/******************************************************************************
 *
 *  Copyright 2014 Google, Inc.
 *
 *  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.
 *
 ******************************************************************************/

#define LOG_TAG "bt_btif_sock"

#include "btif/include/btif_sock.h"

#include <base/functional/callback.h>
#include <bluetooth/log.h>
#include <hardware/bluetooth.h>
#include <hardware/bt_sock.h>

#include <atomic>

#include "bta/include/bta_api.h"
#include "bta_sec_api.h"
#include "btif_metrics_logging.h"
#include "btif_sock_l2cap.h"
#include "btif_sock_logging.h"
#include "btif_sock_rfc.h"
#include "btif_sock_sco.h"
#include "btif_sock_thread.h"
#include "btif_uid.h"
#include "os/log.h"
#include "osi/include/osi.h"  // INVALID_FD
#include "osi/include/thread.h"
#include "types/bluetooth/uuid.h"
#include "types/raw_address.h"

using bluetooth::Uuid;
using namespace bluetooth;

static bt_status_t btsock_listen(btsock_type_t type, const char* service_name,
                                 const Uuid* uuid, int channel, int* sock_fd,
                                 int flags, int app_uid);
static bt_status_t btsock_connect(const RawAddress* bd_addr, btsock_type_t type,
                                  const Uuid* uuid, int channel, int* sock_fd,
                                  int flags, int app_uid);
static void btsock_request_max_tx_data_length(const RawAddress& bd_addr);
static bt_status_t btsock_control_req(uint8_t dlci, const RawAddress& bd_addr,
                                      uint8_t modem_signal,
                                      uint8_t break_signal,
                                      uint8_t discard_buffers,
                                      uint8_t break_signal_seq, bool fc);

static void btsock_signaled(int fd, int type, int flags, uint32_t user_id);
static bt_status_t btsock_disconnect_all(const RawAddress* bd_addr);
static bt_status_t btsock_get_l2cap_local_cid(Uuid& conn_uuid, uint16_t* cid);
static bt_status_t btsock_get_l2cap_remote_cid(Uuid& conn_uuid, uint16_t* cid);

static std::atomic_int thread_handle{-1};
static thread_t* thread;

const btsock_interface_t* btif_sock_get_interface(void) {
  static btsock_interface_t interface = {
      sizeof(interface),
      btsock_listen,
      btsock_connect,
      btsock_request_max_tx_data_length,
      btsock_control_req,
      btsock_disconnect_all,
      btsock_get_l2cap_local_cid,
      btsock_get_l2cap_remote_cid,
  };

  return &interface;
}

bt_status_t btif_sock_init(uid_set_t* uid_set) {
  log::assert_that(thread_handle == -1, "assert failed: thread_handle == -1");
  log::assert_that(thread == NULL, "assert failed: thread == NULL");

  bt_status_t status;
  btsock_thread_init();
  thread_handle = btsock_thread_create(btsock_signaled, NULL);
  if (thread_handle == -1) {
    log::error("unable to create btsock_thread.");
    goto error;
  }

  status = btsock_rfc_init(thread_handle, uid_set);
  if (status != BT_STATUS_SUCCESS) {
    log::error("error initializing RFCOMM sockets: {}", status);
    goto error;
  }

  status = btsock_l2cap_init(thread_handle, uid_set);
  if (status != BT_STATUS_SUCCESS) {
    log::error("error initializing L2CAP sockets: {}", status);
    goto error;
  }

  thread = thread_new("btif_sock");
  if (!thread) {
    log::error("error creating new thread.");
    btsock_rfc_cleanup();
    goto error;
  }

  status = btsock_sco_init(thread);
  if (status != BT_STATUS_SUCCESS) {
    log::error("error initializing SCO sockets: {}", status);
    btsock_rfc_cleanup();
    goto error;
  }

  return BT_STATUS_SUCCESS;

error:;
  thread_free(thread);
  thread = NULL;
  if (thread_handle != -1) btsock_thread_exit(thread_handle);
  thread_handle = -1;
  uid_set = NULL;
  return BT_STATUS_SOCKET_ERROR;
}

void btif_sock_cleanup(void) {
  int saved_handle = thread_handle;
  if (std::atomic_exchange(&thread_handle, -1) == -1) return;

  btsock_thread_exit(saved_handle);
  btsock_rfc_cleanup();
  btsock_sco_cleanup();
  btsock_l2cap_cleanup();
  thread_free(thread);
  thread = NULL;
}

static bt_status_t btsock_control_req(uint8_t dlci, const RawAddress& bd_addr,
                                      uint8_t modem_signal,
                                      uint8_t break_signal,
                                      uint8_t discard_buffers,
                                      uint8_t break_signal_seq, bool fc) {
  return btsock_rfc_control_req(dlci, bd_addr, modem_signal, break_signal,
                                discard_buffers, break_signal_seq, fc);
}

static bt_status_t btsock_listen(btsock_type_t type, const char* service_name,
                                 const Uuid* service_uuid, int channel,
                                 int* sock_fd, int flags, int app_uid) {
  if ((flags & BTSOCK_FLAG_NO_SDP) == 0) {
    log::assert_that(sock_fd != NULL, "assert failed: sock_fd != NULL");
  }

