; Testing input.
;
; Writen in Sux assembly by
; mr b0nk 500 <b0nk@b0nk.xyz>

; Instruction mnemonics,
; and opcodes.
.org $1000
tok:
	.byte "dab"
msg:
	.byte "oof, you divided a, and b on me.\n"

; Input buffer.
.org $2000
buffer:

.org $2800
cmd_buf:

; Initalize some variables.
.org $0
scr_row:
	.byte $0
scr_col:
	.byte $0
a:
	.byte $0
b:
	.byte $0
c:
	.byte $0
d:
	.byte $0
e:
	.byte $0
string:
	.byte "Please, type something.\n"
string2:
	.byte "You typed, "
end:
	.byte $0

; String Pointer
ptr:
	.qword buffer
cptr:
	.qword cmd_buf
tptr:
	.qword tok
mptr:
	.qword msg


; Main program
.org $8000
reset:
	cps
	ldx.w #$FFFF
	txs
	ldy #0
	lda #0
clr_buf:
	cpy.w #$7FF
	beq start
	sta (ptr), y
	iny
	jmp clr_buf

start:
	lda #0
	sta $C000
	tax		; Reset x.
	tay		; Reset y.
	jsl clr_cbuf
	jmp print

clr_cbuf:
	cpy.w #$3FF
	beq clr_cbuf_end
	sta (cptr), y
	iny
	jmp clr_cbuf
clr_cbuf_end:
	ldy #0
	rtl

rset_a:
	lda #1
read:
	lda $C000	; Get control register.
	beq rset_a	; Loop until we get a character.
	jmp getchar	; We got a key.
sleep:
	lda end
	bne spin	; Are we done with getting input?

print:
	lda string, x	; Get character at offset x.
	beq rset_a	; Did we find a null terminator?
	sta $C001	; Print character.
	inx		; Increment offset.
	cmp #$A
	beq inc_row
	inc scr_col
	jmp print
inc_row:
	lda #0
	sta scr_col
	lda #$42
	sta c
	jsl isdown
	jmp print	; Keep printing more characters.

getchar:
	lda $C002	; Get typed character.
	cmp #$1B
	beq esc
	cmp #$A
	beq nl		; Did the user type a newline?
	cmp #8
	beq bs		; Did the user type a backspace?
	cmp #$7F
	beq bs		; Did the user type a backspace?
echo:
	sta a
	ldx scr_col
	cpx #79
	bne echo_print
linewrap:
	inc scr_row
	ldx #0
	stx scr_col
	lda scr_row
	jsl update_pos
echo_print:
	lda a
	sta $C001	; Echo typed character.
	inc scr_col	; Increment the cursor's x coordinate.
	sta (ptr), y	; Store typed character into the input buffer.
	iny
	jmp rset_a	; Start getting user input.

esc:
	lda $C000	; Skip the '['.
	lda $C000	; Get the next character.
	beq read	; We have an error, so discard it, and go back to getting user input.
	lda $C002	; Get the escape code.
	sta c		; Store the escape code, until we need it.
	jsl isup	; Check if the user pressed up.
	lda d
	bne esc_end
	jsl isdown	; Check if the user pressed down.
	lda d
	bne esc_end
	lda #0
	jsl isleft	; Check if the user pressed left.
	lda d
	bne esc_end
	jsl isright	; Check if the user pressed right.
esc_end:
	lda #0
	sta d
	jmp rset_a	; Go back to getting user input.

isup:
	lda scr_row	; Is the cursor at the top of the screen?
	beq isup_done	; Yes, so return.
	lda c		; No, so load the escape code back into the accumulator.
	cmp #$41	; Did the user press the up arrow key?
	beq up		; Yes, so move the cursor up.
isup_done:
	rtl		; End of isup.

isdown:
	lda scr_row	; Start checking the y coordinate of the cursor.
	cmp #23		; Is the cursor at the bottom of the screen?
	beq isdown_done	; Yes, so return.
	lda c		; No, so load the escape code back into the accumulator.
	cmp #$42	; Did the user press the down arrow key?
	beq down	; Yes, so move the cursor down.
isdown_done:
	rtl		; End of isdown.

isright:
	lda scr_col	; Start checking the x coordinate of the cursor.
	cmp #79		; Is the cursor at the far right of the screen?
	beq isright_end	; Yes, so return.
	lda c		; No, so load the escape code back into the accumulator.
	cmp #$43	; Did the user press the right arrow key?
	beq right	; Yes, so move the cursor right.
isright_end:
	rtl		; End of isright.

isleft:
	lda scr_col	; Is the cursor at the far left of the screen?
	beq isleft_done	; Yes, so return.
	lda c		; No, so load the escape code back into the accumulator.
	cmp #$44	; Did the user press the left arrow key?
	beq left	; Yes, so move the cursor left.
isleft_done:
	rtl		; End of isleft.

