qml_tcp_outbound_socket.hpp

#pragma once
#include <ossia/detail/variant.hpp>
#include <ossia/network/context.hpp>
#include <ossia/network/sockets/configuration.hpp>
#include <ossia/network/sockets/line_framing.hpp>
#include <ossia/network/sockets/no_framing.hpp>
#include <ossia/network/sockets/size_prefix_framing.hpp>
#include <ossia/network/sockets/slip_framing.hpp>
#include <ossia/network/sockets/tcp_socket.hpp>
 
#include <ossia-qt/protocols/utils.hpp>
 
#include <QJSValue>
#include <QObject>
#include <QQmlEngine>
 
#include <nano_observer.hpp>
 
#include <verdigris>
 
namespace ossia::qt
{
class qml_tcp_outbound_socket
    : public QObject
    , public Nano::Observer
{
  W_OBJECT(qml_tcp_outbound_socket)
public:
  using socket_t = boost::asio::ip::tcp::socket;
  using decoder_type = ossia::slow_variant<
      ossia::net::no_framing::decoder<socket_t>,
      ossia::net::slip_decoder<socket_t>,
      ossia::net::size_prefix_decoder<socket_t>,
      ossia::net::line_framing_decoder<socket_t>>;
 
  struct state
  {
    ossia::net::tcp_client socket;
    std::atomic_bool alive{true};
    ossia::net::framing framing{ossia::net::framing::none};
    char line_delimiter[8] = {};
    decoder_type decoder;
 
    state(
        const ossia::net::outbound_socket_configuration& conf,
        boost::asio::io_context& ctx,
        ossia::net::framing f = ossia::net::framing::none,
        const std::string& delim = {})
        : socket{conf, ctx}
        , decoder{ossia::in_place_index<0>, socket.m_socket}
    {
      framing = f;
      if(!delim.empty())
      {
        auto sz = std::min(delim.size(), (size_t)7);
        std::copy_n(delim.begin(), sz, line_delimiter);
      }
 
      switch(f)
      {
        default:
        case ossia::net::framing::none:
          break;
        case ossia::net::framing::slip:
          decoder.template emplace<1>(socket.m_socket);
          break;
        case ossia::net::framing::size_prefix:
          decoder.template emplace<2>(socket.m_socket);
          break;
        case ossia::net::framing::line_delimiter:
          decoder.template emplace<3>(socket.m_socket);
          {
            auto& dec = ossia::get<3>(decoder);
            std::copy_n(line_delimiter, 8, dec.delimiter);
          }
          break;
      }
    }
 
    void write_encoded(const char* data, std::size_t sz)
    {
      switch(framing)
      {
        default:
        case ossia::net::framing::none:
          socket.write(data, sz);
          break;
        case ossia::net::framing::slip: {
          ossia::net::slip_encoder<socket_t> enc{socket.m_socket};
          enc.write(data, sz);
          break;
        }
        case ossia::net::framing::size_prefix: {
          ossia::net::size_prefix_encoder<socket_t> enc{socket.m_socket};
          enc.write(data, sz);
          break;
        }
        case ossia::net::framing::line_delimiter: {
          ossia::net::line_framing_encoder<socket_t> enc{socket.m_socket};
          std::copy_n(line_delimiter, 8, enc.delimiter);
          enc.write(data, sz);
          break;
        }
      }
    }
  };
 
  struct receive_callback
  {
    std::shared_ptr<state> st;
    QPointer<qml_tcp_outbound_socket> self;
    QJSValue* target; // points to onMessage or onBytes on the QObject
 
    void operator()(const unsigned char* data, std::size_t sz) const
    {
      if(!st->alive)
        return;
      auto buf = QByteArray((const char*)data, sz);
      auto cb = target;
      ossia::qt::run_async(
          self.get(),
          [self = self, buf, cb] {
        if(!self.get())
          return;
        if(cb->isCallable())
        {
          auto engine = qjsEngine(self.get());
          if(engine)
            cb->call({engine->toScriptValue(buf)});
        }
      },
          Qt::AutoConnection);
    }
 
    bool validate_stream(boost::system::error_code ec) const
    {
      if(ec == boost::asio::error::operation_aborted)
        return false;
      if(ec == boost::asio::error::eof)
        return false;
      return true;
    }
  };
 
  qml_tcp_outbound_socket() { }
 
  ~qml_tcp_outbound_socket()
  {
    if(m_state)
    {
      m_state->alive = false;
      close();
    }
  }
 
