VILLASnode/include/villas/web.hpp

/* LWS-releated functions.
 *
 * Author: Steffen Vogel <post@steffenvogel.de>
 * SPDX-FileCopyrightText: 2014-2023 Institute for Automation of Complex Power Systems, RWTH Aachen University
 * SPDX-License-Identifier: Apache-2.0
 */

#pragma once

#include <atomic>
#include <thread>

#include <jansson.h>
#include <libwebsockets.h>

#include <villas/common.hpp>
#include <villas/log.hpp>
#include <villas/queue.hpp>

namespace villas {
namespace node {

// Forward declarations
class Api;

class Web final {

private:
  enum State state;

  Logger logger;

  lws_context *context; // The libwebsockets server context.
  lws_vhost *vhost;     // The libwebsockets vhost.

  Queue<lws *>
      writables; // Queue of WSIs for which we will call lws_callback_on_writable()

  int port;                    // Port of the build in HTTP / WebSocket server.
  std::string ssl_cert;        // Path to the SSL certitifcate for HTTPS / WSS.
  std::string ssl_private_key; // Path to the SSL private key for HTTPS / WSS.

  std::thread thread;
  std::atomic<bool> running; // Atomic flag for signalizing thread termination.

  Api *api;

  void worker();

public:
  /* Initialize the web interface.
 	 *
 	 * The web interface is based on the libwebsockets library.
 	 */
  Web(Api *a = nullptr);

  ~Web();

  void start();
  void stop();

  static void lwsLogger(int level, const char *msg);
  static int lwsLogLevel(Log::Level lvl);

  // Parse HTTPd and WebSocket related options
  int parse(json_t *json);

  Api *getApi() { return api; }

  // for C-compatability
  lws_context *getContext() { return context; }

  lws_vhost *getVHost() { return vhost; }

  enum State getState() const { return state; }

  void callbackOnWritable(struct lws *wsi);

  bool isEnabled() { return port != CONTEXT_PORT_NO_LISTEN; }
};

} // namespace node
} // namespace villas