/*
 * Copyright (C) 2009-2018 Paul Davis <paul@linuxaudiosystems.com>
 * Copyright (C) 2010-2012 Carl Hetherington <carl@carlh.net>
 * Copyright (C) 2010-2012 David Robillard <d@drobilla.net>
 * Copyright (C) 2015-2018 Robin Gareus <robin@gareus.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#ifndef __ardour_session_event_h__
#define __ardour_session_event_h__

#include <list>
#include <memory>

#include <boost/function.hpp>

#include "pbd/pool.h"
#include "pbd/ringbuffer.h"
#include "pbd/event_loop.h"

#include "ardour/libardour_visibility.h"
#include "ardour/types.h"

namespace ARDOUR {

class TransportMaster;
class Region;
class Track;

class LIBARDOUR_API SessionEvent {
public:
	enum Type {
		SetTransportSpeed,
		SetDefaultPlaySpeed,
		Locate,
		LocateRoll,
		LocateRollLocate,
		SetLoop,
		PunchIn,
		PunchOut,
		RangeStop,
		RangeLocate,
		Overwrite,
		OverwriteAll,
		Audition,
		SetPlayAudioRange,
		CancelPlayAudioRange,
		RealTimeOperation,
		AdjustPlaybackBuffering,
		AdjustCaptureBuffering,
		SetTimecodeTransmission,
		Skip,
		SetTransportMaster,
		StartRoll,
		EndRoll,
		TransportStateChange,
		SyncCues,

		/* only one of each of these events can be queued at any one time */

		AutoLoop,
	};

	enum Action {
		Add,
		Remove,
		Replace,
		Clear
	};

	Type       type;
	Action     action;
	samplepos_t action_sample;
	samplepos_t target_sample;
	double     speed;

	union {
		bool             yes_or_no;
		samplepos_t      target2_sample;
		OverwriteReason  overwrite;
		int32_t          scene;
	};

	std::weak_ptr<Track> track;

	union {
		bool second_yes_or_no;
		double control_value;
		LocateTransportDisposition locate_transport_disposition;
	};

	union {
		bool third_yes_or_no;
	};

	/* 5 members to handle a multi-group event handled in RT context */

	typedef boost::function<void (SessionEvent*)> RTeventCallback;

	std::shared_ptr<AutomationControlList> controls; /* apply to */
	std::shared_ptr<RouteList> routes;     /* apply to */
	boost::function<void (void)> rt_slot;    /* what to call in RT context */
	RTeventCallback              rt_return;  /* called after rt_slot, with this event as an argument */
	PBD::EventLoop*              event_loop;

	std::list<TimelineRange> audio_range;
	std::list<TimelineRange> music_range;

	std::shared_ptr<Region> region;
	std::shared_ptr<TransportMaster> transport_master;

	SessionEvent (Type t, Action a, samplepos_t when, samplepos_t where, double spd, bool yn = false, bool yn2 = false, bool yn3 = false);

	void set_track (std::shared_ptr<Track> t) {
		track = t;
	}

	bool before (const SessionEvent& other) const {
		return action_sample < other.action_sample;
	}

	bool after (const SessionEvent& other) const {
		return action_sample > other.action_sample;
	}

	static bool compare (const SessionEvent *e1, const SessionEvent *e2) {
		return e1->before (*e2);
	}

	void* operator new (size_t);
	void  operator delete (void *ptr, size_t /*size*/);

	static const samplepos_t Immediate = -1;

	static bool has_per_thread_pool ();
	static void create_per_thread_pool (const std::string& n, uint32_t nitems);
	static void init_event_pool ();
	static guint pool_available ();

	PBD::CrossThreadPool* event_pool() const { return own_pool; }

private:
	static PBD::PerThreadPool* pool;
	PBD::CrossThreadPool*      own_pool;

	friend class Butler;
};

class SessionEventManager {
public:
	SessionEventManager () : pending_events (2048),
	                         auto_loop_event(0), punch_out_event(0), punch_in_event(0) {}
	virtual ~SessionEventManager() {}

	virtual void queue_event (SessionEvent *ev) = 0;
	void clear_events (SessionEvent::Type type);
	void clear_events (SessionEvent::Type type, boost::function<void (void)> after);

protected:
	PBD::RingBuffer<SessionEvent*> pending_events;
	typedef std::list<SessionEvent *> Events;
	Events           events;
	Events           immediate_events;
	Events::iterator next_event;

	Glib::Threads::Mutex rb_write_lock;

	/* there can only ever be one of each of these */

	SessionEvent *auto_loop_event;
	SessionEvent *punch_out_event;
	SessionEvent *punch_in_event;

	void dump_events () const;
	void merge_event (SessionEvent*);
	void replace_event (SessionEvent::Type, samplepos_t action_sample, samplepos_t target = 0);
	bool _replace_event (SessionEvent*);
	bool _remove_event (SessionEvent *);
	void _clear_event_type (SessionEvent::Type);

	void add_event (samplepos_t action_sample, SessionEvent::Type type, samplepos_t target_sample = 0);
	void remove_event (samplepos_t sample, SessionEvent::Type type);

	virtual void process_event(SessionEvent*) = 0;
	virtual void set_next_event () = 0;
};

} /* namespace */

LIBARDOUR_API std::ostream& operator<<(std::ostream&, const ARDOUR::SessionEvent&);

#endif /* __ardour_session_event_h__ */
