#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <time.h>
#include <math.h>

#include "bpsk.h"

#define clear() printf("\033[H\033[J")
#define gotoxy(x, y) printf("\033[%d;%dH", (y), (x))

static uint8_t wave_header[44];

int main(int argc, char **argv)
{
    char *wave_file_name = "modulated.wav";
    struct stat statbuf;
    int16_t *wave_buffer;

    if (argc > 1)
    {
        wave_file_name = argv[1];
    }

    printf("Opening %s for demodulation...\n", wave_file_name);
    int fd = open(wave_file_name, O_RDONLY);
    if (fd == -1)
    {
        perror("unable to open wave file");
        return 1;
    }

    if (-1 == fstat(fd, &statbuf))
    {
        perror("unable to determine size of buffer");
        return 1;
    }

    // Read the .wav header (44 bytes) into the wave header array.
    // This effectively discards it.
    if (read(fd, wave_header, sizeof(wave_header)) != sizeof(wave_header))
    {
        fprintf(stderr, "couldn't read wave header");
    }

    // Allocate a buffer for the remainder of the wave file.
    int wave_len_bytes = statbuf.st_size - sizeof(wave_header);
    wave_buffer = malloc(wave_len_bytes);
    if (read(fd, wave_buffer, wave_len_bytes) != wave_len_bytes)
    {
        fprintf(stderr, "short read of wave file\n");
        return 1;
    }

    // Perform a BPSK run on it.
    bpsk_init();
    bpsk_run(wave_buffer, wave_len_bytes / sizeof(uint16_t));

    printf("\n");
    return 0;
}