/****************************************************************************
 * net/bluetooth/bluetooth_sendmsg.c
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.  The
 * ASF licenses this file to you 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.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include <nuttx/config.h>

#include <sys/types.h>
#include <sys/socket.h>

#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <debug.h>

#include <netpacket/bluetooth.h>
#include <arch/irq.h>

#include <nuttx/semaphore.h>
#include <nuttx/mm/iob.h>
#include <nuttx/net/radiodev.h>
#include <nuttx/net/bluetooth.h>
#include <nuttx/net/net.h>
#include <nuttx/net/ip.h>
#include <nuttx/wireless/bluetooth/bt_hci.h>

#include "utils/utils.h"
#include "netdev/netdev.h"
#include "devif/devif.h"
#include "socket/socket.h"
#include "bluetooth/bluetooth.h"

#ifdef CONFIG_NET_BLUETOOTH

/****************************************************************************
 * Private Types
 ****************************************************************************/

/* This structure holds the state of the send operation until it can be
 * operated upon from the event handler.
 */

struct bluetooth_sendto_s
{
  FAR struct socket *is_sock;           /* Points to the parent socket structure */
  FAR struct devif_callback_s *is_cb;   /* Reference to callback instance */
  bt_addr_t is_destaddr;                /* Frame destination address */
  uint16_t is_channel;                  /* Frame destination channel */
  sem_t is_sem;                         /* Used to wake up the waiting thread */
  FAR const uint8_t *is_buffer;         /* User buffer of data to send */
  size_t is_buflen;                     /* Number of bytes in the is_buffer */
  ssize_t is_sent;                      /* The number of bytes sent (or error) */
};

/****************************************************************************
 * Private Functions
 ****************************************************************************/

/****************************************************************************
 * Name: bluetooth_sendto_eventhandler
 ****************************************************************************/

static uint16_t bluetooth_sendto_eventhandler(FAR struct net_driver_s *dev,
                                               FAR void *pvpriv,
                                               uint16_t flags)
{
  FAR struct radio_driver_s *radio;
  FAR struct bluetooth_sendto_s *pstate;
  struct bluetooth_frame_meta_s meta;
  FAR struct iob_s *iob;
  int hdrlen;
  int ret;

  DEBUGASSERT(pvpriv != NULL && dev != NULL);

  /* Ignore polls from non Bluetooth network drivers */

  if (dev->d_lltype != NET_LL_BLUETOOTH)
    {
      return flags;
    }

  /* Make sure that this is the driver to which the socket is connected. */

  /* #warning Missing logic */

  pstate = pvpriv;
  radio  = (FAR struct radio_driver_s *)dev;

  ninfo("flags: %04x sent: %zd\n", flags, pstate->is_sent);

  if (pstate != NULL && (flags & BLUETOOTH_POLL) != 0)
    {
      /* Initialize the meta data */

      BLUETOOTH_ADDRCOPY(&meta.bm_raddr, &pstate->is_destaddr);
      meta.bm_channel = pstate->is_channel;
      meta.bm_proto = pstate->is_sock->s_proto;

      /* Get the Bluetooth MAC header length */

      hdrlen = radio->r_get_mhrlen(radio, &meta);
      if (hdrlen < 0)
        {
          nerr("ERROR: Failed to get header length: %d\n", hdrlen);
          ret = hdrlen;
          goto errout;
        }

      /* Verify that the user buffer can fit within the frame with this
       * MAC header.
       */

      DEBUGASSERT(BLUETOOTH_MAX_FRAMELEN <= CONFIG_IOB_BUFSIZE);
      if (pstate->is_buflen + hdrlen > BLUETOOTH_MAX_FRAMELEN)
        {
          nerr("ERROR: User buffer will not fit into the frame: %u > %u\n",
               (unsigned int)(pstate->is_buflen + hdrlen),
               (unsigned int)CONFIG_IOB_BUFSIZE);
          ret = -E2BIG;
          goto errout;
        }

