/*
  This file is part of Ingen.
  Copyright 2007-2017 David Robillard <http://drobilla.net/>

  Ingen is free software: you can redistribute it and/or modify it under the
  terms of the GNU Affero General Public License as published by the Free
  Software Foundation, either version 3 of the License, or any later version.

  Ingen is distributed in the hope that it will be useful, but WITHOUT ANY
  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  A PARTICULAR PURPOSE.  See the GNU Affero General Public License for details.

  You should have received a copy of the GNU Affero General Public License
  along with Ingen.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef INGEN_ENGINE_DRIVER_HPP
#define INGEN_ENGINE_DRIVER_HPP

#include "types.hpp"

#include "ingen/URI.hpp"
#include "raul/Noncopyable.hpp"

#include <cstddef>

namespace raul {
class Path;
} // namespace raul

namespace ingen {

class Atom;

namespace server {

class Buffer;
class DuplexPort;
class EnginePort;
class RunContext;

/** Engine driver base class.
 *
 * A Driver is responsible for managing system ports, and possibly running the
 * audio graph.
 *
 * \ingroup engine
 */
class Driver : public raul::Noncopyable
{
public:
	virtual ~Driver() = default;

	/** Activate driver (begin processing graph and events). */
	virtual bool activate() { return true; }

	/** Deactivate driver (stop processing graph and events). */
	virtual void deactivate() {}

	/** Create a port ready to be inserted with add_input (non realtime).
	 * May return null if the Driver can not create the port for some reason.
	 */
	virtual EnginePort* create_port(DuplexPort* graph_port) = 0;

	/** Find a system port by path. */
	virtual EnginePort* get_port(const raul::Path& path) = 0;

	/** Add a system visible port (e.g. a port on the root graph). */
	virtual void add_port(RunContext& ctx, EnginePort* port) = 0;

	/** Remove a system visible port.
	 *
	 * This removes the port from the driver in the process thread but does not
	 * destroy the port.  To actually remove the system port, unregister_port()
	 * must be called later in another thread.
	 */
	virtual void remove_port(RunContext& ctx, EnginePort* port) = 0;

	/** Return true iff driver supports dynamic adding/removing of ports. */
	virtual bool dynamic_ports() const { return false; }

	/** Register a system visible port. */
	virtual void register_port(EnginePort& port) = 0;

	/** Register a system visible port. */
	virtual void unregister_port(EnginePort& port) = 0;

	/** Rename a system visible port. */
	virtual void rename_port(const raul::Path& old_path,
	                         const raul::Path& new_path) = 0;

	/** Apply a system visible port property. */
	virtual void port_property(const raul::Path& path,
	                           const URI&        uri,
	                           const Atom&       value) = 0;

	/** Return the audio buffer size in frames */
	virtual SampleCount block_length() const = 0;

	/** Return the event buffer size in bytes */
	virtual size_t seq_size() const = 0;

	/** Return the sample rate in Hz */
	virtual SampleRate sample_rate() const = 0;

	/** Return the current frame time (running counter) */
	virtual SampleCount frame_time() const = 0;

	/** Append time events for this cycle to `buffer`. */
	virtual void append_time_events(RunContext& ctx, Buffer& buffer) = 0;

	/** Return the real-time priority of the audio thread, or -1. */
	virtual int real_time_priority() = 0;
};

} // namespace server
} // namespace ingen

#endif // INGEN_ENGINE_DRIVER_HPP