/*
*
* Copyright (c) 2018 Huawei Technologies Co.,Ltd.
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* 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.
*/

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <dlfcn.h>

#include "nstack_dmm_api.h"

#include "rsocket_adpt.h"
#include "rdma/rsocket.h"

#define RR_EVFD(u64) ((int)((u64) >> 32))
#define RR_RSFD(u64) ((int)((u64) & 0xFFFFFFFF))
#define RR_DATA(evfd, rsfd) ((((uint64_t)(evfd)) << 32) | (uint64_t)(uint32_t)(rsfd))

#define RR_EV_NUM 64

rsocket_var_t g_rr_var = { 0 };

rr_sapi_t g_sapi = { 0 };

int g_rr_log_level = -1;

int
rr_notify_event (void *pdata, int events)
{
  int ret;

  ret = g_rr_var.event_cb (pdata, events);

  RR_DBG ("event_cb(%p, 0x%x)=%d,%d\n", pdata, events, ret, errno);

  return ret;
}

int
rr_epoll_ctl (int op, int evfd, uint32_t events, int rsfd)
{
  int ret;
  struct epoll_event event;
  event.events = events;
  event.data.u64 = RR_DATA (evfd, rsfd);
  ret = GSAPI (epoll_ctl) (g_rr_var.epfd, op, evfd, &event);
  return ret;
}

static void *
rr_epoll_thread (void *arg)
{
  int i, ret, e;
  struct epoll_event events[RR_EV_NUM];

  while (1)
    {
      ret = GSAPI (epoll_wait) (g_rr_var.epfd, events, RR_EV_NUM, 100);
      e = errno;

      for (i = 0; i < ret; ++i)
        {
          if (rr_rs_handle (RR_RSFD (events[i].data.u64), events[i].events))
            {
              (void) rr_ep_del (RR_EVFD (events[i].data.u64));
            }
        }

      if (ret < 0)
        {
          RR_STAT_INC (RR_STAT_EPW_ERR);
          if (e == EINTR)
            {
              RR_STAT_INC (RR_STAT_EPW_EINTR);
            }
          else if (e == ETIMEDOUT)
            {
              RR_STAT_INC (RR_STAT_EPW_ETIMEOUT);
            }
          else
            {
              RR_ERR ("epoll_wait()=%d:%d\n", ret, errno);
            }
        }
    }

  return NULL;
}

static int
rr_init_sapi ()
{
  void *handle = dlopen ("libc.so.6", RTLD_NOW | RTLD_GLOBAL);
  if (!handle)
    {
      RR_ERR ("dlopen(libc.so.6):NULL\n");
      return -1;
    }

#define RR_SAPI(name) \
    GSAPI(name) = dlsym(handle, #name); \
    if (!GSAPI(name)) \
        RR_ERR("dlsym(" #name "):NULL\n");
#include "rsocket_sapi.h"
#undef RR_SAPI

  return 0;
}

static void
rr_init_log ()
{
  int level;
  char *log;

  if (g_rr_log_level >= 0)
    return;

  log = getenv ("RSOCKET_LOG");
  if (!log || !log[0])
    {
      g_rr_log_level = RR_LOG_OFF;
      return;
    }

  level = atoi (log);
  if (level < 0 || level > 99999)
    {
      g_rr_log_level = RR_LOG_OFF;
      return;
    }

  g_rr_log_level = level;
}

static int
rsocket_init ()
{
  int ret;

  rr_init_log ();

  if (rr_init_sapi ())
    {
      return -1;
    }

  g_rr_var.epfd = GSAPI (epoll_create) (1);
  if (g_rr_var.epfd < 0)
    return g_rr_var.epfd;

  ret =
    pthread_create (&g_rr_var.epoll_threadid, NULL, rr_epoll_thread, NULL);
  if (ret)
    {
      GSAPI (close) (g_rr_var.epfd);
      g_rr_var.epfd = -1;
      return ret;
    }
  (void) pthread_setname_np (g_rr_var.epoll_threadid, "rsocket_epoll");

  return 0;
}

int
rsocket_exit ()
{
  if (g_rr_var.epfd >= 0)
    {
      (void) GSAPI (close) (g_rr_var.epfd);
      g_rr_var.epfd = -1;
    }

  return 0;
}

unsigned int
rsocket_ep_ctl (int epFD, int proFD, int ctl_ops, struct epoll_event *event,
                void *pdata)
{
  int ret;
  struct eventpoll *ep;
  unsigned int revents = 0;

  RR_DBG ("(%d, %d, %d, 0x%x, %p)\n", epFD, proFD, ctl_ops, event->events,
          pdata);

  switch (ctl_ops)
    {
    case nstack_ep_triggle_add:
      ret = rr_rs_ep_add (proFD, pdata, &revents);
      if (ret)
        return -1;
      return revents;

    case nstack_ep_triggle_mod:
      ret = rr_rs_ep_mod (proFD, pdata, &revents);
      if (ret)
        return -1;
      return revents;
    case nstack_ep_triggle_del:
      return rr_rs_ep_del (proFD);
    }

  return _err (EPERM);
}

int
rsocket_stack_register (nstack_proc_cb * proc_fun,
                        nstack_event_cb * event_ops)
{
  rr_init_log ();

#define NSTACK_MK_DECL(ret, fn, args) \
    do { \
        proc_fun->socket_ops.pf##fn = dlsym(event_ops->handle, "r"#fn); \
        if (!proc_fun->socket_ops.pf##fn) \
            RR_LOG("socket API '" #fn "' not found\n"); \
    } while (0)
#include "declare_syscalls.h"
#undef NSTACK_MK_DECL

  proc_fun->extern_ops.module_init = rsocket_init;
  proc_fun->extern_ops.ep_ctl = rsocket_ep_ctl;
  proc_fun->extern_ops.ep_getevt = NULL;

  g_rr_var.type = event_ops->type;
  g_rr_var.event_cb = event_ops->event_cb;

  return 0;
}