//===-- UDPSocket.cpp -------------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "lldb/Host/common/UDPSocket.h"

#include "lldb/Core/Log.h"
#include "lldb/Host/Config.h"

#ifndef LLDB_DISABLE_POSIX
#include <arpa/inet.h>
#include <sys/socket.h>
#endif

#include <memory>

using namespace lldb;
using namespace lldb_private;

namespace {

const int kDomain = AF_INET;
const int kType = SOCK_DGRAM;

static const char *g_not_supported_error = "Not supported";
}

UDPSocket::UDPSocket(NativeSocket socket) : Socket(socket, ProtocolUdp, true) {}

UDPSocket::UDPSocket(bool child_processes_inherit, Error &error)
    : UDPSocket(
          CreateSocket(kDomain, kType, 0, child_processes_inherit, error)) {}

size_t UDPSocket::Send(const void *buf, const size_t num_bytes) {
  return ::sendto(m_socket, static_cast<const char *>(buf), num_bytes, 0,
                  m_send_sockaddr, m_send_sockaddr.GetLength());
}

Error UDPSocket::Connect(llvm::StringRef name) {
  return Error("%s", g_not_supported_error);
}

Error UDPSocket::Listen(llvm::StringRef name, int backlog) {
  return Error("%s", g_not_supported_error);
}

Error UDPSocket::Accept(llvm::StringRef name, bool child_processes_inherit,
                        Socket *&socket) {
  return Error("%s", g_not_supported_error);
}

Error UDPSocket::Connect(llvm::StringRef name, bool child_processes_inherit,
                         Socket *&send_socket, Socket *&recv_socket) {
  std::unique_ptr<UDPSocket> final_send_socket;
  std::unique_ptr<UDPSocket> final_recv_socket;

  Log *log(lldb_private::GetLogIfAnyCategoriesSet(LIBLLDB_LOG_CONNECTION));
  if (log)
    log->Printf("UDPSocket::%s (host/port = %s)", __FUNCTION__, name.data());

  Error error;
  std::string host_str;
  std::string port_str;
  int32_t port = INT32_MIN;
  if (!DecodeHostAndPort(name, host_str, port_str, port, &error))
    return error;

  // Setup the receiving end of the UDP connection on this localhost
  // on port zero. After we bind to port zero we can read the port.
  final_recv_socket.reset(new UDPSocket(child_processes_inherit, error));
  if (error.Success()) {
    // Socket was created, now lets bind to the requested port
    SocketAddress addr;
    addr.SetToAnyAddress(AF_INET, 0);

    if (::bind(final_recv_socket->GetNativeSocket(), addr, addr.GetLength()) ==
        -1) {
      // Bind failed...
      SetLastError(error);
    }
  }

  assert(error.Fail() == !(final_recv_socket && final_recv_socket->IsValid()));
  if (error.Fail())
    return error;

  // At this point we have setup the receive port, now we need to
  // setup the UDP send socket

  struct addrinfo hints;
  struct addrinfo *service_info_list = nullptr;

  ::memset(&hints, 0, sizeof(hints));
  hints.ai_family = kDomain;
  hints.ai_socktype = kType;
  int err = ::getaddrinfo(host_str.c_str(), port_str.c_str(), &hints,
                          &service_info_list);
  if (err != 0) {
    error.SetErrorStringWithFormat(
#if defined(_MSC_VER) && defined(UNICODE)
        "getaddrinfo(%s, %s, &hints, &info) returned error %i (%S)",
#else
        "getaddrinfo(%s, %s, &hints, &info) returned error %i (%s)",
#endif
        host_str.c_str(), port_str.c_str(), err, gai_strerror(err));
    return error;
  }

  for (struct addrinfo *service_info_ptr = service_info_list;
       service_info_ptr != nullptr;
       service_info_ptr = service_info_ptr->ai_next) {
    auto send_fd = CreateSocket(
        service_info_ptr->ai_family, service_info_ptr->ai_socktype,
        service_info_ptr->ai_protocol, child_processes_inherit, error);
    if (error.Success()) {
      final_send_socket.reset(new UDPSocket(send_fd));
      final_send_socket->m_send_sockaddr = service_info_ptr;
      break;
    } else
      continue;
  }

  ::freeaddrinfo(service_info_list);

  if (!final_send_socket)
    return error;

  send_socket = final_send_socket.release();
  recv_socket = final_recv_socket.release();
  error.Clear();
  return error;
}