#include "hacks.h"
#define UWORD unsigned short


/* --------------------- forward references --------------------- */
void usage();
void usage_exit();
int write_intel_long(unsigned long, FILE *);
int write_intel_word(unsigned int, FILE *);
int read_motorola_word(int *, FILE *);
int write_wav_header(FILE *, int, int);
int get_file_size(FILE *, int *);
int r_rewind(FILE *);


/* -------------------- start of actual code -------------------- */
void usage()
{
  fprintf(stderr,"\
Usage:  sample_to_wav <infile.sample> <outfile.wav> [sample_rate \
in Hz]\n");
}


void usage_exit()
{
  usage();
  exit(DOOPS);
}


int write_intel_long(l, f)  /* slower but more portable version */
unsigned long l;
FILE *f;
{
  int status;
  unsigned long x;

  x = l mod 256;
  if ((status = fputc(x, f)) eq EOF) {
    fprintf(stderr, "write_intel_long: write error\n");
    return(DOOPS);
  }

  x = l / 256;
  x = x mod 256;
  if ((status = fputc(x, f)) eq EOF) {
    fprintf(stderr, "write_intel_long: write error\n");
    return(DOOPS);
  }

  x = l / 256;
  x = x / 256;
  x = x mod 256;
  if ((status = fputc(x, f)) eq EOF) {
    fprintf(stderr, "write_intel_long: write error\n");
    return(DOOPS);
  }

  x = l / 256;
  x = x / 256;
  x = x / 256;
  x = x mod 256;
  if ((status = fputc(x, f)) eq EOF) {
    fprintf(stderr, "write_intel_long: write error\n");
    return(DOOPS);
  }

  return(OKDOKEY);
}


int write_intel_word(w, f)
unsigned int w;
FILE *f;
{
  int status;
  unsigned int x;

  x = w mod 256;
  if ((status = fputc(x, f)) eq EOF) {
    fprintf(stderr, "write_intel_long: write error\n");
    return(DOOPS);
  }

  x = w / 256;
  x = x mod 256;
  if ((status = fputc(x, f)) eq EOF) {
    fprintf(stderr, "write_intel_long: write error\n");
    return(DOOPS);
  }

  return(OKDOKEY);
}


/* read sample from file into the int */
int read_motorola_word(wtr, f)
int *wtr;
FILE *f;
{
  int c;
  unsigned int x;

  /* read motorola high byte first */
  c = fgetc(f);
  if (c eq EOF)
    return(EOF);
  x = c;
  /* read motorola low byte next */
  c = fgetc(f);
  if (c eq EOF)
    return(c);
  x = (x * 256) + c;
  *wtr = x;
  return(OKDOKEY);
}
                                    

int write_wav_header(f, sample_length, sample_rate)
FILE *f;
int sample_length;
int sample_rate;
{
  int temp;  /* all ints are assumed to be four bytes!!!! */

  fprintf(f, "RIFF");
  sample_length *= 2; /* cause it is 16-bit, which is 2 bytes */
  temp = sample_length;
  temp += 36;                      /* header size */
  write_intel_long(temp, f);       /* this is length of entire .WAV
                                      file. */
  fprintf(f, "WAVE");
  /* now the format chunk "<fmt-ck>" */
  fprintf(f, "fmt ");              /* padded with space (not underline!) on end */
  write_intel_long(16 ,f);         /* size of WAVE section (16 bytes) */

  write_intel_word(1, f);          /* "formatTag" aka "Format catagory"
                                       is "PCM" */
  write_intel_word(1, f);          /* number of channels (1 for mono, 2
                                      for stereo) */
  write_intel_long(sample_rate, f);/* samples per second (sample rate) */
  write_intel_long((sample_rate * 2), f);      /* ? avg bytes per second.
                                                    "for buffer" */
  write_intel_word(2, f);          /* nBlockAlign: number of bytes
                                       per sample * number of channels */
  /* start of "PCM-format-specific: 2 bytes */
  write_intel_word(16, f);         /* bits per sample */
  /* start of data chunk ... */
  fprintf(f, "data");
  write_intel_long(sample_length, f);
  return(OKDOKEY);
}


/* get_file_size.  This function does not rewind the file! It leaves the file
                   pointer at the end of the file.   The file must have already
                   been opened. */
/* -------------------------------------------------------------------------- */
int get_file_size(f, file_size)
FILE *f;
int *file_size;
{
  int status;
  status = fseek(f,0,2); /* seek to end of file */
  if (status neq 0) {
    fprintf(stderr, "get_file_size: file seek error\n");
    return(DOOPS);
  }
  status = ftell(f);
  if (status eq -1L) {
    fprintf(stderr, "get_file_size: file ftell error\n");
    return(DOOPS);
  }
  *file_size = status;
  return(OKDOKEY);
}


int r_rewind(f)
FILE *f;
{
  int status;
  status = fseek(f, 0, SEEK_SET);
  if (status eq -1)
    return(status);
  return(0);
}


main(argc, argv)
int argc;
char *argv[];
{
  int status, sample_length, sample_rate, x, s;
  FILE *f1, *f2;

  if (argc eq 0) exit(DOOPS);
  if (argc < 3) usage_exit();
  if (argc eq 4) {
    sample_rate = atoi(argv[3]);
    if (sample_rate < 1) {
      fprintf(stderr,"error: bad sample rate! %\n", sample_rate);
      exit(DOOPS);
    }
  } else {
    sample_rate = 44100;
  }
  if ((f1 = fopen(argv[1], "rb")) eq NULL) {
    fprintf(stderr,"can't open input file %s\n", argv[1]);
    exit(DOOPS);
  }
  if ((status = setvbuf(f1, NULL, _IOFBF, 16384)) neq 0) {
    fprintf(stderr, "setvbuf error on input file\n");
    exit(DOOPS);
  }
  status = get_file_size(f1, &sample_length);  /* we need this info to
           make a proper WAV header */
  if (status eq DOOPS) {
    fprintf(stderr,"seek error on input file\n");
    exit(DOOPS);
  }
  /* rewind file */
  status = r_rewind(f1);
  if (status neq 0) {
    fprintf(stderr,"rewind error on input file\n");
    exit(DOOPS);
  }
  sample_length /= 2; /* change from byte count to word count */
  if ((f2 = fopen(argv[2], "wb")) eq NULL) {
    fprintf(stderr,"can't create output file %s\n", argv[2]);
    exit(DOOPS);
  }
  if ((status = setvbuf(f2, NULL, _IOFBF, 16384)) neq 0) {
    fprintf(stderr, "setvbuf error on output file\n");
    exit(DOOPS);
  }
  if ((status = write_wav_header(f2, sample_length, sample_rate)) eq DOOPS) {
    fprintf(stderr,"error writing header to wave file %s\n", argv[2]);
    exit(DOOPS);
  }
  printf("file is %d samples long ", sample_length);
  for (x = 0; x neq sample_length; x++) {
    if ((status = read_motorola_word(&s, f1)) eq EOF) {
      fprintf(stderr,"error reading from .sample file\n");
      exit(DOOPS);
    }
    s -= 32768;  /* convert from unisgned (0-65535) range to
                    signed (-32768-32767) range */
    if ((status = write_intel_word(s, f2)) eq EOF) {
      fprintf(stderr,"error writing to .WAV file\n");
      exit(DOOPS);
    }
  }
  fclose(f2);
  fclose(f1);
  printf("\033[7mDone\033[m\n");
  exit(OKDOKEY);
}


/* actual end of this file */