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

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