/*
    Copyright (C) 2007 Paul Davis
    Author: David Robillard

    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.

*/

#include <math.h>
#include <iostream>
#include "ardour/automation_control.h"
#include "ardour/automation_watch.h"
#include "ardour/event_type_map.h"
#include "ardour/session.h"

#include "pbd/memento_command.h"
#include "pbd/stacktrace.h"

#include "i18n.h"

#ifdef COMPILER_MSVC
#include <float.h>
// C99 'isfinite()' is not available in MSVC.
#define isfinite_local(val) (bool)_finite((double)val)
#else
#define isfinite_local isfinite
#endif

using namespace std;
using namespace ARDOUR;
using namespace PBD;

AutomationControl::AutomationControl(ARDOUR::Session&                          session,
                                     const Evoral::Parameter&                  parameter,
                                     const ParameterDescriptor&                desc,
                                     boost::shared_ptr<ARDOUR::AutomationList> list,
                                     const string&                             name)
	: Controllable (name.empty() ? EventTypeMap::instance().to_symbol(parameter) : name)
	, Evoral::Control(parameter, desc, list)
	, _session(session)
	, _desc(desc)
{
}

AutomationControl::~AutomationControl ()
{
	DropReferences (); /* EMIT SIGNAL */
}

bool
AutomationControl::writable() const
{
	boost::shared_ptr<AutomationList> al = alist();
	if (al) {
		return al->automation_state() != Play;
	}
	return true;
}

double
AutomationControl::get_masters_value_locked () const
{
	gain_t v = 1.0;

	for (Masters::const_iterator mr = _masters.begin(); mr != _masters.end(); ++mr) {
		/* get current master value, scale by our current ratio with that master */
		v *= mr->second.master()->get_value () * mr->second.ratio();
	}

	return min (_desc.upper, v);
}

double
AutomationControl::get_value_locked() const
{
	/* read or write masters lock must be held */

	if (_masters.empty()) {
		return Control::get_double (false, _session.transport_frame());
	}

	return get_masters_value_locked ();
}

/** Get the current effective `user' value based on automation state */
double
AutomationControl::get_value() const
{
	bool from_list = _list && ((AutomationList*)_list.get())->automation_playback();

	if (!from_list) {
		Glib::Threads::RWLock::ReaderLock lm (master_lock);
		return get_value_locked ();
	} else {
		return Control::get_double (from_list, _session.transport_frame());
	}
}

/** Set the value and do the right thing based on automation state
 *  (e.g. record if necessary, etc.)
 *  @param value `user' value
 */
void
AutomationControl::set_value (double value, PBD::Controllable::GroupControlDisposition /* group_override */)
{
	bool to_list = _list && ((AutomationList*)_list.get())->automation_write();

	Control::set_double (value, _session.transport_frame(), to_list);

	Changed(); /* EMIT SIGNAL */
}

void
AutomationControl::set_list (boost::shared_ptr<Evoral::ControlList> list)
{
	Control::set_list (list);
	Changed();  /* EMIT SIGNAL */
}

void
AutomationControl::set_automation_state (AutoState as)
{
	if (_list && as != alist()->automation_state()) {

		alist()->set_automation_state (as);
		if (_desc.toggled) {
			return;  // No watch for boolean automation
		}

		if (as == Write) {
			AutomationWatch::instance().add_automation_watch (shared_from_this());
		} else if (as == Touch) {
			if (!touching()) {
				AutomationWatch::instance().remove_automation_watch (shared_from_this());
			} else {
				/* this seems unlikely, but the combination of
				 * a control surface and the mouse could make
				 * it possible to put the control into Touch
				 * mode *while* touching it.
				 */
				AutomationWatch::instance().add_automation_watch (shared_from_this());
			}
		} else {
			AutomationWatch::instance().remove_automation_watch (shared_from_this());
		}
	}
}

void
AutomationControl::set_automation_style (AutoStyle as)
{
	if (!_list) return;
	alist()->set_automation_style (as);
}

void
AutomationControl::start_touch(double when)
{
	if (!_list) {
		return;
	}

	if (!touching()) {

		if (alist()->automation_state() == Touch) {
			/* subtle. aligns the user value with the playback */
			set_value (get_value (), Controllable::NoGroup);
			alist()->start_touch (when);
			if (!_desc.toggled) {
				AutomationWatch::instance().add_automation_watch (shared_from_this());
			}
		}
		set_touching (true);
	}
}

void
AutomationControl::stop_touch(bool mark, double when)
{
	if (!_list) return;
	if (touching()) {
		set_touching (false);

		if (alist()->automation_state() == Touch) {
			alist()->stop_touch (mark, when);
			if (!_desc.toggled) {
				AutomationWatch::instance().remove_automation_watch (shared_from_this());