  bool isOpen() const noexcept { return m_state != nullptr; }
 
  void open(
      const ossia::net::outbound_socket_configuration& conf,
      boost::asio::io_context& ctx,
      ossia::net::framing f = ossia::net::framing::none,
      const std::string& delim = {})
  {
    m_state = std::make_shared<state>(conf, ctx, f, delim);
 
    try
    {
      if(onOpen.isCallable())
        m_state->socket.on_open.connect<&qml_tcp_outbound_socket::on_open>(this);
      if(onClose.isCallable())
        m_state->socket.on_close.connect<&qml_tcp_outbound_socket::on_close>(this);
      if(onError.isCallable())
        m_state->socket.on_fail.connect<&qml_tcp_outbound_socket::on_fail>(this);
      m_state->socket.connect();
    }
    catch(const std::exception& e)
    {
      if(onError.isCallable())
      {
        onError.call({QString::fromStdString(e.what())});
      }
    }
  }
 
  void write(QByteArray buffer)
  {
    if(!m_state)
      return;
    auto st = m_state;
    boost::asio::dispatch(st->socket.m_context, [st, buffer] {
      if(st->alive)
        st->write_encoded(buffer.data(), buffer.size());
    });
  }
  W_SLOT(write)
 
  void close()
  {
    if(!m_state)
      return;
    auto st = m_state;
    boost::asio::post(st->socket.m_context, [st] {
      try
      {
        st->socket.m_socket.shutdown(boost::asio::ip::tcp::socket::shutdown_both);
      }
      catch(...)
      {
      }
      st->socket.m_socket.close();
      st->socket.on_close();
    });
  }
  W_SLOT(close)
 
  void on_open()
  {
    if(!m_state || !m_state->alive)
      return;
 
    // Start receive loop:
    // - onMessage uses the configured framing decoder
    // - onBytes always uses no_framing (raw bytes, backward compatible)
    // - onMessage takes priority if both are set
    auto st = m_state;
    auto self = QPointer{this};
    if(onMessage.isCallable())
    {
      ossia::visit(
          [cb = receive_callback{st, self, &self.data()->onMessage}](
              auto& decoder) mutable { decoder.receive(std::move(cb)); },
          st->decoder);
    }
    else if(onBytes.isCallable())
    {
      // Override decoder to no_framing for raw bytes
      st->decoder.template emplace<0>(st->socket.m_socket);
      ossia::get<0>(st->decoder)
          .receive(receive_callback{st, self, &self.data()->onBytes});
    }
 
    ossia::qt::run_async(
        this, [=, this] { onOpen.call({qjsEngine(this)->newQObject(this)}); },
        Qt::AutoConnection);
  }
  void on_fail()
  {
    if(!m_state || !m_state->alive)
      return;
    ossia::qt::run_async(this, [=, this] { onError.call(); }, Qt::AutoConnection);
  }
  void on_close()
  {
    if(!m_state || !m_state->alive)
      return;
    ossia::qt::run_async(this, [=, this] { onClose.call(); }, Qt::AutoConnection);
  }
 
  void osc(QByteArray address, QJSValueList values)
  {
    if(!m_state)
      return;
 
    QByteArray packet;
    buffer_writer bw{packet};
    using send_visitor = ossia::net::osc_value_send_visitor<
        ossia::net::full_parameter_data, ossia::net::osc_1_0_policy, buffer_writer>;
 
    ossia::net::full_parameter_data p;
    const std::string addr = address.toStdString();
 
    switch(values.size())
    {
      case 0: {
        ossia::value{ossia::impulse{}}.apply(send_visitor{p, addr, bw});
        break;
      }
      case 1: {
        auto v = ossia::qt::value_from_js(values[0]);
        v.apply(send_visitor{p, addr, bw});
        break;
      }
      default: {
        std::vector<ossia::value> vec;
        vec.reserve(values.size());
        for(const auto& v : values)
          vec.push_back(ossia::qt::value_from_js(v));
        ossia::value vvec(std::move(vec));
        vvec.apply(send_visitor{p, addr, bw});
      }
    }
 
    write(packet);
  }
  W_SLOT(osc)
 
  QJSValue onOpen;
  QJSValue onClose;
  QJSValue onError;
  QJSValue onMessage;
  QJSValue onBytes; // raw bytes, ignores Framing (backward compatible)
 
private:
  std::shared_ptr<state> m_state;
};
 
}