; SuBEditor.
;
; 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 $4000
cmd_buf:


; Initalize some variables.
.org $0
scr_row:
	.byte $0
scr_col:
	.byte $0
scr_trow:
	.byte $0
scr_tcol:
	.byte $0
scr_ptr:
	.word $0
a:
	.byte $0
b:
	.byte $0
c:
	.byte $0
d:
	.byte $0
e:
	.byte $0
f:
	.byte $0
string:
	.byte "Please, type something.\n"
string2:
	.byte "You typed, "
end:
	.byte $0
bits:
	.byte $80
	.byte $40
	.byte $20
	.byte $10
	.byte $08
	.byte $04
	.byte $02
	.byte $01
bitmask:
	.byte $0
bitabl:
	.qword $0
	.qword $0
scr_str:
.byte $0
scr_end:
.byte $0
wrapped:
.byte $0

; Pointers
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 #23
	sta scr_end
	lda #0
	sta scr_str
	ldx #8
	sta.q bitabl
	sta.q bitabl, x
	tax
	jsl clr_buf
	jmp start
clr_buf:
	lda #0
	cpy.w #$1FFF
	beq clr_buf_end
	sta (ptr), y
	iny
	jmp clr_buf
clr_buf_end:
	ldy.w #0
	rtl

start:
	lda #0
	tax
	sta $C000
	phy #2
	ldy.w #0
	jsl clr_cbuf
	ply #2
	jmp print

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

pull_y:
	ply #2
rset_a:
	lda #0
	sta $C000
	inc
read:
	lda $C000	; Get control register.
	beq rset_a	; Loop until we get a character.
	jsl getchar	; We got a key.
	beq parse	; We got a newline, so start parsing the line.
	jmp rset_a	; We didn't get a newline, so keep getting more characters.

print:
	phy #2
	txy
	lda string, y	; Get character at offset x.
	beq pull_y	; Did we find a null terminator?
	ply #2
	inx
	jsl print_char
	jmp print

getbit:
	clc
	lda scr_str
	bne getbt0
	ldx scr_row
	jmp getbt1
getbt0:
	lda scr_row
	adc scr_str
	tax
getbt1:
	jsl bitpos
	ldb bitabl, x
	aba
	cmp #1
	jmp bitout

;putbit:
;	ldx scr_row
;putbt1:
;	bcc setbit


clrbit:
	jsl bitpos
	xor #$FF
	ldb bitabl, x
	aba
bitsav:
	sta bitabl, x
bitout:
	ldx bitmask
	rtl

setbit:
	jsl bitpos
	ldb bitabl, x
	oab
	jmp bitsav

bitpos:
	stx bitmask
	txa
	and #7
	tax
	lda bits, x
	pha #1
	lda bitmask
	lsr #3
	tax
	pla #1
	rtl


getchar:
	lda $C002	; Get typed character.
	ldb #0
	stb e
	pha #1
	phy #2
	cmp #10
	beq cmd_cpy
getchar_pnt:
	ply #2
	pla #1
	ldb e
	bne reset_row
getchar_pnt1:
	jsl print_char
	lda a
	cmp #10
	beq getchar_line
	jmp getchar_char
reset_row:
	ldb e
	stb scr_row
	jmp getchar_pnt1


cmd_cpy:
	ldb scr_row
	stb e
	jsl findst
	clc
	lda scr_row
	adc scr_str
	mul #80
	tay
	ldx.w #$0
cmd_cpy_strt:
	lda (ptr), y
	beq getchar_pnt
	phy #2
	txy
	sta (cptr), y
	inx
	ply #2
	iny
	jmp cmd_cpy_strt
getchar_line:
	lda #0
	jmp getchar_end
getchar_char:
	lda #1
getchar_end:
	rtl

findst:
	jsl getbit
	bcc findst_done
	dec scr_row
	bpo findst
	inc scr_row
findst_done:
	rtl