      /* Allocate an IOB to hold the frame data */

      iob = net_ioballoc(false);
      if (iob == NULL)
        {
          nwarn("WARNING: Failed to allocate IOB\n");
          return flags;
        }

      /* Initialize the IOB */

      iob->io_offset = hdrlen;
      iob->io_len    = pstate->is_buflen + hdrlen;
      iob->io_pktlen = pstate->is_buflen + hdrlen;

      /* Copy the user data into the IOB */

      memcpy(&iob->io_data[hdrlen], pstate->is_buffer, pstate->is_buflen);

      /* And submit the IOB to the network driver */

      ret = radio->r_req_data(radio, &meta, iob);
      if (ret < 0)
        {
          nerr("ERROR: r_req_data() failed: %d\n", ret);
          goto errout;
        }

      /* Save the successful result */

      pstate->is_sent = pstate->is_buflen;

      /* Don't allow any further call backs. */

      pstate->is_cb->flags = 0;
      pstate->is_cb->priv  = NULL;
      pstate->is_cb->event = NULL;

      /* Wake up the waiting thread */

      nxsem_post(&pstate->is_sem);
    }

  return flags;

errout:

  /* Don't allow any further call backs. */

  pstate->is_cb->flags = 0;
  pstate->is_cb->priv  = NULL;
  pstate->is_cb->event = NULL;
  pstate->is_sent      = ret;

  /* Wake up the waiting thread */

  nxsem_post(&pstate->is_sem);
  return flags;
}

/****************************************************************************
 * Name: bluetooth_sendto
 *
 * Description:
 *   If sendto() is used on a connection-mode (SOCK_STREAM, SOCK_SEQPACKET)
 *   socket, the parameters to and 'tolen' are ignored (and the error EISCONN
 *   may be returned when they are not NULL and 0), and the error ENOTCONN is
 *   returned when the socket was not actually connected.
 *
 * Input Parameters:
 *   psock    A pointer to a NuttX-specific, internal socket structure
 *   buf      Data to send
 *   len      Length of data to send
 *   flags    Send flags
 *   to       Address of recipient
 *   tolen    The length of the address structure
 *
 * Returned Value:
 *   On success, returns the number of characters sent.  On  error,
 *   a negated errno value is retruend.  See sendto() for the complete list
 *   of return values.
 *
 ****************************************************************************/

static ssize_t bluetooth_sendto(FAR struct socket *psock,
                                FAR const void *buf, size_t len, int flags,
                                FAR const struct sockaddr *to,
                                socklen_t tolen)
{
  FAR struct radio_driver_s *radio;
  FAR struct bluetooth_conn_s *conn;
  struct bluetooth_sendto_s state;
  int ret = OK;

  /* Only SOCK_RAW is supported */

  if (psock->s_type != SOCK_RAW)
    {
      /* EDESTADDRREQ.  Signifies that the socket is not connection-mode and
       * no peer address is set.
       */

      return -EDESTADDRREQ;
    }

  /* Verify that the sockfd corresponds to valid, allocated socket */

  if (psock == NULL || psock->s_conn == NULL)
    {
      return -EBADF;
    }

  conn = psock->s_conn;

  /* Verify that the address is large enough to be a valid PF_BLUETOOTH
   * address.
   */

  if (tolen < sizeof(bt_addr_t))
    {
      return -EDESTADDRREQ;
    }

  /* Get the device driver that will service this transfer */

  if (psock->s_proto == BTPROTO_L2CAP)
    {
      radio = bluetooth_find_device(conn, &conn->bc_laddr);
      if (radio == NULL)
        {
          return -ENODEV;
        }
    }
  else if (psock->s_proto == BTPROTO_HCI)
    {
      /* TODO: should actually look among BT devices */

      radio =
          (FAR struct radio_driver_s *)netdev_findbyindex(conn->bc_ldev + 1);

