////////////////////////////////////////////////////////////////////////////////
/// DISCLAIMER
///
/// Copyright 2014-2016 ArangoDB GmbH, Cologne, Germany
/// Copyright 2004-2014 triAGENS GmbH, Cologne, Germany
///
/// 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.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Jan Steemann
////////////////////////////////////////////////////////////////////////////////

#include "EndpointUnixDomain.h"

#include "Basics/Common.h"
#include "Basics/FileUtils.h"
#include "Logger/Logger.h"

#include "Rest/Endpoint.h"

using namespace arangodb::basics;
using namespace arangodb::rest;

#ifdef TRI_HAVE_LINUX_SOCKETS

////////////////////////////////////////////////////////////////////////////////
/// @brief creates a Unix socket endpoint
////////////////////////////////////////////////////////////////////////////////

EndpointUnixDomain::EndpointUnixDomain(const Endpoint::EndpointType type,
                                       std::string const& specification,
                                       int listenBacklog,
                                       std::string const& path)
    : Endpoint(type, DOMAIN_UNIX, ENCRYPTION_NONE, specification,
               listenBacklog),
      _path(path) {}

////////////////////////////////////////////////////////////////////////////////
/// @brief destroys a Unix socket endpoint
////////////////////////////////////////////////////////////////////////////////

EndpointUnixDomain::~EndpointUnixDomain() {
  if (_connected) {
    disconnect();
  }
}

////////////////////////////////////////////////////////////////////////////////
/// @brief connect the endpoint
////////////////////////////////////////////////////////////////////////////////

TRI_socket_t EndpointUnixDomain::connect(double connectTimeout,
                                         double requestTimeout) {
  TRI_socket_t listenSocket;
  TRI_invalidatesocket(&listenSocket);

  LOG(DEBUG) << "connecting to unix endpoint '" << _specification << "'";

  TRI_ASSERT(!TRI_isvalidsocket(_socket));
  TRI_ASSERT(!_connected);

  if (_type == ENDPOINT_SERVER && FileUtils::exists(_path)) {
    // socket file already exists
    LOG(WARN) << "socket file '" << _path << "' already exists.";

    int error = 0;
    // delete previously existing socket file
    if (FileUtils::remove(_path, &error)) {
      LOG(WARN) << "deleted previously existing socket file '" << _path << "'";
    } else {
      LOG(ERR) << "unable to delete previously existing socket file '" << _path << "'";

      return listenSocket;
    }
  }

  listenSocket = TRI_socket(AF_UNIX, SOCK_STREAM, 0);
  if (!TRI_isvalidsocket(listenSocket)) {
    LOG(ERR) << "socket() failed with " << errno << " (" << strerror(errno) << ")";
    return listenSocket;
  }

  struct sockaddr_un address;

  memset(&address, 0, sizeof(address));
  address.sun_family = AF_UNIX;
  snprintf(address.sun_path, 100, "%s", _path.c_str());

  if (_type == ENDPOINT_SERVER) {
    int result =
        TRI_bind(listenSocket, (struct sockaddr*)&address, SUN_LEN(&address));
    if (result != 0) {
      // bind error
      LOG(ERR) << "bind() failed with " << errno << " (" << strerror(errno) << ")";
      TRI_CLOSE_SOCKET(listenSocket);
      TRI_invalidatesocket(&listenSocket);
      return listenSocket;
    }

    // listen for new connection, executed for server endpoints only
    LOG(TRACE) << "using backlog size " << _listenBacklog;
    result = TRI_listen(listenSocket, _listenBacklog);

    if (result < 0) {
      LOG(ERR) << "listen() failed with " << errno << " (" << strerror(errno) << ")";
      TRI_CLOSE_SOCKET(listenSocket);
      TRI_invalidatesocket(&listenSocket);
      return listenSocket;
    }
  }

  else if (_type == ENDPOINT_CLIENT) {
    // connect to endpoint, executed for client endpoints only

    // set timeout
    setTimeout(listenSocket, connectTimeout);

    if (TRI_connect(listenSocket, (const struct sockaddr*)&address,
                    SUN_LEN(&address)) != 0) {
      TRI_CLOSE_SOCKET(listenSocket);
      TRI_invalidatesocket(&listenSocket);
      return listenSocket;
    }
  }

  if (!setSocketFlags(listenSocket)) {
    TRI_CLOSE_SOCKET(listenSocket);
    TRI_invalidatesocket(&listenSocket);
    return listenSocket;
  }

  if (_type == ENDPOINT_CLIENT) {
    setTimeout(listenSocket, requestTimeout);
  }

  _connected = true;
  _socket = listenSocket;

  return _socket;
}

////////////////////////////////////////////////////////////////////////////////
/// @brief disconnect the endpoint
////////////////////////////////////////////////////////////////////////////////

void EndpointUnixDomain::disconnect() {
  if (_connected) {
    TRI_ASSERT(TRI_isvalidsocket(_socket));

    _connected = false;
    TRI_CLOSE_SOCKET(_socket);

    TRI_invalidatesocket(&_socket);

    if (_type == ENDPOINT_SERVER) {
      int error = 0;
      if (!FileUtils::remove(_path, &error)) {
        LOG(TRACE) << "unable to remove socket file '" << _path << "'";
      }
    }
  }
}

////////////////////////////////////////////////////////////////////////////////
/// @brief init an incoming connection
////////////////////////////////////////////////////////////////////////////////

bool EndpointUnixDomain::initIncoming(TRI_socket_t incoming) {
  return setSocketFlags(incoming);
}

#endif