.model small
.stack 400h
.data
	outStr		db	11	DUP ('$')
	msg_error	db	"Error!!!", 13, 10, '$'
	FileName 	db	"c:\labs\input.txt", 0
	
	buffer		db	20h	DUP (?)
.code

;word ReadWordFromFile (char* file_name, word offset) : AX
ReadWordFromFile proc near
	push	bp
	mov		bp, sp
	;save registers
	push	bx
	push	cx
	push	dx
	push	si
	;=====================
	;	Offset's description
	;===
		;arguments
	__rwff_file_name	=	6		;file name
	__rwff_offset		=	4		;offset in file in bytes
	;+++
	__rwff__stack_par_offset = 4	;offset for function parameters
		;local variables
	__rwff_FileHandle	=	8		;File handle
	__rwff_FileSize		=	10		;File size
	__rwff_readed		=	12		;Real readed bytes
	__rwff_sign			=	14		;Value sign
	__rwff_buffer		=	16		;Char buffer array
	;+++
	__rwff__stack_offset	= 8		;offset for local variables
	sub		sp,	__rwff__stack_offset
	;=====================
	;	FileHandle = OpenFile(file_name);
	mov		dx, [bp + __rwff_file_name]
	mov		al, 0
	mov		ah, 3Dh
	int		21h		;OpenFile
	jnc		@__line_37
	jmp		far ptr @__rwff_Error
@__line_37:
	mov		[bp - __rwff_FileHandle], ax
	
	;	FileSize = LSeek(FileHandle, 0, SEEK_END)
	mov		bx, [bp - __rwff_FileHandle]	;FileHandle
	mov		cx, 0							;Offset
	mov		dx, 0
	mov		al, 2							;SEEK_END
	mov		ah, 42h
	int		21h
	jnc		@__line_49
	jmp		far	ptr @__rwff_Error
@__line_49:
	mov		[bp - __rwff_FileSize], ax	
	
	;	LSeek(FileHandle, offset, SEEK_SET)
	mov		bx, [bp - __rwff_FileHandle]	;FileHandle
	mov		cx, [bp + __rwff_offset]		;offset
	mov		dx, 0
	mov		al, 0							;SEEK_SET
	mov		ah, 42h
	int		21h
	jnc		@__line_61
	jmp		far ptr @__rwff_Error
@__line_61:
	
	;	char* buffer = new char[FileSize]
	mov		[bp - __rwff_buffer], sp
	mov		ax, [bp - __rwff_FileSize]
	sub		sp,	ax
	
	;	readed = FRead(FileHandle, buffer, FileSize - offset)
	mov		bx, [bp - __rwff_FileHandle]	;FileHandle
	lea		dx, buffer ;[bp - __rwff_buffer]		;buffer
	mov		cx,	[bp - __rwff_FileSize]		;FileSize - offset
	sub		cx, [bp + __rwff_offset]
	mov		ah, 3Fh
	int		21h
	jnc		@__line_77
	jmp		far ptr @__rwff_Error
@__line_77:
	mov		[bp - __rwff_readed], ax

	;parse string
	mov		cx, [bp - __rwff_readed]
	mov		word ptr [bp - __rwff_sign], 0
	mov		bx, 10
	xor		ax, ax
	xor 	si, si
	xor		dx, dx
@__rwff_parseLoop:
	mov		dl, buffer[si] ;byte ptr [bp - __rwff_buffer + si]
	cmp		dl, 13
	
	je		@__rwff_parseLoop_exit
	cmp		dl, 10
	je		@__rwff_parseLoop_exit
	cmp		dl, 32
	je		@__rwff_parseLoop_exit
	
	cmp		dl, '-'
	jne		@__rwff_parseLoop_checkInt
	cmp		si, 0
	jne		@__rwff_parseLoop_error
	mov		word ptr [bp - __rwff_sign], 1
	jmp		@__rwff_parseLoop_continue
@__rwff_parseLoop_checkInt:
	cmp		dl, '0'
	jl		@__rwff_parseLoop_error
	cmp		dl, '9'
	jg		@__rwff_parseLoop_error
	push	dx
	imul	bx
	pop		dx
	sub		dl, 30h
	add		ax, dx
@__rwff_parseLoop_continue:
	inc		si
	loop	@__rwff_parseLoop
	jmp		@__rwff_parseLoop_exit
@__rwff_parseLoop_error:
	mov		ax, 0
@__rwff_parseLoop_exit:
	cmp		word ptr [bp - __rwff_sign], 1
	jne		@__rwff_skipAction
	neg		ax
@__rwff_skipAction:
	