      DEBUGASSERT(radio->r_dev.d_lltype == NET_LL_BLUETOOTH);

      if (radio == NULL)
        {
          return -ENODEV;
        }
    }
  else
    {
      return -EOPNOTSUPP;
    }

  /* Perform the send operation */

  /* Initialize the state structure. This is done with the network locked
   * because we don't want anything to happen until we are ready.
   */

  net_lock();
  memset(&state, 0, sizeof(struct bluetooth_sendto_s));
  nxsem_init(&state.is_sem, 0, 0); /* Doesn't really fail */

  state.is_sock   = psock;          /* Socket descriptor to use */
  state.is_buflen = len;            /* Number of bytes to send */
  state.is_buffer = buf;            /* Buffer to send from */

  /* Copy the destination address */

  if (psock->s_proto == BTPROTO_L2CAP)
    {
      FAR struct sockaddr_l2 *destaddr = (FAR struct sockaddr_l2 *)to;
      memcpy(&state.is_destaddr, &destaddr->l2_bdaddr,
             sizeof(bt_addr_t));
    }
  else if (psock->s_proto == BTPROTO_HCI)
    {
      FAR struct sockaddr_hci *destaddr = (FAR struct sockaddr_hci *)to;
      state.is_channel = destaddr->hci_channel;
    }
  else
    {
      ret = -EOPNOTSUPP;
      goto err_with_net;
    }

  if (len > 0)
    {
      /* Allocate resource to receive a callback */

      state.is_cb = bluetooth_callback_alloc(&radio->r_dev, conn);
      if (state.is_cb)
        {
          /* Set up the callback in the connection */

          state.is_cb->flags = PKT_POLL;
          state.is_cb->priv  = (FAR void *)&state;
          state.is_cb->event = bluetooth_sendto_eventhandler;

          /* Notify the device driver that new TX data is available. */

          netdev_txnotify_dev(&radio->r_dev);

          /* Wait for the send to complete or an error to occur.
           * net_sem_wait will also terminate if a signal is received.
           */

          ret = net_sem_wait(&state.is_sem);

          /* Make sure that no further events are processed */

          bluetooth_callback_free(&radio->r_dev, conn, state.is_cb);
        }
    }

  nxsem_destroy(&state.is_sem);
  net_unlock();

  /* Check for a errors, Errors are signaled by negative errno values
   * for the send length
   */

  if (state.is_sent < 0)
    {
      return state.is_sent;
    }

  /* If net_sem_wait failed, then we were probably reawakened by a signal.
   * In this case, net_sem_wait will have returned negated errno
   * appropriately.
   */

  if (ret < 0)
    {
      return ret;
    }

  /* Return the number of bytes actually sent */

  return state.is_sent;

err_with_net:
  nxsem_destroy(&state.is_sem);
  net_unlock();

  return ret;
}

/****************************************************************************
 * Name: bluetooth_l2cap_send
 *
 * Description:
 *   Socket send() method for the PF_BLUETOOTH socket over BTPROTO_L2CAP.
 *
 * Input Parameters:
 *   psock    An instance of the internal socket structure.
 *   buf      Data to send
 *   len      Length of data to send
 *   flags    Send flags
 *
 * Returned Value:
 *   On success, returns the number of characters sent.  On  error, a negated
 *   errno value is returned (see send() for the list of appropriate error
 *   values.
 *
 ****************************************************************************/

static ssize_t bluetooth_l2cap_send(FAR struct socket *psock,
                                    FAR const void *buf,
                                    size_t len, int flags)
{
  struct sockaddr_l2 to;
  FAR struct bluetooth_conn_s *conn;
  ssize_t ret;

  conn = psock->s_conn;

  if (!_SS_ISCONNECTED(conn->bc_conn.s_flags))
    {
      ret = -ENOTCONN;
    }
  else
    {
      to.l2_family = AF_BLUETOOTH;
      memcpy(&to.l2_bdaddr, &conn->bc_raddr, sizeof(bt_addr_t));
      to.l2_cid = conn->bc_channel;

