#include <cmath>
#include <cstdlib>
#include <cstdio>
#include <cstring>

#include <iostream>
#include <string>

#include "pbd/cartesian.h"

#include "ardour/amp.h"
#include "ardour/audio_buffer.h"
#include "ardour/buffer_set.h"
#include "ardour/pan_controllable.h"
#include "ardour/pannable.h"
#include "ardour/speakers.h"

#include "vbap.h"
#include "vbap_speakers.h"

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

static PanPluginDescriptor _descriptor = {
        "VBAP 2D panner",
        -1, -1,
        VBAPanner::factory
};

extern "C" { PanPluginDescriptor* panner_descriptor () { return &_descriptor; } }

VBAPanner::Signal::Signal (Session& session, VBAPanner& p, uint32_t n, uint32_t n_speakers)
{
        resize_gains (n_speakers);

        desired_gains[0] = desired_gains[1] = desired_gains[2] = 0;
        outputs[0] = outputs[1] = outputs[2] = -1;
        desired_outputs[0] = desired_outputs[1] = desired_outputs[2] = -1;
}

void
VBAPanner::Signal::Signal::resize_gains (uint32_t n)
{
        gains.assign (n, 0.0);
}        

VBAPanner::VBAPanner (boost::shared_ptr<Pannable> p, boost::shared_ptr<Speakers> s)
	: Panner (p)
	, _speakers (new VBAPSpeakers (s))
{
        _pannable->pan_azimuth_control->Changed.connect_same_thread (*this, boost::bind (&VBAPanner::update, this));
        _pannable->pan_width_control->Changed.connect_same_thread (*this, boost::bind (&VBAPanner::update, this));

        update ();
}

VBAPanner::~VBAPanner ()
{
        clear_signals ();
}

void
VBAPanner::clear_signals ()
{
        for (vector<Signal*>::iterator i = _signals.begin(); i != _signals.end(); ++i) {
                delete *i;
        }
        _signals.clear ();
}

void
VBAPanner::configure_io (ChanCount in, ChanCount /* ignored - we use Speakers */)
{
        uint32_t n = in.n_audio();

        clear_signals ();

        for (uint32_t i = 0; i < n; ++i) {
                Signal* s = new Signal (_pannable->session(), *this, i, _speakers->n_speakers());
                _signals.push_back (s);
                
        }

        update ();
}

void
VBAPanner::update ()
{
        /* recompute signal directions based on panner azimuth and width (diffusion) parameters)
         */

        /* panner azimuth control is [0 .. 1.0] which we interpret as [0 .. 360] degrees
         */

        double center = _pannable->pan_azimuth_control->get_value() * 360.0;

        /* panner width control is [-1.0 .. 1.0]; we ignore sign, and map to [0 .. 360] degrees
           so that a width of 1 corresponds to a signal equally present from all directions, 
           and a width of zero corresponds to a point source from the "center" (above)
        */

        double w = fabs (_pannable->pan_width_control->get_value()) * 360.0;

        double min_dir = center - w;
        min_dir = max (min (min_dir, 360.0), 0.0);

        double max_dir = center + w;
        max_dir = max (min (max_dir, 360.0), 0.0);

        double degree_step_per_signal = (max_dir - min_dir) / _signals.size();
        double signal_direction = min_dir;

        for (vector<Signal*>::iterator s = _signals.begin(); s != _signals.end(); ++s) {

                Signal* signal = *s;

                signal->direction = AngularVector (signal_direction, 0.0);
                compute_gains (signal->desired_gains, signal->desired_outputs, signal->direction.azi, signal->direction.ele);
                signal_direction += degree_step_per_signal;
        }
}

void 
VBAPanner::compute_gains (double gains[3], int speaker_ids[3], int azi, int ele) 
{
	/* calculates gain factors using loudspeaker setup and given direction */
	double cartdir[3];
	double power;
	int i,j,k;
	double small_g;
	double big_sm_g, gtmp[3];

	azi_ele_to_cart (azi,ele, cartdir[0], cartdir[1], cartdir[2]);  
	big_sm_g = -100000.0;

	gains[0] = gains[1] = gains[2] = 0;
	speaker_ids[0] = speaker_ids[1] = speaker_ids[2] = 0;

