/*
 * Copyright (C) 2016-2017 Paul Davis <paul@linuxaudiosystems.com>
 *
 * 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_solo_control_h__
#define __ardour_solo_control_h__

#include <memory>
#include <string>

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

namespace ARDOUR {

class Session;
class Soloable;
class Muteable;

class LIBARDOUR_API SoloControl : public SlavableAutomationControl
{
  public:
	SoloControl (Session& session, std::string const & name, Soloable& soloable, Muteable& m, Temporal::TimeDomainProvider const &);

	double get_value () const;
	double get_save_value() const { return self_soloed(); }

	bool can_solo() const;

	/* Export additional API so that objects that only get access
	 * to a Controllable/AutomationControl can do more fine-grained
	 * operations with respect to solo. Obviously, they would need
	 * to dynamic_cast<SoloControl> first.
	 *
	 * Solo state is not representable by a single scalar value,
	 * so set_value() and get_value() is not enough.
	 *
	 * This means that the Controllable is technically
	 * asymmetric. It is possible to call ::set_value (0.0) to
	 * disable (self)solo, and then call ::get_value() and get a
	 * return of 1.0 because the control is soloed by
	 * upstream/downstream or a master.
	 */

	void mod_solo_by_others_upstream (int32_t delta);
	void mod_solo_by_others_downstream (int32_t delta);

	/* API to check different aspects of solo substate
	 */

	bool self_soloed () const {
		return _self_solo;
	}
	bool soloed_by_masters () const {
		return get_masters_value();
	}
	bool soloed_by_self_or_masters () const {
		return self_soloed() || get_masters_value ();
	}
	bool soloed_by_others () const {
		return _soloed_by_others_downstream || _soloed_by_others_upstream || get_masters_value ();
	}
	uint32_t soloed_by_others_upstream () const {
		return _soloed_by_others_upstream;
	}
	uint32_t soloed_by_others_downstream () const {
		return _soloed_by_others_downstream;
	}
	bool soloed() const { return self_soloed() || soloed_by_others(); }

	/* The session object needs to respond to solo
	   changes, but to do so accurately it needs to know if we transition
	   into or out of solo. The normal Changed signal doesn't make that
	   possible.
	*/

	int32_t transitioned_into_solo () const { return _transition_into_solo; }

	void clear_all_solo_state ();

	int set_state (XMLNode const&, int);
	XMLNode& get_state () const;

  protected:
	void actually_set_value (double, PBD::Controllable::GroupControlDisposition group_override);
	void master_changed (bool from_self, GroupControlDisposition, std::weak_ptr<AutomationControl> m);
	void pre_remove_master (std::shared_ptr<AutomationControl>);
	void post_add_master (std::shared_ptr<AutomationControl>);

  private:
	Soloable& _soloable;
	Muteable& _muteable;
	bool      _self_solo;
	uint32_t  _soloed_by_others_upstream;
	uint32_t  _soloed_by_others_downstream;
	int32_t   _transition_into_solo;

	void set_self_solo (bool yn);
	void set_mute_master_solo ();
};

} /* namespace */

#endif /* __libardour_solo_control_h__ */