	;	delete[] buffer
	;mov		bx, [bp - __rwff_FileSize]
	add		sp, [bp - __rwff_FileSize]
	
	;	CloseFile(FileHandle)
	push	ax
	mov		bx, [bp - __rwff_FileHandle]
	mov		ah, 3Eh
	int		21h
	jnc		@__line_126
	jmp		far ptr @__rwff_Error
@__line_126:
	pop		ax
	jmp		@__rwff_exit
	
@__rwff_Error:
	add		sp, __rwff__stack_offset
	mov		ax, 0
	stc
	jmp		@__rwff_sp_skip
@__rwff_exit:
	;=====================
	;remove local variables
	add		sp, __rwff__stack_offset
@__rwff_sp_skip:
	;restore registers
	pop		bx
	pop		cx
	pop		dx
	pop		si
	pop		bp
	;add		sp, __rwff__stack_par_offset
	ret
ReadWordFromFile endp

;void	PrintStr (char *str, byte color)
PrintStr proc near
	push	bp
	mov		bp, sp
	;save registers
	push	ax
	push	dx
	push	bx
	;=====================
	;	Offset's description
	;===
		;arguments
	__ps_str	=	6		;printed string
	__ps_color	=	4		;color
	;+++
	__ps__stack_par_offset = 4	;offset for function parameters
	;=====================	
	;	setcolor(color)
	;mov		ah, 0Eh
	;mov		al, '+'
	;mov		bl, 01h;[bp + __ps_color]
	;int		10h
	
	mov	dx, [bp + __ps_str]
	mov	ah, 09h
	int	21h
	
	;restore registers
	pop		bx
	pop		dx
	pop		ax
	pop		bp
	ret
PrintStr endp

;word	Word2ThrChr (word value, char *out) : AX
Word2ThrChr proc near	
	push	bp
	mov		bp, sp
	;сохранение регистров
	push	bx
	push	cx
	push	dx
	push	si
	push	di
	;выделение локальных переменных
;============================================	
	;выполнение процедуры
	
	mov		ax, [bp + 6]	;value
	
	xor		si, si
	cmp		ax, 0
	jge		Word2ThrChr_isPositive
	mov		bx, [bp + 4]	;*out
	mov		byte ptr [bx + si], '-'
	inc		si
	neg		ax
Word2ThrChr_isPositive:
	xor		cx, cx
	mov		bx, 3
Word2ThrChr_divLoop:
	xor		dx, dx
	div		bx
	push	dx
	inc		cx
	test	ax, ax
	jnz		Word2ThrChr_divLoop
	mov		bx,	[bp + 4]	;*out
	mov		ax, 0
Word2ThrChr_movLoop:
	pop		dx
	cmp		si, 10
	jge		Word2ThrChr_skip
	add		dl, 30h
	mov		byte ptr [bx + si], dl
	inc		si
	jmp		Word2ThrChr_continue
Word2ThrChr_skip:
	mov		ax, 1
Word2ThrChr_continue:
	loop	Word2ThrChr_movLoop
	
;============================================
	;удаление выделенных локальных переменных
	;восстановление значений регистра
	pop		di
	pop		si
	pop		dx
	pop		cx
	pop		bx
	pop		bp
	ret	
Word2ThrChr endp

__main:
	mov		ax, @data
	mov		ds,	ax
	xor		ax, ax
	
	lea		ax, FileName	;FileName
	push	ax
	mov		ax, 0			;Offset
	push	ax
	call	ReadWordFromFile
	add		sp,	4
	
	jnc		__main_normal
	lea		ax, msg_error	;Str
	push	ax
	mov		al, 00h			;Color
	push	ax
	call	PrintStr
	jmp		__main_endif
__main_normal:
	push	ax				;Value
	lea		ax, outStr		;OutStr
	push	ax
	call	Word2ThrChr
	
	lea		ax, outStr		;Str
	push	ax
	mov		al, 0h			;Color
	call	PrintStr
__main_endif:
	
	mov		ax, 4C00h
	int		21h
end __main