	for (i = 0; i < _speakers->n_tuples(); i++) {

		small_g = 10000000.0;

		for (j = 0; j < _speakers->dimension(); j++) {

			gtmp[j] = 0.0;

			for (k = 0; k < _speakers->dimension(); k++) {
				gtmp[j] += cartdir[k] * _speakers->matrix(i)[j*_speakers->dimension()+k]; 
			}

			if (gtmp[j] < small_g) {
				small_g = gtmp[j];
			}
		}

		if (small_g > big_sm_g) {

			big_sm_g = small_g;

			gains[0] = gtmp[0]; 
			gains[1] = gtmp[1]; 

			speaker_ids[0] = _speakers->speaker_for_tuple (i, 0);
			speaker_ids[1] = _speakers->speaker_for_tuple (i, 1);

			if (_speakers->dimension() == 3) {
				gains[2] = gtmp[2];
				speaker_ids[2] = _speakers->speaker_for_tuple (i, 2);
			} else {
				gains[2] = 0.0;
				speaker_ids[2] = -1;
			}
		}
	}
        
	power = sqrt (gains[0]*gains[0] + gains[1]*gains[1] + gains[2]*gains[2]);

	if (power > 0) {
		gains[0] /= power; 
		gains[1] /= power;
		gains[2] /= power;
	}
}

void
VBAPanner::distribute (BufferSet& inbufs, BufferSet& obufs, gain_t gain_coefficient, pframes_t nframes)
{
        uint32_t n;
        vector<Signal*>::iterator s;

        assert (inbufs.count().n_audio() == _signals.size());

        for (s = _signals.begin(), n = 0; s != _signals.end(); ++s, ++n) {

                Signal* signal (*s);

                distribute_one (inbufs.get_audio (n), obufs, gain_coefficient, nframes, n);

                memcpy (signal->outputs, signal->desired_outputs, sizeof (signal->outputs));
        }
}

void
VBAPanner::distribute_one (AudioBuffer& srcbuf, BufferSet& obufs, gain_t gain_coefficient, pframes_t nframes, uint32_t which)
{
	Sample* const src = srcbuf.data();
        Signal* signal (_signals[which]);

	/* VBAP may distribute the signal across up to 3 speakers depending on
	   the configuration of the speakers.

           But the set of speakers in use "this time" may be different from
           the set of speakers "the last time". So we have up to 6 speakers
           involved, and we have to interpolate so that those no longer
           in use are rapidly faded to silence and those newly in use
           are rapidly faded to their correct level. This prevents clicks
           as we change the set of speakers used to put the signal in
           a given position.

           However, the speakers are represented by output buffers, and other
           speakers may write to the same buffers, so we cannot use
           anything here that will simply assign new (sample) values
           to the output buffers - everything must be done via mixing
           functions and not assignment/copying.
	*/

        vector<double>::size_type sz = signal->gains.size();

        assert (sz == obufs.count().n_audio());

        int8_t outputs[sz]; // on the stack, no malloc
        
        /* set initial state of each output "record"
         */

        for (uint32_t o = 0; o < sz; ++o) {
                outputs[o] = 0;
        }

        /* for all outputs used this time and last time,
           change the output record to show what has
           happened.
        */

        for (int o = 0; o < 3; ++o) {
                if (signal->outputs[o] != -1) {
                        /* used last time */
                        outputs[signal->outputs[o]] |= 1;
                } 

                if (signal->desired_outputs[o] != -1) {
                        /* used this time */
                        outputs[signal->desired_outputs[o]] |= 1<<1;
                } 
        }

        /* at this point, we can test a speaker's status:

           (outputs[o] & 1)      <= in use before
           (outputs[o] & 2)      <= in use this time
           (outputs[o] & 3) == 3 <= in use both times
            outputs[o] == 0      <= not in use either time
           
        */

	for (int o = 0; o < 3; ++o) {
                pan_t pan;
                int output = signal->desired_outputs[o];

		if (output == -1) {
                        continue;
                }

                pan = gain_coefficient * signal->desired_gains[o];
                
                if (pan == 0.0 && signal->gains[output] == 0.0) {
                        
                        /* nothing deing delivered to this output */

                        // cerr << "VBAP: output " << output << " silent - no data delivered\n";
                        signal->gains[o] = 0.0;
                        
