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

const float SAMPLINGRATE = 1000000.0;
const float FFT_LEN = 256;

int main() {
    FILE* output = fopen("output.csv", "w");
    FILE* input = fopen("input.raw", "r");

    float complex * fft_in = (float complex*) malloc(FFT_LEN * sizeof(float complex));
    float complex * fft_out = (float complex*) malloc(FFT_LEN * sizeof(float complex));

    // create FFT plan
    fftplan fft = fft_create_plan(FFT_LEN, fft_in, fft_out, LIQUID_FFT_FORWARD, 0);

    int pos = 0;
    float in[2];
    while(fread(in, sizeof(float), 2, input) == 2) {
        fft_in[pos] = (in[1] + I * in[0]);
        pos += 1;
        if(pos == FFT_LEN) {
            pos = 0;
            fft_execute(fft);

            float fft_min = cabsf(fft_out[0]);
            float fft_max = cabsf(fft_out[0]);
            for(int i = 0; i < FFT_LEN; i++) {
                float mag = cabsf(fft_out[i]);
                if(mag < fft_min) {
                    fft_min = mag;
                }
                if(mag > fft_max) {
                    fft_max = mag;
                }
            }
            //printf("Min: %f Max: %f\n", fft_min, fft_max);

            for(int i = FFT_LEN / 2; i < FFT_LEN; i++) {
                float mag = cabsf(fft_out[i]);
                mag = (mag - fft_min) / (fft_max - fft_min);
                fprintf(output, "%f;", mag);
            }

            for(int i = 0; i < FFT_LEN / 2; i++) {
                float mag = cabsf(fft_out[i]);
                mag = (mag - fft_min) / (fft_max - fft_min);
                fprintf(output, "%f;", mag);
            }


            fprintf(output, "\n");
        }
    }

    fft_destroy_plan(fft);
    free(fft_in);
    free(fft_out);

    fclose(output);
    fclose(input);

    return 0;
}