up:
	dec scr_row
	jsl update_pos
	lda #1
	sta d
	jmp isup_done
down:
	inc scr_row
	jsl update_pos
	lda #1
	sta d
	jmp isdown_done
right:
	inc scr_col
	jsl update_pos
	jmp isright_end
left:
	dec scr_col
	jsl update_pos
	lda #1
	sta d
	jmp isleft_done

update_pos:
	lda #$1B	; Print an escape character
	sta $C001	; to the screen.
	lda #$5B	; Print '['
	sta $C001	; to the screen, and start the escape sequence.
	jsl getrow	; Start printing the row number to the screen.
	jsl getcol	; Start printing the column number to the screen.
	lda #$48	; Print 'H'
	sta $C001	; to the screen.
	rtl		; End of update_pos.
getrow:
	lda scr_row	; Get the cursor's y coordinate.
	div #10		; Divide A by 10.
	adc #$30	; Convert it to ascii, and
	sta $C001	; print to the screen.
	tba		; Get the remainder.
	adc #$30	; Convert it to ascii, and
	sta $C001	; print to the screen.
	rtl		; End of getrow.
getcol:
	lda #$3B	; Print ';'
	sta $C001	; to the screen.
	lda scr_col	; Get the cursor's x coordinate.
	div #10		; Divide A by 10.
	adc #$30	; Convert it to ascii, and
	sta $C001	; print to the screen.
	tba		; Get the remainder.
	adc #$30	; Convert it to ascii, and
	sta $C001	; print to the screen.
	rtl		; End of getrow.

nl:
	lda #0
	sta scr_col
	sta (ptr), y	; Store said terminator into the input buffer.
	lda #$42
	sta c
	jsl isdown
	ldy.w #0	; Reset y, to print the result.
	jsl dabbed
	beq start
	ldy #0
	jmp result

back:
	sta $C001	; Print backspace.
	lda #0		; Put a null terminator, in place of the backspace.
	sta (ptr), y	; Place it into the input buffer.
	dey		; Decrement buffer offset.
	dec scr_col
	jmp read	; Get next character.

bs:
	cpy #0		; Are we at the start of the buffer?
	beq rset_a	; We are, so do not store the backspace into the buffer.
	jmp back	; We are not, so add the backspace to the buffer.

result:
	ldx scr_col
	cpx #79
	bne result_print
linewrap2:
	inc scr_row
	ldx #$0
	stx scr_col
	jsl update_pos
result_print:
	lda string2, y
	beq rset_y	; Reset y, if we hit the null terminator.
	sta $C001	; Print 'You have typed, '
	inc scr_col	; Increment the cursor's x coordinate.
	iny		; Increment offset.
	jmp result	; Keep printing.

rset_y:
	ldy.w #0	; Reset y.
	ldx.w #0	; Reset x.
	lda.w #0	; Reset a.
	jmp print_buf	; Print the input buffer.
dabbed:
	lda (ptr), y	; Get a character from the input buffer.
	beq dab_nend	; Are we done with printing the buffer?
	cmp (tptr), y
	bcs dab_nend
	beq chk_str
	bcc dab_nend
chk_str:
	iny
	cpy #3
	bne dabbed
	ldy #0
pnt_msg:
	ldx scr_col
	cpx #79
	bne msg_pnt
linewrap3:
	inc scr_row
	ldx #0
	stx scr_col
	jsl update_pos
msg_pnt:
	lda (mptr), y	; Get a character from the input buffer.
	beq dab_eqnd	; Are we done with printing the buffer?
	sta $C001	; Print said character.
	inc scr_col	; Increment the cursor's x coordinate.
	iny
	jmp pnt_msg	; Keep printing the buffer.
dab_nend:
	lda #1
	jmp dab_end
dab_eqnd:
	lda #0
	jmp dab_end
dab_end:
	rtl



print_buf:
	ldx scr_col
	cpx #79
	bne buf_print
linewrap4:
	inc scr_row
	ldx #0
	stx scr_col
	jsl update_pos
buf_print:
	lda (ptr), y	; Get a character from the input buffer.
	beq cmd_clr	; Are we done with printing the buffer?
	sta $C001	; Print said character.
	inc scr_col	; Increment the cursor's x coordinate.
	iny
	jmp print_buf	; Keep printing the buffer.

cmd_clr:
	lda #0
	sta scr_col
	lda #$42
	sta c
	jsl isdown
	jmp start

scr_to_buf:
	tax
	mul #80
	adc scr_col
	tay
	txa
	rtl

spin:
	nop
	nop
	nop
	jmp spin

.org $1000
v
.org $1100
v
.org $1200
v
.org $8000
v
.org $8100
v
.org $8200
v
.org $8300
v
.org $FFC0
.qword reset

.org $FF50
.qword spin
.qword spin
.qword spin
.qword spin
.qword spin
.qword spin
.qword spin
.org $FF50
v
done