                } else if (fabs (pan - signal->gains[output]) > 0.00001) {
                        
                        /* signal to this output but the gain coefficient has changed, so 
                           interpolate between them.
                        */

                        // cerr << "VBAP: output " << output << " interpolate to new gain\n";
                        
                        AudioBuffer& buf (obufs.get_audio (output));
                        buf.accumulate_with_ramped_gain_from (srcbuf.data(), nframes, signal->gains[output], pan, 0);
                        signal->gains[output] = pan;

                } else {
                        
                        /* signal to this output, same gain as before so just copy with gain
                         */
                           
                        // cerr << "VBAP: output " << output << " use current gain\n";

                        mix_buffers_with_gain (obufs.get_audio (output).data(),src,nframes,pan);
                        signal->gains[output] = pan;
                }
	}

        /* clean up the outputs that were used last time but not this time
         */

        for (uint32_t o = 0; o < sz; ++o) {
                if (outputs[o] == 1) {
                        /* take signal and deliver with a rapid fade out
                         */
                        AudioBuffer& buf (obufs.get_audio (o));
                        buf.accumulate_with_ramped_gain_from (srcbuf.data(), nframes, signal->gains[o], 0.0, 0);
                        signal->gains[o] = 0.0;
                }
        }

        /* note that the output buffers were all silenced at some point
           so anything we didn't write to with this signal (or any others)
           is just as it should be.
        */
}

void 
VBAPanner::distribute_one_automated (AudioBuffer& src, BufferSet& obufs,
                                     framepos_t start, framepos_t end, pframes_t nframes, pan_t** buffers, uint32_t which)
{
}

XMLNode&
VBAPanner::get_state ()
{
	return state (true);
}

XMLNode&
VBAPanner::state (bool full_state)
{
        XMLNode& node (Panner::get_state());
	node.add_property (X_("type"), _descriptor.name);
	return node;
}

int
VBAPanner::set_state (const XMLNode& node, int /*version*/)
{
	return 0;
}

Panner*
VBAPanner::factory (boost::shared_ptr<Pannable> p, boost::shared_ptr<Speakers> s)
{
	return new VBAPanner (p, s);
}

ChanCount
VBAPanner::in() const
{
        return ChanCount (DataType::AUDIO, _signals.size());
}

ChanCount
VBAPanner::out() const
{
        return ChanCount (DataType::AUDIO, _speakers->n_speakers());
}

std::set<Evoral::Parameter> 
VBAPanner::what_can_be_automated() const
{
        set<Evoral::Parameter> s;
        s.insert (Evoral::Parameter (PanAzimuthAutomation));
        s.insert (Evoral::Parameter (PanWidthAutomation));
        return s;
}
        
string
VBAPanner::describe_parameter (Evoral::Parameter p)
{
        switch (p.type()) {
        case PanAzimuthAutomation:
                return _("Direction");
        case PanWidthAutomation:
                return _("Diffusion");
        default:
                return _pannable->describe_parameter (p);
        }
}

string 
VBAPanner::value_as_string (boost::shared_ptr<AutomationControl> ac) const
{
        /* DO NOT USE LocaleGuard HERE */
        double val = ac->get_value();

        switch (ac->parameter().type()) {
        case PanAzimuthAutomation: /* direction */
                return string_compose (_("%1"), val * 360.0);
                
        case PanWidthAutomation: /* diffusion */
                return string_compose (_("%1%%"), (int) floor (100.0 * fabs(val)));
                
        default:
                return _pannable->value_as_string (ac);
        }
}

AngularVector
VBAPanner::signal_position (uint32_t n) const
{
        if (n < _signals.size()) {
                return _signals[n]->direction;
        }

        return AngularVector();
}

boost::shared_ptr<Speakers>
VBAPanner::get_speakers () const 
{
        return _speakers->parent();
}

void
VBAPanner::set_position (double p)
{
        _pannable->pan_azimuth_control->set_value (p);
}

void
VBAPanner::set_width (double p)
{
        _pannable->pan_width_control->set_value (p);
}