#include <cmath>

#include <ardour/session.h>

#include "mackie_jog_wheel.h"

#include "mackie_control_protocol.h"
#include "surface_port.h"
#include "controls.h"
#include "surface.h"

#include <algorithm>

using namespace Mackie;
using std::isnan;

JogWheel::JogWheel( MackieControlProtocol & mcp )
: _mcp( mcp )
, _transport_speed( 4.0 )
, _transport_direction( 0 )
, _shuttle_speed( 0.0 )
{
}

JogWheel::State JogWheel::jog_wheel_state() const
{
	if ( !_jog_wheel_states.empty() )
		return _jog_wheel_states.top();
	else
		return scroll;
}

void JogWheel::zoom_event (SurfacePort &, Control &, const ControlState &)
{
}

void JogWheel::scrub_event (SurfacePort &, Control &, const ControlState &)
{
}

void JogWheel::speed_event (SurfacePort &, Control &, const ControlState &)
{
}

void JogWheel::scroll_event (SurfacePort &, Control &, const ControlState &)
{
}

void JogWheel::jog_event (SurfacePort &, Control &, const ControlState & state)
{
	// TODO use current snap-to setting?
	switch ( jog_wheel_state() )
	{
	case scroll:
		_mcp.ScrollTimeline( state.delta * state.sign );
		break;
	
	case zoom:
		// Chunky Zoom.
		// TODO implement something similar to ScrollTimeline which
		// ends up in Editor::control_scroll for smoother zooming.
		if ( state.sign > 0 )
			for ( unsigned int i = 0; i < state.ticks; ++i ) _mcp.ZoomIn();
		else
			for ( unsigned int i = 0; i < state.ticks; ++i ) _mcp.ZoomOut();
		break;
		
	case speed:
		// locally, _transport_speed is an positive value
		_transport_speed += _mcp.surface().scaled_delta( state, _mcp.get_session().transport_speed() );

		// make sure no weirdness gets to the session
		if ( _transport_speed < 0 || isnan( _transport_speed ) )
		{
			_transport_speed = 0.0;
		}
		
		// translate _transport_speed speed to a signed transport velocity
		_mcp.get_session().request_transport_speed( transport_speed() * transport_direction() );
		break;
	
	case scrub:
	{
		if ( state.sign != 0 )
		{
			add_scrub_interval( _scrub_timer.restart() );
			// x clicks per second => speed == 1.0
			float speed = _mcp.surface().scrub_scaling_factor() / average_scrub_interval() * state.ticks;
			_mcp.get_session().request_transport_speed( speed * state.sign );
		}
		else
		{
			// we have a stop event
			check_scrubbing();
		}
		break;
	}
	
	case shuttle:
		_shuttle_speed = _mcp.get_session().transport_speed();
		_shuttle_speed += _mcp.surface().scaled_delta( state, _mcp.get_session().transport_speed() );
		_mcp.get_session().request_transport_speed( _shuttle_speed );
		break;
	
	case select:
		std::cout << "JogWheel select not implemented" << std::endl;
		break;
	}
}

void JogWheel::check_scrubbing()
{
	// if the last elapsed is greater than the average + std deviation, then stop
	if ( !_scrub_intervals.empty() && _scrub_timer.elapsed() > average_scrub_interval() + std_dev_scrub_interval() )
	{
		_mcp.get_session().request_transport_speed( 0.0 );
		_scrub_intervals.clear();
	}
}

void JogWheel::push( State state )
{
	_jog_wheel_states.push( state );
}

void JogWheel::pop()
{
	if ( _jog_wheel_states.size() > 0 )
	{
		_jog_wheel_states.pop();
	}
}

void JogWheel::zoom_state_toggle()
{
	if ( jog_wheel_state() == zoom )
		pop();
	else
		push( zoom );
}

JogWheel::State JogWheel::scrub_state_cycle()
{
	State top = jog_wheel_state();
	if ( top == scrub )
	{
		// stop scrubbing and go to shuttle
		pop();
		push( shuttle );
		_shuttle_speed = 0.0;
	}
	else if ( top == shuttle )
	{
		// default to scroll, or the last selected
		pop();
	}
	else
	{
		// start with scrub
		push( scrub );
	}
	
	return jog_wheel_state();
}

void JogWheel::add_scrub_interval( unsigned long elapsed )
{
	if ( _scrub_intervals.size() > 5 )
	{
		_scrub_intervals.pop_front();
	}
	_scrub_intervals.push_back( elapsed );
}

float JogWheel::average_scrub_interval()
{
	float sum = 0.0;
	for ( std::deque<unsigned long>::iterator it = _scrub_intervals.begin(); it != _scrub_intervals.end(); ++it )
	{
		sum += *it;
	}
	return sum / _scrub_intervals.size(); 
}

float JogWheel::std_dev_scrub_interval()
{
	float average = average_scrub_interval();
	
	// calculate standard deviation
	float sum = 0.0;
	for ( std::deque<unsigned long>::iterator it = _scrub_intervals.begin(); it != _scrub_intervals.end(); ++it )
	{
		sum += pow( *it - average, 2 );
	}
	return sqrt( sum / _scrub_intervals.size() -1 );
}