;reads from stdin 256 bytes into a buffer then parses it
;fork and exec ;TODO then take care of children

format ELF64 executable 3
;use64
entry main

align 16
segment readable writeable
kaksetozove db "ish: "

align 16
line: rb 256
master_pid: rq 1
current_cwd: rb 128
tokens: rb 128
argv: rb 128
envp: rb 8
filename: rb 128
fileproperties: rb 128
tmp: rb 128
align 16
sigaction: 
rb 4*8
align 16
termios:
rb 3*8
align 16
termios_old:
rb 3*8

align 16
segment readable executable

main:
mov rcx, [rsp] ;argc
mov rax, rsp
add rax, 8 ;argv
shl rcx, 3
add rcx, 8
add rax, rcx ;envp
mov [envp], rax
;jmp debug

mov rax, 39 ;getpid
syscall
mov [master_pid], rax

mov rsi, 128
mov rdi, current_cwd
mov rax, 79 ;getcwd
syscall

;setup terminal IO
mov rdx, termios
mov rsi, 0x5401
mov rdi, 0
mov rax, 16 ;ioctl
syscall
xor rcx, rcx
backup_termios:
mov rax, [termios+rcx]
mov [termios_old+rcx], rax
add rcx,8
cmp rcx, 3*8
jnz backup_termios
;set new terminal IO
mov eax, 0000012o
not eax
and dword [termios+12], eax ;-echo -icanon
mov rdx, termios
mov rsi, 0x5402
mov rdi, 0
mov rax, 16 ;ioctl
syscall

;setup SIGINT handler
mov rax, sigact
mov dword [sigaction], sigact
mov rax, sigrest
or rax, 0x04000000
mov [sigaction+8], rax
mov r10, 8
mov rdx, 0
mov rsi, sigaction
mov rdi, 2
mov rax, 13 ;sigaction
syscall

;anounce ourselfs
mov rdx, 5    ; message string length
mov rsi, kaksetozove    ; message address
mov rdi, 1        ; stdout
mov rax, 1        ; sys_write
syscall

;ioctl TCSETSW and pointer to termios struct
ish_loop:
mov rbp, 0
mov rax, 0
getline:
add rbp, rax
no_char:
mov rsi, rbp
mov rdx, 1    ; message string length
add rsi, line    ; message address
mov rdi, 0        ; stdin
mov rax, 0        ; sys_read
syscall
;Its a tarp!
cmp byte [line+rbp], 4
jz exit
cmp byte [line+rbp], 27 ;ESC
jnz esc_char
mov rdx, 2
mov rsi, tmp
mov rdi, 0
mov rax, 0
syscall
;cmp byte [line+rbp], 91 ;[
;jz no_char
;cmp byte [line+rbp], 65 ;up
;jz no_char
jmp no_char
esc_char:
cmp byte [line+rbp], 127 ;del
jz del_char
cmp byte [line+rbp], 8 ;backspace
jnz delete_char
del_char:
cmp rbp, 0
jz no_char
dec rbp
mov dword [line+rbp], 0x4B5B1B08 ;backspace+some esc sequence to delete
mov rdx, 4
mov rsi, rbp
add rsi, line
mov rdi, 1
mov rax, 1
syscall
jmp no_char
delete_char:
;asdasdasdasdasd
mov rdx, 1
mov rsi, rbp
add rsi, line
mov rdi, 1
mov rax, 1
syscall
mov bl, byte [line+rbp] ;quick UTF hax, TODO move and not forget
shr bl, 6
cmp bl, 2
jnz no_utf
dec rbp
;mov bl, byte [line+rbp]
;shr bl, 6
;cmp bl, 3
;jnz no_char
no_utf:
cmp byte [line+rbp], 10
jnz getline
cmp rbp, 0
jz no_char
mov byte [line+rbp], 0 ;for hax (newline haxed out)
;autocomplete uses getdents
;ctrl+c uses SIGINT

