#include "stdio.h"
#include "stdlib.h"
#include "math.h"
#include "sethead.h"
#include <sys/types.h>
#include <time.h>
  
/*
	Minimal conversion program for Neuroscan average files
	The output file is as follows
	First line:      nchannels adcrate nevents nsamples
   Second line:     "sample event elec_1 elec_2 .... elec_nchannels"
   Rest of file:    sample event# sample_1 sample_2 .... sample_nchannels
*/

#define TRUE  1
#define FALSE 0
#define MIN(x,y) (x < y ? x : y)
#define MAX(x,y) (x > y ? x : y)

int main(argc,argv)
int argc;
char **argv;
{
	int i,j,readok,foundevent;
	float sample,scale;
	float themin=1e32,themax=-1e32;
	short unsigned nchannels;
	short unsigned adc;
	short unsigned nsamples;
	long c,filesize=0;
	char ename[16];
	FILE *fptr;
	float **data;

	/* Do we have enough arguments */
	if (argc < 2) {
		fprintf(stderr,"Usage: %s avgfile scale\n",argv[0]);
		exit(0);
	}

	/* Attempt to open the average EEG file */
	if ((fptr = fopen(argv[1],"r")) == NULL) {
		fprintf(stderr,"Unable to open file <%s>\n",argv[1]);
		exit(0);
	}
	
	/* Calculate the file size */
	while ((c = fgetc(fptr)) != EOF)
		filesize++;
	fseek(fptr,0L,SEEK_SET);

	/* Read the number of channels */
	fseek(fptr,370L,SEEK_SET);
	readok = ReadUShort(fptr,&nchannels,TRUE);  
	if (!readok || nchannels < 1 || nchannels > 64) {
		fprintf(stderr,"Unexpected number of channels <%d>\n",nchannels);
		exit(0);
	}
	printf("%d ",nchannels);

   /* Read the ADC rate */
   fseek(fptr,376L,SEEK_SET);
   readok = ReadUShort(fptr,&adc,TRUE);
   if (!readok || adc < 1) {
      fprintf(stderr,"Unexpected error reading adc rate\n",adc);
      exit(0);
   }
   printf("%d 0 ",adc);

	/* Calculate the number of expected samples */
   nsamples = ((filesize - 900 - nchannels*75) / nchannels - 5) / 4;
	if (nsamples < 1) {
		fprintf(stderr,"Unexpected number of samples <%ld>\n",nsamples);
		exit(0);
	}
	printf("%ld\n",(long)nsamples);

	/* Read the electrode names */
	printf("sample event ");
	for (i=0;i<nchannels;i++) {
		fseek(fptr,900L + i * 75,SEEK_SET);
		readok = ReadString(fptr,ename,10);
		printf("%s ",ename);
	}
	printf("\n");

	/* Allocate memory for the samples */
	data = (float **)malloc(nchannels*sizeof(float *));
	for (i=0;i<nchannels;i++)
		data[i] = (float *)malloc(nsamples*sizeof(float));

	/* Read the samples */
	fseek(fptr,900 + 75 * nchannels,SEEK_SET);
	for (i=0;i<nchannels;i++) {
		
		/* Read past the 5 byte header */
		for (j=0;j<5;j++)
			c = fgetc(fptr);

		/* Read nsamples for this channel */
		for (j=0;j<nsamples;j++) {
			if (!ReadFloat(fptr,&(data[i][j]),TRUE)) {
            fprintf(stderr,"Unexpected end of samples\n");
            exit(0);
         }
			themin = MIN(themin,data[i][j]);
			themax = MAX(themax,data[i][j]);
		}
	}

	/* Write the data as ascii */
	for (j=0;j<nsamples;j++) {
		printf("%ld 0 ",j);
		for (i=0;i<nchannels;i++) 
			printf("%d ",(int)(10000*(data[i][j]-themin)/(themax-themin)-5000));
		printf("\n");
	}

	fclose(fptr);
}