parse:
	lda #0
	tax
	jsl dabbed
	beq start
	lda #0
	tax
	jmp result

print_char:
	sta a
	cmp #$1B
	beq esc
	cmp #$A
	beq nl		; Did the user type a newline?
	cmp #$C
	beq clr_scr
	cmp #19
	beq en_step
	cmp #18
	beq dis_step
	cmp #8
	beq bs		; Did the user type a backspace?
	cmp #$7F
	beq bs		; Did the user type a backspace?
	sta a
printc:
	lda a
	sta (ptr), y	; Store typed character into the input buffer.
	inc scr_col	; Increment the cursor's x coordinate.
	iny
printc_2:
	ldb #1
	stb f
	ldb scr_col
	cpb #80
	bcs printc_4
printc_3:
	sta $C001	; Echo typed character.
	ldb f
	beq printc_wrap
	jmp printc_end
printc_4:
	ldb scr_row
	cpb #23
	bcs printc_scrl
printc_5:
	ldb #0
	stb f
	jmp printc_3
printc_scrl:
	sta $C001	; Echo typed character.
	clc
	lda #1
	sta wrapped
	jsl scrl_down
printc_wrap:
	ldb #0
	stb scr_col
	ldb scr_row
	cpb #23
	bcs printc_wrap2
printc_wrap1:
	inc scr_row
printc_wrap2:
	phx #2
	clc
	lda scr_row
	adc scr_str
	tax
	jsl setbit
	plx #2
	jsl update_pos
printc_end:
	rtl

nl:
	lda #0
	sta (ptr), y	; Store said terminator into the input buffer.
	sta scr_col
	lda scr_row
	cmp #23
	bne nl_inc
	jsl scrl_down
	lda #10
	sta a
	jmp printc_end
nl_inc:
	inc scr_row
	jsl update_pos
	lda #10
	sta a
	jmp printc_end

clr_scr:
	lda #23
	sta scr_end
	lda #0
	sta scr_str
	ldx #8
	sta.q bitabl
	sta.q bitabl, x
	tay
	jsl clr_buf
	sta scr_col
	sta scr_row
	jsl update_pos
	lda #$C
	sta $C001
	jmp printc_end

en_step:
	lda $C010
	beq step_en
	jmp stp_end
step_en:
	lda #1
	sta $C010
	jmp stp_end

dis_step:
	lda $C010
	bne step_dis
	jmp stp_end
step_dis:
	lda #0
	sta $C010
stp_end:
	jmp printc_end

back:
	lda #$7F
	sta $C001
	dey		; Decrement buffer offset.
	lda #0		; Put a null terminator, in place of the backspace.
	sta (ptr), y	; Place it into the input buffer.
	dec scr_col
	jsl update_pos
	jmp printc_end	; Get next character.

bs:
	lda scr_col	; Are we at the start of the buffer?
	beq back_wrap
	jmp back	; We are not, so add the backspace to the buffer.
back_wrap:
	jsl getbit
	bcs back_wrap1
	jmp printc_end
back_wrap1:
	lda scr_row
	beq back_wrap2
	jmp backwrp
back_wrap2:
	lda scr_str
	bne back_scrl
	jmp printc_end
back_scrl:
	clc
	jsl scrl_up
	inc scr_row
backwrp:
	clc
	lda scr_row
	adc scr_str
	tax
backwrp2:
	dec scr_row
	jsl clrbit
	ldb #80
	stb scr_col
	jsl update_pos
	jmp back

esc:
	lda $C000	; Skip the '['.
	lda $C002
	cmp #$1B
	beq shftesc
	lda $C000	; Get the next character.
	beq printc_end	; 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.
	lda #0
	sta d
	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 printc_end	; Go back to getting user input.

shftesc:
	lda $C000	; Skip the '['.
	lda $C000	; Get the next character.
	beq printc_end	; 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.
	lda #0
	sta d
	jsl isshftup	; Check if the user pressed shift+up.
	lda d
	bne shftesc_end
	jsl isshftdown	; Check if the user pressed shift+down.
shftesc_end:
	lda #0
	sta d
	jmp printc_end	; Go back to getting user input.