;break by tokens
tokenize:
mov rdx, line
mov rax, tokens
mov [argv], qword rax
mov rcx, 0
dec rdx
toke_loop:
inc rdx
cmp [rdx], byte " "
jz toke_loop
cmp [rdx], byte 0
jz toke_end
store_token:
mov [argv+rcx], rax
add rcx, 8
copy_token:
movzx r9, byte [rdx]
mov [rax], qword r9
inc rdx
inc rax
cmp [rdx], byte 92 ; its "\"
jz toke_esc_char
cmp [rdx], byte " "
jz toke_add_null
cmp [rdx], byte 0
jz toke_end
jmp copy_token
toke_esc_char:
add rdx, 1
jmp copy_token
toke_add_null:
mov [rax], byte 0
inc rax
jmp toke_loop
toke_end:
mov [argv+rcx], dword 0

;check if builtin
mov rax, [argv]
cmp [rax], word "cd"
jnz not_cd
jmp chdir ;hax, later path concatenateing
xor rdx, rdx
mov rax, [argv+8]
get_chdir:
mov cl, [rax+rdx]
mov [current_cwd+rdx], cl
cmp cl, 0
jz chdir
inc rdx
jmp get_chdir
chdir:
mov rdi, [argv+8]
mov rax, 80 ;chdir
syscall
cmp rax, 0
;jz ish_loop
jmp print ;add error checking
not_cd:

;call fork
mov rax, 57 ;fork
syscall
;check if child, if not save child pid !
cmp rax, 0
jnz wait_child
;remember pid ?

prepare_file_name:
mov rax, [envp]
sub rax, 8
filename_find_PATH:
add rax, 8
cmp [rax], dword 0
jz filename_path ;TODO should be PATH NOT FOUND
mov rcx, [rax]
cmp [rcx], dword "PATH"
jnz filename_find_PATH
mov rdi, [rax+8] ;TODO check if 0
filename_path:
add rcx, 4
find_path:
push rdi
mov rax, filename
xor rsi, rsi
fn_path_loop:
add rcx, 1
mov dl, [rcx]
mov [rax+rsi], dl
inc rsi
cmp rcx, rdi
jne last_char_in_path
dec rax
jmp last_path
last_char_in_path:
jg not_found
cmp dl, ":"
jnz fn_path_loop
last_path:
push rcx
add rax, rsi
mov [rax-1], byte "/"
;path inserting should be different maybe
mov rsi, -1
cat_name_to_path:
inc rsi
mov dl, [line+rsi]
cmp dl, 0
jz cat_name_end
cmp dl, " "
jz cat_name_end
mov [rax+rsi], dl
jmp cat_name_to_path
cat_name_end:
mov [rax+rsi], byte 0
;check if exists, can check lots of things
mov rsi, fileproperties
mov rdi, filename
mov rax, 4 ;stat
syscall
pop rcx
pop rdi
cmp rax, -2 ;ENOENT
jz find_path

;set enviroment
;set pipes
execve_sys:
mov rdx, [envp]
mov rsi, argv
mov rdi, filename
mov rax, 59 ;execve
syscall

not_found:
;if anything exit
mov rdi, -99
mov rax, 60
syscall

;move to process controll 
wait_child:
mov rcx, 0
mov rdx, 0
mov rsi, 0
mov rdi, -1
mov rax, 61
syscall

jmp print
debug:
mov rdx, 100
mov rsi, rax
mov rdi, 1
mov rax, 1
syscall
;ret

print:
mov rdx, 5
mov rsi, kaksetozove
mov rdi, 1 ;stdout
mov rax, 1 ;sys_write
syscall

jmp ish_loop

align 16
sigrest:
mov rax, 15
syscall
align 16
sigact:
jmp ish_loop

exit:
;restore terminal IO
mov rdx, termios_old
mov rsi, 0x5402
mov rdi, 0
mov rax, 16
syscall
;print newline
mov byte [line], 10
mov rdx, 1
mov rsi, line
mov rdi, 1
mov rax, 1
syscall
mov rax, 60
syscall
    

; Hash function for Strings in JAVA.
function hash, string_cmd
{
   h = 0;
   for(c in string_cmd){
     h = h * 31 + c;
  }
   return h;
}


; Define a table of hashes to look up
hashes:
.cd     dd 0x12345
.exec  dd 0x6789A
    

>> Enter command: cd "usr/bin" 
i = find_index(hash("cd"))

if i >= 0
   call_fn_by_index, i, substr(strstr("cd ")+1) ; get everything after 1st space
else
  print "Command not found"
endif