/*
 * tone.c
 *
 *  Created on: May 14, 2022
 *      Author: bruce
 */

#include "systick.h"
#include "tone.h"

#define CPU_SPEED (80000000.0)
#define MAX_TONES (10)

static float notes[] = {
/* Octave -1 */			   8.18,    8.66,    9.18,    9.73,   10.30,   10.92,   11.56,   12.25,   12.98,   13.75,   14.57,   13.44,
/* Octave  0 */           16.35,   17.32,   18.35,   19.45,   20.60,   21.83,   23.12,   24.50,   25.96,   27.50,   29.14,   30.87,
/* Octave  1 */  	      32.70,   34.65,   36.71,   38.89,   41.20,   43.65,   46.25,   49.00,   51.91,   55.00,   58.27,   61.74,
/* Octave  2 */			  65.41,   69.30,   73.42,   77.78,   82.41,   87.31,   92.50,   98.00,  103.83,  110.00,  116.54,  123.47,
/* Octave  3 */			 130.81,  138.59,  146.83,  155.56,  164.81,  174.61,  185.00,  196.00,  207.65,  220.00,  233.08,  246.94,
/* Octave  4 */			 261.63,  277.18,  293.66,  311.13,  329.63,  349.23,  369.99,  392.00,  415.30,  440.00,  466.16,  493.88,
/* Octave  5 */          523.25,  554.37,  587.33,  622.25,  659.25,  698.46,  739.99,  783.99,  830.61,  880.00,  932.33,  987.77,
/* Octave  6 */         1046.50, 1108.73, 1174.66, 1244.51, 1318.51, 1396.91, 1479.98, 1567.98, 1661.22, 1760.00, 1864.66, 1975.53,
/* Octave  7 */         2093.00, 2217.46, 2349.32, 2489.02, 2637.02, 2793.83, 2959.96, 3135.96, 3322.44, 3520.00, 3729.31, 3951.07,
/* Octave  8 */         4186.01, 4434.92, 4698.63, 4978.03, 5274.04, 5587.65, 5919.91, 6271.93, 6644.88, 7040.00, 7458.62, 7902.13,
/* Octave  9 */         8372.02, 8869.84, 9397.26, 9956.06,10548.08,11175.30,11839.82,12543.86};

typedef struct {
	uint32_t note;
	uint16_t power;
} tone_info;

static uint32_t counter = 0;

static tone_info NULL_TONE = {0,0};
static tone_info tones[MAX_TONES];

/* You will want to integrate this with your existing one
   but it is here for standalone testing                 
*/
//void SysTick_Handler() {
//	counter++;
//}

uint32_t get_tick_speed ();

void tones_init() {
	for (int i = 0; i < MAX_TONES; i++) {
		tones[i] = NULL_TONE;
	}
}


// Convert from hertz to ticks
uint32_t hertz_to_systicks (float hertz) {
	float ticks_per_second = CPU_SPEED / (SysTick->LOAD + 1);
	if (hertz == 0)
		return 0;
	float duration = 1 / hertz;
	return (uint32_t) (duration * ticks_per_second);
}

// Accessor for the counter
uint32_t get_counter () {
	return counter;
}

void reset_counter () {
	counter = 0;
}

// Add a tone to the tones array
uint8_t add_tone (uint8_t note, uint8_t velocity) {
	for (int i = 0; i < MAX_TONES; i++) {
		if (tones[i].note == NULL_TONE.note) {
			tones[i] = (tone_info){note, velocity};
			return 1;
		}
	}
	return 0;
}

// Remove a tone from the tones array
uint8_t remove_tone (uint8_t note) {
	for (int i = 0; i < MAX_TONES; i++) {
		if (tones[i].note == note) {
			tones[i] = NULL_TONE;
			return 1;
		}
	}
	return 0;
}

// Play any tones in the array
void play_tones () {
	int power_sum = 0;
	for (int i = 0; i < MAX_TONES; i++) {
	    uint32_t rollover = hertz_to_systicks (notes [tones[i].note]);
	    if ((systick_get_count () % rollover) < (rollover >> 1)) {
	    	power_sum += tones[i].power * 10;
	    }
	}
	DAC_Set_Value(power_sum);
}