isup:
	lda c		; No, so load the escape code back into the accumulator.
	cmp #$41	; Did the user press the up arrow key?
	bne isup_done	; Yes, so return.
	lda #1
	sta d
	lda scr_row	; Is the cursor at the top of the screen?
	beq isup_scrl	; Yes, so return.
isup_2:
	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.
	jmp isup_done
isup_scrl:
	lda scr_str
	beq isup_done
	jsl scrl_up
isup_done:
	rtl		; End of isup.

isdown:
	lda c		; No, so load the escape code back into the accumulator.
	cmp #$42	; Did the user press the down arrow key?
	bne isdown_done
	lda scr_row	; Start checking the y coordinate of the cursor.
	cmp #23		; Is the cursor at the bottom of the screen?
	beq isdown_scrl	; 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.
	jmp isdown_done
isdown_scrl:
	lda scr_row
	sta scr_trow
	lda scr_col
	sta scr_tcol
	jsl scrl_down
	lda scr_trow
	sta scr_row
	lda scr_tcol
	sta scr_col
isdown_done:
	rtl		; End of isdown.

isright:
	lda c		; No, so load the escape code back into the accumulator.
	cmp #$43	; Did the user press the right arrow key?
	bne isright_done
	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_wrp	; Yes, so check if this is a wrapped line.
	jmp right	; No, so move the cursor right, like normal.
isright_wrp:
	inc scr_row
	jsl getbit
	bcs wrap_inc
	dec scr_row
	jmp isright_done
isright_scrl:
	lda scr_str
	beq isright_end
	lda #1
	sta wrapped
	jsl scrl_down
	dec scr_row
	jmp isright_end
wrap_inc:
	lda #0
	sta scr_col
	lda scr_row
	cmp #23
	bcs isright_scrl
isright_end:
	jsl update_pos
isright_done:
	lda #0
	sta wrapped
	rtl		; End of isright.

isleft:
	lda c
	cmp #$43
	beq isleft_done
	lda scr_col	; Is the cursor at the far left of the screen?
	beq isleft_wrp	; Yes, so start checking if this is a wrapped line.
	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.
	jmp isleft_done
isleft_wrp:
	jsl getbit
	bcs wrap_dec
	jmp isleft_done
wrap_dec:
	lda scr_row
	beq wrap_dec1
	lda #1
	sta wrapped
	dec scr_row
wrap_dec1:
	lda #79
	sta scr_col
	lda #1
	sta d
	lda scr_row
	beq isleft_scrl
	jmp isleft_end
isleft_scrl:
	lda wrapped
	bne isleft_end
	lda scr_str
	beq isleft_done
	jsl scrl_up
	jmp isleft_done
isleft_end:
	jsl update_pos
isleft_done:
	lda #0
	sta wrapped
	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_done
left:
	dec scr_col
	jsl update_pos
	lda #1
	sta d
	jmp isleft_done

isshftup:
	lda c		; Load the escape code back into the accumulator.
	cmp #$41	; Did the user press the up arrow key?
	bne isshftup_done
	lda #1
	sta d
	lda scr_str
	beq isshftup_done
	jmp shftup
isshftup_done:
	rtl

isshftdown:
	lda c		; Load the escape code back into the accumulator.
	cmp #$42	; Did the user press the down arrow key?
	bne isshftdown_done
	lda #1
	sta d
	lda scr_end
	cmp #71
	bcs isshftdown_done
	jmp shftdown
isshftdown_done:
	rtl

shftup:
	jsl scrl_up
	lda #1
	sta d
	jmp isshftup_done

shftdown:
	jsl scrl_down
	lda #1
	sta d
	jmp isshftdown_done

update_pos:
	ldb #1
	stb f
	clc
	lda scr_row
	adc scr_str
	clc
	mul #80
	clc
	adc scr_col
	tay
	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.
	clc
	adc #$30	; Convert it to ascii, and
	sta $C001	; print to the screen.
	tba		; Get the remainder.
	clc
	adc #$30	; Convert it to ascii, and
	sta $C001	; print to the screen.
	rtl		; End of getrow.

