils/LOG/log.h"
#include "executables/softmodem-common.h"
#include "common/config/config_paramdesc.h"
#include "common/config/config_userapi.h"
#include "common/cmake_defs.h"

#define MAX_GAP 100ULL
const char *const devtype_names[MAX_RF_DEV_TYPE] =
    {"", "USRP B200", "USRP X300", "USRP N300", "USRP X400", "BLADERF", "LMSSDR", "IRIS", "No HW", "UEDv2", "RFSIMULATOR"};

const char *get_devname(int devtype) {
  if (devtype < MAX_RF_DEV_TYPE && devtype !=MIN_RF_DEV_TYPE )
    return devtype_names[devtype];
  return "none";
}

int set_device(openair0_device_t *device)
{
  const char *devname = get_devname(device->type);
    if (strcmp(devname,"none") != 0) {
      LOG_I(HW,"[%s] has loaded %s device.\n",((device->host_type == RAU_HOST) ? "RAU": "RRU"),devname);
    } else {
      LOG_E(HW,"[%s] invalid HW device.\n",((device->host_type == RAU_HOST) ? "RAU": "RRU"));
      return -1;
    }
  return 0;
}

int set_transport(openair0_device_t *device)
{
  switch (device->transp_type) {
    case ETHERNET_TP:
      LOG_I(HW,"[%s] has loaded ETHERNET trasport protocol.\n",((device->host_type == RAU_HOST) ? "RAU": "RRU"));
      return 0;
      break;

    case NONE_TP:
      LOG_I(HW,"[%s] has not loaded a transport protocol.\n",((device->host_type == RAU_HOST) ? "RAU": "RRU"));
      return 0;
      break;

    default:
      LOG_E(HW,"[%s] invalid transport protocol.\n",((device->host_type == RAU_HOST) ? "RAU": "RRU"));
      return -1;
      break;
  }
}

typedef int (*devfunc_t)(openair0_device_t *, openair0_config_t *, eth_params_t *);

/* look for the interface library and load it */
int load_lib(openair0_device_t *device, openair0_config_t *openair0_cfg, eth_params_t *cfg, uint8_t flag)
{
  loader_shlibfunc_t shlib_fdesc[1];
  int ret=0;
  char *deflibname=OAI_RF_LIBNAME;
  openair0_cfg->command_line_sample_advance = get_softmodem_params()->command_line_sample_advance;
  openair0_cfg->recplay_mode = read_recplayconfig(&(openair0_cfg->recplay_conf),&(device->recplay_state));

  if (openair0_cfg->recplay_mode == RECPLAY_RECORDMODE) {
    IS_SOFTMODEM_IQRECORDER = true; // softmodem has to know we use the iqrecorder to workaround randomized algorithms
  }
  if (openair0_cfg->recplay_mode == RECPLAY_REPLAYMODE) {
  	  deflibname=OAI_IQPLAYER_LIBNAME;
  	  shlib_fdesc[0].fname="device_init";
      IS_SOFTMODEM_IQPLAYER = true; // softmodem has to know we use the iqplayer to workaround randomized algorithms
  } else if (IS_SOFTMODEM_RFSIM && flag == RAU_LOCAL_RADIO_HEAD) {
	  deflibname=OAI_RFSIM_LIBNAME;
	  shlib_fdesc[0].fname="device_init";
  } else if (flag == RAU_LOCAL_RADIO_HEAD) {
	  if (IS_SOFTMODEM_RFSIM)
		  deflibname="rfsimulator";
	  else
          deflibname=OAI_RF_LIBNAME;
      shlib_fdesc[0].fname="device_init";
  } else if (flag == RAU_REMOTE_THIRDPARTY_RADIO_HEAD) {
    deflibname=OAI_THIRDPARTY_TP_LIBNAME;
    shlib_fdesc[0].fname="transport_init";
  } else {
	  deflibname=OAI_TP_LIBNAME;
	  shlib_fdesc[0].fname="transport_init";
  }
  
  char *devname=NULL;
  paramdef_t device_params[]=DEVICE_PARAMS_DESC ;
  int numparams = sizeofArray(device_params);
  int devname_pidx = config_paramidx_fromname(device_params,numparams, CONFIG_DEVICEOPT_NAME);
  device_params[devname_pidx].defstrval=deflibname;

