#include <sys/errno.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include <q.h>

#include "shaped-trap.h"

int
main(int argc, char **argv) {
  uint8_t data[50000], shapelen, codegap, slew1, slew2, dcofs;
  uint16_t plen, ncode;
  uint32_t shapesamples, nsamples, idx;
  q_t dcscale, stepsize;
  char *code, tmps[20];

  if (argc != 7) {
    printf("Bad usage\n");
    exit(1);
  }
  plen = atoi(argv[1]);
  code = argv[2];
  ncode = strlen(code);
  shapelen = sizeof(shaped_trap);
  codegap = atoi(argv[3]);
  slew1 = atoi(argv[4]);
  slew2 = atoi(argv[5]);
  dcofs = atoi(argv[6]);

  dcscale = qdiv(qsub(qint(255), qint(dcofs)), qint(255));
  qsprint(dcscale, tmps, sizeof(tmps));
  printf("dcscale = %s\n", tmps);

  if (ncode == 1) {
    // Number of samples for half of the pulse
    // Can't use q library here because it is Q16.16 so not large enough
    shapesamples = (plen * shapelen) / 100;
    // Number of samples for everything
    nsamples = shapesamples * 2 + slew1 + slew2;
  } else {
    shapesamples = plen;
    nsamples = shapesamples * 2 * ncode + codegap * (ncode - 1) + slew1 + slew2;
  }

  if (nsamples > sizeof(data)) {
    printf("Pulse too long (%d > %lu)\n", nsamples, sizeof(data));
    exit(1);
  }

  // Number of samples per step in the pulse shape
  stepsize = qdiv(qint(shapesamples), qint(shapelen));
  qsprint(stepsize, tmps, sizeof(tmps));
  printf("shapelen = %d shapesamples = %u nsamples = %u stepsize = %s\n", shapelen, shapesamples, nsamples, tmps);

  if (shapesamples < 2) {
    printf("Pulse too short (%u < %d)\n", shapesamples, 2);
    exit(1);
  }

  idx = 0;

  // Up slew
  for (uint16_t i = 0; i < slew1; i++)
    data[idx++] = qtoi(qdiv(qmul(qint(dcofs), qint(i)), qint(slew1)));

  for (uint16_t c = 0; c < ncode; c++) {
    // Pulse up
    for (uint16_t i = 0; i < shapesamples; i++)
      data[idx++] = dcofs + qtoi(qmul(qint(shaped_trap[qtoi(qdiv(qint(i), stepsize))]), dcscale));

    // Pulse down
    for (uint16_t i = 0; i < shapesamples; i++)
      data[idx++] = dcofs + qtoi(qmul(qint(shaped_trap[qtoi(qdiv(qint(shapesamples - i - 1), stepsize))]), dcscale));

    // Code gap
    if (c < ncode - 1)
      for (uint16_t i = 0; i < codegap; i++)
	data[idx++] = dcofs;
  }

  // Down slew
  for (uint16_t i = 0; i < slew2; i++)
    data[idx++] = qtoi(qdiv(qmul(qint(dcofs), qint(slew2 - i)), qint(slew2)));

  FILE *fh;

  if ((fh = fopen("/tmp/out.bin", "w")) == NULL) {
    printf("Unable to open file: %s\n", strerror(errno));
    exit(1);
  }
  fwrite(data, idx, 1, fh);
  fclose(fh);

  exit(0);
}