scrl_down:

	inc scr_str
	inc scr_end
	lda #$1B	; Print an escape character
	sta $C001	; to the screen.
	lda #$5B	; Print '['
	sta $C001	; to the screen, and start the escape sequence.
	lda #$54	; Print 'T'
	sta $C001	; to the screen, and end the escape sequence.
	lda wrapped
	beq scrldn_save
scrldn1:
	jsl rdrw_row
	lda wrapped
	beq scrldn_load
	jmp scrldn_end
scrldn_save:
	lda scr_row
	pha #1
	lda scr_col
	pha #1
	jmp scrldn1
scrldn_load:
	pla #1
	sta scr_col
	pla #1
	sta scr_row
	jsl update_pos
scrldn_end:
	lda #0
	sta wrapped
scrldn_done:
	rtl

scrl_up:
	dec scr_str
	dec scr_end
	lda #$1B	; Print an escape character
	sta $C001	; to the screen.
	lda #$5B	; Print '['
	sta $C001	; to the screen, and start the escape sequence.
	lda #$53	; Print 'S'
	sta $C001	; to the screen, and end the escape sequence.
	lda scr_row
	pha #1
	lda scr_col
	pha #1
	lda #0
	sta scr_row
	jsl rdrw_row
	pla #1
	sta scr_col
	pla #1
	sta scr_row
	jsl update_pos
scrlup_done:
	rtl

rdrw_row:
	lda #0
	sta scr_col
	jsl update_pos
rdrow_st:
	lda (ptr), y
	beq rdrow_inc
	sta $C001
rdrow_inc:
	inc scr_col
	lda (ptr), y
	beq rdrow_skip
	iny
rdrow_inc1:
	lda scr_col
	cmp #80
	bcs rdrow_end
	jmp rdrow_st
rdrow_skip:
	jsl update_pos
	jmp rdrow_inc1
rdrow_end:
	lda #0
	sta scr_col
	jsl update_pos
rdrow_done:
	rtl


;rdrw_scr:
;	lda #$C
;	sta $C001
;	lda scr_col
;	sta scr_tcol
;	lda scr_row
;	sta scr_trow
;	lda #0
;	sta scr_col
;	sta scr_row
;	phy #2
;	jsl update_pos
;	ply #2
;	ldx scr_ptr
;	phy #2
;	txy
;	lda (ptr), y
;	sta $C001
;	ply #2
;	rtl

result:
	phy #2
	txy
	lda string2, y
	beq rset_y	; Reset y, if we hit the null terminator.
	ply #2
	jsl print_char	; Print 'You have typed, '
	inx
	jmp result	; Keep printing.

rset_y:
	ply #2
	lda #0		; Reset a.
	tax		; Reset y.
	jmp print_buf	; Print the input buffer.

dabbed:
	phy #2
	txy
	lda (cptr), y	; Get a character from the input buffer.
	beq dab_pend	; Are we done with printing the buffer?
	cmp (tptr), y
	bcc dab_pend
	beq chk_str
	bcs dab_pend
chk_str:
	ply #2
	inx
	cpx #3
	bne dabbed
	ldx #0
pnt_msg:
	phy #2
	txy
	lda (mptr), y	; Get a character from the input buffer.
	beq dab_peqnd	; Are we done with printing the buffer?
	ply #2
	jsl print_char
	inx
	jmp pnt_msg	; Keep printing the buffer.
dab_pend:
	ply #2
	lda #1
	jmp dab_end
dab_peqnd:
	ply #2
	lda #0
	jmp dab_end
dab_end:
	rtl

print_buf:
	phy #2
	txy
	lda (cptr), y	; Get a character from the input buffer.
	beq cmd_clr	; Are we done with printing the buffer?
	ply #2
	jsl print_char
	inx
	jmp print_buf	; Keep printing the buffer.

cmd_clr:
	ply #2
	lda #10
	jsl print_char
	jmp start

.org $FFC0
.qword reset

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