#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include "hardware.h"
#include "kiss_fft.h"


#include "stm32f4_discovery.h"
#include "stm32f4xx_tim.h"

volatile int g_milliseconds = 0;

#define RINGBUFFER_SIZE (4 * BUFFER_SIZE)
uint32_t g_ringbuffer[RINGBUFFER_SIZE];
int g_ringbufferReadIndex = 0;
int g_ringbufferWriteIndex = 0;

// called at 1 kHz
void tick()
{
    g_milliseconds++;
    if (g_milliseconds > 500) {
        setGreenLed(1);
    } else {
        setGreenLed(0);
    }
    if (g_milliseconds == 1000) g_milliseconds = 0;
}

void onFillSamples(uint32_t* samples, uint32_t count)
{
    int i;
    for (i = 0; i < count; i++) {
        samples[i] = g_ringbuffer[g_ringbufferReadIndex++];
        if (g_ringbufferReadIndex == RINGBUFFER_SIZE) g_ringbufferReadIndex = 0;
    }
}

void onSamplesReceived(uint32_t* samples, uint32_t count)
{
    static int c = 0;
    int i;
    for (i = 0; i < count; i++) {
        g_ringbuffer[g_ringbufferWriteIndex++] = samples[i];
        if (g_ringbufferWriteIndex == RINGBUFFER_SIZE) g_ringbufferWriteIndex = 0;
        if (c++ >= 192000) {
            //static int tick = 0;
            //printf(++tick&1 ? "tick\n" : "tack\n");
            c = 0;
        }
    }
}


#define MAX_FFT_SIZE 2048

kiss_fft_cfg mycfg;
kiss_fft_cpx fin[MAX_FFT_SIZE];
kiss_fft_cpx fout[MAX_FFT_SIZE];

void startTimer()
{
    resetTime();
}

int getMilliseconds()
{
    return getTime() / 1000;
}

void testFFT(int size, int do_dB)
{
    mycfg = kiss_fft_alloc(size, size, NULL, NULL);
    float sum = 0;
    int count = 10000;
    int c;
    startTimer();
    for (c = 0; c < count; c++) {
        int j;
        for (j = 0; j < size; j++) {
            fin[j].r = c + j;
            fin[j].i = c * j * 0.1f;
        }
        kiss_fft(mycfg, fin, fout);
        if (do_dB) {
            for (j = 0; j < size; j++) {
                float r = fout[j].r;
                float i = fout[j].i;
                sum += 10 * log10f(r * r + i * i);  // == 20 * log10(sqrt(..))
            }
        } else {
            for (j = 0; j < size; j++) {
                sum += fout[j].r;
                sum += fout[j].i;
            }
        }
    }
    int ms = getMilliseconds();
    printf("size: %i, time: %f ms, with dB: %s, sum: %f\n", size, ((float) ms) / ((float) count), do_dB ? "yes" : "no", sum);
}

int main()
{
    int i;
    for (i = 0; i < RINGBUFFER_SIZE / 2; i++) {
        g_ringbuffer[g_ringbufferWriteIndex++] = 0;
    }
    initHardware();
    printf("hardware initialized\n");
    int size = 256;
    while (1) {
        testFFT(size, 0);
        testFFT(size, 1);
        size *= 2;
        if (size > MAX_FFT_SIZE) break;
    }
    printf("test end\n");
    return 0;
}