  config_get(config_get_if(), device_params, numparams, DEVICE_SECTION);

  ret=load_module_shlib(devname,shlib_fdesc,1,NULL);
  AssertFatal( (ret >= 0),
  	           "Library %s couldn't be loaded\n",devname);

  return ((devfunc_t)shlib_fdesc[0].fptr)(device,openair0_cfg,cfg);
}

int openair0_device_load(openair0_device_t *device, openair0_config_t *openair0_cfg)
{
  int rc=0;
  rc=load_lib(device, openair0_cfg, NULL,RAU_LOCAL_RADIO_HEAD );

  if ( rc >= 0) {
    if ( set_device(device) < 0) {
      LOG_E(HW, "%s %d:Unsupported radio head\n", __FILE__, __LINE__);
      return -1;
	}
  } else
    AssertFatal(false, "can't open the radio device: %s\n", get_devname(device->type));

  pthread_mutex_init(&device->reOrder.mutex_store, NULL);
  pthread_mutex_init(&device->reOrder.mutex_write, NULL);
  return rc;
}

int openair0_transport_load(openair0_device_t *device, openair0_config_t *openair0_cfg, eth_params_t *eth_params)
{
  int rc;
  rc=load_lib(device, openair0_cfg, eth_params, RAU_REMOTE_RADIO_HEAD);

  if ( rc >= 0) {
    if ( set_transport(device) < 0) {
      LOG_E(HW, "%s %d:Unsupported transport protocol\n", __FILE__, __LINE__);
      return -1;
    }
  }

  return rc;
}

static void writerEnqueue(re_order_t *ctx, openair0_timestamp_t timestamp, void **txp, int nsamps, int nbAnt, int flags)
{
  pthread_mutex_lock(&ctx->mutex_store);
  LOG_D(HW, "Enqueue write for TS: %lu\n", timestamp);
  int i;
  for (i = 0; i < WRITE_QUEUE_SZ; i++)
    if (!ctx->queue[i].active) {
      ctx->queue[i].timestamp = timestamp;
      ctx->queue[i].active = true;
      ctx->queue[i].nsamps = nsamps;
      ctx->queue[i].nbAnt = nbAnt;
      ctx->queue[i].flags = flags;
      AssertFatal(nbAnt <= NB_ANTENNAS_TX, "");
      for (int j = 0; j < nbAnt; j++)
        ctx->queue[i].txp[j] = txp[j];
      break;
    }
  AssertFatal(i < WRITE_QUEUE_SZ, "Write queue full\n");
  pthread_mutex_unlock(&ctx->mutex_store);
}

typedef struct PHY_VARS_NR_UE_s PHY_VARS_NR_UE;
typedef int (*nrue_ru_write_t)(PHY_VARS_NR_UE *UE, openair0_timestamp_t timestamp, void **txp, int nsamps, int nbAnt, int flags);

static void writerProcessWaitingQueue(nrue_ru_write_t nrue_ru_write, PHY_VARS_NR_UE *UE, openair0_device_t *device)
{
  bool found = false;
  re_order_t *ctx = &device->reOrder;
  do {
    found = false;
    pthread_mutex_lock(&ctx->mutex_store);
    for (int i = 0; i < WRITE_QUEUE_SZ; i++) {
      if (ctx->queue[i].active && llabs(ctx->queue[i].timestamp - ctx->nextTS) < MAX_GAP) {
        openair0_timestamp_t timestamp = ctx->queue[i].timestamp;
        LOG_D(HW, "Dequeue write for TS: %lu\n", timestamp);
        int nsamps = ctx->queue[i].nsamps;
        int nbAnt = ctx->queue[i].nbAnt;
        int flags = ctx->queue[i].flags;
        void *txp[NB_ANTENNAS_TX];
        AssertFatal(nbAnt <= NB_ANTENNAS_TX, "");
        for (int j = 0; j < nbAnt; j++)
          txp[j] = ctx->queue[i].txp[j];
        ctx->queue[i].active = false;
        pthread_mutex_unlock(&ctx->mutex_store);
        found = true;
        if (flags || IS_SOFTMODEM_RFSIM) {
          int wroteSamples;
          if (nrue_ru_write)
            wroteSamples = nrue_ru_write(UE, timestamp, txp, nsamps, nbAnt, flags);
          else
            wroteSamples = device->trx_write_func(device, timestamp, txp, nsamps, nbAnt, flags);
          if (wroteSamples != nsamps)
            LOG_W(HW, "Failed to write to RF: wrote %d out of %d samples\n", wroteSamples, nsamps);
        }
        ctx->nextTS = timestamp + nsamps;
        pthread_mutex_lock(&ctx->mutex_store);
      }
    }
    pthread_mutex_unlock(&ctx->mutex_store);
  } while (found);
}

