/***************************************************************************
 *		  Copyright (C) 1994  Charles P. Peterson                  *
 *	     4007 Enchanted Sun, San Antonio, Texas 78244-1254             *
 *              Email: Charles_P_Peterson@fcircus.sat.tx.us                *
 *                                                                         *
 *		  This is free software with NO WARRANTY.                  *
 *	      See gfft.c, or run program itself, for details.              *
 *		      Support is available for a fee.                      *
 ***************************************************************************
 *
 * Program:     gfft--General FFT analysis
 * File:        okread.c
 * Purpose:     OK! Read the data
 * Author:      Charles Peterson (CPP)
 * History:     24-July-1993 CPP; Created.
 *              6-Jan-95 CPP (1.31); add progress indicator and check stop
 * Comment:
 */

#define PROGRESS_INCREMENT 2048

#include <stdio.h>
#include <string.h>

#ifdef _AMIGA
#ifdef _M68881
#include <m68881.h>
#endif
#endif

#include "gfft.h"
#include "settings.h"
#include "wbench.h"

static unsigned long save_data_entered (void);

static unsigned long save_data_index = 0;

static unsigned long started = FALSE;

static unsigned long current_frame_count = 0;

unsigned long ok_read (float *indata, unsigned long number_samples)
{
    static unsigned long save_data_length = 0;
    unsigned long i;
    int j;

    union {
	unsigned short u;
	signed short s;
    } word;

    union {
	unsigned char u;
	signed char s;
    } byte;
/*
 * If indata pointer is NULL, we're just scanning to find file length
 * Rewind file and return when done
 */
    if (!indata)
    {
	if (OkFrames != ULONG_MAX)  /* Already known or specified */
	{
	    return OkFrames;
	}
	if (ReadPtr != stdin)
	{
	    error_message (SCANNING_FILE);  /* This might take some time */
	    for (i = 0; i < OkOffset; i++)
	    {
		if (!fread (&byte, sizeof byte, 1, ReadPtr))
		{
		    return 0L;
		}
	    }
	    if (InputFormat.bits <= 8)
	    {
		for (i = 0; fread (&byte, sizeof byte, 1, ReadPtr); i++);
	    }
	    else
	    {
		for (i = 0; fread (&word, sizeof word, 1, ReadPtr); i++);
	    }
	    rewind (ReadPtr);
	    i /= OkChannels;
	    FileFrames = i;  /* This value is now known */
	    if (i >= StartFrame)
	    {
		i -= StartFrame;
	    }
	    else
	    {
		i = 0L;
	    }
	    return i;
	}
	else
	{
	    if (!Save_Data)
	    {
		save_data_length = save_data_entered ();
	    }
	    return save_data_length;
	}
    }