			}
		}
	}
}

void
AutomationControl::commit_transaction (bool did_write)
{
	if (did_write) {
		if (alist ()->before ()) {
			_session.begin_reversible_command (string_compose (_("record %1 automation"), name ()));
			_session.commit_reversible_command (new MementoCommand<AutomationList> (*alist ().get (), alist ()->before (), &alist ()->get_state ()));
		}
	} else {
		alist ()->clear_history ();
	}
}

double
AutomationControl::internal_to_interface (double val) const
{
	if (_desc.integer_step) {
		// both upper and lower are inclusive.
		val =  (val - lower()) / (1 + upper() - lower());
	} else {
		val =  (val - lower()) / (upper() - lower());
	}

	if (_desc.logarithmic) {
		if (val > 0) {
			val = pow (val, 1./2.0);
		} else {
			val = 0;
		}
	}

	return val;
}

double
AutomationControl::interface_to_internal (double val) const
{
	if (!isfinite_local (val)) {
		val = 0;
	}
	if (_desc.logarithmic) {
		if (val <= 0) {
			val = 0;
		} else {
			val = pow (val, 2.0);
		}
	}

	if (_desc.integer_step) {
		val =  lower() + val * (1 + upper() - lower());
	} else {
		val =  lower() + val * (upper() - lower());
	}

	if (val < lower()) val = lower();
	if (val > upper()) val = upper();

	return val;
}


void
AutomationControl::add_master (boost::shared_ptr<AutomationControl> m)
{
	double current_value;
	std::pair<Masters::iterator,bool> res;

	{
		Glib::Threads::RWLock::WriterLock lm (master_lock);
		current_value = get_value_locked ();

		/* ratio will be recomputed below */

		res = _masters.insert (make_pair<PBD::ID,MasterRecord> (m->id(), MasterRecord (m, 1.0)));

		if (res.second) {

			recompute_masters_ratios (current_value);

			/* note that we bind @param m as a weak_ptr<AutomationControl>, thus
			   avoiding holding a reference to the control in the binding
			   itself.
			*/

			m->DropReferences.connect_same_thread (masters_connections, boost::bind (&AutomationControl::master_going_away, this, m));

			/* Store the connection inside the MasterRecord, so that when we destroy it, the connection is destroyed
			   and we no longer hear about changes to the AutomationControl.
			*/

			m->Changed.connect_same_thread (res.first->second.connection, boost::bind (&PBD::Signal0<void>::operator(), &Changed));
		}
	}

	if (res.second) {
		MasterStatusChange (); /* EMIT SIGNAL */
	}
}

void
AutomationControl::master_going_away (boost::weak_ptr<AutomationControl> wm)
{
	boost::shared_ptr<AutomationControl> m = wm.lock();
	if (m) {
		remove_master (m);
	}
}

void
AutomationControl::remove_master (boost::shared_ptr<AutomationControl> m)
{
	double current_value;
	Masters::size_type erased = 0;

	{
		Glib::Threads::RWLock::WriterLock lm (master_lock);
		current_value = get_value_locked ();
		erased = _masters.erase (m->id());
		if (erased) {
			recompute_masters_ratios (current_value);
		}
	}

	if (erased) {
		MasterStatusChange (); /* EMIT SIGNAL */
	}
}

void
AutomationControl::clear_masters ()
{
	bool had_masters = false;

	{
		Glib::Threads::RWLock::WriterLock lm (master_lock);
		if (!_masters.empty()) {
			had_masters = true;
		}
		_masters.clear ();
	}

	if (had_masters) {
		MasterStatusChange (); /* EMIT SIGNAL */
	}
}

bool
AutomationControl::slaved_to (boost::shared_ptr<AutomationControl> m) const
{
	Glib::Threads::RWLock::ReaderLock lm (master_lock);
	return _masters.find (m->id()) != _masters.end();
}

bool
AutomationControl::slaved () const
{
	Glib::Threads::RWLock::ReaderLock lm (master_lock);
	return !_masters.empty();
}