// We assume the data behind *txp are permanently allocated
// When we will go further, we can remove all RC.xxx.txdata buffers in xNB, in UE
// but to make zerocopy and agnostic design, we need to make a proper ring buffer with mutex protection
// mutex (or atomic flags) will be mandatory because this out order system root cause is there are several writer threads

int openair0_write_reorder_common(nrue_ru_write_t nrue_ru_write,
                                  PHY_VARS_NR_UE *UE,
                                  openair0_device_t *device,
                                  openair0_timestamp_t timestamp,
                                  void **txp,
                                  int nsamps,
                                  int nbAnt,
                                  int flags)
{
  int wroteSamples = 0;
  re_order_t *ctx = &device->reOrder;
  LOG_D(HW, "received write order ts: %lu, nb samples %d, next ts %luflags %d\n", timestamp, nsamps, timestamp + nsamps, flags);
  pthread_mutex_lock(&ctx->mutex_store);
  if (!ctx->initDone) {
    ctx->nextTS = timestamp;
    for (int i = 0; i < WRITE_QUEUE_SZ; i++) {
      ctx->queue[i].txp = malloc(sizeof(void *) * NB_ANTENNAS_TX);
    }
    ctx->initDone = true;
  }
  pthread_mutex_unlock(&ctx->mutex_store);
  if (pthread_mutex_trylock(&ctx->mutex_write) == 0) {
    // We have the write exclusivity
    if (llabs(timestamp - ctx->nextTS) < MAX_GAP) { // We are writing in sequence of the previous write
      if (flags || IS_SOFTMODEM_RFSIM) {
        if (nrue_ru_write)
          wroteSamples = nrue_ru_write(UE, timestamp, txp, nsamps, nbAnt, flags);
        else
          wroteSamples = device->trx_write_func(device, timestamp, txp, nsamps, nbAnt, flags);
        if (wroteSamples != nsamps)
          LOG_W(HW, "Failed to write to RF: wrote %d out of %d samples\n", wroteSamples, nsamps);
      } else
        wroteSamples = nsamps;
      ctx->nextTS = timestamp + nsamps;

    } else {
      writerEnqueue(ctx, timestamp, txp, nsamps, nbAnt, flags);
    }
    writerProcessWaitingQueue(nrue_ru_write, UE, device);
    pthread_mutex_unlock(&ctx->mutex_write);
    return wroteSamples ? wroteSamples : nsamps;
  }
  writerEnqueue(ctx, timestamp, txp, nsamps, nbAnt, flags);
  if (pthread_mutex_trylock(&ctx->mutex_write) == 0) {
    writerProcessWaitingQueue(nrue_ru_write, UE, device);
    pthread_mutex_unlock(&ctx->mutex_write);
  }
  return nsamps;
}

int openair0_write_reorder(openair0_device_t *device, openair0_timestamp_t timestamp, void **txp, int nsamps, int nbAnt, int flags)
{
  return openair0_write_reorder_common(NULL, NULL, device, timestamp, txp, nsamps, nbAnt, flags);
}

void openair0_write_reorder_clear_context(openair0_device_t *device)
{
  LOG_I(HW, "received write reorder clear context\n");
  re_order_t *ctx = &device->reOrder;
  if (!ctx->initDone)
    return;
  if (pthread_mutex_trylock(&ctx->mutex_write) != 0)
    LOG_E(HW, "write_reorder_clear_context call while still writing on the device\n");
  else
    pthread_mutex_unlock(&ctx->mutex_write);
  pthread_mutex_lock(&ctx->mutex_store);
  for (int i = 0; i < WRITE_QUEUE_SZ; i++) {
    ctx->queue[i].active = false;
    free(ctx->queue[i].txp);
  }
  ctx->initDone = false;
  pthread_mutex_unlock(&ctx->mutex_store);
}