#include "compute.h"

#include "fft.h"
#include <math.h>

#define MIN_SAMPLES 256
#define MAX_SAMPLES 2048
//static inline float todB_a(const float *x);
void compute_spectrum(float * data, int width, double rate, float *output);


gfloat compute_level(const float *data, size_t nsamples, size_t nchan) {

	double rate=44100; //TODO dynamique
	size_t i; 
	float input[MAX_SAMPLES], output[128];
	float value;
	int gain=20, range=80;

	if (nsamples >= MAX_SAMPLES) {
		printf("WARN : nsamples >= MAX_SAMPLES : %i >= %i\n", nsamples, MAX_SAMPLES);
		nsamples=MAX_SAMPLES;
	}
	if (nsamples < MIN_SAMPLES) {
		printf("WARN : nsamples < MIN_SAMPLES : %i >= %i\n", nsamples, MIN_SAMPLES);
		for (i=0;i<MIN_SAMPLES;i++) {
			if ( (i/nsamples)%2==1 )
				input[i]=data[i/**nchan*/];
			else
				input[i]=data[nsamples-i-1];
		}
		nsamples=MIN_SAMPLES;
	} else {
		for (i=0;i<nsamples;i++) {
			input[i]=data[i/**nchan*/];
		}
	}

	compute_spectrum(input, nsamples, rate, output);
	//printf("%f\n", output[0]);
	value=0.f;
	for (i=1;i<128;i++) {
		value+=output[i];
	}
	// Mean value
	value/=127.f;
	// 0.0 to 1.0 range
	value=(value + gain + range) / (double)range;
	value=MAX(0.f,value);
	value=MIN(value,1.f);

//	printf("DEBUG: nsamples=%8i value==%f\n", nsamples, value);
	return value;
}
/*
static inline float todB_a(const float *x){
  return (float)((*(int32_t *)x)&0x7fffffff) * 7.17711438e-7f -764.6161886f;
}
*/
// Adapted from Audacity 
void compute_spectrum(float * data, int width, double rate, float *output) {

	int i;
	float processed[256]={0.0f};
//TODO : remove init here(handy for step by step debug)
	float in[256]={0.0f};
	float out[256]={0.0f};

	int start = 0;
	int windows = 0;
	while (start + 256 <= width) {
		for (i=0; i<256; i++)
			in[i] = data[start + i];

		// Windowing : Hanning
		for (i=0; i<256; i++)
			in[i] *= 0.50 - 0.50 * cos(2 * M_PI * i / (256 - 1));

		PowerSpectrum(in, out);

		// Take real part of result
		for (i=0; i<256/2; i++)
			processed[i] += out[i];

		start += 256/2;
		windows++;
	}
	// Convert to decibels
	// But do it safely; -Inf is nobody's friend
	for (i = 0; i < 256/2; i++){
		float temp=(processed[i] / 256 / windows);
		if (temp > 0.0)
			processed[i] = 10*log10(temp);
		else
			processed[i] = 0;
	}
	for(i=0;i<256/2;i++)
		output[i] = processed[i];
}

void audio2hsv_1(gint audio_level, gint *light_h, gint *light_s, gint *light_v) {
	// Dummy code
	*light_h=-audio_level;
	*light_s=audio_level;
	*light_v=65535;
}

		
void hsv2rgb(gint h, gint s, gint v, gint *r, gint *g, gint *b) {
   /*
    * Purpose:
    * Convert HSV values to RGB values
    * All values are in the range [0..65535]
    */
   float F, M, N, K;
   int   I;
   
   if ( s == 0 ) {
      /* 
       * Achromatic case, set level of grey 
       */
      *r = v;
      *g = v;
      *b = v;
   } else {
      I = (int) h/(65535/6);	/* should be in the range 0..5 */
      F = h - I;		/* fractional part */

      M = v * (1 - s);
      N = v * (1 - s * F);
      K = v * (1 - s * (1 - F));

      if (I == 0) { *r = v; *g = K; *b = M; }
      if (I == 1) { *r = N; *g = v; *b = M; }
      if (I == 2) { *r = M; *g = v; *b = K; }
      if (I == 3) { *r = M; *g = N; *b = v; }
      if (I == 4) { *r = K; *g = M; *b = v; }
      if (I == 5) { *r = v; *g = M; *b = N; }
   }
}