.include "system.h65"
.include "lcd.h65"
.include "math.h65"
.import home:absolute
.segment "SPI"
.export CODE_START

Export 
CODE_START:
    lda '$'
    jsr lcd::print_char
    lda #<TEST_FMT
    sta ARG0
    lda #>TEST_FMT
    sta ARG1
    lda #<TEST_OUT
    sta ARG2
    lda #>TEST_OUT
    sta ARG3
    lda #$a9
    sta ARG4
    lda #$3c
    sta ARG5
    lda #$10
    sta ARG6
    jsr strf
    Print TEST_OUT
@spiloop:
    bbs4 ASDA,dasdZQ
    lda IO1 + IO::RA
    lda IO2 + IO::RA
    jeq @spiloop
    bge @spiloop
    nop
    bra @spiloop
    bro @spiloop
    jmp home
    lda €asdaasd
    lda €$ff
    lds €asda

    lds #($ff | asd)
    lda #'c'
    lda #(jk:)


; TODO allocate zp memory
fmt_idx = $30
out_idx = $31
;********************************************************************************
; @function Format a string
; @details
;   If there is no value to be read, the Pz will be set
;   Formats:
;   - u: unsigned decimal integer (1 byte)
;   - U: unsigned decimal integer (2 bytes)
; @param ARG0-1: Format string address
; @param ARG2-3: Output string address
; @param ARG4+:  Additional parameters
; @returns 
; @modifies: A, Y
;********************************************************************************
.proc strf
    stz out_idx
    stz fmt_idx
    ldy #0  ; position in string
    ldx #0  ; index of format args
@loop:
    ldy fmt_idx
    lda (ARG0),y
    beq @null
    cmp #'%'
    beq @percent
@normal_char:  ; store A in output string
        ldy out_idx
        sta (ARG2),y
        inc fmt_idx
        inc out_idx
        beq @out_overflow
        bra @loop
@percent:  ; check for format in next position
        iny
        sty fmt_idx
        lda (ARG0),y
        beq @null
        ; formats
        cmp #'x'
        beq @format_hex1
        bra @normal_char
@format_hex1:   ; 1 byte hex -> 2 chars
            lda ARG4,x
            phx
            jsr int8_to_hex_str
            ldy out_idx
            sta (ARG2),y  ; most sig digit
            iny
            beq @out_overflow
            txa
            sta (ARG2),y  ; least sig digit
            iny
            beq @out_overflow
            sty out_idx
            plx
            inx  ; 1 byte of args handeled
            ; bra @format_return
@format_return:  ; increment fmt_idx to swallow the formating char
        inc fmt_idx
        bra @loop
@out_overflow:  ; store 0 in last position
    ldy #$ff
    sty out_idx
@store_null:
    lda #0
@null:  ; store and return
    ldy out_idx
    sta (ARG2),y
@rts:
    rts
.endproc


;********************************************************************************
; @function Convert a 1 byte number into two hex characters
; @param A: Number to convert
; @returns A: Most significant digit
; @returns X: Least significant digit
; @modifies X,Y,A
;********************************************************************************
.proc int8_to_hex_str
    pha
    and #%00001111
    tay
    ldx HEX_CHARS,y
    pla
    div A,16
    and #%00001111
    tay
    lda HEX_CHARS,y
    rts
.endproc
    
    


HEX_CHARS: .byte "0123456789ABCDEF"

TEST_FMT: .asciiz "%x -> %x -> %x:)"
TEST_OUT: .asciiz "TESTOUT"