  *sock_fd = INVALID_FD;
  bt_status_t status = BT_STATUS_SOCKET_ERROR;

  log::info(
      "Attempting listen for socket connections for device: {}, type: {}, "
      "channel: {}, app_uid: {}",
      RawAddress::kEmpty, type, channel, app_uid);
  btif_sock_connection_logger(
      RawAddress::kEmpty, 0, type, SOCKET_CONNECTION_STATE_LISTENING,
      SOCKET_ROLE_LISTEN, app_uid, channel, 0, 0, service_name);
  switch (type) {
    case BTSOCK_RFCOMM:
      status = btsock_rfc_listen(service_name, service_uuid, channel, sock_fd,
                                 flags, app_uid);
      break;
    case BTSOCK_L2CAP:
      status =
          btsock_l2cap_listen(service_name, channel, sock_fd, flags, app_uid);
      break;
    case BTSOCK_L2CAP_LE:
      status = btsock_l2cap_listen(service_name, channel, sock_fd,
                                   flags | BTSOCK_FLAG_LE_COC, app_uid);
      break;
    case BTSOCK_SCO:
      status = btsock_sco_listen(sock_fd, flags);
      break;

    default:
      log::error("unknown/unsupported socket type: {}", type);
      status = BT_STATUS_UNSUPPORTED;
      break;
  }
  if (status != BT_STATUS_SUCCESS) {
    log::error(
        "failed to listen for socket connections for device: {}, type: {}, "
        "channel: {}, app_uid: {}",
        RawAddress::kEmpty, type, channel, app_uid);
    btif_sock_connection_logger(
        RawAddress::kEmpty, 0, type, SOCKET_CONNECTION_STATE_DISCONNECTED,
        SOCKET_ROLE_LISTEN, app_uid, channel, 0, 0, service_name);
  }
  return status;
}

static bt_status_t btsock_connect(const RawAddress* bd_addr, btsock_type_t type,
                                  const Uuid* uuid, int channel, int* sock_fd,
                                  int flags, int app_uid) {
  log::assert_that(bd_addr != NULL, "assert failed: bd_addr != NULL");
  log::assert_that(sock_fd != NULL, "assert failed: sock_fd != NULL");

  log::info(
      "Attempting socket connection for device: {}, type: {}, channel: {}, "
      "app_uid: {}",
      *bd_addr, type, channel, app_uid);

  *sock_fd = INVALID_FD;
  bt_status_t status = BT_STATUS_SOCKET_ERROR;

  btif_sock_connection_logger(*bd_addr, 0, type,
                              SOCKET_CONNECTION_STATE_CONNECTING,
                              SOCKET_ROLE_CONNECTION, app_uid, channel, 0, 0,
                              uuid ? uuid->ToString().c_str() : "");
  switch (type) {
    case BTSOCK_RFCOMM:
      status =
          btsock_rfc_connect(bd_addr, uuid, channel, sock_fd, flags, app_uid);
      break;

    case BTSOCK_L2CAP:
      status = btsock_l2cap_connect(bd_addr, channel, sock_fd, flags, app_uid);
      break;
    case BTSOCK_L2CAP_LE:
      status = btsock_l2cap_connect(bd_addr, channel, sock_fd,
                                    (flags | BTSOCK_FLAG_LE_COC), app_uid);
      break;
    case BTSOCK_SCO:
      status = btsock_sco_connect(bd_addr, sock_fd, flags);
      break;

    default:
      log::error("unknown/unsupported socket type: {}", type);
      status = BT_STATUS_UNSUPPORTED;
      break;
  }
  if (status != BT_STATUS_SUCCESS) {
    log::error(
        "Socket connection failed for device: {}, type: {}, channel: {}, "
        "app_uid: {}",
        *bd_addr, type, channel, app_uid);
    btif_sock_connection_logger(*bd_addr, 0, type,
                                SOCKET_CONNECTION_STATE_DISCONNECTED,
                                SOCKET_ROLE_CONNECTION, app_uid, channel, 0, 0,
                                uuid ? uuid->ToString().c_str() : "");
  }
  return status;
}

static void btsock_request_max_tx_data_length(const RawAddress& remote_device) {
  BTA_DmBleRequestMaxTxDataLength(remote_device);
}

static void btsock_signaled(int fd, int type, int flags, uint32_t user_id) {
  switch (type) {
    case BTSOCK_RFCOMM:
      btsock_rfc_signaled(fd, flags, user_id);
      break;
    case BTSOCK_L2CAP:
    case BTSOCK_L2CAP_LE:
      /* Note: The caller may not distinguish between BTSOCK_L2CAP and
       * BTSOCK_L2CAP_LE correctly */
      btsock_l2cap_signaled(fd, flags, user_id);
      break;
    default:
      log::fatal("Invalid socket type! type={} fd={} flags={} user_id={}", type,
                 fd, flags, user_id);
      break;
  }
}

static bt_status_t btsock_disconnect_all(const RawAddress* bd_addr) {
  log::assert_that(bd_addr != NULL, "assert failed: bd_addr != NULL");

  bt_status_t rfc_status = btsock_rfc_disconnect(bd_addr);
  bt_status_t l2cap_status = btsock_l2cap_disconnect(bd_addr);
  /* SCO is disconnected via btif_hf, so is not handled here. */

  log::info("rfc status: {}, l2cap status: {}", rfc_status, l2cap_status);

  /* Return error status, if any. */
  if (rfc_status == BT_STATUS_SUCCESS) {
    return l2cap_status;
  }
  return rfc_status;
}

static bt_status_t btsock_get_l2cap_local_cid(Uuid& conn_uuid, uint16_t* cid) {
  return btsock_l2cap_get_l2cap_local_cid(conn_uuid, cid);
}

static bt_status_t btsock_get_l2cap_remote_cid(Uuid& conn_uuid, uint16_t* cid) {
  return btsock_l2cap_get_l2cap_remote_cid(conn_uuid, cid);
}