#include <chrono>
#include <condition_variable>
#include <cstring>
#include <giomm.h>
#include <glibmm.h>
#include <iostream>
#include <memory>
#include <mutex>
#include <thread>

namespace
{

Glib::RefPtr<Glib::MainLoop> loop;

bool verbose = false;
bool non_blocking = false;
bool use_udp = false;
bool use_source = false;
bool use_ipv6 = false;
int cancel_timeout = 0;
bool stop_thread = false;
std::mutex mutex_thread;
std::condition_variable cond_thread;

class ClientOptionGroup : public Glib::OptionGroup
{
public:
  ClientOptionGroup() : Glib::OptionGroup("client_group", "", "")
  {
    Glib::OptionEntry entry;
    entry.set_long_name("cancel");
    entry.set_short_name('c');
    entry.set_description("Cancel any op after the specified amount of seconds");
    add_entry(entry, cancel_timeout);

    entry.set_long_name("udp");
    entry.set_short_name('u');
    entry.set_description("Use UDP instead of TCP");
    add_entry(entry, use_udp);

    entry.set_long_name("verbose");
    entry.set_short_name('v');
    entry.set_description("Be verbose");
    add_entry(entry, verbose);

    entry.set_long_name("non-blocking");
    entry.set_short_name('n');
    entry.set_description("Enable non-blocking I/O");
    add_entry(entry, non_blocking);

    entry.set_long_name("use-source");
    entry.set_short_name('s');
    entry.set_description("Use Gio::SocketSource to wait for non-blocking I/O");
    add_entry(entry, use_source);

    entry.set_long_name("use-ipv6");
    entry.set_short_name('6');
    entry.set_description("Use IPv6 address family");
    add_entry(entry, use_ipv6);
  }
};

Glib::ustring
socket_address_to_string(const Glib::RefPtr<Gio::SocketAddress>& address)
{
  Glib::RefPtr<Gio::InetAddress> inet_address;
  Glib::ustring str, res;
  int port;

  auto isockaddr = Glib::RefPtr<Gio::InetSocketAddress>::cast_dynamic(address);
  if (!isockaddr)
    return Glib::ustring();
  inet_address = isockaddr->get_address();
  str = inet_address->to_string();
  port = isockaddr->get_port();
  res = Glib::ustring::compose("%1:%2", str, port);
  return res;
}

static bool source_ready(Glib::IOCondition /*condition*/)
{
  loop->quit();
  return false;
}

static void
ensure_condition(const Glib::RefPtr<Gio::Socket>& socket, const Glib::ustring& where,
  const Glib::RefPtr<Gio::Cancellable>& cancellable, Glib::IOCondition condition)
{
  if (!non_blocking)
    return;

  if (use_source)
  {
    auto source = socket->create_source(condition, cancellable);
    source->connect(sigc::ptr_fun(&source_ready));
    source->attach();
    loop->run();
  }
  else
  {
    try
    {
      socket->condition_wait(condition, cancellable);
    }
    catch (const Gio::Error& error)
    {
      std::cerr << Glib::ustring::compose("condition wait error for %1: %2\n", where, error.what());
      exit(1);
    }
  }
}

static void
cancel_thread(Glib::RefPtr<Gio::Cancellable> cancellable)
{
  std::unique_lock<std::mutex> lock(mutex_thread);
  if (!cond_thread.wait_for(
        lock, std::chrono::seconds(cancel_timeout), []() { return stop_thread; }))
  {
    // !stop_thread, i.e. timeout
    std::cout << "Cancelling\n";
    cancellable->cancel();
  }
}

class JoinAndDelete
{
public:
  void operator()(std::thread* thread)
  {
    stop_thread = true;
    cond_thread.notify_all();
    thread->join();
    delete thread;
  }
};

} // end anonymous namespace

int
main(int argc, char* argv[])
{
  Glib::RefPtr<Gio::Socket> socket;
  Glib::RefPtr<Gio::SocketAddress> src_address;
  Glib::RefPtr<Gio::SocketAddress> address;
  Gio::SocketType socket_type;
  Gio::SocketFamily socket_family;
  Glib::RefPtr<Gio::Cancellable> cancellable;
  Glib::RefPtr<Gio::SocketAddressEnumerator> enumerator;
  Glib::RefPtr<Gio::SocketConnectable> connectable;

  Gio::init();

