/*
    Copyright (C) 2016 Paul Davis

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#ifndef __libardour_presentation_info_h__
#define __libardour_presentation_info_h__

#include <iostream>
#include <string>

#include <stdint.h>

#include "ardour/libardour_visibility.h"

class XMLNode;

namespace ARDOUR {

class LIBARDOUR_API PresentationInfo
{
  public:

	/* a PresentationInfo object exists to share information between
	 * different user interfaces (e.g. GUI and a Mackie Control surface)
	 * about:
	 *
	 *     - ordering
	 *     - selection status
	 *     - visibility
	 *     - object identity
	 *
	 * ORDERING
	 *
	 * One UI takes control of ordering by setting the "order" value for
	 * the PresentationInfo component of every Stripable object. In Ardour,
	 * this is done by the GUI (mostly because it is very hard for the user
	 * to re-order things on a control surface).
	 *
	 * Ordering is a complex beast, however. Different user interfaces may
	 * display things in different ways. For example, the GUI of Ardour
	 * allows the user to mix busses in between tracks. A control surface
	 * may do the same, but may also allow the user to press a button that
	 * makes it show only busses, or only MIDI tracks. At that point, the
	 * ordering on the surface differs from the ordering in the GUI.
	 *
	 * There are several pathways for the order being set:
	 *
	 *   - object created during session loading from XML
	 *           - numeric order will be set during ::set_state(), based on
	 *           - type will be set during ctor call
	 *
	 *   - object created in response to user request
	 *		- numeric order will be set by Session, before adding
	 *		     to container.
	 *		- type set during ctor call
	 *
	 *
	 * OBJECT IDENTITY
	 *
	 * Control surfaces/protocols often need to be able to get a handle on
	 * an object identified only abstractly, such as the "5th audio track"
	 * or "the master out". A PresentationInfo object uniquely identifies
	 * all objects in this way through the combination of its _order member
	 * and part of its _flags member. The _flags member identifies the type
	 * of object, as well as selection/hidden status. The type may never
	 * change after construction (not strictly the constructor itself, but
	 * a more generalized notion of construction, as in "ready to use").
	 *
	 * SELECTION
	 *
	 * When an object is selected, its _flags member will have the Selected
	 * bit set.
	 *
	 * VISIBILITY
	 *
	 * When an object is hidden, its _flags member will have the Hidden
	 * bit set.
	 *
	 *
	 */

	enum Flag {
		/* Type information */
		AudioTrack = 0x1,
		MidiTrack = 0x2,
		AudioBus = 0x4,
		MidiBus = 0x8,
		VCA = 0x10,
		MasterOut = 0x20,
		MonitorOut = 0x40,
		Auditioner = 0x80,
		/* These are for sharing Stripable states between the GUI and other
		 * user interfaces/control surfaces
		 */
		Selected = 0x100,
		Hidden = 0x200,
		/* single bit indicates that the group order is set */
		GroupOrderSet = 0x400,

		/* special mask to delect out "state" bits */
		StatusMask = (Selected|Hidden)
	};

	static const Flag Route;
	static const Flag Track;
	static const Flag Bus;

	typedef uint32_t order_t;
	typedef uint64_t global_order_t;

	PresentationInfo (Flag f) : _order (0), _flags (Flag (f & ~GroupOrderSet)) { /* GroupOrderSet is not set */ }
	PresentationInfo (order_t o, Flag f) : _order (o), _flags (Flag (f | GroupOrderSet)) { /* GroupOrderSet is set */ }

	static const order_t max_order;

	order_t  order() const { return _order; }

	PresentationInfo::Flag flags() const { return _flags; }

	bool order_set() const { return _flags & GroupOrderSet; }

	bool hidden() const { return _flags & Hidden; }
	bool selected() const { return _flags & Selected; }
	bool special() const { return _flags & (MasterOut|MonitorOut|Auditioner); }

	void set_flag (PresentationInfo::Flag f) {
		_flags = PresentationInfo::Flag (_flags | f);
	}

	void unset_flag (PresentationInfo::Flag f) {
		_flags = PresentationInfo::Flag (_flags & ~f);
	}

	void set_flags (Flag f) {
		_flags = f;
	}

	bool flag_match (Flag f) const {
		/* no flags, match all */

		if (f == Flag (0)) {
			return true;
		}

		if (f & StatusMask) {
			/* status bits set, must match them */
			if ((_flags & StatusMask) != (f & StatusMask)) {
				return false;
			}
		}

		/* Generic flags in f, match the right stuff */

		if (f == Bus && (_flags & Bus)) {
			/* some kind of bus */
			return true;
		}
		if (f == Track && (_flags & Track)) {
			/* some kind of track */
			return true;
		}
		if (f == Route && (_flags & Route)) {
			/* any kind of route */
			return true;
		}

		return f == _flags;
	}

	std::string to_string () const;

	uint64_t to_integer () const {
		return ((uint64_t) _flags << (8*sizeof(order_t))) | _order;
	}

	bool operator< (PresentationInfo const& other) const {
		return order() < other.order();
	}

	PresentationInfo& operator= (std::string const& str) {
		parse (str);
		return *this;
	}

	bool match (PresentationInfo const& other) const {
		return (_order == other.order()) && flag_match (other.flags());
	}

	bool operator==(PresentationInfo const& other) {
		return (_order == other.order()) && (_flags == other.flags());
	}

	bool operator!=(PresentationInfo const& other) {
		return (_order != other.order()) || (_flags != other.flags());
	}

	static Flag get_flags (XMLNode const& node);

  protected:
	friend class Stripable;
	void set_order (order_t order) { _order = order; _flags = Flag (_flags|GroupOrderSet); }

  private:
	order_t _order;
	Flag    _flags;

	PresentationInfo (std::string const & str);
	int parse (std::string const&);
	int parse (order_t, Flag f);
};

}

std::ostream& operator<<(std::ostream& o, ARDOUR::PresentationInfo const& rid);

#endif /* __libardour_presentation_info_h__ */