pagesize	86

	include	bufseg.a86	;buffer definitions

data	dseg	byte public
	extrn	textseg: word
;data	ends

code	cseg	byte public

	;*** assume	cs:code, ds:data, es:data

	extrn	count_lines: near
	extrn	read_mark?: near
	extrn	adjust_marks_ins: near
	extrn	paint_window: near
	extrn	ccpm_create_file:near
	extrn	ccpm_open_file:near
	extrn	ccpm_close_file:near
	extrn	ccpm_write_file:near
	extrn	ccpm_read_file:near
	extrn	ccpm_delete_file:near
	extrn	ccpm_lseek_file:near


	public	write_file
write_file:
;enter with si->filename desired, al=mark.
;exit with al=0 if ok, al=1 if disk full, or al=2 if directory full.
	push	si			;save a pointer to the filename.

	push	ax			;save the mark to write to.
	mov	dx,si
	mov	cx,0
;	mov	ah,3ch			;create file.
;	int	21h
	call	ccpm_create_file
	pop	bx			;get the mark back
	jc	write_2_5		;if any problem, report dir full.
	xchg	bx,ax			;put the mark in ax, handle in bx.

	push	ds
	mov	ds,textseg		;read_mark? assumes ds:textseg
	push	bx
	call	read_mark?
	pop	bx
	mov	dx,si			;set the disk transfer address
;	mov	ah,40h			;write out what they requested.
;	int	21h
	call	ccpm_write_file
	pop	ds
	jc	write_2_4		;if any problems, disk full.

	cmp	ax,cx			;did we write the whole thing?
	jne	write_2_4		;no - disk full.

;close the file.
;	mov	ah,3eh			;close file.
;	int	21h
	call	ccpm_close_file
	jc	write_2_4		;if any problems, say disk full.
	pop	si
	mov	al,0
	ret
write_2_4:
;	mov	ah,3eh			;close file.
;	int	21h
	call	ccpm_close_file
	pop	si
	mov	dx,si			;delete their file.
;	mov	ah,41h
;	int	21h
	call	ccpm_delete_file
	mov	al,1
	ret
write_2_5:
	pop	si
	mov	al,2
	ret


	public	read_file
read_file:
;enter with si->filename desired.
;exit with al=0 if ok, al=1 if file too large, or al=2 if file not found.
	mov	dx,si
;	mov	ax,3d00h		;open for reading.
;	int	21h
	call	ccpm_open_file
	jc	read_2_5
	mov	bx,ax

;	mov	ax,4202h		;get the file's size.
	mov	cx,0
	mov	dx,cx
;	int	21h
	mov	al,2
	call	ccpm_lseek_file
	mov	cx,ax			;remember the file's size lobyte.

	push	ds
	mov	ds,textseg
	;*** assume	ds:bufseg
	mov	ax,bottop		;get size of available memory.
	sub	ax,topbot
	pop	ds
	;*** assume	ds:data

;check the size of the file (dx:cx) against buffer size (ax)
	or	dx,dx			;is file too big?
	jne	read_2_2
	cmp	ax,margin
	jb	read_2_2		;not enough memory.
	sub	ax,margin
	cmp	ax,cx			;enough memory to read the file in?
	jb	read_2_2		;no.

;if the file's empty, don't try to read it in.
	jcxz	read_2_7

;seek to the beginning again.

	push	cx
;	mov	ax,4200h		;rewind the file.
	mov	cx,0
	mov	dx,cx
;	int	21h
	mov	al,0
	call	ccpm_lseek_file
	pop	cx

;read the file in.

	push	ds
	mov	ds,textseg
	;*** assume	ds:bufseg
	mov	dx,topbot		;read the file before the cursor.
;	mov	ah,3fh
;	int	21h
	call	ccpm_read_file
	pop	ds
	;*** assume	ds:data
	jc	read_2_4		;problem with read - give up.

	cmp	cx,ax			;compare the amount desired again the amount read.
	pushf
	mov	cx,ax			;adjust for the amount read.
	push	bx			;preserve the file handle.
	call	read_adjust
	pop	bx
	popf
	jnz	read_2_4		;if any not read, give up.


;close the file.
read_2_7:
;	mov	ah,3eh			;close the file.
;	int	21h
	call	ccpm_close_file
	jc	read_2_4		;if any trouble, give up.
	mov	al,0
	jmps read_2_exit
read_2_2:
	mov	al,1			;not enough memory.
	jmps read_2_exit
read_2_4:
;	mov	ah,3eh			;close the file.
;	int	21h
	call	ccpm_close_file
	mov	al,3			;other read error.
	jmps read_2_exit
read_2_5:
	mov	al,2			;file not found.
read_2_exit:
	ret


read_adjust:
;update topbot, line counters.
	push	cx			;save count
	mov	ds,textseg
	;*** assume	ds:bufseg
	mov	ax,cx
	call	adjust_marks_ins
	mov	di,topbot
	push	es
	pop	ds
	;*** assume	ds:data
	pop	cx			;get the count back.
	push	cx
	call	count_lines		;count NEWLINES in text we just read in.
	mov	ds,textseg
	;*** assume	ds:bufseg
	add	linesbefore,bx		;the text is before the cursor, so add
	add	linecount,bx
	mov	buffer_modified,1
	pop	cx			;restore count
	add	topbot,cx		;add the amount of file that was read in.
	push	es
	pop	ds
	;*** assume	ds:data
	call	paint_window
	ret


	public	compute_free
compute_free:
;enter with dl=drive.
;exit with cy if invalid drive, or nc and:
;  ax=sectors/cluster,		====================================
;  bx=free clusters,		>>>> must be changed under CCPM <<<<
;  cx=bytes/sector,		====================================
;  dx=total clusters.
	mov	dx,7fffh
	mov	cx,128		;>>>> temp. solution <<<<
	mov	bx,7fffh
	mov	ax,16
	clc
	ret
;*****************************
;**	mov	ah,30h			;get the version number
;**	int	21h
;**	cmp	al,2			;al<2 for versions 1.?
;**	jb	compute_free_5
;**	mov	ah,36h			;get disk stats for version 2.0+
;**	int	21h			;dl already set
;**	cmp	ax,-1			;valid drive?
;**	jne	compute_free_4		;yes.
;**	push	ds
;**compute_free_6:
;**	pop	ds
;**	stc
;**	ret
;**compute_free_5:
;**	push	ds
;**	mov	ah,1ch			;get the fat.
;**	int	21h
;**	or	bx,bx
;**	je	compute_free_6
;**	mov	ah,0
;**	push	ax			;save the sectors/cluster
;**	push	cx			;save the bytes/sector
;**	mov	cx,dx			;we need the count in cx.
;**	xor	ax,ax			;start with no free clusters.
;**	mov	si,2			;start at the first cluster.
;**compute_free_1:
;**	mov	di,si
;**	shr	di,1
;**	add	di,si
;**	mov	di,[bx+di]
;**	test	si,001
;**	jz	compute_free_2
;**	shr	di,1
;**	shr	di,1
;**	shr	di,1
;**	shr	di,1
;**compute_free_2:
;**	and	di,0fffh		;seperate out the bits.
;**	jnz	compute_free_3		;free? no.
;**	inc	ax			;count a free cluster.
;**compute_free_3:
;**	inc	si			;go to the next.
;**	loop	compute_free_1		;until we've looked at them all.
;**	mov	bx,ax			;save the free clusters in bx.
;**	pop	cx			;restore bytes/sector
;**	pop	ax			;restore sectors/cluster.
;**	pop	ds
;**compute_free_4:
;**	clc
;**	ret

;code	ends

	end