NAME_MAX := 256

CMD.builtins.dir:
    push nx0

    sub nx0, nx0        # no. of files found

    mov ax0, .dirmsg
    call print

.dirmsg = "Directory of C:\\\n\n"

.first:
    mov ax0, .buf
    mov ax1, NAME_MAX
    call DISK.FindFirst
    jmp .list

.next:
    mov ax0, .buf
    mov ax1, NAME_MAX
    call DISK.FindNext

.list:
    test rax, rax
    j.z .end

    ; found something
    inc nx0

    ; separate extension from file name
    mov rcx, NAME_MAX
    mov r10, .buf
    mov r11, r10
    scasb.rep.nz r10, '.'

.print_file_name:
    prn b[r11]
    inc r11

    cmp r11, r10
    j.b .print_file_name

    ; calculate where to put extension
    ksub r11, r10, .buf
    dec r11

.ext_pad:
    ; print at least 11 non-space characters before extension
    cmp r11, 11
    j.ae .print_ext
    prn ' '
    inc r11
    jmp .ext_pad

.print_ext:
    ; here we print at least 4 characters excluding '.'
    mov rcx, 4
    prn ' '

    cmp b[r10], '.'
    inc.z r10

.print_ext.1:
    cmp b[r10], 0
    j.z .print_ext.2

    ; print and decrease rcx, unless it's already 0
    prn b[r10]
    inc r10
    test rcx, rcx
    dec.nz rcx

    jmp .print_ext.1

.print_ext.2:
    ; did we print at least 4 bytes?
    test rcx, rcx
    j.z .print_bytes    ; yes, carry on

    prn.rep ' '
    jmp .print_ext.2

.print_bytes:
    ; print file size in bytes
    prn ' '
    prn ' '
    prn ' '

    mov rax, rdx
    shr rax, 10
    and rdx, 1023

    mov ax0, .bytesstr
    push rdx
    push rax
    call printf
    add rsp, 16

.bytesstr = "%d kilobytes + %d bytes"

.prepare_next:
    ; go find next entry
    prn 10
    jmp .next

.end:
    mov ax0, .endstr1
    push nx0
    call printf
    add rsp, 8

    mov ax0, .endstr2
    call print

    pop nx0
    ret

.buf = [256]
.endstr1 = "             %d file(s)\n"
.endstr2 = "             0 dir(s)\n"