      /* Then perform the send() as sendto() */

      ret = bluetooth_sendto(psock, buf, len, flags,
                             (FAR const struct sockaddr *)&to,
                             sizeof(struct sockaddr_l2));
    }

  return ret;
}

/****************************************************************************
 * Name: bluetooth_hci_send
 *
 * Description:
 *   Socket send() method for the PF_BLUETOOTH socket over BTPROTO_HCI.
 *
 * Input Parameters:
 *   psock    An instance of the internal socket structure.
 *   buf      Data to send
 *   len      Length of data to send
 *   flags    Send flags
 *
 * Returned Value:
 *   On success, returns the number of characters sent.  On  error, a negated
 *   errno value is returned (see send() for the list of appropriate error
 *   values.
 *
 ****************************************************************************/

static ssize_t bluetooth_hci_send(FAR struct socket *psock,
                                  FAR const void *buf,
                                  size_t len, int flags)
{
  /* We only support sendto() for HCI sockets */

  return -EPFNOSUPPORT;
}

/****************************************************************************
 * Name: bluetooth_send
 *
 * Description:
 *   Socket send() method for the PF_BLUETOOTH socket.
 *
 * Input Parameters:
 *   psock    An instance of the internal socket structure.
 *   buf      Data to send
 *   len      Length of data to send
 *   flags    Send flags
 *
 * Returned Value:
 *   On success, returns the number of characters sent.  On  error, a negated
 *   errno value is returned (see send() for the list of appropriate error
 *   values.
 *
 ****************************************************************************/

static ssize_t bluetooth_send(FAR struct socket *psock, FAR const void *buf,
                              size_t len, int flags)
{
  ssize_t ret;

  /* Only SOCK_RAW is supported */

  if (psock->s_type == SOCK_RAW)
    {
      switch (psock->s_proto)
        {
          case BTPROTO_L2CAP:
            {
              ret = bluetooth_l2cap_send(psock, buf, len, flags);
              break;
            }

          case BTPROTO_HCI:
            {
              ret = bluetooth_hci_send(psock, buf, len, flags);
              break;
            }

          default:
            ret = -EPFNOSUPPORT;
        }
    }
  else
    {
      ret = -EINVAL;
    }

  return ret;
}

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/****************************************************************************
 * Name: bluetooth_sendmsg
 *
 * Description:
 *   If sendmsg() is used on a connection-mode (SOCK_STREAM, SOCK_SEQPACKET)
 *   socket, the parameters 'msg_name' and 'msg_namelen' are ignored (and the
 *   error EISCONN may be returned when they are not NULL and 0), and the
 *   error ENOTCONN is returned when the socket was not actually connected.
 *
 * Input Parameters:
 *   psock    A pointer to a NuttX-specific, internal socket structure
 *   msg      data to send
 *   flags    Send flags
 *
 * Returned Value:
 *   On success, returns the number of characters sent.  On error,
 *   a negated errno value is returned.  See sendmsg() for the complete list
 *   of return values.
 *
 ****************************************************************************/

ssize_t bluetooth_sendmsg(FAR struct socket *psock, FAR struct msghdr *msg,
                          int flags)
{
  FAR const void *buf = msg->msg_iov->iov_base;
  size_t len = msg->msg_iov->iov_len;
  FAR const struct sockaddr *to = msg->msg_name;
  socklen_t tolen = msg->msg_namelen;

  /* Validity check, only single iov supported */

  if (msg->msg_iovlen != 1)
    {
      return -ENOTSUP;
    }

  return to ? bluetooth_sendto(psock, buf, len, flags, to, tolen) :
              bluetooth_send(psock, buf, len, flags);
}

#endif /* CONFIG_NET_BLUETOOTH */