/*
 * An actual file pointer has been provided; read from file
 */
    if (ReadPtr != stdin)
    {
	if (!started)
	{
	/*
	 * Skip over start bytes
	 */
	    for (i = 0L; i < OkOffset; i++)
	    {
		if (!fread (&byte, sizeof byte, 1, ReadPtr))
		{
		    return 0L;
		}
	    }
        /*
         * Skip over start frames
	 */
	    if (InputFormat.bits <= 8)
	    {
		ULONG start_samples = OkChannels * OkStartFrame;
		for (i = 0L; i < start_samples; i++)
		{
		    if (!fread (&byte, sizeof byte, 1, ReadPtr))
		    {
			return 0L;
		    }
		}
	    }
	    else  /* InputFormat.bits > 8 */
	    {
		ULONG start_samples = OkChannels * OkStartFrame;
		for (i = 0L; i < start_samples; i++)
		{
		    if (!fread (&word, sizeof word, 1, ReadPtr))
		    {
			return 0L;
		    }
		}
	    }
	    started = TRUE;
	}
    /*
     * Here is the main read loop
     */
	for (i = 0L; i < number_samples; i++)
	{
	    if (i % PROGRESS_INCREMENT == 0)  
	      progress_requester__check_stop ();
	    if (++current_frame_count > OkFrames)
	    {
		break;
	    }
	    if (Channel > 1)
	    {
		for (j = 1; j < Channel; j++)
		{
		    if (InputFormat.bits <= 8)
		    {
			if (!fread (&byte, sizeof byte, 1, ReadPtr))
			{
			    return i;
			}
		    }
		    else
		    {
			if (!fread (&word, sizeof word, 1, ReadPtr))
			{
			    return i;
			}
		    }
		}                          /* end for (j...) */
	    }                              /* end if Channel > 1 */
	    if (InputFormat.bits <= 8)
	    {
		if (!fread (&byte, sizeof byte, 1, ReadPtr))
		{
		    break;
		}
		if (!InputFormat.zero)
		{
		    for (j = InputFormat.bits; j < 8; j++)
		    {
			byte.s /= 2;
		    }
		    *indata++ = byte.s;
		}
		else
		{
		    for (j = InputFormat.bits; j < 8; j++)
		    {
			byte.u /= 2;
		    }
		    if (byte.u >= InputFormat.zero)
		    {
			*indata++ = byte.u - InputFormat.zero;
		    }
		    else
		    {
			*indata = InputFormat.zero - byte.u;
			*indata = (- (*indata));
			indata++;
		    }
		}
	    }
	    else /* Sizes greater than 16 bits not currently supported */
	    {
		if (!fread (&word, sizeof word, 1, ReadPtr))
		{
		    break;
		}
		if (!InputFormat.zero)
		{
		    for (j = InputFormat.bits; j < 16; j++)
		    {
			word.s /= 2;
		    }
		    *indata++ = word.s;
		}
		else
		{
		    for (j = InputFormat.bits; j < 16; j++)
		    {
			word.u /= 2;
		    }
		    if (word.u >= InputFormat.zero)
		    {
			*indata++ = word.u - InputFormat.zero;
		    }
		    else
		    {
			*indata = InputFormat.zero - word.u;
			*indata = (- (*indata));
			indata++;
		    }
		}
	    }
	    if (Parseval)
	    {
		Sample_Sum_Of_Squares += indata[-1] * indata[-1];
	    }
	    Sample_Frame_Count++;
	    if (Channel < OkChannels)
	    {
		for (j = Channel; j < OkChannels; j++)
		{
		    if (InputFormat.bits <= 8)
		    {
			if (!fread (&byte, sizeof byte, 1, ReadPtr))
			{
			    return i;
			}
		    }
		    else
		    {
			if (!fread (&word, sizeof word, 1, ReadPtr))
			{
			    return i;
			}
		    }
		}                          /* end for j */
	    }                              /* end if Channel... */
	}                                  /* end for current_frame_count */
    }                                      /* end if ReadPtr != stdin */
    else
/*
 * Interactive input
 * Read data from terminal into buffer
 * then output as demanded
 */
    {
	if (!Save_Data)
	{
	    save_data_length = save_data_entered ();
	}
	for (i = 0L; i < number_samples; i++)
	{
	    if (i + save_data_index >= save_data_length) 
	    {
		break;
	    }
	    *indata++ = Save_Data[i + save_data_index];
	    if (Parseval)
	    {
		Sample_Sum_Of_Squares += indata[-1] * indata[-1];
	    }
	    Sample_Frame_Count++;
	}
	save_data_index += i;
    }
    return i;
}
	
static unsigned long save_data_entered (void)
{
    unsigned long allocated_length = 1;
    unsigned long i;
    char inputline[1024];
    float inputf;

    Save_Data = gmalloc (allocated_length * sizeof (float), 
			 NOTHING_SPECIAL);
    for (i = 0L; TRUE; i++)
    {
	printf ("Enter <value> (float OK) or <newline> to end input [%i]: ",i);
	gets (inputline);
	if (strlen (inputline) == 0) 
	{
	    break;
	}
	if (1 != sscanf (inputline,"%g",&inputf))
	{
	    error_message (INVALID_NUMBER);
	    i--;
	    continue;
	}
	if (i >= allocated_length)
	{
	    Save_Data = grealloc (Save_Data, (i+1) * 
				  sizeof (float), NOTHING_SPECIAL);
	    allocated_length = i+1;
	}
	Save_Data[i] = inputf;
    }
    return i;
}


void ok_rewind (void)
{
    started = FALSE;
    current_frame_count = 0;
    if (ReadPtr != stdin)
    {
	rewind (ReadPtr);
    }
    else
    {
	save_data_index = 0;
    }
}