#include <liquid/liquid.h>
#include <math.h>
#include <complex.h>
#include <stdio.h>
#include <stdlib.h>

const float SAMPLINGRATE = 1000000.0;
const float TEST_TONE = 0.0;

const int FFT_SIZE = 1024;

int main() {

    nco_crcf test_tone = nco_crcf_create(LIQUID_NCO);
    nco_crcf_set_phase(test_tone, 0.0f);
    float freq = (2 * M_PI * TEST_TONE) / SAMPLINGRATE;
    nco_crcf_set_frequency(test_tone, freq);


    // allocated memory arrays
    float complex * x = (float complex*) malloc(FFT_SIZE * sizeof(float complex));
    float complex * y = (float complex*) malloc(FFT_SIZE * sizeof(float complex));

    // create FFT plan
    fftplan fft = fft_create_plan(FFT_SIZE, x, y, LIQUID_FFT_FORWARD, 0);

    for(int i = 0; i < FFT_SIZE; i++) {
        nco_crcf_step(test_tone);
        nco_crcf_cexpf(test_tone, &x[i]);
    }

    fft_execute(fft);

    float mag_max = cabsf(y[0]);
    for(int i = 0; i < FFT_SIZE; i++) {
        float mag = cabsf(y[i]);
        if(mag >  mag_max) {
            mag_max = mag;
        }
    }

    for(int i = 0; i < FFT_SIZE; i++) {
        float mag = cabsf(y[i]);
        mag = mag / mag_max;

        float freq;
        if(i < FFT_SIZE/2) {
            freq = i * SAMPLINGRATE / FFT_SIZE;
        } else {
            freq = (i-FFT_SIZE/2) * SAMPLINGRATE / FFT_SIZE - SAMPLINGRATE/2;
        }
        printf("%f %f\n", freq, mag);
    }


    nco_crcf_destroy(test_tone);
    fft_destroy_plan(fft);

    free(x);
    free(y);

    return 0;
}