  Glib::OptionContext option_context(" <hostname>[:port] - Test Gio::Socket client stuff");
  option_context.set_summary("Default port: 7777\n"
                             "For a local test with socket-server:\n"
                             "  ./socket-client [option...] localhost\n"
                             "or, if that fails\n"
                             "  ./socket-client [option...] 127.0.0.1  (IPv4)\n"
                             "  ./socket-client [option...] ::1        (IPv6)");
  ClientOptionGroup option_group;
  option_context.set_main_group(option_group);
  try
  {
    option_context.parse(argc, argv);
  }
  catch (const Glib::Error& error)
  {
    std::cerr << Glib::ustring::compose("%1: %2\n", argv[0], error.what());
    return 1;
  }

  if (argc != 2)
  {
    const auto error_message = "Need to specify hostname";
    std::cerr << Glib::ustring::compose("%1: %2\n", argv[0], error_message);
    return 1;
  }

  std::unique_ptr<std::thread, JoinAndDelete> thread;
  if (cancel_timeout)
  {
    cancellable = Gio::Cancellable::create();
    thread.reset(new std::thread(&cancel_thread, cancellable));
  }

  loop = Glib::MainLoop::create();

  socket_type = use_udp ? Gio::SOCKET_TYPE_DATAGRAM : Gio::SOCKET_TYPE_STREAM;
  socket_family = use_ipv6 ? Gio::SOCKET_FAMILY_IPV6 : Gio::SOCKET_FAMILY_IPV4;

  try
  {
    socket = Gio::Socket::create(socket_family, socket_type, Gio::SOCKET_PROTOCOL_DEFAULT);
  }
  catch (const Gio::Error& error)
  {
    std::cerr << Glib::ustring::compose("%1: %2\n", argv[0], error.what());
    return 1;
  }

  try
  {
    connectable = Gio::NetworkAddress::parse(argv[1], 7777);
  }
  catch (const Gio::Error& error)
  {
    std::cerr << Glib::ustring::compose("%1: %2\n", argv[0], error.what());
    return 1;
  }

  enumerator = connectable->enumerate();
  while (true)
  {
    try
    {
      address = enumerator->next(cancellable);
      if (!address)
      {
        std::cerr << Glib::ustring::compose("%1: No more addresses to try\n", argv[0]);
        return 1;
      }
    }
    catch (const Gio::Error& error)
    {
      std::cerr << Glib::ustring::compose("%1: %2\n", argv[0], error.what());
      return 1;
    }

    try
    {
      socket->connect(address, cancellable);
      break;
    }
    catch (const Gio::Error& error)
    {
      std::cerr << Glib::ustring::compose("%1: Connection to %2 failed: %3, trying next\n", argv[0],
        socket_address_to_string(address), error.what());
    }
  }

  std::cout << Glib::ustring::compose("Connected to %1\n", socket_address_to_string(address));

  /* TODO: Test non-blocking connect */
  if (non_blocking)
    socket->set_blocking(false);

  try
  {
    src_address = socket->get_local_address();
  }
  catch (const Gio::Error& error)
  {
    std::cerr << Glib::ustring::compose("Error getting local address: %1\n", error.what());
    return 1;
  }
  std::cout << Glib::ustring::compose("local address: %1\n", socket_address_to_string(src_address));

  while (true)
  {
    gchar buffer[4096] = {};
    gssize size;
    gsize to_send;

    if (!std::cin.getline(buffer, sizeof buffer - 1))
      break;

    to_send = strlen(buffer);
    buffer[to_send++] = '\n';
    buffer[to_send] = '\0';
    while (to_send > 0)
    {
      ensure_condition(socket, "send", cancellable, Glib::IO_OUT);
      try
      {
        if (use_udp)
          size = socket->send_to(address, buffer, to_send, cancellable);
        else
          size = socket->send(buffer, to_send, cancellable);
      }
      catch (const Gio::Error& error)
      {
        if (error.code() == Gio::Error::WOULD_BLOCK)
        {
          std::cout << "socket send would block, handling\n";
          continue;
        }
        else
        {
          std::cerr << Glib::ustring::compose("Error sending to socket: %1\n", error.what());
          return 1;
        }
      }

      std::cout << Glib::ustring::compose("sent %1 bytes of data\n", size);

      if (size == 0)
      {
        std::cerr << "Unexpected short write\n";
        return 1;
      }

      to_send -= size;
    }

    ensure_condition(socket, "receive", cancellable, Glib::IO_IN);
    try
    {
      if (use_udp)
        size = socket->receive_from(src_address, buffer, sizeof buffer, cancellable);
      else
        size = socket->receive(buffer, sizeof buffer, cancellable);
    }
    catch (const Gio::Error& error)
    {
      std::cerr << Glib::ustring::compose("Error receiving from socket: %1\n", error.what());
      return 1;
    }

    if (size == 0)
      break;

    std::cout << Glib::ustring::compose("received %1 bytes of data", size);
    if (use_udp)
      std::cout << Glib::ustring::compose(" from %1", socket_address_to_string(src_address));
    std::cout << std::endl;

    if (verbose)
      g_print("-------------------------\n"
              "%.*s"
              "-------------------------\n",
        (int)size, buffer);
  }

  std::cout << "closing socket\n";

  try
  {
    socket->close();
  }
  catch (const Gio::Error& error)
  {
    std::cerr << Glib::ustring::compose("Error closing master socket: %1\n", error.what());
    return 1;
  }

  return 0;
}