; Native: Shawn Jefferson, December 2005
; POSIX: Stefan Haubenthal, April 2008

                .include  "atari.inc"
                .export   _opendir, _readdir, _closedir
                .import   findfreeiocb, clriocb
                .import   __oserror, return0, __do_oserror
                .importzp ptr1, tmp1
.ifdef  DEFAULT_DEVICE
                .import __defdev
.endif


.proc   _opendir
                sta     ptr1
                stx     ptr1+1
                jsr     findfreeiocb
                beq     @iocbok
                bne     cioerr
@iocbok:        stx     diriocb
                jsr     clriocb
                ldx     diriocb
                ldy     #0              ; '.' -> "D:*.*"
                lda     (ptr1),y
                cmp     #'.'
                bne     @use_parm

; "." was given as parameter, use default device/dir

.ifdef DEFAULT_DEVICE
                ; construct a "Dn:*.*" like string from the default drive
                lda     __defdev+1
                sta     dddefdev+1      ; copy drive number (overwrite 2nd 'D')
                lda     #<dddefdev
                sta     ICBAL,x
                lda     #>dddefdev
                sta     ICBAH,x
                bne     @cont
.else
                lda     #<defdev
                sta     ICBAL,x
                lda     #>defdev
                sta     ICBAH,x
                bne     @cont
.endif

@use_parm:      lda     ptr1
                sta     ICBAL,x
                lda     ptr1+1
                sta     ICBAH,x

@cont:          lda     #OPEN
                sta     ICCOM,x
                lda     #OPNIN|DIRECT
                sta     ICAX1,x
                jsr     CIOV
                bmi     cioerr
                lda     #0
                sta     __oserror
                tax
                lda     diriocb
                rts
.endproc

cioerr:         sty     __oserror
                lda     #CLOSE
                sta     ICCOM,x
                jsr     CIOV            ; close IOCB again since open failed
                jmp     return0

.proc   _readdir
                tax
                lda     #GETREC
                sta     ICCOM,x
                lda     #<entry
                sta     ICBAL,x
                sta     ptr1
                lda     #>entry
                sta     ICBAH,x
                sta     ptr1+1
                lda     #DSCTSZ
                sta     ICBLL,x
                lda     #0
                sta     ICBLH,x
                jsr     CIOV
                bmi     cioerr
                ldy     #0              ; FREE SECTORS
                lda     (ptr1),y
                cmp     #'0'
                bcs     cioerr
                dey
@next:          iny                     ; remove trailing spaces
                iny
                iny
                lda     (ptr1),y
                dey
                dey
                sta     (ptr1),y
                cpy     #8
                bcs     @break
                cmp     #' '
                bne     @next

@break:         lda     #'.'            ; extension dot
                sta     (ptr1),y
                iny                     ; copy extension
                sty     tmp1
                ldy     #10
                lda     (ptr1),y
                cmp     #' '
                bne     @hasext

; no extension present: remove the trailing dot and be done
                ldy     tmp1
                dey
                bne     @done

@hasext:        jsr     copychar
                ldy     #13             ; d_type
                sta     (ptr1),y
                ldy     #11
                jsr     copychar
                ldy     #12
                jsr     copychar

@done:          lda     #0              ; end of string
                sta     (ptr1),y
                lda     ptr1
                ldx     ptr1+1
                rts


copychar:       lda     (ptr1),y        ; src=y dest=tmp1
                ldy     tmp1
                cmp     #' '
                beq     @break
                sta     (ptr1),y
                iny
                sty     tmp1
@break:         rts
.endproc

.proc   _closedir
                tax
                lda     #CLOSE
                sta     ICCOM,x
                jsr     CIOV
                bmi     @cioerr
                ldx     #0
                stx     __oserror               ; clear system specific error code
                txa
                rts
@cioerr:        jmp     __do_oserror
.endproc

                .data
.ifdef DEFAULT_DEVICE
dddefdev:       .byte   "D"
.endif
defdev:         .asciiz "D:*.*"

                .bss
diriocb:        .res    1
entry:          .res    DSCTSZ