; The OS/K Team licenses this file to you under the MIT license.
; See the LICENSE file in the project root for more information.

N := 11

.handle_DIR:
    push rbp
    mov rbp, rsp

    push r12, r13
    push r14, r15

    nul r12     ; no. of files found
    nul r13     ; no. of directories found
    nul r14     ; total amount of bytes found

    call print, .dirmsg

.first:
    mov rax, Sys.FindFirst
    mov ax0, .buf
    mov ax1, FNAME_MAX
    trap 0

    jmp .list

.next:
    mov rax, Sys.FindNext
    mov ax0, .buf
    mov ax1, FNAME_MAX
    trap 0

.list:
    jraxz .end

    mov r15, rcx ; file size
    inc r14, rcx

    ; directory?
    bnz rdx, .is_dir

    ; found a file
    inc r12

    ; separate extension from file name
    mov rcx, FNAME_MAX
    mov rsi, .buf
    mov rdi, rsi
    scasb rsi, '.'

    ; print file name
    sub ax1, rsi, rdi
    dec ax1
    call nprint, rdi

    ; calculate where to put extension
    sub rdi, rsi, .buf
    dec rdi

.ext_pad:
    ; print at least N non-space characters before extension
    blte N, rdi, .print_ext
    prn ' '
    inc rdi
    jmp .ext_pad

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

    bne b[rsi], '.', .print_ext.1
    inc rsi

.print_ext.1:
    bzr b[rsi], .print_ext.2

    ; print and decrease rcx, unless it's already 0
    prn b[rsi]
    inc rsi
    jrcxz .print_ext.1

    dec rcx
    jmp .print_ext.1

.print_ext.2:
    ; did we print at least 4 bytes?
    jrcxz .print_bytes    ; yes, carry on

.pe2.l:
    prn ' '
    loop .pe2.l

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

    shr rax, r15, 10
    and r15, 1023

    push r15, rax
    call printf, .bytesstr
    inc rsp, 16

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

.end:
    shr rax, r14, 10
    shr rdx, rax, 10
    and rax, 1023
    and r14, 1023

    push r14, rax, rdx
    call printf, .endstr0
    inc rsp, 24

    push r13, r12
    call printf, .endstr1
    inc rsp, 16

    pop r15, r14
    pop r13, r12

    leave
    jmp .print_prompt

    ; special case: direcory
.is_dir:
    inc r13

    ; use printf instead of print
    ; because it returns # of printed
    ; characters
    call printf, .buf

    blte N, rax, .dir_no_pad
    sub rcx, N, rax
    dec rcx

.dir.l:
    prn ' '
    loop .dir.l

.dir_no_pad:
    call print, .dir_ext

    jmp .print_bytes

.buf = [FNAME_MAX]
.dir_ext = " <DIR> "
.endstr0 = "             total %dMB + %dKB + %dB\n"
.endstr1 = "             found %d file(s), %d dir(s)\n"
.dirmsg = "Directory of C:\\\n\n"

.bytesstr = "%d kilobytes + %d bytes"
# .bytesstr = "%dMB + %dKB + %dB" # too soon