/* This file is part of Machina.
 * Copyright (C) 2007 Dave Robillard <http://drobilla.net>
 * 
 * Machina 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.
 * 
 * Machina 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 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
 */

#include "raul/SharedPtr.h"
#include "machina/Machine.hpp"
#include "machina/Node.hpp"
#include "machina/Edge.hpp"
#include "machina/MidiAction.hpp"

namespace Machina {


Machine::Machine()
	: _is_activated(false)
	, _is_finished(false)
	, _time(0)
{
}


Machine::~Machine()
{
}


void
Machine::add_node(SharedPtr<Node> node)
{
	_nodes.push_back(node);
}


/** Exit all active states and reset time to 0.
 */
void
Machine::reset()
{
	if (!_is_finished) {
		for (Nodes::const_iterator n = _nodes.begin(); n != _nodes.end(); ++n) {
			const SharedPtr<Node> node = (*n);

			if (node->is_active())
				node->exit(_time);
		}
	}

	_time = 0;
	_is_finished = false;
}


/** Return the active Node with the earliest exit time.
 */
SharedPtr<Node>
Machine::earliest_node() const
{	
	SharedPtr<Node> earliest;
	
	for (Nodes::const_iterator n = _nodes.begin(); n != _nodes.end(); ++n) {
		const SharedPtr<Node> node = (*n);
		
		if (node->is_active())
			if (!earliest || node->exit_time() < earliest->exit_time())
				earliest = node;
	}

	return earliest;
}


/** Exit an active node at the current _time.
 */
void
Machine::exit_node(const SharedPtr<Node> node)
{
	node->exit(_time);

	// Activate all successors to this node
	// (that aren't aready active right now)
	for (Node::EdgeList::const_iterator s = node->outgoing_edges().begin();
			s != node->outgoing_edges().end(); ++s) {
		SharedPtr<Node> dst = (*s)->dst();

		if (!dst->is_active())
			dst->enter(_time);

	}
}


/** Run the machine for @a nframes frames.
 *
 * Returns the duration of time the machine actually ran (from 0 to nframes).
 * Caller can check is_finished() to determine if the machine still has any
 * active states.  If not, time() will return the exact time stamp the
 * machine actually finished on (so it can be restarted immediately
 * with sample accuracy if necessary).
 */
FrameCount
Machine::run(FrameCount nframes)
{
	using namespace std;
	if (_is_finished) {
		cerr << "FINISHED\n";
		return 0;
	}

	const FrameCount cycle_end = _time + nframes;

	//std::cerr << "Start: " << _time << std::endl;
	
	assert(_is_activated);

	// Initial run, enter all initial states
	if (_time == 0) {
		bool entered = false;
		if ( ! _nodes.empty()) {
			for (Nodes::const_iterator n = _nodes.begin(); n != _nodes.end(); ++n) {
				
				assert( ! (*n)->is_active());
				
				if ((*n)->is_initial()) {
					(*n)->enter(0);
					entered = true;
				}

			}
		}
		if (!entered) {
			_is_finished = true;
			return 0;
		}
	}
	
	FrameCount this_time = 0;

	while (true) {

		SharedPtr<Node> earliest = earliest_node();

		// No more active states, machine is finished
		if (!earliest) {
			_is_finished = true;
			break;

		// Earliest active state ends this cycle
		} else if (earliest->exit_time() < cycle_end) {
			this_time += earliest->exit_time() - _time;
			_time = earliest->exit_time();
			exit_node(earliest);

		// Earliest active state ends in the future, done this cycle
		} else {
			_time = cycle_end;
			this_time = nframes; // ran the entire cycle
			break;
		}

	}

	//std::cerr << "Done: " << this_time << std::endl;

	assert(this_time <= nframes);
	return this_time;
}


/** Push a node onto the learn stack.
 *
 * NOT realtime (actions are allocated here).
 */
void
Machine::learn(SharedPtr<LearnRequest> learn)
{
	std::cerr << "LEARN\n";

	/*LearnRequest request(node,
		SharedPtr<MidiAction>(new MidiAction(4, NULL)),
		SharedPtr<MidiAction>(new MidiAction(4, NULL)));*/

	//_pending_learns.push_back(learn);
	_pending_learn = learn;
}


} // namespace Machina